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nebularain
2004-Jun-10, 02:27 PM
Hey -

I've missed being able to hang on the Boards. Too much school work and job work to do. Sigh.

Anyway, I was in a converstion which led to a thought question I wasn't sure how to answer.

Does gravity have an affect on time?

Likewise, considering that "time" is considered another dimension, what exactly is Time? I mean, what are the characteristics, the parameters, the "substance" if you will of Time?

Any answers are appreciated. Thanks!

Taibak
2004-Jun-10, 02:38 PM
Hey -

I've missed being able to hang on the Boards. Too much school work and job work to do. Sigh.

Anyway, I was in a converstion which led to a thought question I wasn't sure how to answer.

Does gravity have an affect on time?

Yes. Time slows down in a gravitational field.


Likewise, considering that "time" is considered another dimension, what exactly is Time? I mean, what are the characteristics, the parameters, the "substance" if you will of Time?

Any answers are appreciated. Thanks!

Not touching that one. Only characteristic I can give you about time is that we can only move through it in one direction - fancy-like talk for us always going into the future.

TravisM
2004-Jun-10, 04:16 PM
Time slows in a gravity field and high inertial frames of reference. That's neat. High gravity, slower realative time; high speed, slower realative time... There really is no distinguishing factor for acceleration and gravity, is there? (Not meant to jack the thread!)

Taibak
2004-Jun-10, 04:44 PM
*Removed to get rid of a totally stupid, mistake that's not worth fixing and will be totally misleading if left.*

Move along folks... nothing to see here.

Sam5
2004-Jun-10, 04:59 PM
Hey -

I've missed being able to hang on the Boards. Too much school work and job work to do. Sigh.

Anyway, I was in a converstion which led to a thought question I wasn't sure how to answer.

Does gravity have an affect on time?

Likewise, considering that "time" is considered another dimension, what exactly is Time? I mean, what are the characteristics, the parameters, the "substance" if you will of Time?

Any answers are appreciated. Thanks!



The oscillations of atoms slow down in a gravity field, therefore atomic clocks slow down in a gravity field. However, pendulum clocks speed up in a gravity field, and balance-wheel clocks are unaffected except for some increased bearing friction effects.

Time is kinetic energy causing things to move. Various kinds of time are atomic, thermodynamic, rotational-mass, swinging-mass, straight-line moving mass, and a few others.

Ricimer
2004-Jun-10, 08:45 PM
Taibak: Travis said:
acceleration and gravity

And there isn't a differnce, so you're right travis. Einstien said you cannot tell the difference between acceleration, and gravitation, and so they are equivelant.

Taibak was pointing out the differences between speed and gravitation effects (which you seem to have speed confused with acceleration).

Taibak
2004-Jun-10, 08:49 PM
Taibak: Travis said:
acceleration and gravity

And there isn't a differnce, so you're right travis. Einstien said you cannot tell the difference between acceleration, and gravitation, and so they are equivelant.

Taibak was pointing out the differences between speed and gravitation effects (which you seem to have speed confused with acceleration).

:oops: #-o

Damn... misread that last 'acceleration' as 'speed.'

I need coffee....

Ricimer
2004-Jun-10, 08:59 PM
Well, travis does seem to link speed and acceleration (thats who the comment was directed to).

He says speed slows time, gravity slows time, so there's no difference between acceleration and gravity...

See the stumbling point?

milli360
2004-Jun-10, 09:52 PM
See the stumbling point?
Worse, it's not the strength of gravity directly that does it.

Two objects could be experiencing the same acceleration, the same apparent gravity, and the one that's "lower" will experience a different rate of time than the one that's "higher".

John Dlugosz
2004-Jun-10, 10:55 PM
A great explaination of how time's characterized as a dimension, see http://gregegan.customer.netspace.net.au/FOUNDATIONS/02/found02.html.

You asked about gravity, but the previous page on that article (special relativity) explains how time can be defined as a 4th dimension but subtracted when finding the hyponinuse, rather than added.

Ricimer
2004-Jun-11, 01:41 AM
milli: I...at the moment have to disagree. Then again, I don't follow GR all to closely (as may be noticed from time to time).

So...anywhere I can see that backed up?

Sam5
2004-Jun-11, 03:40 AM
See the stumbling point?
Worse, it's not the strength of gravity directly that does it.

Two objects could be experiencing the same acceleration, the same apparent gravity, and the one that's "lower" will experience a different rate of time than the one that's "higher".

I think you’re getting the accelerated box thought experiment a little mixed up. Two atomic clocks at different positions in the moving accelerating box in deep space will tick at the same rate. Two resting at different elevations on earth will tick at different rates.

The two in the moving accelerating box are experiencing the same rate of acceleration, but the two at different elevations on earth are not.

This applies specifically to atomic clocks.

Taibak
2004-Jun-11, 06:14 AM
See the stumbling point?
Worse, it's not the strength of gravity directly that does it.

Two objects could be experiencing the same acceleration, the same apparent gravity, and the one that's "lower" will experience a different rate of time than the one that's "higher".

I think you’re getting the accelerated box thought experiment a little mixed up. Two atomic clocks at different positions in the moving accelerating box in deep space will tick at the same rate. Two resting at different elevations on earth will tick at different rates.

The two in the moving accelerating box are experiencing the same rate of acceleration, but the two at different elevations on earth are not.

I agree. Gravitational force drops off with distance squared, meaning that the acceleration due to gravity does the same. So, theoretically speaking, g is slightly smaller atop Mt. Everest than it is at the Dead Sea. Objects at those two locations are not at the same gravitational potential and time passes slower at the Dead Sea than it does atop Mt. Everest.

AstroSmurf
2004-Jun-11, 07:30 AM
Worse, it's not the strength of gravity directly that does it.

Two objects could be experiencing the same acceleration, the same apparent gravity, and the one that's "lower" will experience a different rate of time than the one that's "higher".
I think you’re getting the accelerated box thought experiment a little mixed up. Two atomic clocks at different positions in the moving accelerating box in deep space will tick at the same rate. Two resting at different elevations on earth will tick at different rates.
Taibak, I think you missed what Sam5 said. He's saying that gravitational dilatation arises only from a difference in the gradient.

However, that's not how reality behaves. The GR contribution to time dilation depends on the difference in gravitational potential, not the gravitational gradient. This is true even where the gradient is zero, as in an accelerating spaceship, So the bolded part of his statement is only true if they're at the same "height" in the spaceship.

To show you the math, we define gravitational potential from a mass M:

Phi = - G * M / R, so that gravitational potential energy for test mass m becomes U = Phi * m. To express it otherwise, Phi = - g(R) * R, and dPhi ~ - g(R) * dh.
For an accelerating spaceship, dPhi = - a * dh

Gravitational time dilation follows the relationship:
T = T0 / sqrt(1 + 2 * Phi / c²).
A Taylor expansion of this gives us:
dT/T = dPhi / c² + O(dPhi² / c^4)

http://hyperphysics.phy-astr.gsu.edu/hbase/relativ/gratim.html#c4

milli360
2004-Jun-11, 08:26 AM
See the stumbling point?
Worse, it's not the strength of gravity directly that does it.

Two objects could be experiencing the same acceleration, the same apparent gravity, and the one that's "lower" will experience a different rate of time than the one that's "higher".

I think you’re getting the accelerated box thought experiment a little mixed up. Two atomic clocks at different positions in the moving accelerating box in deep space will tick at the same rate.

Not according to general relativity, and that is what we are talking about here.


Two resting at different elevations on earth will tick at different rates.

The two in the moving accelerating box are experiencing the same rate of acceleration, but the two at different elevations on earth are not.

They could be.

Objects at zero elevation at the pole and equator experience different accelerations due to gravity, because the equator is farther away from the center of the Earth. Put an object at a high elevation at the pole, and it could experience the same acceleration as an object at low elevation at the equator.

Grand_Lunar
2004-Jun-11, 11:04 AM
Glad someone posted this topic, as I have a question about it (sort of).
I explained to a friend of mine an experiment conducted to go about proving realitivity.
Two atomic clocks, both sychronized, were used. One stayed on the ground, the other went into space on the shuttle. When the other clock was returned, it was found to be off by a minute yet signifigant amount for an atomic clock. My friend countered by saying that a clock would operated different in a vaccum than on Earth. I told him it was inside the spacecraft. He then countered it would act different in space than on Earth. I didn't think so.
Who's right? And is my info correct that such an experiment was conducted? I think I read about it somewhere. I think it was mentioned on that ever-so-famous science show, "Bill Nye: The Science Guy".

Sam5
2004-Jun-11, 04:36 PM
See the stumbling point?
Worse, it's not the strength of gravity directly that does it.

Two objects could be experiencing the same acceleration, the same apparent gravity, and the one that's "lower" will experience a different rate of time than the one that's "higher".

I think you’re getting the accelerated box thought experiment a little mixed up. Two atomic clocks at different positions in the moving accelerating box in deep space will tick at the same rate. Two resting at different elevations on earth will tick at different rates.

The two in the moving accelerating box are experiencing the same rate of acceleration, but the two at different elevations on earth are not.

I agree. Gravitational force drops off with distance squared, meaning that the acceleration due to gravity does the same. So, theoretically speaking, g is slightly smaller atop Mt. Everest than it is at the Dead Sea. Objects at those two locations are not at the same gravitational potential and time passes slower at the Dead Sea than it does atop Mt. Everest.


Yes, I basically agree, except that this happens only with atomic clocks and I believe we should call this, specifically, “atomic time” rather than all of “time itself”, since it does not apply to pendulum or balance-wheel clocks. Long ago the field of physics began to think of “atomic time” as representing “true time” and “time itself”, but other fields of science don’t use atomic time and they use other kinds of time and other kinds of clocks that don’t follow the same laws of physics that atomic clocks follow.

Here’s what Einstein said about the difference between the reaction atomic clocks have to gravity effects and accelerating box effects, in his 1911 paper:

“This has a consequence which is of fundamental impor-
tance for our theory. For if we measure the velocity of light
at different places in the accelerated, gravitation-free system
K', employing clocks U of identical constitution, we obtain
the same magnitude at all these places. The same holds
good, by our fundamental assumption, for the system K as
well. But from what has just been said we must use clocks
of unlike constitution, for measuring time at places with
differing gravitation potential. For measuring time at a
place which, relatively to the origin of. the co-ordinates, has
the gravitation potential Φ, we must employ a clock which
when removed to the origin of co-ordinates goes (1 + Φ /c^2)
times more slowly than the clock used for measuring time at
the origin of co-ordinates.”


This is not the best wording to describe the two different situations 1) in the accelerating box and 2) at different places at the surface of the earth.

The “equivalence principle” has some stipulations and conditions. For example, with the gravity effect on earth, you are right about an atomic clock running faster on top of Mt. Everest. But in an accelerating box in deep space, an atomic clock 29,000 feet “above” another atomic clock will tick at the same rate as the “bottom” clock, since all fixed places inside the accelerating box in deep space are experiencing exactly the same amount of acceleration, while the clock on top of Mt. Everest is not experiencing the same amount of acceleration as a clock at sea level.

Sam5
2004-Jun-11, 04:56 PM
Glad someone posted this topic, as I have a question about it (sort of).
I explained to a friend of mine an experiment conducted to go about proving realitivity.
Two atomic clocks, both sychronized, were used. One stayed on the ground, the other went into space on the shuttle. When the other clock was returned, it was found to be off by a minute yet signifigant amount for an atomic clock. My friend countered by saying that a clock would operated different in a vaccum than on Earth. I told him it was inside the spacecraft. He then countered it would act different in space than on Earth. I didn't think so.
Who's right? And is my info correct that such an experiment was conducted? I think I read about it somewhere. I think it was mentioned on that ever-so-famous science show, "Bill Nye: The Science Guy".

This happens with atomic clocks. The reason is that an atomic clock will tick slower when resting in a strong gravity field, and it will tick faster when “floating” up in space. It has something to do with the force placed on the atoms when the clock is resting at the surface of the earth. The “tick rate” of an atomic clock is based on the internal oscillation rates of the atoms that are used for the timing mechanism of the clock. The oscillation rate slows down when the clock is resting in a gravity field, and it speeds up when the clock is “floating” in space.

My personal view is that this is specifically a phenomenon experienced by atomic clocks and it does not represent a change in all of “time itself”. Since, when pendulum clocks are taken up in altitude on earth, they slow down while atomic clocks speed up. If a pendulum clock “floats” in space, it won’t tick at all. On the other hand, the oscillation rate of a balance-wheel clock is not influenced by different gravitational potentials.

I personally think there are different kinds of “time” that are represented by different kinds of “clocks”, with each different kind of “time” and “clock” being regulated by different laws of physics. So, if we find a way to slow one kind of clock down, that does not represent a complete slowdown in all of “time itself” but only a slowdown in that particular kind of time as represented by that particular kind of clock. Several guys on this board disagree with me about this point of view, but that’s ok.

Sam5
2004-Jun-11, 04:59 PM
I’m not sure that the word “potential” is the right word to use when comparing atomic clock rates in the accelerating box to atomic clock rates at different elevations on earth.

It’s my understanding that if a guy is on a fixed platform 29,000 feet above the “floor” of an accelerating box that is accelerating at 1 g in deep space, and if he jumps off the platform, he actually will be sort of floating in space while the “floor” of the box will come up to hit him. Then if another guy jumps off 29,000-feet-high Mt. Everest, he will fall and hit the earth at sea level at the same force as the guy who is hit by the accelerating floor of the accelerating box. In one case the box accelerates, and in the other case the guy accelerates. However, an atomic clock in the box will tick at the same rate at all places within the box since all places within the box are experiencing 1 g acceleration, while two atomic clocks, one on top of Mt. Everest and another at sea level on earth, will tick at different rates.

Taibak, Milli, what do you think about this?

milli360
2004-Jun-11, 05:40 PM
But in an accelerating box in deep space, an atomic clock 29,000 feet “above” another atomic clock will tick at the same rate as the “bottom” clock, since all fixed places inside the accelerating box in deep space are experiencing exactly the same amount of acceleration
Not according to general relativity.

That's why I've been insisting that that example is the counterexample to your theory, and why your version of the way things act is against the mainstream.

I’m not sure that the word “potential” is the right word to use when comparing atomic clock rates in the accelerating box to atomic clock rates at different elevations on earth.

Why not?


Taibak, Milli, what do you think about this?
Thanks for asking. :)

Ricimer
2004-Jun-11, 06:05 PM
Glad someone posted this topic, as I have a question about it (sort of).
I explained to a friend of mine an experiment conducted to go about proving realitivity.
Two atomic clocks, both sychronized, were used. One stayed on the ground, the other went into space on the shuttle. When the other clock was returned, it was found to be off by a minute yet signifigant amount for an atomic clock. My friend countered by saying that a clock would operated different in a vaccum than on Earth. I told him it was inside the spacecraft. He then countered it would act different in space than on Earth. I didn't think so.
Who's right? And is my info correct that such an experiment was conducted? I think I read about it somewhere. I think it was mentioned on that ever-so-famous science show, "Bill Nye: The Science Guy".


We'll leave Sam5's comments alone...because as he's said, that's his personal view (which is fine by me) but is definetly counter to...basically everyone else. I.e. Sam, I don't want to start that debate again, let alone here, so I'll just explain things my way, and we can part in piece. That cool?


Grand: The point is it is acting differently in space, the clock runs faster. The atomic clock is amazingly insensitive to the conditions around it (due to construction and the mechanism itself).

The key here is that the shift in timing in the atomic clock wasn't just any shift (as your friend seems to imply)...but one that agrees strongly with GR predictions.

thefish7
2004-Jun-11, 06:49 PM
Not a physicist here, but, what Sam5 is saying makes a fair amount of sense to me. I think the fundamental problem is that we represent time using a device of some kind to acheive that representation. In the case of the pedulum clock, it's the swinging pendulum, in the mind of a guitarist it's his own innate sense of tempo and mathematics to define rhythm. My point is, time probably doesn't care one way or another how we're measuring it, it just does what it does. Our perception, on the other hand changes.

We can accept that time is something we don't well understand, somebody in an earlier post noted that for some reason it only goes in one direction. Relativistic notions of time make one assumption of the behavior of time in certain situations, but the universe as a whole continues on its merry way along time... so what does all this mean? I dunno, I'm just bored at work on a Friday. :)

Ricimer
2004-Jun-11, 07:02 PM
thefish: How well do you understand distance?

Do you have qualms with length contraction?

We merely use a meter stick to measure distance, just as we use a clock to measure time.


If no conditions around the clock change, that directly effect it's timing mechanism (such as gravity changing, which effects pendulums timing mechanism directly) then any shift in it's timing rate should be a shift in time.

Just like: If you take a meter stick, an d assuming nothing changes the stick (its humid so it warps for instance) if the span you measure is a different length, you won't argue with that will you?

So take a quartz watch, make sure the current to it is steady. If you put it in a situation that, without changing anything that it relies on to keep time, it measures a faster rate of time...you've actually got time going faster...just like with a longer thing you've measured with a meter stick.

Now, what do I mean by directly effecting the timing mechanism. A pendulum relies on gravity for its oscillations. Change gravity, and you change the oscillation rate, directly. So if you intend to keep accurate time at places with different gravities, you should probably use something like a quartz watch.

With a quartz watch pressure, gravity, incident light, and other things don't effect it, so you can rule those out as changing the timing device itself. Just like you use a meter stick that's rigid, and not made of playdoe, if you want an accurate distance.

Sam5
2004-Jun-11, 07:20 PM
But in an accelerating box in deep space, an atomic clock 29,000 feet “above” another atomic clock will tick at the same rate as the “bottom” clock, since all fixed places inside the accelerating box in deep space are experiencing exactly the same amount of acceleration
Not according to general relativity.


Well, tell us how, give us some references, explain what you mean. I’m willing to listen to your opinion, but just saying, “Not according to general relativity,” isn’t enough information to support your contention. In the post where I quoted the 1911 paper, Einstein clearly made a distinction between the case of clocks resting inside the moving box and clocks resting at different elevations on the earth.

Objects resting on platforms at different places inside the accelerating moving box can’t not experience different amounts of acceleration, since that would cause different parts of the box to split apart since different parts of it would have to be experiencing different accelerations.

Sam5
2004-Jun-11, 07:41 PM
I.e. Sam, I don't want to start that debate again, let alone here, so I'll just explain things my way, and we can part in piece. That cool?

Yes, that’s fine.

Sam5
2004-Jun-11, 08:03 PM
Not a physicist here, but, what Sam5 is saying makes a fair amount of sense to me. I think the fundamental problem is that we represent time using a device of some kind to acheive that representation. In the case of the pedulum clock, it's the swinging pendulum, in the mind of a guitarist it's his own innate sense of tempo and mathematics to define rhythm. My point is, time probably doesn't care one way or another how we're measuring it, it just does what it does. Our perception, on the other hand changes.


My point of view, based on many years of experience of working with different kinds of clocks, is that while “time” as measured or determined by different kinds of clocks is basically the “same thing”, time does not flow at the same rate everywhere or anywhere, since different laws of physics determine how rapidly different kinds of things move, oscillate, vibrate, etc., and those different laws govern the different rates of the different kinds of clocks. So, from my point of view, no single kind of clock can represent all of “time itself” even though every kind of clock represents “true time”. Thus, while atomic clocks do represent “true time”, they do not represent all of “time itself,” where ever they are located.

If we have an atomic clock sitting next to a pendulum clock at sea level, and we adjust their rates to be the same, if we move both of them to Denver, the atomic clock will speed up and the pendulum clock will slow down. While both measure “true time”, both do not measure all of “time itself” at either location. The speed up of the atomic clock and the slowdown of the pendulum clock are caused by two different sets or groups of physical laws, and both groups are equally valid and equally represent “true time”, but neither group represents all of “time itself”.

One big reason I think physicists have come to think of atomic clocks as representing both “true time” and “time itself” is because they are the most steady kinds of clocks on earth, and it just “feels right” to say that the most steady kind of clock “must be” telling or measuring true “time itself”. But I say that “true time” does not have to be perfectly steady in order to be “true time”. All it has to do is “flow” and progress and move forward by means of a repetitive series of cause-and-effect events. But it doesn’t have to be absolutely “steady” in order to be real and “true” time, just as our heartbeats don’t have to be absolutely steady.

When you drive to work, you don’t have to drive at an absolutely steady rate. You’ll move through time and get to work just the same, whether you are in stop and go traffic or if travel at an absolutely steady rate of 60 mph. But in the field of physics, the best kind of clock is an absolutely steady clock, and so far I think atomic clocks are the most steady, so it has become a custom in physics of thinking of them as not only "true time" clocks but also representing all of "time itself" where ever they are located.

milli360
2004-Jun-11, 09:11 PM
But in an accelerating box in deep space, an atomic clock 29,000 feet “above” another atomic clock will tick at the same rate as the “bottom” clock, since all fixed places inside the accelerating box in deep space are experiencing exactly the same amount of acceleration
Not according to general relativity.


Well, tell us how, give us some references, explain what you mean. I’m willing to listen to your opinion, but just saying, “Not according to general relativity,” isn’t enough information to support your contention.
We've had this discussion before though. :)

AstroSmurf provided some equations, in a post just above.

Sam5
2004-Jun-11, 10:59 PM
Worse, it's not the strength of gravity directly that does it.

Two objects could be experiencing the same acceleration, the same apparent gravity, and the one that's "lower" will experience a different rate of time than the one that's "higher".
I think you’re getting the accelerated box thought experiment a little mixed up. Two atomic clocks at different positions in the moving accelerating box in deep space will tick at the same rate. Two resting at different elevations on earth will tick at different rates.
Taibak, I think you missed what Sam5 said. He's saying that gravitational dilatation arises only from a difference in the gradient.

However, that's not how reality behaves. The GR contribution to time dilation depends on the difference in gravitational potential, not the gravitational gradient. This is true even where the gradient is zero, as in an accelerating spaceship, So the bolded part of his statement is only true if they're at the same "height" in the spaceship.


Milli seems to support your point of view, but it is not quite correct. The position inside the moving spaceship doesn’t matter for an atomic clock, since the acceleration is the same for all positions fixed rigidly to any place inside the spaceship, therefore all atomic clocks resting anywhere inside the accelerating spaceship will tick at the same rate. It is the Kräfte, the “forces” on the atoms inside the clocks that causes their oscillation rates to slow down, and all accelerative forces on all clocks fixed any place inside the accelerating spaceship are the same. In that regard there is no “above” or “below” inside the spaceship as far as the tick rate of an atomic clock is concerned.

Milli take note and give me your opinion about this.

Sam5
2004-Jun-11, 11:13 PM
When considering the gravitational forces at the earth, the “acceleration” forces placed on an atomic clock are stronger at sea level than they are on a mountain top, so in this case the “elevation” or vertical separation distance does matter when it comes to the tick rates of resting atomic clocks.

But in an accelerating spaceship in deep space, the “acceleration” forces placed on resting clocks inside the spaceship are the same at the “bottom” of the spaceship as they are on a platform at the “top” of the spaceship. So in the accelerating spaceship, all resting atomic clocks will tick at the same rate, no mater what their resting position or vertical separation distance is.

dvb
2004-Jun-12, 01:05 AM
umm, there's no gravity in a spaceship. So I can't see how it would make a difference where in the ship the clocks are, they should all be the same regardless I would think. And even if the spaceship did have gravity plating, wouldn't it still be the same since we're accelerating at the same speed in the same ship, going in the same direction with the same amount of gravity on all decks of the ship? :o

That's a mouthful.

And another thing. I'd like to see Sam5's arguments heard. How do scientists define time and with what type of clock.

When we say that time slows down, do we really mean the effect gravity has on atoms? In other words, as gravity or acceleration increases, all atomic behaviour slows down? Is that the real definition of time?

But that doesn't make much sense does it? :o

I mean if we reached the speed of light, that would mean all atomic activity would stop wouldn't it?

Anyways, I'm no scientist either. I'm just here to learn.

So please, teach me! :)

Sam5
2004-Jun-12, 02:12 AM
Ok, I’ll tell you the following as “my opinion”. There will be guys here who object to it and disagree with me, so that’s why I’m telling you this is “my opinion”. They will give you “their opinion”.




When we say that time slows down, do we really mean the effect gravity has on atoms?


I think that is exactly it. Physicists tend to not think that way, because they tend to think that “atomic time” represents all of “true time” and “time itself”. But I disagree, because I’ve worked with a lot of different kinds of clocks in my lifetime, and I’ve seen many different things age at different rates for different physical reasons that don’t have anything to do with the “tick rates” of “atomic clocks”.

I searched for years to find the origin of the concept of “atomic clocks” and “atomic time”, and I finally found it in a reprint of an old Maxwell book from 1873. Seems that physicists in those days knew that the color of light emitted by hot atoms was related to the internal oscillation rates of the atoms, and the oscillation rates in the atoms in stars tended to be fairly steady, so as far as I can tell, it was Maxwell who first proposed the idea of “atomic time”, because it was so steady.

I read a lot of old science books, and I discovered that in the 1890s H.A. Lorentz suggested that atomic oscillation rates could slow down if the atoms experienced certain kinds of “forces”.

Then in 1911 Einstein theorized that the oscillation rates of atoms would slow down if the atoms existed in a strong gravity field, and they would speed up if the atoms were in a weak gravity field. And from about that era on, “true time” in physics began to be thought of as being exactly the same as “atomic time,” which was determined by atomic oscillation rates. In 1938 a scientist named Ives wrote a paper titled “An Experimental Study of the Rate of a Moving Atomic Clock.” Ives was talking about rapidly moving atoms, since modern manufactured atomic clocks had not yet been invented.

I think part of the reasoning that “atomic time” represented the only “true time” was because since atomic oscillation rates are so steady, and since about everything is made up of atoms, then maybe “atomic time” is indeed the only form of “true time”.

And so, when you read about how “time slows down” under such and such conditions, that is generally what the physicists are talking about, the oscillation rates of atoms, the “tick rate” of atomic clocks. They generally do not consider a slow down in any other kind of clock as representing a “true time” slowdown, and I disagree with that point of view.

For example, go to Wal-Mart and buy a couple of cheap plastic storage boxes. Keep one in the house and put the other outdoors in the summer sunlight. You’ll find that the one that stays in the sunlight begins to age, disintegrate, and break apart much faster than the one in the house. Why? Because that kind of plastic ages faster when it is bombarded by ultra-violet light from the sun. A plastic box like that will last only one or two summers in the sun, while the one you keep in the house will last ten years or more before it begins to break apart. As far as I can tell, there is no difference in the aging rate for that kind of plastic when it is placed under different gravitational potentials, so its aging rate does not follow the “tick rate” changes of atomic clocks. The aging of the plastic doesn’t follow the “atomic clock” laws, it follows some of the “molecular clock” laws. The UV light seems to have a disintegrating effect on the molecular bonds of the plastic the box is made up of, so here we have a clear case of a type of “molecular time,” which is different from “atomic time”.

dvb
2004-Jun-12, 02:53 AM
Very interesting concepts. This gave me an idea, and please correct me if I'm wrong.

IIRC, atoms stop (is that the right word?) when they reach absolute zero with the exception of helium. Now according to relativity, time stops when we reach light speed. Which I would think means that atoms stop as well.

These are both examples of atomic time and molecular time. What would happen if we had an atom at absolute zero traveling at the speed of light? Would we still have just a dead atom?

If you froze a clock solid, no matter what kind of clock it is, time will stop for it. Same for if you freeze a human I would think. Is there any relation here to absolute zero and the speed of light?

Both are effective at stopping time in the atomic/molecular sense, or are they?

Sam5
2004-Jun-12, 03:39 AM
Very interesting concepts. This gave me an idea, and please correct me if I'm wrong.

IIRC, atoms stop (is that the right word?) when they reach absolute zero with the exception of helium. Now according to relativity, time stops when we reach light speed. Which I would think means that atoms stop as well.

These are both examples of atomic time and molecular time. What would happen if we had an atom at absolute zero traveling at the speed of light? Would we still have just a dead atom?

If you froze a clock solid, no matter what kind of clock it is, time will stop for it. Same for if you freeze a human I would think. Is there any relation here to absolute zero and the speed of light?

Both are effective at stopping time in the atomic/molecular sense, or are they?

Hmm.... I don’t think a pendulum would stop swinging if you froze it to absolute zero. I think you could probably stop a balance-wheel clock by freezing it, since the turn of its wheel depends on the tension in a tiny spring, and I don’t think the spring would continue to work like a regular spring if it was frozen so much. But I think an inertial flywheel clock would keep turning even if you froze it to absolute zero.

I’ve read in a few books that atoms do (I think) stop oscillating at absolute zero, and of course molecules stop bouncing around, but I’m not sure if you could stop everything from moving. I think a planet or a ball or a disk turning while at absolute zero would not stop turning.

As far as “time stopping at the speed of light”, there is some new thinking going on about that, since a lot of distant galaxies have been found that appear (due to the Doppler shift of their light) to be moving away from us at several times faster than the speed of light. And of course they glow (that’s why we can see them) so we know that molecular and atomic time has not stopped in those galaxies. This discovery is actually fairly new, just with the past 20 or so years, so this has to be mulled over by all the scientists.

There are some conditions and loopholes in the “speed limit of c” rule, which was actually invented by Lorentz in the 1890s. We might be able to consider there to be a “speed limit” inside a strong gravity field but not a “speed limit” outside a strong gravity field. This might explain why particles can not be accelerated on earth up to the speed of c, yet the distant galaxies seem to be moving at greater than c relative to the earth. Since they aren’t moving through our locally strong gravity fields, there might not be any speed limit outside of strong gravity fields.

I guess I need to point out that these are my personal ideas and are not “official” ideas in physics.

The problem with freezing a human is that the water in his cells freeze and rupture the cells, so you can freeze him but he will be dead when you thaw him out. However, you can freeze human embryos by carefully removing all water from them, and they will be “time suspended” for several years before they are rehydrated and thawed out. The oldest kid I know about was frozen as an embryo for 7 years before he was born. So, he was 7 earth years old when he was born, but only a baby in his time frame.

dvb
2004-Jun-12, 04:07 AM
Hmm.... I don’t think a pendulum would stop swinging if you froze it to absolute zero. I think you could probably stop a balance-wheel clock by freezing it, since the turn of its wheel depends on the tension in a tiny spring, and I don’t think the spring would continue to work like a regular spring if it was frozen so much. But I think an inertial flywheel clock would keep turning even if you froze it to absolute zero.

I would think that we can't make much use of energy at absolute zero when you consider every component in the clock would be frozen meaning it would be unable to store or use any energy right?


I’ve read in a few books that atoms do (I think) stop oscillating at absolute zero, and of course molecules stop bouncing around, but I’m not sure if you could stop everything from moving.


That's what I read about atoms in an old 70's I think it was physics book. I just wasn't sure if I remembered it right. :)


As far as “time stopping at the speed of light”, there is some new thinking going on about that, since a lot of distant galaxies have been found that appear (due to the Doppler shift of their light) to be moving away from us at several times faster than the speed of light. And of course they glow (that’s why we can see them) so we know that molecular and atomic time has not stopped in those galaxies. This discovery is actually fairly new, just with the past 20 or so years, so this has to be mulled over by all the scientists.

There are some conditions and loopholes in the “speed limit of c” rule, which was actually invented by Lorentz in the 1890s. We might be able to consider there to be a “speed limit” inside a strong gravity field but not a “speed limit” outside a strong gravity field. This might explain why particles can not be accelerated on earth up to the speed of c, yet the distant galaxies seem to be moving at greater than c relative to the earth. Since they aren’t moving through our locally strong gravity fields, there might not be any speed limit outside of strong gravity fields.

Very interesting stuff. I'd like to see more info on galexies traveling faster than light for reading. I remember hearing about this before, but I wasn't sure if it was just urban legend or something of that sort. Seems to me it could change relativity as we know it, or could it?


The problem with freezing a human is that the water in his cells freeze and rupture the cells, so you can freeze him but he will be dead when you thaw him out. However, you can freeze human embryos by carefully removing all water from them, and they will be “time suspended” for several years before they are rehydrated and thawed out. The oldest kid I know about was frozen as an embryo for 7 years before he was born. So, he was 7 earth years old when he was born, but only a baby in his time frame.

I know that you'll end up with a dead human if you defrost them. :lol:

I was just trying to make a point there. :)

Ricimer
2004-Jun-12, 04:20 AM
Very interesting concepts. This gave me an idea, and please correct me if I'm wrong.

IIRC, atoms stop (is that the right word?) when they reach absolute zero with the exception of helium. Now according to relativity, time stops when we reach light speed. Which I would think means that atoms stop as well.

These are both examples of atomic time and molecular time. What would happen if we had an atom at absolute zero traveling at the speed of light? Would we still have just a dead atom?

If you froze a clock solid, no matter what kind of clock it is, time will stop for it. Same for if you freeze a human I would think. Is there any relation here to absolute zero and the speed of light?

Both are effective at stopping time in the atomic/molecular sense, or are they?


Time can be measured many ways, the most accurate (i.e that effected by the enviroment the least) is atomic vibrations. By measuring those in a specific setup (one where we isolate it from interfering factors, like fluctuating temperature) any change in its vibrations, since it isn't outside factors (the point Sam5, I and others often clash over) it has to be the time duration that has changed.

When you put anything at absolute zero, there is no energy in the system, there is no kinetic energy, no motion, nada, zilch. Not even atoms spinning or vibrating.

For ANYTHING (even helium).

The problems: You can't get there in reality. You require a perfectly isolated system, t hat can't be in contact with anything...which is impossible.

Another one: YOu can't get there theoretically. I'd show you the proof, but its a tricky one. Basically it requires (even theoretically) an infinite number of steps to remove that last bit of energy. Just like it takes an infinite number of steps to reach the speed of light.

As an object goes faster, its measured temperature will drop, at C it will read (to us stationary observers) as absolute zero. But, ya can't get there, or to C, so you don't have a problem there.

But basically relativity says time actually slows down.

Now, the person won't notice a bloody thing. Everythign slows down, so any measurement the traveller makes, will be slowed the same (even "biological" process) and they won't notice the difference. Chemical reactions, atomic vibrations, clocks, falling objects etc, will all be slower. Heck, the traveller will think everybody else is "frozen".


P.s. the reason we aren't "hearing out" Sam5 isn't because we don't want to hear it. We've just heard it before, and each tiem it all ends u pin a massive, long series of posts (mroe that 15 pages worth last time IIRC) with him on one side and basically everyone else on the other (it's relatively civil, we're not ganging up on him, it's just everybody basically disagrees).

So I'd just rather not get into that agian, and set this thread on that large of a tangent.

Tensor
2004-Jun-12, 04:58 AM
umm, there's no gravity in a spaceship. So I can't see how it would make a difference where in the ship the clocks are, they should all be the same regardless I would think. And even if the spaceship did have gravity plating, wouldn't it still be the same since we're accelerating at the same speed in the same ship, going in the same direction with the same amount of gravity on all decks of the ship? :o

That's a mouthful.

And another thing. I'd like to see Sam5's arguments heard.

If you want to see Sam5's arguments, and the rebuttals to those arguments, try here (http://badastronomy.com/phpBB/viewtopic.php?t=12739&postdays=0&postorder=asc&sta rt=0&sid=d0e2387194858099ae2a905996eea958) or here (http://www.badastronomy.com/phpBB/viewtopic.php?t=9731&start=0&postdays=0&postorder= asc&highlight=relativity). I'll warn you though, there are 41 pages in the first and 84 in the second.

dvb
2004-Jun-12, 04:58 AM
Ricimer, first I'd like to thank you for giving me your 2 cents.


By measuring those in a specific setup (one where we isolate it from interfering factors, like fluctuating temperature) any change in its vibrations, since it isn't outside factors (the point Sam5, I and others often clash over) it has to be the time duration that has changed.

Thank you for clarifying this. So you don't argue that time for scientific purposes is based on atomic cycles right?


The problems: You can't get there in reality. You require a perfectly isolated system, t hat can't be in contact with anything...which is impossible.

What about in space?


Now, the person won't notice a bloody thing. Everythign slows down, so any measurement the traveller makes, will be slowed the same (even "biological" process) and they won't notice the difference. Chemical reactions, atomic vibrations, clocks, falling objects etc, will all be slower. Heck, the traveller will think everybody else is "frozen".

I can't wrap my head around this. #-o

Ok, let me get this straight now. At absolute zero we cannot use energy, but to attain the speed of light we must use infinite energy. If we could reach the speed of light, matter would be frozen at absolute zero?

Wouldn't that mean that if we tried to travel at the speed of light, we'd end up frozen at some point? Or would it only appear to be frozen from someone elses POV?

Either this isn't making any sense to me, or I'm just going about it all wrong. Please correct me.

dvb
2004-Jun-12, 05:00 AM
If you want to see Sam5's arguments, and the rebuttals to those arguments, try here (http://badastronomy.com/phpBB/viewtopic.php?t=12739&postdays=0&postorder=asc&sta rt=0&sid=d0e2387194858099ae2a905996eea958) or here (http://www.badastronomy.com/phpBB/viewtopic.php?t=9731&start=0&postdays=0&postorder= asc&highlight=relativity). I'll warn you though, there are 41 pages in the first and 84 in the second.

Thank you Tensor

Sam5
2004-Jun-12, 05:04 AM
Hmm.... I don’t think a pendulum would stop swinging if you froze it to absolute zero. I think you could probably stop a balance-wheel clock by freezing it, since the turn of its wheel depends on the tension in a tiny spring, and I don’t think the spring would continue to work like a regular spring if it was frozen so much. But I think an inertial flywheel clock would keep turning even if you froze it to absolute zero.

I would think that we can't make much use of energy at absolute zero when you consider every component in the clock would be frozen meaning it would be unable to store or use any energy right?


Well, sort of, but still there is the issue of the rotation of a flywheel or a sphere. I don’t see how freezing either would stop them.

Some kinds of clocks tend to consume energy in order to keep going, such as a balance wheel and pendulum clock, but I think a rotating planet or disk in space can keep rotating without consuming energy.




Very interesting stuff. I'd like to see more info on galexies traveling faster than light for reading. I remember hearing about this before, but I wasn't sure if it was just urban legend or something of that sort. Seems to me it could change relativity as we know it, or could it?

Well, uhh, yes, as it is commonly known today, that’s true.

Tensor
2004-Jun-12, 05:12 AM
Well, sort of, but still there is the issue of the rotation of a flywheel or a sphere. I don’t see how freezing either would stop them.

It's not a question of just freezing Sam5, if anything gets to absolute zero (although as Ricimer pointed out we can't in reality) there is no energy. If something is rotating, the object has energy and the object would not be at absolute zero.

Sam5
2004-Jun-12, 05:19 AM
As an object goes faster, its measured temperature will drop, at C it will read (to us stationary observers) as absolute zero. But, ya can't get there, or to C, so you don't have a problem there.


"Thus for the largest known redshift of z=6.3, the recession velocity is not 6.3*c = 1,890,000 km/sec. It is also not the 285,254 km/sec given by the special relativistic Doppler formula 1+z = sqrt((1+v/c)/(1-v/c)). The actual recession velocity for this object depends on the cosmological parameters, but for an OmegaM=0.3 vacuum-dominated flat model the velocity is 585,611 km/sec. This is faster than light.”

LINK TO SOURCE (http://www.astro.ucla.edu/~wright/doppler.htm)



with him on one side and basically everyone else on the other

It’s not really “everyone else”. It’s just 5 or 6 guys.

“Everyone” would be 6.5 billion people.

Sam5
2004-Jun-12, 05:25 AM
Now, the person won't notice a bloody thing. Everythign slows down, so any measurement the traveller makes, will be slowed the same (even "biological" process) and they won't notice the difference. Chemical reactions, atomic vibrations, clocks, falling objects etc, will all be slower. Heck, the traveller will think everybody else is "frozen".

No, that’s not true. Biological processes are mainly determined by heat energy and people don’t “freeze” just because they are in motion “relative” to something else. After all, we are traveling at several c relative to the most distant visible galaxies and we are not frozen, nor or they, since they are glowing because of rapid molecular movement. Face it, SR was just wrong in that regard. We don't see them as "frozen" at all, because we see them as hot and glowing. That means their molecules are vibrating rapidly.

Sam5
2004-Jun-12, 05:28 AM
Well, sort of, but still there is the issue of the rotation of a flywheel or a sphere. I don’t see how freezing either would stop them.

It's not a question of just freezing Sam5, if anything gets to absolute zero (although as Ricimer pointed out we can't in reality) there is no energy. If something is rotating, the object has energy and the object would not be at absolute zero.

Do you think that freezing a rapidly spinning disk in space slows it down?

Sam5
2004-Jun-12, 05:42 AM
Wouldn't that mean that if we tried to travel at the speed of light, we'd end up frozen at some point? Or would it only appear to be frozen from someone elses POV?

Either this isn't making any sense to me, or I'm just going about it all wrong. Please correct me.

Uhh, my opinion is that some of it “doesn’t make sense” because it is basically “wrong”. This is a 100-year-old out of date theory that was taught in universities in the ‘60s – ‘90s, but it has been made obsolete just within the past couple of decades, because of the discovery of the superluminal galaxies. They are hot, they are glowing, they are not “frozen”, and they have redshifts that indicate they are moving at 2 to 4 times the speed of light, relative to the earth. This was not known just a couple of decades ago, so some of the old theories are in the process of being changed.

Here is a problem I’ve noticed while going through life... we spend our first 20 to 25 years cramming our brains with a lot of information as we try to learn all we can. Then we try to sort out all that information and turn it into some sort of comprehensible overall “world view”. Then, as soon as we do that, maybe by the time we are 30 years old, a bunch of guys come along and start changing all the rules and laws and even the history books. So what do we do? Many of us resist the change at first. After all, we’ve spent 30 years trying to figure everything out, based on all the old laws and the old rules, and now they make new discoveries and have to change the laws and rules.

So, some people are opposed to changing some of the old laws and rules, so they simply refuse to accept the observational evidence that the distant galaxies are moving faster than c relative to the earth. They just ignore the new evidence and pretend it doesn’t exist.

Well, I did that for a while, for many years, but I finally began to realize that this always happens, it has always happened in the past and it will always happen in the future. So we must learn to accept new evidence and change the old laws and rules where necessary, whether we like it or not, because time marches on and we can’t stop progress.

dvb
2004-Jun-12, 06:00 AM
Thank you Sam5. I realize that everybody isn't against you, and I'm more interested in knowing the truth than debating. I'll leave that to you guys, and figure the rest out after trying to make sense of everyones arguments. Don't worry though, I'll make my own arguments when things don't add up in my head. :)

I like to have more than just a 1 sided view of things as it allows me to think better outside the box.

I'm sure that a great deal of our theories are wrong. We still have a lot to explain that physics hasn't taught us yet, so I'm open to new ideas.

After all, we can't assume that all the great scientists are always right, even if their theories are sound. I know that there's a great deal of work put behind these theories as well, and won't throw them out the door at the first sign of trouble.

milli360
2004-Jun-12, 08:17 AM
Milli seems to support your point of view, but it is not quite correct. The position inside the moving spaceship doesn’t matter for an atomic clock, since the acceleration is the same for all positions fixed rigidly to any place inside the spaceship, therefore all atomic clocks resting anywhere inside the accelerating spaceship will tick at the same rate. It is the Kräfte, the “forces” on the atoms inside the clocks that causes their oscillation rates to slow down, and all accelerative forces on all clocks fixed any place inside the accelerating spaceship are the same. In that regard there is no “above” or “below” inside the spaceship as far as the tick rate of an atomic clock is concerned.

Milli take note and give me your opinion about this.
Noted.

I haven't checked AstroSmurf's equations completely, but I agree in essence. When it comes to general relativity, what you say above is completely wrong, and AstroSmurf is right.

That's why I've always said your ideas are against the mainstream. There is a slim chance that they may yet turn out to be true, but there's not much chance of it (for instance, one possibility that we haven't ruled out yet is that a fairy throws pixie dust in the eyes of every researcher just as a critical test is made :) )

swansont
2004-Jun-12, 12:16 PM
This happens with atomic clocks. The reason is that an atomic clock will tick slower when resting in a strong gravity field, and it will tick faster when “floating” up in space. It has something to do with the force placed on the atoms when the clock is resting at the surface of the earth. The “tick rate” of an atomic clock is based on the internal oscillation rates of the atoms that are used for the timing mechanism of the clock. The oscillation rate slows down when the clock is resting in a gravity field, and it speeds up when the clock is “floating” in space.

My personal view is that this is specifically a phenomenon experienced by atomic clocks and it does not represent a change in all of “time itself”. Since, when pendulum clocks are taken up in altitude on earth, they slow down while atomic clocks speed up. If a pendulum clock “floats” in space, it won’t tick at all. On the other hand, the oscillation rate of a balance-wheel clock is not influenced by different gravitational potentials.

I personally think there are different kinds of “time” that are represented by different kinds of “clocks”, with each different kind of “time” and “clock” being regulated by different laws of physics. So, if we find a way to slow one kind of clock down, that does not represent a complete slowdown in all of “time itself” but only a slowdown in that particular kind of time as represented by that particular kind of clock. Several guys on this board disagree with me about this point of view, but that’s ok.

And those of who have disagreed have actual experiments to back us up.

Local position invariance has been tested. If you go here (http://www.exphy.uni-duesseldorf.de/PublicationsInst2002.html) and download paper #11, you will see. It's a Phys Rev Letter about LPI with a cryogenic oscillator, and has references for other comparisons as well.

What Sam has never addressed is an actual mechanism other than "gravity does it somehow." The actual tests show that there is no difference in the change of oscillation rates if you use spin transitions, electronic transitions, nuclear transitions or a quartz oscillator. One would expect interactions of different strengths to scale differently when compared to g, but they don't. One generally concludes that g is a negligible direct contribution to those interactions.

Sam5
2004-Jun-12, 02:11 PM
Noted.

I haven't checked AstroSmurf's equations completely, but I agree in essence.


So you think that clocks near the floor in an accelerating box in deep space will tick slower than clocks resting on a platform at the top of the box, even though all the clocks are experiencing the same accelerative force? Please explain how and why this happens. Tell me in your own words why you think this happens.

Sam5
2004-Jun-12, 03:34 PM
swansont,

Tests were already conducted in the 19th Century. Pendulum clocks slow down at high altitude while balance wheel clocks don’t change their rates due to gravitational potential changes. In the 20th Century it was learned that atomic clocks speed up at high altitudes.

So they got a crystal/laser clock to match the tick rate of an iodine atomic clock, and they found that the earth is not moving through a universal ether at 18.6 mps. Michelson and Morley discovered that in 1887. Any type of clock that uses a laser is a type of “atomic clock” and is subject to atomic oscillation changes just like any other type of atomic clock. So the test involved two different types of atomic clocks. They did not involve two completely different kinds of clocks.

LINK (http://216.239.57.104/search?q=cache:SstNqoeYkAAJ:physicsweb.org/article/news/6/1/2+laser+frequency+drift+relativity&hl=en&ie=UTF-8)


See also:

“The availability of optical oscillators with instability lower than 10^(-17) over long periods of time (days) would allow to repeat a series of fundamental physics experiments with improved accuracy. Among these are tests of special relativity, and of the principle of local position invariance, a postulate of General Relativity. In addition, it appears feasible to use appropriately constructed COREs to measure changes in local gravitational acceleration, the gravitational constant, and the dislocation dynamics in solids. Another interesting application is as a displacement sensor for monitoring the excitation of gravitational bar antennas.”

“Finally, it should be noted that according to General Relativity any oscillator, including a cavity-stabilized laser, experiences a gravitational frequency shift which is due to the daily and yearly variation of the solar gravitational potential at the clock's location.”

LINK (http://www.exphy.uni-duesseldorf.de/Publikationen/papers/Schiller95SPIEcore.pdf)

Sam5
2004-Jun-12, 03:47 PM
What Sam has never addressed is an actual mechanism other than "gravity does it somehow."

Lorentz said it has something to do with electrodynamic “forces” experienced by the atoms when they experienced different accelerations. This is a quantum mechanics effect.

You’ve never explained why your atomic clocks run fast at Denver and slow at sea level. Please tell us why they do.

Grand_Lunar
2004-Jun-12, 04:25 PM
The problems: You can't get there in reality. You require a perfectly isolated system, t hat can't be in contact with anything...which is impossible.

What about in space?



The average temperature in space is 2.7 Kelvin. In science, that's well above absolute zero. Colder temps have been achieved in labs than that! To a thousandth, I belive. Weird stuff happens then. But that's another thread. "The Absolute Zero Thread"?
As for atomic clocks, I don't see them as representing either "true time" or "time itself". I see them as a more accurate standard to measure time. True time is realitive. Time itself, I belive, is part of the space-time continum. Least, that's how I see it.
I doubt Earth's gravity is strong enough to alter quantum mechanics in an atomic clock to effect it as much as Sam5 says. From what I've read, gravity effects things on larger scales, and isn't so effective on smaller things (except us!). I think scientists conducting a sychronazation experitment would account variations, if any, in their experiment. As for the "outside force besides gravity", it could very well be a slight effect of GR. There's my two cents. :o

milli360
2004-Jun-12, 04:36 PM
Noted.

I haven't checked AstroSmurf's equations completely, but I agree in essence.


So you think that clocks near the floor in an accelerating box in deep space will tick slower than clocks resting on a platform at the top of the box, even though all the clocks are experiencing the same accelerative force? Please explain how and why this happens. Tell me in your own words why you think this happens.
I've done this sort of thing before (http://mentock.home.mindspring.com/twin2.htm) but it does involve math, as does most general relativitistic results.

What's wrong with what AstroSmurf said?

Ricimer
2004-Jun-12, 04:41 PM
Ricimer, first I'd like to thank you for giving me your 2 cents.


By measuring those in a specific setup (one where we isolate it from interfering factors, like fluctuating temperature) any change in its vibrations, since it isn't outside factors (the point Sam5, I and others often clash over) it has to be the time duration that has changed.

Thank you for clarifying this. So you don't argue that time for scientific purposes is based on atomic cycles right?


The problems: You can't get there in reality. You require a perfectly isolated system, t hat can't be in contact with anything...which is impossible.

What about in space?


Now, the person won't notice a bloody thing. Everythign slows down, so any measurement the traveller makes, will be slowed the same (even "biological" process) and they won't notice the difference. Chemical reactions, atomic vibrations, clocks, falling objects etc, will all be slower. Heck, the traveller will think everybody else is "frozen".

I can't wrap my head around this. #-o

Ok, let me get this straight now. At absolute zero we cannot use energy, but to attain the speed of light we must use infinite energy. If we could reach the speed of light, matter would be frozen at absolute zero?

Wouldn't that mean that if we tried to travel at the speed of light, we'd end up frozen at some point? Or would it only appear to be frozen from someone elses POV?

Either this isn't making any sense to me, or I'm just going about it all wrong. Please correct me.



Sam: That Omega: 0.3 z=>6 stuff...thats expansionary. I have no qualms with something going faster than C due to expansionary means, cause it's not moving through space faster than C (that's disallowed), instead it's carried by space to that speed.

Now, on to dvb:

Time is not based on atomic oscillations. Those are accurate ways of measuring however.

Saying time is based on atomic oscillations is the same as saying the distance between me and you is based upon the meter stick. Change the meter stick, and you change the distance (the actual distance). Thats a bit easier to grasp, and is obviously not hte case.

In space: No, for reasons Grand Lunar said. And I think the coldest temp achieved is actually on the order of a hundred thousandth or closer maybe. I know a hundred thousandth is routinely reached at the JILA labs during their Bose-Einstein Condensate experiments.

If you were to get up to ~C (close, but not quite there) and measured your temp, time, and physical dimensions: All would be normal. Because you don't seem to move, compared to yourself. It's like riding in a car or airplane. Sure, someone tells you that you're zipping around at X mph, but everything behaves the same.

Someone else, who is "stationary" seeing you zip by however would notice: You time is slower, your temp is lower, your length is shorter, and your density is higher. You also have more inertia than Newton predicts (not mass, thats a misnomer, just inertia which mass usually represents).

Sam5
2004-Jun-12, 04:52 PM
Noted.

I haven't checked AstroSmurf's equations completely, but I agree in essence.


So you think that clocks near the floor in an accelerating box in deep space will tick slower than clocks resting on a platform at the top of the box, even though all the clocks are experiencing the same accelerative force? Please explain how and why this happens. Tell me in your own words why you think this happens.
I've done this sort of thing before (http://mentock.home.mindspring.com/twin2.htm) but it does involve math, as does most general relativitistic results.


Well, in the first place, this is not correct: ”The Twin Paradox of Einstein is an interesting thought experiment involving two twins (who are nearly the same age of course), one of whom sets out on a journey into space and back.”

The SR thought experiment involved two balance-wheel clocks, not two “twins”. Neither of the clocks were resting on the earth. Both were moving relatively in deep space. And no acceleration or gravity effects were involved with the paradox.

Anyway, this doesn’t have anything to do with the accelerating box experiment. In the box, all points experience the same acceleration. On earth, different points of elevation experience different acceleration. Atomic clocks at different points in the box all tick at the same rate. Atomic clocks at different elevations on earth don’t. This is GR theory, and you need to learn it.

milli360
2004-Jun-12, 05:07 PM
Trivial objections aside, the math and theory remain.


And no acceleration or gravity effects were involved with the paradox.
O, yes there were, from the beginning (his 1905 paper). We've gone over this before. The "peculiar consequence" is the genesis of the paradox, and that peculiar consequence analysis does involve changes in direction, which are accelerations.


Anyway, this doesn’t have anything to do with the accelerating box experiment.
How can you tell? :)


In the box, all points experience the same acceleration. On earth, different points of elevation experience different acceleration.

Not all of them. Some points at the same elevation experience different accelerations.


Atomic clocks at different points in the box all tick at the same rate.

Not according to general relativity.

This is GR theory, and you need to learn it.
No it's not. It's your own theory.

Sam5
2004-Jun-12, 05:07 PM
Sam: That Omega: 0.3 z=>6 stuff...thats expansionary. I have no qualms with something going faster than C due to expansionary means, cause it's not moving through space faster than C (that's disallowed), instead it's carried by space to that speed.

What you call “moving through space” is what I call “moving through a strong gravity field”. It’s what Lorentz called “moving through the ether”.

I’ve consistently said that c does seem to be a speed limit in the strong gravity field of the earth. But since the distant galaxies are not moving at superluminal speeds through the earth’s local gravity field, they don’t have the speed limit.

However, they are “moving through space”. That’s why their distance gets greater and greater as they move. They aren’t “carried by space” to that speed because empty space can’t carry anything. It’s just there. It’s the gravity and other fields in space that do things, move things, carry things, and also other forces such as projectile impulses causing things to move through space. We see that in nova explosions. Space isn't "expanding" around the nova. The dang thing just blew up and the stuff moves out from it as a result of a projectile force.

Sam5
2004-Jun-12, 05:22 PM
Trivial objections aside, the math and theory remain.


What do you mean? All you do is say “the math, the math”, but that explains nothing. In your thought experiment you’ve got Bob feeling a gravity field but you say there is none. This is nonsense. This is double-talk that explains nothing. You say, "Bob will have to experience tremendous acceleration, while not moving. How is this possible?" Then you say, "Bob doesn't sit in a gravity field attributable to matter" So, he doesn't move and he is not resting in a gravity field, so where does the "acceleration" come from? Do you know a new source of "acceleration" other than through motion or gravity? Wow! Tell us about it!





And no acceleration or gravity effects were involved with the paradox.




O, yes there were, from the beginning (his 1905 paper). We've gone over this before. The "peculiar consequence" is the genesis of the paradox, and that peculiar consequence analysis does involve changes in direction, which are accelerations.


No. There is no change in direction in his first “peculiar consequence” thought experiment, and that is the one that leads to the paradox.

Sam5
2004-Jun-12, 05:29 PM
In the box, all points experience the same acceleration. On earth, different points of elevation experience different acceleration.




Not all of them. Some points at the same elevation experience different accelerations.

You know very well that I’m talking about different distances from the center of the earth. You are used to playing with the minds of teenagers, but that stuff won’t work on me.

milli360
2004-Jun-12, 05:50 PM
What do you mean? All you do is say “the math, the math”, but that explains nothing.
AstroSmurf posted some, and I also.


In your thought experiment you’ve got Bob feeling a gravity field but you say there is none. This is nonsense. This is double-talk that explains nothing. You say, "Bob will have to experience tremendous acceleration, while not moving. How is this possible?"

It's a matter of applying the principle of relativity. Under general relativity, all reference frames are valid. Thus, if Bob is feeling an acceleration, but his reference frame is such that his coordinates in that reference frame are constant, then he is considered to be unmoving, in that reference frame.


No. There is no change in direction in his first “peculiar consequence” thought experiment, and that is the one that leads to the paradox.
It's in his 1905 paper, in black and white. You could look it up (http://www.fourmilab.ch/etexts/einstein/specrel/www/).

He says "If one of two synchronous clocks at A is moved in a closed curve with constant velocity until it returns to A" You can't go away from A and return to A without changing direction.



In the box, all points experience the same acceleration. On earth, different points of elevation experience different acceleration.




Not all of them. Some points at the same elevation experience different accelerations.

You know very well that I’m talking about different distances from the center of the earth.
Doesn't matter. It's still true, even if you disregard the acceleration due to inertial forces, the centrifictional force (http://www.badastronomy.com/phpBB/viewtopic.php?p=29784#29784).


You are used to playing with the minds of teenagers, but that stuff won’t work on me.
I know.

Sam5
2004-Jun-12, 06:00 PM
It's a matter of applying the principle of relativity. Under general relativity, all reference frames are valid. Thus, if Bob is feeling an acceleration, but his reference frame is such that his coordinates in that reference frame are constant, then he is considered to be unmoving, in that reference frame.


You say, "Bob will have to experience tremendous acceleration, while not moving. How is this possible?" Then you say, "Bob doesn't sit in a gravity field attributable to matter" So, he doesn't move and he is not resting in a gravity field, so where does the "acceleration" come from?

Simple question. Please answer it.

milli360
2004-Jun-12, 06:05 PM
It's a matter of applying the principle of relativity. Under general relativity, all reference frames are valid. Thus, if Bob is feeling an acceleration, but his reference frame is such that his coordinates in that reference frame are constant, then he is considered to be unmoving, in that reference frame.


You say, "Bob will have to experience tremendous acceleration, while not moving. How is this possible?" Then you say, "Bob doesn't sit in a gravity field attributable to matter" So, he doesn't move and he is not resting in a gravity field, so where does the "acceleration" come from?

Simple question. Please answer it.
I thought I had.

If someone is pulled up in an elevator, in space, they will experience an acceleration just like that of gravity, but it is not attributable to matter. If the reference frame is the elevator itself, then they can consider themselves to be at rest--in that reference frame. Same idea for someone in a spaceship.

swansont
2004-Jun-12, 06:07 PM
swansont,

Tests were already conducted in the 19th Century. Pendulum clocks slow down at high altitude while balance wheel clocks don’t change their rates due to gravitational potential changes. In the 20th Century it was learned that atomic clocks speed up at high altitudes.

You say this about pendulum clocks like it's a new discovery and nobody else is aware of it. There is an explicit dependence on g for a pendulum clock - there's an equation for frequency, and g is in there. Anybody who has taken freshman physics is aware of this.

What relativity predicts is that two clocks at different altitudes, after they were adjusted to tick at the same nominal frequency (i.e. the length was changed by the same fraction as g), would still tick at different rates, because there is a second effect.

All clocks will do this. But because the effect is a part in 10^16 per meter, you aren't going to find any mechanical clocks that are precise enough to see the effect.


So they got a crystal/laser clock to match the tick rate of an iodine atomic clock, and they found that the earth is not moving through a universal ether at 18.6 mps. Michelson and Morley discovered that in 1887. Any type of clock that uses a laser is a type of “atomic clock” and is subject to atomic oscillation changes just like any other type of atomic clock. So the test involved two different types of atomic clocks. They did not involve two completely different kinds of clocks.

No, they tested a molecular clock using an electronic transition with an optical resonator - i.e. light. They referenced experiments in which other atomic and nuclear transitions were used, as well as a quartz oscillator. And it wasn't the ether experiment - the gravitational potential changed, and the oscillators' frequencies changed at the same rate. All of the referenced experiments did similar things.

Let's say you have an interaction of some strength, and a given change in g causes a 1% shift in frequency. If you now use a different interaction that is 10 times stronger. The same change is g should cause a 0.1% change in frequency, if g is directly affecting the oscillation rate. That's not what has been shown.

I invite you to find equations showing the g dependence of atomic oscillation rates.

swansont
2004-Jun-12, 06:11 PM
What Sam has never addressed is an actual mechanism other than "gravity does it somehow."

Lorentz said it has something to do with electrodynamic “forces” experienced by the atoms when they experienced different accelerations. This is a quantum mechanics effect.

Please demonstrate how gravity is an electrodynamic effect, and any relevant Lorentz equation that has gravitational acceleration in it.


You’ve never explained why your atomic clocks run fast at Denver and slow at sea level. Please tell us why they do.

LOL. It's called general relativity. You should learn about it sometime.

And, technically they run on time at sea level (rather than fast), since our time is defined at the geoid.

Sam5
2004-Jun-12, 06:21 PM
No. There is no change in direction in his first “peculiar consequence” thought experiment, and that is the one that leads to the paradox.

It's in his 1905 paper, in black and white. You could look it up (http://www.fourmilab.ch/etexts/einstein/specrel/www/).

He says "If one of two synchronous clocks at A is moved in a closed curve with constant velocity until it returns to A" You can't go away from A and return to A without changing direction.

I said the FIRST one.

Here’s the one that started the clock paradox debate:

“From this there ensues the following peculiar consequence. If at the points A and B of K there are stationary clocks which, viewed in the stationary system, are synchronous; and if the clock at A is moved with the velocity v along the line AB to B, then on its arrival at B the two clocks no longer synchronize, but the clock moved from A to B lags behind the other which has remained at B by 1/2tv^2/c^2 (up to magnitudes of fourth and higher order), t being the time occupied in the journey from A to B.”

In this one, observers with clock A see the B clock slow down and “time dilate”, and observers with the B clock see the A clock slow down and “time dilate”. Yet only one clock “lags behind” the other at the end of the thought experiment. This is the “clock paradox” of the SR theory.

You, like other apologists, try to claim that in the other thought experiment, one of the clocks that moves in a closed curve from point A and back to A time dilates, but keep in mind that in the SR theory there are observers stationary with both of two clocks. Observer 1 will see observer 2 and clock 2 move in the closed curve and time dilate, while observer 2 will see observer 1 and clock 1 move in the closed curve and time dilate. Both see each other's clock time dilate in the same amount, so one can not "lag behind" the other when they unite. This is the clock paradox. In SR theory, only “relative motion” is considered, both points of view are equally valid, and no accelerative effects are considered.

You are trying to GRize SR theory to cover up his SR mistakes. Shame on you. What he should have done was not write the SR theory and wait a few years until he knew what he was talking about, then there would be no paradox since there is no clock paradox in GR theory. Remember, I’m not a teenager.

swansont
2004-Jun-12, 06:28 PM
In space: No, for reasons Grand Lunar said. And I think the coldest temp achieved is actually on the order of a hundred thousandth or closer maybe. I know a hundred thousandth is routinely reached at the JILA labs during their Bose-Einstein Condensate experiments.


Around a billionth of a degree or so for BEC. They've gotten colder on occasion, IIRC.

Sam5
2004-Jun-12, 06:30 PM
It's a matter of applying the principle of relativity. Under general relativity, all reference frames are valid. Thus, if Bob is feeling an acceleration, but his reference frame is such that his coordinates in that reference frame are constant, then he is considered to be unmoving, in that reference frame.


You say, "Bob will have to experience tremendous acceleration, while not moving. How is this possible?" Then you say, "Bob doesn't sit in a gravity field attributable to matter" So, he doesn't move and he is not resting in a gravity field, so where does the "acceleration" come from?

Simple question. Please answer it.
I thought I had.

If someone is pulled up in an elevator, in space, they will experience an acceleration just like that of gravity, but it is not attributable to matter. If the reference frame is the elevator itself, then they can consider themselves to be at rest--in that reference frame. Same idea for someone in a spaceship.

You say on your web page specifically that Bob is “not moving”, and now you say that he is “moving”. [Note: stuff removed during edit]

milli360
2004-Jun-12, 06:36 PM
No. There is no change in direction in his first “peculiar consequence” thought experiment, and that is the one that leads to the paradox.

It's in his 1905 paper, in black and white. You could look it up (http://www.fourmilab.ch/etexts/einstein/specrel/www/).

He says "If one of two synchronous clocks at A is moved in a closed curve with constant velocity until it returns to A" You can't go away from A and return to A without changing direction.

I said the FIRST one.

I noticed that. The exchange (http://www.badastronomy.com/phpBB/viewtopic.php?p=277271#277271) was:



O, yes there were, from the beginning (his 1905 paper). We've gone over this before. The "peculiar consequence" is the genesis of the paradox, and that peculiar consequence analysis does involve changes in direction, which are accelerations.

No. There is no change in direction in his first “peculiar consequence” thought experiment, and that is the one that leads to the paradox.
The one I mentioned is in fact in the 1905 paper. I'm not sure what it is you're saying "no" to (bolded in the above).

This is the “clock paradox” of the SR theory.
It wasn't called the clock paradox in that 1905 paper, and the usual version of the clock paradox usually has the twins reuniting.


You, like other apologists, try to claim that in the other thought experiment, one of the clocks that moves in a closed curve from point A and back to A time dilates

Not just apologists. That was Einstein's claim, in that 1905 paper. It's born out in general relativity too.


In SR theory, only “relative motion” is considered, both points of view are equally valid, and no accelerative effects are considered.

See the quote above. A change in direction is an "accelerative effect".


You are trying to GRize SR theory to cover up his SR mistakes. Shame on you. What he should have done was not write the SR theory and wait a few years until he knew what he was talking about, then there would be no paradox since there is no clock paradox in GR theory.
There is no clock paradox is SR theory either. It's just called a "paradox".

I guess he could have boxed everything up and waited for his estate to publish it after he died. Wait a minute, if what you say is true, don't you think you should be holding off posting your theories until you learn some basic math?


Remember, I’m not a teenager.
I'll never forget.

PS:

You say on your web page specifically that Bob is “not moving”, and now you say that he is “moving”. You are just trying to trick people on your web page. You are using double-talk and tricky manipulations.
Whether a person is moving or not moving is a matter of reference frame. In one they could be moving--in another they would not be moving. That's the basic idea behind the principle of relativity.

Don't accuse me of trying to trick people.

Sam5
2004-Jun-12, 07:02 PM
Don't accuse me of trying to trick people.

I humbly apologize and I removed the distasteful accusation. I don’t know what came over me. It must be the summer heat.

But you clearly say on your webpage that Bob is not moving, and now you say he is moving. Don’t you realize that this can be confusing to some people who don’t know you as well as I do?

Here, maybe you need to read some of Einstein’s stuff:

“To the middle of the lid of the chest is fixed externally a hook with rope attached, and now a " being " (what kind of a being is immaterial to us) begins pulling at this with a constant force. The chest together with the observer then begin to move "upwards" with a uniformly accelerated motion. In course of time their velocity will reach unheard-of values — provided that we are viewing all this from another reference-body which is not being pulled with a rope.”

See chapter 20 of his book.

So, he said the box is clearly “moving”.

So, if you don’t have Bob in a gravity well, yet he is experiencing acceleration, then he must be moving. I'm sure Bob is smart enough to know that. But why would Bob not be in a gravity well, since your experiment starts out on earth? Why is Ann “at home” on earth in a gravity well on one of your pages, then Bob is not “at home” on earth in a gravity well on the other and he's moving? In your second example, both Bob and Ann are moving. None of this stuff has anything to do with the SR clock paradox, and there is no clock paradox in GR theory.

milli360
2004-Jun-12, 07:16 PM
I humbly apologize and I removed the distasteful accusation. I don’t know what came over me. It must be the summer heat.
And besides, the BA is on the rampage (http://www.badastronomy.com/phpBB/viewtopic.php?p=277337#277337), lockin' and bannin' :)

Apology accepted. I'm glad you decided to hang around.


But you clearly say on your webpage that Bob is not moving, and now you say he is moving. Don’t you realize that this can be confusing to some people who don’t know you as well as I do?

I suppose it could be. That's why the first paragraph includes this: "The reason that this is considered a paradox is that the theory of relativity seems to imply that either one can be considered at rest, with the other one moving. In order to resolve the paradox, it is crucial that we pay strict attention to the reference frame in which we are calculating."

Hopefully, someone reading it will realize that I am talking about the theory of relativity, where different reference frames can be used to derive valid results.


So, if you don’t have Bob in a gravity well, yet he is experiencing acceleration, then he must be moving.

Depends upon the reference frame. How are you defining "moving" in your theory?


None of this stuff has anything to do with the SR clock paradox, and there is no clock paradox in GR theory.
I wrote two pages, as you know (well, three). The first was a treatment of special relativity, the second was general relativity. We've been talking about the second.

And there is no paradox in special relativity either.

Sam5
2004-Jun-12, 07:22 PM
What Sam has never addressed is an actual mechanism other than "gravity does it somehow."

Lorentz said it has something to do with electrodynamic “forces” experienced by the atoms when they experienced different accelerations. This is a quantum mechanics effect.

Please demonstrate how gravity is an electrodynamic effect, and any relevant Lorentz equation that has gravitational acceleration in it.

Try starting with Einstein’s paper, “Is There a Gravitational Effect Which is Analogous to Electrodynamic Induction?”, 1912, page 126 of “Collected Papers”, English edition, Volume 4.

Sam5
2004-Jun-12, 07:35 PM
Hopefully, someone reading it will realize that I am talking about the theory of relativity, where different reference frames can be used to derive valid results.

My opinion is that you can’t solve the whole “paradox” problem with just a few paragraphs, because when you try to abbreviate your explanation, you’ve got to leave some information out, because if you don’t, you’ll go on and on for many pages and your reconciliation will be more complicated than the original theory itself.

It took Einstein at least 10 pages in 1918 in an attempt to try to do it, and even then he had to add acceleration effects, gravity fields, and he had to have the clocks move “to and fro” several times. It was obvious that he was “shaking” the clocks to get them to slow down, because by 1918 he had switched over from balance wheel clocks to atomic clocks, and he knew by then that atomic clocks would react to accelerative effects in a certain way that balance wheel clocks would not.

I’ve seen so many twins paradox reconciliation pages on the internet, and none of them are the same and none of them use the technique that Einstein himself used.

But ha! My approach is much better! He simply made some mistakes in the SR theory, and that’s what led to the original paradox. By 1911 he cleared up some of those mistakes, and, consequently, the GR theory does not contain a paradox. The atomic clock that experiences the most acceleration in GR theory is the one that slows down the most. The slow clock measures the faster clock to tick faster, and the faster clock measures the slower clock to tick slower. No paradox.

There, I summed it up in one short paragraph.

I’ve got to go out for a while. I’ll talk to you later.

Diamond
2004-Jun-12, 08:29 PM
Hopefully, someone reading it will realize that I am talking about the theory of relativity, where different reference frames can be used to derive valid results.

My opinion is that you can’t solve the whole “paradox” problem with just a few paragraphs, because when you try to abbreviate your explanation, you’ve got to leave some information out, because if you don’t, you’ll go on and on for many pages and your reconciliation will be more complicated than the original theory itself.

It took Einstein at least 10 pages in 1918 in an attempt to try to do it, and even then he had to add acceleration effects, gravity fields, and he had to have the clocks move “to and fro” several times. It was obvious that he was “shaking” the clocks to get them to slow down, because by 1918 he had switched over from balance wheel clocks to atomic clocks, and he knew by then that atomic clocks would react to accelerative effects in a certain way that balance wheel clocks would not.

I’ve seen so many twins paradox reconciliation pages on the internet, and none of them are the same and none of them use the technique that Einstein himself used.

But ha! My approach is much better! He simply made some mistakes in the SR theory, and that’s what led to the original paradox. By 1911 he cleared up some of those mistakes, and, consequently, the GR theory does not contain a paradox. The atomic clock that experiences the most acceleration in GR theory is the one that slows down the most. The slow clock measures the faster clock to tick faster, and the faster clock measures the slower clock to tick slower. No paradox.

There, I summed it up in one short paragraph.

I’ve got to go out for a while. I’ll talk to you later.

It looks like Sam5 has taken over yet another relativity thread to spout rubbish.

He's even wheeled out the "pendulum clocks slow down at altitude" canard that was debunked by his own citation.

How remarkable.

Kaptain K
2004-Jun-12, 08:49 PM
And, once again, Sam5 cannot tell the difference between time and clocks.

A meter stick measures distance, but it is not the distance itself. Likewise, clocks measure time, but they are not time. Just as distances exist whether we measure them or not, time exists whether we measure it or not!

swansont
2004-Jun-12, 10:23 PM
What Sam has never addressed is an actual mechanism other than "gravity does it somehow."

Lorentz said it has something to do with electrodynamic “forces” experienced by the atoms when they experienced different accelerations. This is a quantum mechanics effect.

Please demonstrate how gravity is an electrodynamic effect, and any relevant Lorentz equation that has gravitational acceleration in it.

Try starting with Einstein’s paper, “Is There a Gravitational Effect Which is Analogous to Electrodynamic Induction?”, 1912, page 126 of “Collected Papers”, English edition, Volume 4.

Do you have relevant information or not? I've gone down this path before. Papers you quote have a tendancy not to support the position you think they support.

Sam5
2004-Jun-12, 10:58 PM
Papers you quote have a tendancy not to support the position you think they support.

Read it and give me your opinion. I'm not going to photocopy it for you.

Diamond
2004-Jun-13, 01:34 AM
Papers you quote have a tendancy not to support the position you think they support.

Read it and give me your opinion. I'm not going to photocopy it for you.

How about "put up or shut up"?

You've quoted papers before that do not support your contention. Try quoting exact page numbers and give relevant citations. It is not for the rest of us to read your entire book collection.

Diamond
2004-Jun-13, 02:45 AM
The oscillations of atoms slow down in a gravity field, therefore atomic clocks slow down in a gravity field. However, pendulum clocks speed up in a gravity field, and balance-wheel clocks are unaffected except for some increased bearing friction effects.

You missed "Miller time" which is when the laws of the Universe are affected by lite beer.


Time is kinetic energy causing things to move. Various kinds of time are atomic, thermodynamic, rotational-mass, swinging-mass, straight-line moving mass, and a few others.

By the way, this has to be the record for stupidist reply to a relativity question ever.

If the OP is still watching, Sam5 is the resident anti-Einstein troll. Unable, it appears to stay in the "Against the Mainstream" where he belongs, he spews on as many relativity threads as he can find.

Grand_Lunar
2004-Jun-13, 09:09 AM
All this time I just thought Relativity was just when one goes at or near light speed and the outside world appears to have slowed down relative to your aspect. From this thread, much more is involved! #-o
I agree with you, Diamond. It even says it on the Index (I'm just paraphrasing here): "If you have beef with theories, like relativity, this is the place".

milli360
2004-Jun-13, 10:29 AM
My opinion is that you can’t solve the whole “paradox” problem with just a few paragraphs, because when you try to abbreviate your explanation, you’ve got to leave some information out, because if you don’t, you’ll go on and on for many pages and your reconciliation will be more complicated than the original theory itself.


The atomic clock that experiences the most acceleration in GR theory is the one that slows down the most. The slow clock measures the faster clock to tick faster, and the faster clock measures the slower clock to tick slower. No paradox.

There, I summed it up in one short paragraph.
Unfortunately, it's wrong. As we've said, it's not that simple. Two clocks can experience the same acceleration and not keep the same time.

Diamond
2004-Jun-13, 11:46 AM
All this time I just thought Relativity was just when one goes at or near light speed and the outside world appears to have slowed down relative to your aspect. From this thread, much more is involved! #-o
I agree with you, Diamond. It even says it on the Index (I'm just paraphrasing here): "If you have beef with theories, like relativity, this is the place".

I'm glad you think so. The concept of time and space being not absolute but depending on the relative motion of the observer trips up the great and the not-so-great intellects when they first encounter it (unfortunately some never get past it).

Time dilation for example happens all the time (no pun intended) but is usually too small to measure/worry about. But its the only way to explain why muons created in the upper atmosphere manage to reach the ground before decaying when according to Newtonian physics, they should have decayed within a short distance.

The honest answer is to read some good books, which means that you get the Relativity straight without the Sam5 trollfest.

I would recommend:

About Time by Paul Evans (http://www.amazon.com/exec/obidos/tg/detail/-/0684818221/qid=1087126541/sr=1-3/ref=sr_1_3/102-9940631-2045766?v=glance&s=books) which is a good non-mathematical introduction to Einstein's time including an excellent description of the so-called Twins Paradox (which turns out not to be a paradox) as well as the experimental basis for Special Relativity and General Relativity.

For a slightly mathematical introduction (high school math only) then Spacetime Physics by Taylor and Wheeler (http://www.amazon.com/exec/obidos/tg/detail/-/0716723271/qid=1087126748/sr=1-1/ref=sr_1_1/102-9940631-2045766?v=glance&s=books) is superb. A really non-scary introduction to Special Relativity.

If you read at least one of these, then you too can spend time in amazement at how many howlers Sam5 produces in a single sentence.

On the web, there are some resources you can have a look at John Baez's page for sci.physics at http://math.ucr.edu/home/baez/physics/ which includes some excellent links to explanations of Special Relativity and General Relativity.

It also includes (for Sam5 watchers) the ever popular Crackpot Index (http://math.ucr.edu/home/baez/crackpot.html) where we are all keeping score.

nebularain
2004-Jun-13, 12:53 PM
Wow!
What a response I've gotten! =D>

Glad you guys are having so much fun with this question!

Continue.

Sam5
2004-Jun-13, 04:31 PM
Two clocks can experience the same acceleration and not keep the same time.

Are you talking about this:

LINK (http://216.239.53.104/search?q=cache:K7QuZy_TeiwJ:math.ucr.edu/home/baez/physics/Relativity/SR/clock.html+clocks+acceleration&hl=en&ie=UTF-8)

The speeds of two clocks at two different elevations in the accelerating box are the same. The clocks aren’t moving apart, they are accelerating at the same rate and traveling at the same speed, and their tick rates are the same.

What this guy says implies that clocks on earth, since they are continuously accelerating, would continuously slow down their tick rates. But that doesn’t happen.

If this is not what you are talking about, perhaps you could direct me to a link that explains your point of view.

milli360
2004-Jun-13, 05:37 PM
Two clocks can experience the same acceleration and not keep the same time.

Are you talking about this:

LINK (http://216.239.53.104/search?q=cache:K7QuZy_TeiwJ:math.ucr.edu/home/baez/physics/Relativity/SR/clock.html+clocks+acceleration&hl=en&ie=UTF-8)

Not directly, but I wouldn't mind discussing it.


The speeds of two clocks at two different elevations in the accelerating box are the same. The clocks aren’t moving apart, they are accelerating at the same rate and traveling at the same speed, and their tick rates are the same.
I searched that page for "box" and couldn't find anything. Are you referring to the box in our thought experiment? On what are you basing your claim?


What this guy says implies that clocks on earth, since they are continuously accelerating, would continuously slow down their tick rates. But that doesn’t happen.
I don't see how that is implied by what he says.


If this is not what you are talking about, perhaps you could direct me to a link that explains your point of view.
That physics faq is a good place to start, as far as I'm concerned.

Sam5
2004-Jun-13, 06:16 PM
Two clocks can experience the same acceleration and not keep the same time.

Are you talking about this:

LINK (http://216.239.53.104/search?q=cache:K7QuZy_TeiwJ:math.ucr.edu/home/baez/physics/Relativity/SR/clock.html+clocks+acceleration&hl=en&ie=UTF-8)

Not directly, but I wouldn't mind discussing it.


The speeds of two clocks at two different elevations in the accelerating box are the same. The clocks aren’t moving apart, they are accelerating at the same rate and traveling at the same speed, and their tick rates are the same.
I searched that page for "box" and couldn't find anything. Are you referring to the box in our thought experiment? On what are you basing your claim?



I think maybe you and I have been talking about two different boxes. The one I’m talking about is a large one, and I think you’ve been talking about one about the size of an elevator. Perhaps we should clear up our box size issue so we won’t confuse each other.

My contention is that under the terms of the 1911 theory, atomic clocks in different places inside a very large accelerating box will all tick at the same rate, since all are traveling at the same speed, none are moving away from one another at any speed, and all experience the same amount of acceleration.

You seem to think that two clocks at different places in an accelerating box will experience different tick rates. Am I right about this? And if so, why?

But in a big box on the earth, an atomic clock at sea level (the floor of the box) will tick at a slower rate than an atomic box resting at 29,000 feet above sea level (equivalent to the height of Mt. Everest). In this case, the higher resting clock is existing under a weaker gravity field (weaker acceleration) than the clock at sea level. But in the moving accelerating box in space, all clocks resting everywhere inside the box are experiencing the same 1) speed, 2) acceleration rate, 3) forces, and they should tick at the same rate. I base this information on what I’ve read about GR during the past 10-15 years, and it seems to be confirmed by plenty of evidence and various scientific reports about atomic clocks.

Maybe you can explain to me what you are basing your information on so we can figure out what each other is talking about.

Sam5
2004-Jun-13, 06:23 PM
Two clocks can experience the same acceleration and not keep the same time.

You keep saying this, but exactly what are you talking about? Give us some examples of two atomic clocks sitting side by side and ticking at different rates.

We all know that no two clocks in our houses or offices tick at the same rate, but that is due to conditions and forces inside each clock. Maybe you can explain exactly what you are basing your claim on.

milli360
2004-Jun-13, 10:15 PM
But in the moving accelerating box in space, all clocks resting everywhere inside the box are experiencing the same 1) speed, 2) acceleration rate, 3) forces, and they should tick at the same rate. I base this information on what I’ve read about GR during the past 10-15 years, and it seems to be confirmed by plenty of evidence and various scientific reports about atomic clocks.

Maybe you can explain to me what you are basing your information on so we can figure out what each other is talking about.
The two clocks are at different potentials. In general relativity, that makes a difference.

I've said this all before.

Sam5
2004-Jun-14, 01:45 AM
The two clocks are at different potentials. In general relativity, that makes a difference.


Is this what you’re talking about?

See frames 8 and 9:

LINK (http://216.239.57.104/search?q=cache:4pRFYFuIxTAJ:instruct1.cit.cornell. edu/courses/astro101/lec24.htm+clock+accelerating+box+room&hl=en&ie=UTF-8)

milli360
2004-Jun-14, 02:38 PM
The two clocks are at different potentials. In general relativity, that makes a difference.


Is this what you’re talking about?

See frames 8 and 9:

LINK (http://216.239.57.104/search?q=cache:4pRFYFuIxTAJ:instruct1.cit.cornell. edu/courses/astro101/lec24.htm+clock+accelerating+box+room&hl=en&ie=UTF-8)
It's an illustration of it, yes. Clock A is at a higher potential than clock B. That page uses the accelerating box example to derive principles to apply to gravity fields such as the Earth--two places on Earth can have the same acceleration due to gravity, but be at different potentials also.

Here is a more direct link to the same info (http://instruct1.cit.cornell.edu/courses/astro101/lec24.htm).

Sam5
2004-Jun-14, 06:52 PM
-two places on Earth can have the same acceleration due to gravity, but be at different potentials also.

Ok thanks. Could you give me an example of what you mean by this? Such as, name two specific places on earth where two different clocks can “have the same acceleration due to gravity, but be at different potentials also.”

SeanF
2004-Jun-14, 08:03 PM
Hey, how'd I miss all this? More importantly, how come I couldn't have missed it a little bit longer? #-o

Sam5, I thought you gave up on the 1911 paper because Einstein revised it later? At any rate, the different tick rates for atomic clocks inside an accelerating box is in there - I've shown it to you before.

E1 = E2 (1 + yh/c²)

y is the rate of acceleration and h is the distance between the two clocks. c is the speed of light. QED.

milli360
2004-Jun-15, 10:34 AM
-two places on Earth can have the same acceleration due to gravity, but be at different potentials also.

Ok thanks. Could you give me an example of what you mean by this? Such as, name two specific places on earth where two different clocks can “have the same acceleration due to gravity, but be at different potentials also.”
It gets complicated by the centrifictional forces of the Earth's rotation, but in general the Earth's "geoid" is sealevel, an equipotential surface. That is, every point on it is at the same potential. However, the points at the equator are farther from the center of the Earth, and so experience less force due to gravity than points at the poles--plus they experience the centrifictional force which further decreases the experienced force.

So, a tall mountain at the poles (or, nearer the poles) would be needed for someone there to experience the decreased gravity that is enjoyed at the equator--but it would be high above sealevel. That is, it would be at a higher potential, but experiencing the same acceleration.

Sam5
2004-Jun-15, 01:50 PM
Hey, how'd I miss all this? More importantly, how come I couldn't have missed it a little bit longer?

Hi Sean,

Glad you are here.

Could you take a look at these drawings and give me you opinion. See frame 8 titled “Clocks in GR Accelerating Bodies.” Does frame 8 imply that d3 < d2?

LINK (http://instruct1.cit.cornell.edu/courses/astro101/lec24.htm)

Tensor
2004-Jun-15, 01:58 PM
Could you take a look at these drawings and give me you opinion. See frame 8 titled “Clocks in GR Accelerating Bodies.” Does frame 8 imply that d3 < d2?

LINK (http://instruct1.cit.cornell.edu/courses/astro101/lec24.htm)

Sam5, did you mean d1 instead of d3? I looked and didn't see any d3 on that site.

Sam5
2004-Jun-15, 02:06 PM
Could you take a look at these drawings and give me you opinion. See frame 8 titled “Clocks in GR Accelerating Bodies.” Does frame 8 imply that d3 < d2?

LINK (http://instruct1.cit.cornell.edu/courses/astro101/lec24.htm)

Sam5, did you mean d1 instead of d3? I looked and didn't see any d3 on that site.

With the box continuing to accelerate, and with the author saying that distance d2 < d1, in the continuing sequence d3 would come in the sequence after d2. That implies a longer sequence would go like this: d5<d4<d3<d2<d1

Sam5
2004-Jun-15, 02:20 PM
Hey, how'd I miss all this? More importantly, how come I couldn't have missed it a little bit longer? #-o

Sam5, I thought you gave up on the 1911 paper because Einstein revised it later? At any rate, the different tick rates for atomic clocks inside an accelerating box is in there - I've shown it to you before.

E1 = E2 (1 + yh/c²)

y is the rate of acceleration and h is the distance between the two clocks. c is the speed of light. QED.


Your equation comes from page 102 of “The Principle of Relativity”. Now read the first two sentences of paragraph 2 on page 106, starting with "This has a consequence..."

Sam5
2004-Jun-15, 02:24 PM
Milli, Sean, and Tensor, do you believe that in an accelerated box in deep space, a clock that is resting on the floor of the box will tick faster or slower than a clock that is resting on a platform fixed to the wall of the box that is located higher up in the box?

SeanF
2004-Jun-15, 03:19 PM
Hey, how'd I miss all this? More importantly, how come I couldn't have missed it a little bit longer?
Hi Sean,

Glad you are here.

Could you take a look at these drawings and give me you opinion. See frame 8 titled “Clocks in GR Accelerating Bodies.” Does frame 8 imply that d3 < d2?

LINK (http://instruct1.cit.cornell.edu/courses/astro101/lec24.htm)
Looks like it to me, yes. Why?



Hey, how'd I miss all this? More importantly, how come I couldn't have missed it a little bit longer? #-o

Sam5, I thought you gave up on the 1911 paper because Einstein revised it later? At any rate, the different tick rates for atomic clocks inside an accelerating box is in there - I've shown it to you before.

E1 = E2 (1 + yh/c²)

y is the rate of acceleration and h is the distance between the two clocks. c is the speed of light. QED.
Your equation comes from page 102 of “The Principle of Relativity”. Now read the first two sentences of paragraph 2 on page 106, starting with "This has a consequence..."
You can't start with something that says, "This has . . . " because you need to know what "this" is. As a journalist, you should know that.

Read (and understand) what comes immediately before that paragraph, first.

Normandy6644
2004-Jun-15, 03:54 PM
If you guys waita few weeks I can ask Professor Herter which one he means to be ticking faster. 8)

Sam5
2004-Jun-15, 04:19 PM
Hey, how'd I miss all this? More importantly, how come I couldn't have missed it a little bit longer?
Hi Sean,

Glad you are here.

Could you take a look at these drawings and give me you opinion. See frame 8 titled “Clocks in GR Accelerating Bodies.” Does frame 8 imply that d3 < d2?

LINK (http://instruct1.cit.cornell.edu/courses/astro101/lec24.htm)
Looks like it to me, yes. Why?

If d3 < d2, then this professor seems to have the A clock continuously speeding up its tick rate relative to the B clock, rather than just ticking faster than the B clock. What do you think?

Sam5
2004-Jun-15, 04:22 PM
You can't start with something that says, "This has . . . " because you need to know what "this" is.

Yes, the paragraph starts out, “This has...”

What do you think the first two sentences mean?

Ricimer
2004-Jun-15, 05:23 PM
He's saying: That the "this has..." refers to the paragraph prior to the sentence, not something two pages before.

While the paragraph prior may deal with the same subject matter, I'm sure a few key details have arisen in the subsequent pages (otherwise the "this has..." would be earlier in the paper).

Sam5
2004-Jun-15, 05:34 PM
He's saying: That the "this has..." refers to the paragraph prior to the sentence, not something two pages before.

While the paragraph prior may deal with the same subject matter, I'm sure a few key details have arisen in the subsequent pages (otherwise the "this has..." would be earlier in the paper).

Right. That’s usually the way it works. And I’m asking him what he thinks the two sentences starting with “This has....” mean. I’m asking his opinion. If you have the book, you can give me your opinion too. In fact, anyone here who has that book can give me their opinion.

SeanF
2004-Jun-15, 06:08 PM
If d3 < d2, then this professor seems to have the A clock continuously speeding up its tick rate relative to the B clock, rather than just ticking faster than the B clock. What do you think?
How do you get that? If d2=.5d1, and d3=.5d2, and d4=.5d3, then the ratio of d(x) to d(x-1) is always 2/1. Just because d(x) is always less than d(x-1) doesn't mean the ratio changes - and so neither would the relative clock rates.



He's saying: That the "this has..." refers to the paragraph prior to the sentence, not something two pages before.

While the paragraph prior may deal with the same subject matter, I'm sure a few key details have arisen in the subsequent pages (otherwise the "this has..." would be earlier in the paper).
Right. That’s usually the way it works. And I’m asking him what he thinks the two sentences starting with “This has....” mean. I’m asking his opinion. If you have the book, you can give me your opinion too. In fact, anyone here who has that book can give me their opinion.
Why don't you give your opinion first? What do you think the "this" at the start of that sentence refers to? Feel free to use your own words or just cite Einstein's.

This just all seems so similar to the discussion we had a while back in regards to "Now, in reality . . ." Remember that?

milli360
2004-Jun-15, 06:14 PM
Milli, Sean, and Tensor, do you believe that in an accelerated box in deep space, a clock that is resting on the floor of the box will tick faster or slower than a clock that is resting on a platform fixed to the wall of the box that is located higher up in the box?
Well, that's what general relativity says.

I'm not going to commit to a belief one way or another. But this is General Astronomy, not Against the Mainstream, right? And general relativity is the mainstream theory, nowadays.

Sam5
2004-Jun-15, 07:20 PM
Why don't you give your opinion first?

Come on man, I just want your opinion. I don’t want a big argument. I just want your opinion.

Sam5
2004-Jun-15, 07:23 PM
Milli, Sean, and Tensor, do you believe that in an accelerated box in deep space, a clock that is resting on the floor of the box will tick faster or slower than a clock that is resting on a platform fixed to the wall of the box that is located higher up in the box?
Well, that's what general relativity says.

Faster or slower?

Sam5
2004-Jun-15, 07:31 PM
If d3 < d2, then this professor seems to have the A clock continuously speeding up its tick rate relative to the B clock, rather than just ticking faster than the B clock. What do you think?
How do you get that? If d2=.5d1, and d3=.5d2, and d4=.5d3, then the ratio of d(x) to d(x-1) is always 2/1. Just because d(x) is always less than d(x-1) doesn't mean the ratio changes - and so neither would the relative clock rates.


If clock A is assumed to tick slower than clock B because “Flashes arrive less than 1 second apart” in the d2 < d1 situation, then if d gets shorter and shorter, won’t the flashes arrive in less and less time, indicating that the A clock rate is speeding up?

Sam5
2004-Jun-15, 07:40 PM
I'm not going to commit to a belief one way or another. But this is General Astronomy, not Against the Mainstream, right? And general relativity is the mainstream theory, nowadays.

It’s not quite as simple as that. Some astronomy websites say the distant galaxies are not traveling faster than c relative to the earth, and others say they are, so, not everyone in “mainstream” astronomy agrees on what is being observed, and they don’t all agree on the exact same interpretation of General Relativity. I’m not disagreeing with General Relativity, in general, I’m trying to find out how different people interpret different parts of it.

That’s why I asked Sean about the meaning of the first two sentences in that paragraph. I think if 5 or 6 of us wrote up our own individual opinions, without seeing each other’s opinions first, we’d come up with 5 or 6 different interpretations.

The reason I ask Sean about it first was because he was the only person on this board (other than me) who noticed the error in the paragraph from the 1918 paper that I posted earlier. If I had pointed out the error first, someone would have accused me of insulting Einstein, and 5 or 6 other guys would have agreed with that guy. So I had to wait to see if anyone else noticed the error, and Sean was the only one who mentioned it. So, I want his opinion about the two 1911 sentences, because he is pretty good at interpreting hundred-year-old thought experiments. I don’t want an argument, I want a discussion.

SeanF
2004-Jun-15, 08:29 PM
If clock A is assumed to tick slower than clock B because “Flashes arrive less than 1 second apart” in the d2 < d1 situation, then if d gets shorter and shorter, won’t the flashes arrive in less and less time, indicating that the A clock rate is speeding up?
dx represents the distance pulse x has to travel to get from one clock to the other. When combined with the speed of light, it can represent the time between pulse x being sent and being received. It does not represent the amount of time between x being sent and x+1 (or x-1) being sent, so it does not directly give the clock rates.

Look at it this way. A sends signals every second - at 0:01.0, 0:02.0, 0:03.0, 0:04.0. B receives the signals every half-second. At 1:01.0, 1:01.5, 1:02.0, 1:02.5.

The first signal was sent at 0:01.0 and arrived at 1:01.0. Travel time 1 minute, distance 1 light-minute.
The second signal was sent at 0:02.0 and arrived at 1:01.5. Travel time 59.5 seconds, distance 59.5 light-seconds.
The third signal was sent at 0:03.0 and arrived at 1:02.0. Travel time 59 seconds, distance 59 light-seconds.
The fourth signal was sent at 0:04.0 and arrived at 1:02.5. Travel time 58.5 seconds, distance 58.5 light-seconds.

So, although the distance traveled is decreasing by 0.5 light-seconds every pulse, the one-per-second emissions are resulting in one-per-half-second receptions and that never changes. You can continue this all the way up to a travel distance of 0 (indicating the acceleration has reached infinite velocity). The whole time, you will have the travel distance decreasing with each pulse, but the rates will remain at one-per-second and one-per-half-second until the end.


That’s why I asked Sean about the meaning of the first two sentences in that paragraph. I think if 5 or 6 of us wrote up our own individual opinions, without seeing each other’s opinions first, we’d come up with 5 or 6 different interpretations.
So, again, why the insistence that I provide mine first?

[Edit: And if you do insist on my opinions then . . . I don't have a copy of that book. The 1911 paper is online here (http://www.itba.edu.ar/cargrado/fismat/fismod/transf/htm/einstein_5.htm), but I know you've mentioned that the book is extended. If you provide me with the entire text between the end of the online version and the paragraph in question, I'll give you my opinion. Otherwise, you'll have to wait until I get around to finding and buying a copy of the book, and that could be . . . who knows?]

Sam5
2004-Jun-15, 08:51 PM
If clock A is assumed to tick slower than clock B because “Flashes arrive less than 1 second apart” in the d2 < d1 situation, then if d gets shorter and shorter, won’t the flashes arrive in less and less time, indicating that the A clock rate is speeding up?
dx represents the distance pulse x has to travel to get from one clock to the other. When combined with the speed of light, it can represent the time between pulse x being sent and being received. It does not represent the amount of time between x being sent and x+1 (or x-1) being sent, so it does not directly give the clock rates.

Look at it this way. A sends signals every second - at 0:01.0, 0:02.0, 0:03.0, 0:04.0. B receives the signals every half-second. At 1:01.0, 1:01.5, 1:02.0, 1:02.5.

The first signal was sent at 0:01.0 and arrived at 1:01.0. Travel time 1 minute, distance 1 light-minute.
The second signal was sent at 0:02.0 and arrived at 1:01.5. Travel time 59.5 seconds, distance 59.5 light-seconds.
The third signal was sent at 0:03.0 and arrived at 1:02.0. Travel time 59 seconds, distance 59 light-seconds.
The fourth signal was sent at 0:04.0 and arrived at 1:02.5. Travel time 58.5 seconds, distance 58.5 light-seconds.

So, although the distance traveled is decreasing by 0.5 light-seconds every pulse, the one-per-second emissions are resulting in one-per-half-second receptions and that never changes. You can continue this all the way up to a travel distance of 0 (indicating the acceleration has reached infinite velocity). The whole time, you will have the travel distance decreasing with each pulse, but the rates will remain at one-per-second and one-per-half-second until the end.

Ok, let me think this over a little.


That’s why I asked Sean about the meaning of the first two sentences in that paragraph. I think if 5 or 6 of us wrote up our own individual opinions, without seeing each other’s opinions first, we’d come up with 5 or 6 different interpretations.



So, again, why the insistence that I provide mine first?

Because I don’t want 5-6 guys to jump in and tell me I’m wrong before I hear your opinion. Maybe we can exchange opinions by PM. I just want your opinion. I don’t know if yours will be different from mine or not.




[Edit: And if you do insist on my opinions then . . . I don't have a copy of that book. The 1911 paper is online here (http://www.itba.edu.ar/cargrado/fismat/fismod/transf/htm/einstein_5.htm), but I know you've mentioned that the book is extended. If you provide me with the entire text between the end of the online version and the paragraph in question, I'll give you my opinion. Otherwise, you'll have to wait until I get around to finding and buying a copy of the book, and that could be . . . who knows?]


Ok, when I have time, I'll copy the part that is not online, and I'll send it to you by PM. Then we can discuss it without any interference.

Sam5
2004-Jun-16, 02:52 AM
dx represents the distance pulse x has to travel to get from one clock to the other.

I’m still thinking about your thought experiment. I don’t see how the rapidity at which clock B receives the instantaneous blip signal from clock A would have anything to do with how fast or slow the A clock ticks. The acceleration of B would move B faster toward the oncoming signal from the A clock, but what would that have to do with the tick rate of the A clock? The A clock doesn’t know anything is behind it. It doesn’t know to change rates because the B clock is receiving its signal sooner. This is a Doppler effect that the professor is talking about.

The professor says, “Flashes arrive less than 1 second apart. Clock A runs faster than Clock B.”

Just because the B clock receives the ticks faster because it is accelerating, why would that make the A clock run faster than the B clock?

If the A clock were on a planet somewhere and the B clock was accelerating toward it, the B clock would see the tick rates at a faster rate, due to the Doppler effect, because the B clock was accelerating, but that would not affect the tick rate of the A clock at all.

In the thought experiment, the A and B clocks are traveling at the same speeds, they are accelerating at the same rates, they are always the same distance apart. So what makes the professor think the A clock will “run faster” than the B clock, in an accelerating box in deep space? I'd appreciate your opinion.

Grey
2004-Jun-16, 04:23 PM
I've been staying out of the conversation, since generally someone else has made any points I might have, and I've no wish to make you feel like everyone is jumping down your throat, Sam5. But it looks like nobody has addressed this point, unless SeanF has already done so in a private message.


The professor says, “Flashes arrive less than 1 second apart. Clock A runs faster than Clock B.”

Just because the B clock receives the ticks faster because it is accelerating, why would that make the A clock run faster than the B clock?
Because that's the entire meaning of an observer at B seeing a clock at A run fast. You seem to be imagining that an observer sitting next to the clock at A will suddenly see it running fast or slow because of something that's going on elsewhere, and this seems to be your biggest problem with relativity. But relativity never says this will happen, it only says that you'll see other clocks running at different speeds, or that other people will see your clock running at a rate different than they'd expect. If an observer B sees the clock at A steadily gaining time compared to the clock at B, well, that's what we mean when we say an observer at B sees a clock at A running fast.

In this case, of course, it's not really the direct result that's interesting, since, just as you suggest, this is really just a Doppler effect resulting from the finite speed of light causing a propagation delay and the acceleration that takes place during that delay. What's interesting here is the implication of the result and how it relates to clocks in a gravitational field.

Since the principle of equivalence says that there is no measurable difference between a uniform gravitational field and a steady acceleration, a clock at a higher gravitational potential must appear to run faster to an observer at a lower potential, even if the gravitational field strength were the same throughout the region of interest, by exactly the amount its rate would appear to be shifted if the two clocks were instead accelerating together in a box in deep space. Otherwise, we could tell the difference between the two circumstances. Thus, as several people have already pointed out, it's the difference in gravitational potential that causes the apparent difference in clock rate, not the difference in the strength of the gravitational field.

Sam5
2004-Jun-16, 05:41 PM
Since the principle of equivalence says that there is no measurable difference between a uniform gravitational field and a steady acceleration, a clock at a higher gravitational potential must appear to run faster to an observer at a lower potential, even if the gravitational field strength were the same throughout the region of interest, by exactly the amount its rate would appear to be shifted if the two clocks were instead accelerating together in a box in deep space. Otherwise, we could tell the difference between the two circumstances. Thus, as several people have already pointed out, it's the difference in gravitational potential that causes the apparent difference in clock rate, not the difference in the strength of the gravitational field.

Look at it this way:

Let’s say we have two clocks attached to the inside of a spaceship that is accelerating at 1g in deep space. Both clocks are ticking at the same rate.

Clock B is resting on lower platform inside the spaceship. The platform is affixed to the wall of the spaceship. Clock A is resting on a platform 32 feet above clock B. Clock A’s platform is affixed to the wall of the spaceship. Both clocks are experiencing 1 g acceleration.

Let’s say we have a marble-ejecting device attached to Clock A. Every second, clock A ejects a marble out to the side and the marble “falls” toward the platform that clock B is resting on and hits the platform after a 1 second fall.

The first marble falls 32 feet in the first second and hits the platform of clock B. The second marble falls 32 feet in the second second and hits the platform of clock B. The third marble falls 32 feet in the third second and hits the platform of clock B. The length “d” of the distance of the fall of the marbles is always 32 feet and does not change as time goes by, as long as the acceleration rate of the spaceship is 1 g.

So, d1 = d2 = d3 = d4 = d5

Clock A is ticking at 1 second per second, and so is Clock B. Clock B sees the marbles hit the B platform every second. Both clocks are always traveling at the same speed relative to each other, both are always experiencing the same acceleration as each other, and both are always the same distance apart, so why should Clock A tick faster than Clock B? The truth is, it doesn’t. By using the falling marbles, we don’t have to fret with light signals or their red or blue shifts or the Doppler effects.

Both the A and B clocks will also tick at the same rate if we place them under 1 g of gravity at the same place on the surface of the earth, side by side on a table for example.

milli360
2004-Jun-16, 05:47 PM
The length “d” of the distance of the fall of the marbles is always 32 feet and does not change as time goes by, as long as the acceleration rate of the spaceship is 1 g.

Why do you say that?

Grand_Lunar
2004-Jun-17, 09:43 AM
All this time I just thought Relativity was just when one goes at or near light speed and the outside world appears to have slowed down relative to your aspect. From this thread, much more is involved! #-o
I agree with you, Diamond. It even says it on the Index (I'm just paraphrasing here): "If you have beef with theories, like relativity, this is the place".

I'm glad you think so. The concept of time and space being not absolute but depending on the relative motion of the observer trips up the great and the not-so-great intellects when they first encounter it (unfortunately some never get past it).

Time dilation for example happens all the time (no pun intended) but is usually too small to measure/worry about. But its the only way to explain why muons created in the upper atmosphere manage to reach the ground before decaying when according to Newtonian physics, they should have decayed within a short distance.

The honest answer is to read some good books, which means that you get the Relativity straight without the Sam5 trollfest.

I would recommend:

About Time by Paul Evans (http://www.amazon.com/exec/obidos/tg/detail/-/0684818221/qid=1087126541/sr=1-3/ref=sr_1_3/102-9940631-2045766?v=glance&s=books) which is a good non-mathematical introduction to Einstein's time including an excellent description of the so-called Twins Paradox (which turns out not to be a paradox) as well as the experimental basis for Special Relativity and General Relativity.

For a slightly mathematical introduction (high school math only) then Spacetime Physics by Taylor and Wheeler (http://www.amazon.com/exec/obidos/tg/detail/-/0716723271/qid=1087126748/sr=1-1/ref=sr_1_1/102-9940631-2045766?v=glance&s=books) is superb. A really non-scary introduction to Special Relativity.

If you read at least one of these, then you too can spend time in amazement at how many howlers Sam5 produces in a single sentence.

On the web, there are some resources you can have a look at John Baez's page for sci.physics at http://math.ucr.edu/home/baez/physics/ which includes some excellent links to explanations of Special Relativity and General Relativity.

It also includes (for Sam5 watchers) the ever popular Crackpot Index (http://math.ucr.edu/home/baez/crackpot.html) where we are all keeping score.

I have read "About Time" a few times (no pun). Some parts I understood, some part reduced me to a hopeless muddle. Maybe if I reread it, more will make better sense to me. Right now, I have it at my real home in Florida. Anyway, thanks.

Grey
2004-Jun-18, 03:22 AM
Let’s say we have a marble-ejecting device attached to Clock A. Every second, clock A ejects a marble out to the side and the marble “falls” toward the platform that clock B is resting on and hits the platform after a 1 second fall.
Ah, now this is a slightly different situation. Nevertheless, the rate at which the marbles fall will indeed be different from what you'd expect. However, I see that I'd need to postulate the constancy of the velocity of light in order to demonstrate that. Since, after much debate in a previous discussion, you acknowledged that you believe this postulate is invalid (in spite of the fact that you also claim to accept general relativity), I won't bother trying to convince you of it here. I will go over and make a comment on the other thread, though.

Sam5
2004-Jun-18, 06:01 AM
Let’s say we have a marble-ejecting device attached to Clock A. Every second, clock A ejects a marble out to the side and the marble “falls” toward the platform that clock B is resting on and hits the platform after a 1 second fall.
Ah, now this is a slightly different situation.

The only difference is that we are getting a direct reading of the tick rate of the A clock at the B clock by using a direct tick rate measurement method without using light signals.



Nevertheless, the rate at which the marbles fall will indeed be different from what you'd expect. However, I see that I'd need to postulate the constancy of the velocity of light in order to demonstrate that. Since, after much debate in a previous discussion, you acknowledged that you believe this postulate is invalid (in spite of the fact that you also claim to accept general relativity), I won't bother trying to convince you of it here. I will go over and make a comment on the other thread, though.



Yes, in 1912 and 1915 Einstein said it was invalid. Get a copy of Vol. 4 of “Collected Papers”.

For example, in the 1912 paper, “The Speed of Light and the Statics of the Gravitational Field,” he said:

“But at the same time it turned out that one of the basic principles of that theory, namely, the principle of the constancy of the velocity of light, is valid only for space-time regions of constant gravitational potential. Even though this result rules out the universal applicability of the Lorentz transformation, it should not frighten us away from the further pursuit of the path we have taken...”

And in the 1912 paper, “Relativity and Gravitation”, he says:

“Abraham notes that I have delivered the coup de grace to the relativity theory by abandoning the postulate of the constancy of the velocity of light and by the therewith connected relinquishment of the invariance of the systems of equations with respect to the Lorentz transformations.”

This was in response to statements that Abraham published in the Annalen der Physik:

“Already before a period of one year, A. Einstein, by accepting an influence of the gravitation potential on the speed of light, gave up the postulate of the constant speed of light essential for his earlier theory 1); in a work appeared recently 2)......”

In the 1912 paper, “Theory of Relativity”, as published in “Physik”, Emil Warburg, Leipzig, 1915, Einstein said this about the SR theory:

“Finally, one more important question: Does the theory of relativity possess unlimited validity? Even the supporters of the theory of relativity have different views on this question. The majority are of the opinion that the propositions of the theory of relativity – especially its conception of time and space – can claim unlimited validity.

However, the writer of these lines is of the opinion that the theory of relativity is still in need of a generalization, in the sense that the principle of the constancy of the velocity of light is to be abandoned.”

So, the famous “constancy” postulate of the 1905 SR theory did not exist after 1912, and it doesn’t exist today.

Grey
2004-Jun-18, 06:44 AM
“But at the same time it turned out that one of the basic principles of that theory, namely, the principle of the constancy of the velocity of light, is valid only for space-time regions of constant gravitational potential. Even though this result rules out the universal applicability of the Lorentz transformation, it should not frighten us away from the further pursuit of the path we have taken...”
Right. Special relativity only holds if we can neglect gravity. We know that. In this case, that might seem to be a problem, since the observers in the box feel an apparent gravitational force. But we can always look at the box from a non-accelerating reference frame, and imagine that we're a long ways from any external gravitational fields, so it's not material to this problem.


The only difference is that we are getting a direct reading of the tick rate of the A clock at the B clock by using a direct tick rate measurement method without using light signals.
Let me ask you something. We've established that the light signals arrive faster than expected in an accelerating box, since you haven't disputed that. You think that the metal balls will arrive at 1 per second in the accelerated box, and presumably also in a constant gravitational field. What do you think happens to the light signals in a constant gravitational field? Note that I'm not talking about here on Earth, because here the strength of gravity weakens as you get farther away. Instead, imagine that we've moved the box to an infinite flat surface, with just the right mass density to give us an acceleration of g, so that the strength of gravity is independent of the distance from the surface.

Ricimer
2004-Jun-18, 03:13 PM
“Abraham notes that I have delivered the coup de grace to the relativity theory by abandoning the postulate of the constancy of the velocity of light and by the therewith connected relinquishment of the invariance of the systems of equations with respect to the Lorentz transformations.

And I'm sure Einstein just left it at that. Saying someone said they caught him, that he was wrong, and all of SR is completely bunk and should be thrown out the window.

No, I'm sure he didn't say anything after that, some response, along the lines of: While true, that doesn't invalidate SR in such and such a case.

No, of course he left it at that.


Sam5, you should know better than anyone (being a journalist) the power of context and getting the whole picture. So stop pulling only the parts of quotes that support you, and leave out the pertinent details.

Diamond
2004-Jun-19, 01:07 AM
All this time I just thought Relativity was just when one goes at or near light speed and the outside world appears to have slowed down relative to your aspect. From this thread, much more is involved! #-o
I agree with you, Diamond. It even says it on the Index (I'm just paraphrasing here): "If you have beef with theories, like relativity, this is the place".

I'm glad you think so. The concept of time and space being not absolute but depending on the relative motion of the observer trips up the great and the not-so-great intellects when they first encounter it (unfortunately some never get past it).

Time dilation for example happens all the time (no pun intended) but is usually too small to measure/worry about. But its the only way to explain why muons created in the upper atmosphere manage to reach the ground before decaying when according to Newtonian physics, they should have decayed within a short distance.

The honest answer is to read some good books, which means that you get the Relativity straight without the Sam5 trollfest.

I would recommend:

About Time by Paul Evans (http://www.amazon.com/exec/obidos/tg/detail/-/0684818221/qid=1087126541/sr=1-3/ref=sr_1_3/102-9940631-2045766?v=glance&s=books) which is a good non-mathematical introduction to Einstein's time including an excellent description of the so-called Twins Paradox (which turns out not to be a paradox) as well as the experimental basis for Special Relativity and General Relativity.

For a slightly mathematical introduction (high school math only) then Spacetime Physics by Taylor and Wheeler (http://www.amazon.com/exec/obidos/tg/detail/-/0716723271/qid=1087126748/sr=1-1/ref=sr_1_1/102-9940631-2045766?v=glance&s=books) is superb. A really non-scary introduction to Special Relativity.

If you read at least one of these, then you too can spend time in amazement at how many howlers Sam5 produces in a single sentence.

On the web, there are some resources you can have a look at John Baez's page for sci.physics at http://math.ucr.edu/home/baez/physics/ which includes some excellent links to explanations of Special Relativity and General Relativity.

It also includes (for Sam5 watchers) the ever popular Crackpot Index (http://math.ucr.edu/home/baez/crackpot.html) where we are all keeping score.

I have read "About Time" a few times (no pun). Some parts I understood, some part reduced me to a hopeless muddle. Maybe if I reread it, more will make better sense to me. Right now, I have it at my real home in Florida. Anyway, thanks.

If you wish, please quote the bits you were confused by (by PM if you like your questions Sam5-free) and I'll attempt to explain them.

Sam5
2004-Jun-19, 03:40 PM
Sam5, you should know better than anyone (being a journalist) the power of context and getting the whole picture. So stop pulling only the parts of quotes that support you, and leave out the pertinent details.
In articles, books, and science papers, quotes are used to support the thesis of the guy writing the paper. The guy tries to find the most appropriate quotes that summarize his position and that are not “taken out of context.”

If someone wants to read the entire paper that is quoted, he usually goes out and buys a book that contains the entire paper. He doesn’t usually write the author who has used the quote and whine because the author didn’t include the entire text of the quoted paper.

For the past 14 years I’ve read many books and papers that briefly quote other books and papers, and I’ve tracked down and bought many of the original books that the quotes I read were taken from. Einstein quoted an Abraham paper in his (Einstein’s) 1912 paper, but he did not reproduce the entire Abraham paper. I had to go out and find the Abraham paper in an internet library archive in Germany.

The Einstein paper I quoted is in Volume 4, English translation, of “The Collected Papers of Albert Einstein”, available via the internet for about $45. I bought my copy, and you can buy your copy.

Ricimer
2004-Jun-19, 04:51 PM
Sure I can...(looks into account of poor college student working away from home for the summer...) or maybe not.

That's not the point. THe point is you routinely set up the quotes to infer something different.

Like this quote we're squabbling over. Did Einstien say anything in defense of SR after he quoted Abraham? That would be an intersting quote to learn from, and would help elaborate and clarify a few points about SR.

Instead you just take the lead in and leave it.

Sam5
2004-Jun-19, 08:25 PM
Sure I can...(looks into account of poor college student working away from home for the summer...) or maybe not.

Ok, well, then... girls, midnight snacks, and fun on the weekend always rank higher than physics. But you can check your university library.

Here’s a valuable tip: All the Hardbound editions of “Collected Papers” are in the original German, while all the Softbound editions are the English translations. Both sets of 8 Volumes carry the same title, so there are really 16 Volumes in all, but only 8 titles, and both sets are numbered 1-8. Blame this weird and confusing idea on someone at the Princeton press.

Unfortunately, seems that most university librarians who ordered the entire 8 Volumes, ordered only the Hardbound set, thinking they were getting the “best quality”, but what they got were only the German-language editions, so most of their students can’t read them.

However, you can order free copies of certain papers from University libraries that have the Softbound set, through your interlibrary loan system. Poverty is no excuse for ignorance.




That's not the point. THe point is you routinely set up the quotes to infer something different.

Not true. I try to set up the quotes to reflect the true “in context” meaning of the quotes. Occasionally I do make mistakes, like everyone else, but I try not to.




Like this quote we're squabbling over. Did Einstien say anything in defense of SR after he quoted Abraham? That would be an intersting quote to learn from, and would help elaborate and clarify a few points about SR.

Instead you just take the lead in and leave it.


Yes, he did say some things in defense of SR, but he fully admitted the “constancy” postulate was no longer valid after his 1911 discovery of the effect gravity has on the speed of light. He did say that the “constancy” postulate would apply in the case of no field being present, but he later said there is no place in space where there is no field present. And generally, a light emitter, such as a star, is right in the middle of a very strong field.

Basically, his “relativity” theory evolved. He first called the SR theory “the relativity theory”, but in 1911 he called it “the ordinary theory of relativity”. By 1912 he was calling his new theory “the generalized theory of relativity”, and by 1916 he had separated both of them into “the Special Theory” (with no fields or acceleration) and “the General Theory” (with fields and acceleration). Over the years he modified both theories. For example, in 1932 he modified the General Theory to allow for expansion of the universe, and when he did this, he had to remove the “curved universal space” concept of 1916, so that no longer would a light signal traverse the entire universe and return to its source. After the BB theory was developed, he realized a light signal could actually travel in a fairly straight line without returning to its source. However, if you just read his 1916 paper, and not read his 1932 paper, you will see where he said the light signal would return to its source.

So, to study “relativity”, you need to study more than just two books, “The Principle of Relativity” and “Relativity: The Special and General Theory”, and you also need to study some Lorentz theory, which is where Einstein got most of his basic ideas from for his 1905 paper. He modified the theory reported in the 1895 Lorentz book. He tried to improve upon the Lorentz theory, and he made some errors in the process, some of which he corrected later, in the expensive books. So, if you want a $19.90 relativity education, you can read only the two cheap standard paperback relativity books, but if you want a better relativity education, you need to read some of the articles that are published in the $45 books, and also in Lorentz’s 1895 book.

milli360
2004-Jun-20, 01:40 AM
So, to study “relativity”, you need to study more than just two books, “The Principle of Relativity” and “Relativity: The Special and General Theory”, and you also need to study some Lorentz theory, which is where Einstein got most of his basic ideas from for his 1905 paper.
And, don't forget, math. :)

Sam5
2004-Jun-20, 04:05 AM
The first marble falls 32 feet in the first second and hits the platform of clock B.


Dang! I made a math mistake. :oops: The marbles will fall only 16 feet during their first second since they don’t start out traveling at a speed of 32 feet per second! At the end of the first second they will be falling at the speed of 32 feet per second, but they will fall only 16 feet during the first second.

Oh, well, the concept is the same. The A clock will eject a marble every second, and the B clock, 16 feet below, will receive one marble from the A clock every second. The A clock is running at the same rate as the B clock.

LOL, am I the only one who noticed the math error??

Here’s a link to an acceleration calculator. Click on "table":

LINK (http://www.unf.edu/~tbratina/hec/example/outofthisworld/fallingobject.htm)

Grey
2004-Jun-20, 04:21 PM
LOL, am I the only one who noticed the math error??
It wasn't important to the actual issue. You still haven't answered my question. We've established that in an accelerating box, the light signals arrive with a shorter time interval between them, and you've stated that you believe that the marbles will arrive at exactly one per second. I assume that you also think the marbles will arrive at one per second in a uniform gravitational field; what do you think would happen to the light signals in a uniform gravitational field?

Sam5
2004-Jun-20, 05:08 PM
what do you think would happen to the light signals in a uniform gravitational field?

I don’t know. What do you think will happen?

I’m not sure there is such a thing as a “uniform gravitational field” where a box accelerates at g.

Where can we find a “uniform gravitational field” that will accelerate two separated clocks at 1 g?


I’ll give you my opinion about what happens in my thought experiments, and you can critique my opinion. You give your opinion about what happens in your thought experiments, and I’ll critique your opinion. But I don’t think I’m qualified to give my opinion about what happens in your thought experiments.

The professor was wrong, wasn’t he? He relied on math and his own “light signal” theory and incorrectly concluded the A clock was ticking faster than the B clock. He judged the A clock’s rate on the arrival time of the light signals from A, in an accelerating frame of reference, and he came to the wrong conclusion. Do you know the mistakes he made? Can you list some of them?

milli360
2004-Jun-20, 09:42 PM
am I the only one who noticed the math error??
errors

Grey
2004-Jun-22, 08:11 PM
I don’t know. What do you think will happen?
I'm very much hoping to get your thoughts first, without influencing you.


I’m not sure there is such a thing as a “uniform gravitational field” where a box accelerates at g.

Where can we find a “uniform gravitational field” that will accelerate two separated clocks at 1 g?
It's true that a uniform gravitational field isn't the most common sort we see, since most gravitational fields are created by more or less spherical bodies. However, these produce variable gravitational fields that may be difficult to analyze, and difficult to compare with our accelerating box (which experiences no external gravitational field, but both the top and the bottom of the box are assumed to be accelerating at the same rate).

We can certainly construct an object which will have a uniform gravitational field, though, as I suggested. A really big flat slab of material will do the job nicely. We can put it in deep intergalactic space where no other significant gravity will be felt, and although the field will not be perfectly uniform (unless our slab is infinitely large), we can make it as close to uniform as we feel the need. For our purposes, let's agree that we can neglect any effects created because the field is not perfectly uniform.


I’ll give you my opinion about what happens in my thought experiments, and you can critique my opinion. You give your opinion about what happens in your thought experiments, and I’ll critique your opinion. But I don’t think I’m qualified to give my opinion about what happens in your thought experiments.
Frankly, I'm surprised by this comment coming from you. You've already made it clear that you think the professional physicists who I learned from don't understand relativity as well as you do (either that, or they were deliberately lying to me, an even more egregious accusation than incompetence). If that's true, then you understand such matters better than anyone else, and yet you can't analyze the outcome of a particular thought experiment?


The professor was wrong, wasn’t he? He relied on math and his own “light signal” theory and incorrectly concluded the A clock was ticking faster than the B clock. He judged the A clock’s rate on the arrival time of the light signals from A, in an accelerating frame of reference, and he came to the wrong conclusion. Do you know the mistakes he made? Can you list some of them?
I don't think there are errors in the analysis of the situation. If you think there are, you'll need to point them out. For now, though, let's avoid discussion of whether the rate of clock A "really" changes, and just concentrate on the rate of arrival of signals from it, whether they be light flashes or marbles.

So, there are four situations I'd like to compare. One is the original experiment, with light pulses coming from a clock in an accelerating box. Another would be the same light pulses, but now coming from a clock at the top of a box in a uniform gravitational field. Then we could replace the two light-flashing clocks in these two circumstances with marble-dropping clocks. We've established that the light flashes will arrive faster than once per second in the original experiment, and you've already stated that you believe the marbles will hit at exactly one per second in the accelerating box. I assume you'd also expect the marbles to hit one per second if the box were resting in a uniform gravitational field. I'm curious how you think the light-flashing clock will behave in a uniform gravitational field.

Sam5
2004-Jun-23, 03:53 PM
You've already made it clear that you think the professional physicists who I learned from don't understand relativity as well as you do (either that, or they were deliberately lying to me, an even more egregious accusation than incompetence).

No, I did not say that. All I said was that the professor is wrong about the accelerating A clock in the box ticking faster than the B clock in the box. During my 45 years of working with photography and working with clocks and the Doppler effects, I’ve learned a few real things about light, time, clocks, and the optical illusions created by delayed light and sound signals. I don’t know if the professor has ever made any other errors in his life, but the A clock in an accelerating box ticks at the same rate as the B clock.

I think maybe the professor doesn’t understand the basic difference between the fall-off in gravity effects with distance and the non-fall-off of the accelerative force inside a box with distance.

You can draw up a little graph of the thought experiment and see what I’m talking about.

Look, when I was young I had professors tell me that there were “green plants” growing on the surface of Mars. They turned out to be wrong. The “green” areas were just an optical illusion seen in the earth-based telescopes.

Sam5
2004-Jun-23, 04:04 PM
We can certainly construct an object which will have a uniform gravitational field, though, as I suggested. A really big flat slab of material will do the job nicely. We can put it in deep intergalactic space where no other significant gravity will be felt, and although the field will not be perfectly uniform (unless our slab is infinitely large), we can make it as close to uniform as we feel the need. For our purposes, let's agree that we can neglect any effects created because the field is not perfectly uniform.

I think that will give us a big oval field around the slab, not a “uniform” field. the strength of gravity will still be stronger at the surface of the slab and weaker at some distance from the slab.

milli360
2004-Jun-23, 04:18 PM
You've already made it clear that you think the professional physicists who I learned from don't understand relativity as well as you do (either that, or they were deliberately lying to me, an even more egregious accusation than incompetence).

No, I did not say that. All I said was that the professor is wrong about the accelerating A clock in the box ticking faster than the B clock in the box.

Is that the same professor that you thought (http://www.badastronomy.com/phpBB/viewtopic.php?p=279178#279178) would have one clock speeding up faster and faster? You misinterpreted that too.


During my 45 years of working with photography and working with clocks and the Doppler effects, I’ve learned a few real things about light, time, clocks, and the optical illusions created by delayed light and sound signals.
But no experiments with general relativity, I bet. :)


I don’t know if the professor has ever made any other errors in his life, but the A clock in an accelerating box ticks at the same rate as the B clock.
Is that the potential box (http://www.badastronomy.com/phpBB/viewtopic.php?p=198351#198351) thing that we've talked about before? It shows that your theory disagrees with general relativity.

Sam5
2004-Jun-23, 05:28 PM
Is that So you believe as Grey, that a big flat slab in space will generate a uniform gravity field? I’m a little surprised that you would agree with that.

milli360
2004-Jun-23, 05:50 PM
Is that So you believe as Grey, that a big flat slab in space will generate a uniform gravity field? I’m a little surprised that you would agree with that.
That's an interesting conclusion--I hadn't commented on that yet.

What I think Grey is talking about is just Newtonian physics. The math is like electric field calculations (http://scienceworld.wolfram.com/physics/InfiniteParallelPlanes.html), since charge to charge they fall off as the inverse squared too, just as gravity does.

Sam5
2004-Jun-23, 05:54 PM
That's

Why don’t you give us a full monograph about your “potential box” theory, and let us analyze it?

milli360
2004-Jun-23, 06:31 PM
That's

Why don’t you give us a full monograph about your “potential box” theory, and let us analyze it?
Whoa. I've suffered your "analysis" before. My pages have held up. Where are your monographs?

Grey
2004-Jun-23, 07:31 PM
You've already made it clear that you think the professional physicists who I learned from don't understand relativity as well as you do (either that, or they were deliberately lying to me, an even more egregious accusation than incompetence).

No, I did not say that.
Actually, you have. You've expressed a clear view that special relativity is flawed, and complained that this "nonsense", as you've described it, is still being taught, deceiving the minds of people trying to understand it. You've said that physics professors should know better than this. So if you're right , either they don't know better, in which case you must understand matters better than they do, and they have no business teaching it, or they know that it's wrong and are deliberately teaching falsehoods to their students. Do I need to go back through the hundreds of pages of conversation to find quotes from you to demonstrate that you've claimed these things?


I think that will give us a big oval field around the slab, not a “uniform” field. the strength of gravity will still be stronger at the surface of the slab and weaker at some distance from the slab.
Now see, this is one of the difficulties in carrying on a discussion with you. Rather than address the actual question (which was, if you'll recall, how quickly the light flashes will arrive when the box is at rest in a uniform gravitational field), you've concentrated on a triviality (whether a big slab of material will in fact produce such a uniform gravitational field). Really, I could have just imagined that such a field is being generated somehow, without worrying about it. Not only that, but you don't really even have enough of a grounding in physics to understand how to work out the gravitational field of some unusually shaped object, you're simply guessing what it might be, based on your gut intuition. But I'll spend a moment to address your questions anyway.

The page milli360 linked was close, but that's actually for a pair of oppositely charged parallel plates, so it's not quite the same situation. You can look at this page (http://scienceworld.wolfram.com/physics/InfinitePlane.html), from the same site, to see the derivation of the electric field for a single infinite plane. As milli360 rightly pointed out, the derivation for the gravitational field strength would be exactly the same, except that you'd be using mass density instead of charge density, and the gravitational constant. In general, for a spherical mass, gravity goes like the inverse square of distance, if you had an infinite massive wire, the strength of gravity from it would go like 1/r, and if you have an infinite flat plane, the strength does not vary with your distance from it. It's easy enough to work out the math.

Now, of course this is an approximation, since our slab won't really be infinite and perfectly flat. So, we'll want to make sure that the thickness of the slab is small compared to the size of our box, so we can treat it as flat. We'll want to make sure we're a long ways from the edge, so that our approximation of it as infinite won't cause us to be off by too much. Likewise, this was a classical derivation, so if the mass density were really high, we'd run into problems. Likewise, if our slab is many light years across, under general relativity we might have effects from how long it had been in existence and other differences from the Newtonian picture, so again we'll just assume that it's been around for a very long time, and so forth. There might also be engineering difficulties in constructing such a slab, and in getting to deep intergalactic space so that we don't have to worry about other gravitational fields, but that's why this is a thought experiment. In principle, we could minimize these other effects enough that the effects from general relativity would be apparent.

So, we can in principle create an object that will give us as close to a uniform gravitational field as we'd like. Let's agree that we'll neglect the differences caused by our flat plate not being quite infinite, and move on.


Why don’t you give us a full monograph about your “potential box” theory, and let us analyze it?
Why don't you give us your thoughts on how quickly the light flashes would arrive, once we've placed our box in a uniform gravitational field, and we can go from there.

milli360
2004-Jun-23, 07:45 PM
The page milli360 linked was close, but that's actually for a pair of oppositely charged parallel plates, so it's not quite the same situation. You can look at this page (http://scienceworld.wolfram.com/physics/InfinitePlane.html), from the same site, to see the derivation of the electric field for a single infinite plane.
Of course it's linked at the bottom of the page I gave. Don't know why I didn't look for it there!

Sam5
2004-Jun-23, 10:06 PM
You've already made it clear that you think the professional physicists who I learned from don't understand relativity as well as you do (either that, or they were deliberately lying to me, an even more egregious accusation than incompetence).

No, I did not say that.
Actually, you have.



Sorry, I thought you were talking about that specific one professor and his website.

The Piltdown Man was taught for about 50 years. There was even a picture of a “reconstructed” statue of the Piltdown man published in a Smithsonian Institution book in the 1930s. I’ve got the copy right here. I was taught the Piltdown man hoax in school in the 1950s.


Also remember, “eugenics” was taught in schools from the 1860s, through the mid 1940s, until all the concentration camps in China, Japan, Germany, and other places in Europe were opened up by the allies in 1945, then suddenly the world’s scientists realized that their glorious “eugenics” theory had an extremely dangerous flaw in it. The people who decide who is “fit” and “not fit”, can speed up eugenics by killing all the people they deem to be “unfit”, thus leading to about 60 million murders in Europe and the Orient between 1938 and 1945. If you had been in school in the US and other countries in the 1930s, you would have been taught that there was no flaws or errors in the theory of “eugenics”.

If you are young enough, some day you will learn that I am right about SR theory.

1) It was based on Lorentz’s 1895 book and theory.

2) It removed Lorentz’s ether, fields, acceleration, and forces.

3) As a result, it was wrong and contained errors.

4) Einstein gradually realized the errors and he began to correct them. You can find his corrections in several of his papers.

5) He fibbed about a resolution to the “clock paradox” in his 1918 paper, for two reasons.

6) His fibs about the clock paradox gradually became legends, and they are still legends today.


Your comments about my comments about the "slab":


Now see, this is one of the difficulties in carrying on a discussion with you. Rather than address the actual question (which was, if you'll recall, how quickly the light flashes will arrive when the box is at rest in a uniform gravitational field),

I’ve already said I don’t think there is any such thing as a “uniform gravitational field” in which “1 g” acceleration can be experienced at several “elevations”.

Why don’t you go right ahead and explain your thought experiment, and stop trying to get me to make a commitment about what will happen in your thought experiment. You want MY opinion about YOUR thought experiment before you have given me YOUR opinion about YOUR thought experiment, and I gave you my opinion already, by saying I don’t think there is any such thing as a “uniform gravitational field” in which “1 g” acceleration can be experienced at several “elevations”.

Normandy6644
2004-Jun-23, 10:57 PM
Wow Sam you never stop do you. I can't wait to read your paper disproving SR and sending physics into a new revolution. :roll:

Sam5
2004-Jun-23, 11:29 PM
Wow Sam you never stop do you. I can't wait to read your paper disproving SR and sending physics into a new revolution.

It would not lead to a “new revolution”. It would merely shift certain attributions to Lorentz and certain effects to real causes, rather than just “relative motion”. It also might help encourage someone to try to pin down the reason for the phenomenon of light from approaching and receding binaries remaining in synch, and it might also explain how and where in space these shifts occur:

LINK (http://im1.shutterfly.com/procserv/47b4db35b3127ccebed4d4ac83030000001610)

Sam5
2004-Jun-23, 11:46 PM
My pages have held up.
No, it has never “held up”. It was wrong from the beginning.

On your first page, you have Bob turning around in 4 years by his clock and returning to earth in another 4 years by his clock, although Ann sees him travel for 5 years on her clock, turn around, then travel another 5 years on her clock, while she sees 4 and 8 years transpire on Bob’s clock. So you have Bob seeing his own clock slow down, which you’ve told me many times doesn’t happen in SR.

milli360
2004-Jun-24, 05:53 AM
My pages have held up.
No, it has never “held up”. It was wrong from the beginning.

On your first page, you have Bob turning around in 4 years by his clock and returning to earth in another 4 years by his clock, although Ann sees him travel for 5 years on her clock, turn around, then travel another 5 years on her clock, while she sees 4 and 8 years transpire on Bob’s clock. So you have Bob seeing his own clock slow down, which you’ve told me many times doesn’t happen in SR.
How does Bob see his own clock slow down? He's going as fast as it is. Wouldn't he need two clocks to notice that, anyway? His watch?

Kaptain K
2004-Jun-24, 12:34 PM
It's easy enough to work out the math.
Unless you're totally math illiterate, like Sam5.

Sam5
2004-Jun-24, 05:57 PM
My pages have held up.
No, it has never “held up”. It was wrong from the beginning.

On your first page, you have Bob turning around in 4 years by his clock and returning to earth in another 4 years by his clock, although Ann sees him travel for 5 years on her clock, turn around, then travel another 5 years on her clock, while she sees 4 and 8 years transpire on Bob’s clock. So you have Bob seeing his own clock slow down, which you’ve told me many times doesn’t happen in SR.
How does Bob see his own clock slow down? He's going as fast as it is. Wouldn't he need two clocks to notice that, anyway? His watch?

Sure, Ann’s clock that shows 5 years to her when he turns around. You have him turning around at 4 years in what he sees on Ann’s clock and that is also what he sees on his clock. So he sees sees his clock read what Ann sees his clock read, thus he sees his own clock slow down. This is not in SR theory.

Sam5
2004-Jun-24, 05:59 PM
Unless you're totally math illiterate, like Sam5.
Don’t you ever get tired of posting ad hominem insults? If you were capable of discussng the physics involved, you wouldn’t constantly post ad hominem insults. Don’t you realize that is obvious?

SeanF
2004-Jun-24, 06:13 PM
Sure, Ann’s clock that shows 5 years to her when he turns around. You have him turning around at 4 years in what he sees on Ann’s clock and that is also what he sees on his clock. So he sees sees his clock read what Ann sees his clock read, thus he sees his own clock slow down. This is not in SR theory.
His clock would only be "slow" if he sees Ann's clock at 5 when his own clock says 4 (ie, at turn-around). He doesn't.

He sees Ann's clock at 3.2 immediately before he turns around and at 6.8 immediately after.

milli360
2004-Jun-24, 06:18 PM
Sure, Ann’s clock that shows 5 years to her when he turns around. You have him turning around at 4 years in what he sees on Ann’s clock and that is also what he sees on his clock. So he sees sees his clock read what Ann sees his clock read, thus he sees his own clock slow down. This is not in SR theory.
I'm going to agree that that does not happen in SR theory. :)

But you're misinterpreting the webpage. Bob is using his own clock to measure four years, not Ann's. Unless I am misunderstanding what you wrote--I think I know what you meant by "sees sees" so it's not that though.

If you mean he notices his own clock is different than Ann's when they reunite, and that's when he realizes that his own clock has gone slow, then yes in that sense he sees his own clock go slow. But that's obvious. And it is a result of special relativity--Einstein derived that in his first paper on the subject.

Sam5 (http://www.badastronomy.com/phpBB/viewtopic.php?p=285477#285477):
If you were capable of discussng the physics involved, you wouldn’t constantly post ad hominem insults.
Boggle. :)

Sam5
2004-Jun-24, 06:29 PM
Sure, Ann’s clock that shows 5 years to her when he turns around. You have him turning around at 4 years in what he sees on Ann’s clock and that is also what he sees on his clock. So he sees sees his clock read what Ann sees his clock read, thus he sees his own clock slow down. This is not in SR theory.
I'm going to agree that that does not happen in SR theory. :)

But you're misinterpreting the webpage. Bob is using his own clock to measure four years, not Ann's. Unless I am misunderstanding what you wrote--I think I know what you meant by "sees sees" so it's not that though.

If you mean he notices his own clock is different than Ann's when they reunite, and that's when he realizes that his own clock has gone slow,



No, he must know that from the beginning or he wouldn’t know to turn around at 4 on his clock.

The whole thought experiment last 10 years by the fastest clock.

SR says that Bob would not see his own clock run slow, so he should turn around at 5 years by his clock. But you have him turning around at 4, so he must know that his clock runs slow from the very beginning.

So now you want to change your earlier position and say that Bob DOES see his own clock slow down? He must, because Ann is in the K frame and sees his clock slow down from 5 to 4, and if he turns around at 4, he is reacting to what Ann sees on his clock, which means he sees his own clock slow down the same amount as Ann sees it slow down.

This is not SR theory, it’s Milli theory. Shall we now debate Milli theory? Ok, so what force slows down Bob’s clock? Since Ann is moving relative to Bob, why does she not feel this force? Are you saying, like Lorentz, that Ann is stationary in the “ether” while Bob is moving through it? Your first webpage proves Lorentz theory, not SR theory. SR theory says that Bob will not see his own clock slow down, but Lorentz theory says he will. :D

Sam5
2004-Jun-24, 06:35 PM
Sure, Ann’s clock that shows 5 years to her when he turns around. You have him turning around at 4 years in what he sees on Ann’s clock and that is also what he sees on his clock. So he sees sees his clock read what Ann sees his clock read, thus he sees his own clock slow down. This is not in SR theory.
His clock would only be "slow" if he sees Ann's clock at 5 when his own clock says 4 (ie, at turn-around). He doesn't.

No, you’re using a double Lorentz transformation instead of a single one.

If Ann’s clock is at 5 when he turns around, he will see it at 4. If he sees his own at 4, then he sees his own clock slow down.

If he sees his at 8 at the end, and agrees with Ann, then he sees his clock run slow the whole time.

The end times are 10 and 8.


He sees Ann's clock at 3.2 immediately before he turns around and at 6.8 immediately after.

Oh, LOL, the ol’ “jumping clock” ruse. :D Sorry, there are no “jumping clocks” in SR theory.


And of course there is no “turn around” in that first SR thought experiment, so the “turn around” is a ruse too. A double ruse. I think you end up with a quadrodox rather than just a paradox.
:lol:


If Ann and Bob were doctors, you’d have a pairo'docs.
:D

milli360
2004-Jun-24, 06:54 PM
Sam5:
No, he must know that from the beginning or he wouldn’t know to turn around at 4 on his clock.

The whole thought experiment last 10 years by the fastest clock.

SR says that Bob would not see his own clock run slow, so he should turn around at 5 years by his clock. But you have him turning around at 4, so he must know that his clock runs slow from the very beginning.

What if he just decides to turn around then? It's my thought experiment, and that's exactly what he does. He's a good bit away from Ann, so he's not really looking at her clock anyway. :)


So now you want to change your earlier position and say that Bob DOES see his own clock slow down?
No. LOL.


He must, because Ann is in the K frame and sees his clock slow down from 5 to 4, and if he turns around at 4, he is reacting to what Ann sees on his clock, which means he sees his own clock slow down the same amount as Ann sees it slow down.
Wow. :)


This is not SR theory, it’s Milli theory. Shall we now debate Milli theory? Ok, so what force slows down Bob’s clock?

Force has nothing to do with it. Check out those potential box links.

Sam5
2004-Jun-24, 07:16 PM
Sam5:
No, he must know that from the beginning or he wouldn’t know to turn around at 4 on his clock.

The whole thought experiment last 10 years by the fastest clock.

SR says that Bob would not see his own clock run slow, so he should turn around at 5 years by his clock. But you have him turning around at 4, so he must know that his clock runs slow from the very beginning.

What if he just decides to turn around then? It's my thought experiment, and that's exactly what he does. He's a good bit away from Ann, so he's not really looking at her clock anyway. :)

Well, if we see the whole thing from Bob’s point of view, and if he turns around at 4 on his clock, and arrives back at earth at 8 on his clock, he will see Ann’s clock “lag behind” and read 6.4.

If we see the whole thing from Ann’s point of view, and if she sees Bob turn around at 5 on her clock, and arrive back at 10 on her clock, she will see his clock “lag behind” and read 8.

With your new suggestion, you wind up with 3 end times but only 2 clocks. You wind up with a double-paradox, a quadradox, a phantom ghost clock, and a real good sci fi movie plot. But you’ll need to add some shooting, some loud explosions, a lot of chasing around, and a beautiful actress so it will generate box office attraction. Frankly, I think it will have great Poential Box office attraction. :D

SeanF
2004-Jun-24, 07:23 PM
Sam5:
No, he must know that from the beginning or he wouldn’t know to turn around at 4 on his clock.

The whole thought experiment last 10 years by the fastest clock.

SR says that Bob would not see his own clock run slow, so he should turn around at 5 years by his clock. But you have him turning around at 4, so he must know that his clock runs slow from the very beginning.

What if he just decides to turn around then? It's my thought experiment, and that's exactly what he does. He's a good bit away from Ann, so he's not really looking at her clock anyway. :)

Well, if we see the whole thing from Bob’s point of view, and if he turns around at 4 on his clock, and arrives back at earth at 8 on his clock, he will see Ann’s clock “lag behind” and read 6.4.

If we see the whole thing from Ann’s point of view, and if she sees Bob turn around at 5 on her clock, and arrive back at 10 on her clock, she will see his clock “lag behind” and read 8.
Dang, Sam5, do you have any idea how close you are? Now, go back to the 1905 paper and read it again - pay special attention to the issue of "simultaneity."

Understand how an observer at Bob's turn-around point who is moving away from Ann will see Ann's clock differently than an observer at the same point who is moving towards Ann - those coordinate transformation equations are dependent on the sign of v. It's there, in the 1905 paper, and it explains why Ann's clock ends up at 10 even though the time dilation would seem to indicate 6.4.

Sam5
2004-Jun-24, 07:28 PM
Force has nothing to do with it. Check out those potential box links.

From you PM link:



Your first clue should have been the equivalence of gravity and acceleration, in general relativity. That's key.

The equivalence is the same when atomic clocks experience the same g force, whether achieved by gravity or accelerated motion. Two clocks at sea level experience 1 g and tick at the same rate. The clock on the mountain does not experience the same g force as the clock at sea level, so the mountain clock runs fast. But the clock at the top of the accelerating box is experiencing the same g as the clock at the bottom, so they run at the same rate.

SeanF
2004-Jun-24, 07:33 PM
The equivalence is the same when atomic clocks experience the same g force, whether achieved by gravity or accelerated motion. Two clocks at sea level experience 1 g and tick at the same rate. The clock on the mountain does not experience the same g force as the clock at sea level, so the mountain clock runs fast. But the clock at the top of the accelerating box is experiencing the same g as the clock at the bottom, so they run at the same rate.
Checked your PM, Sam5?

milli360
2004-Jun-24, 07:37 PM
Sam5:
Well, if we see the whole thing from Bob’s point of view, and if he turns around at 4 on his clock, and arrives back at earth at 8 on his clock, he will see Ann’s clock “lag behind” and read 6.4.
That's like dividing by zero. You can't do that, it's not allowed under the theory of special relativity. You've been misapplying it. You can only consistently apply it if you use it within an inertial reference frame--although two observers side-by-side can synchronize. If you follow those principles, you end up with the same results as Einstein.

Sam5
2004-Jun-24, 07:40 PM
Dang, Sam5, do you have any idea how close you are? Now, go back to the 1905 paper and read it again - pay special attention to the issue of "simultaneity."

Understand how an observer at Bob's turn-around point who is moving away from Ann will see Ann's clock differently than an observer at the same point who is moving towards Ann - those coordinate transformation equations are dependent on the sign of v. It's there, in the 1905 paper, and it explains why Ann's clock ends up at 10 even though the time dilation would seem to indicate 6.4.


In SR, E mixed Doppler effects with Lorentz effects and became confused. He spent the next 13 years trying to straighten out his error.

Under Doppler theory, Ann and Bob would see each other’s clocks slow down when moving apart and speed up when moving together. At the end, there are no lost ticks and their clocks would read the same.

Under Lorentz theory, which ever clock that moved through the ether would slow down because of an electrodynamics force placed on the oscillating atoms of the atomic clock. Plus, both observers would also see the classical Doppler effects. The combined phenomena are called “the relativistic Doppler effects”, which Lorentz described in 1895.

In SR theory that are no electrodynamic forces, just “kinematical” manipulations, so there is no reason for either clock to slow down.

By around 1911 E added electrodynamical forces to atomic clocks and then he began to straighten out the error he had made in 1905, and the paradox disappeared. He finally accepted a Lorentz type electrodynamical force as causing atomic clocks to change rates. In 1918 he described this, 23 years after Lorentz had already described it and published a book about it.

It would really help you guys if you would get a copy of Lorentz’s book, and all 8 Volumes of “The Collected Papers of Albert Einstein”. That way you would be able to see his progression from Lorentz theory to the erroneous SR theory to the more correct GR theory and back to Lorentz theory. The paradox of SR would (or should) become obvious to you. You would also see that atomic clocks need a force on them to change rates.

milli360
2004-Jun-24, 07:44 PM
Sam5:
But the clock at the top of the accelerating box is experiencing the same g as the clock at the bottom, so they run at the same rate.
You've said this before, and that is exactly why you are in disagreement with general relativity. What you say here is not true, in general relativity.

It's exactly what I mean by the "potential box". The clocks at the top of the accelerating box are at a higher potential than the clocks at the bottom. They tick at different rates, even though they experience the same acceleration.

Your version of a theory is wrong.

SeanF
2004-Jun-24, 07:57 PM
Dang, Sam5, do you have any idea how close you are? Now, go back to the 1905 paper and read it again - pay special attention to the issue of "simultaneity."

Understand how an observer at Bob's turn-around point who is moving away from Ann will see Ann's clock differently than an observer at the same point who is moving towards Ann - those coordinate transformation equations are dependent on the sign of v. It's there, in the 1905 paper, and it explains why Ann's clock ends up at 10 even though the time dilation would seem to indicate 6.4.
In SR, E mixed Doppler effects with Lorentz effects and became confused. He spent the next 13 years trying to straighten out his error.
Okay, that's what we call a "non sequitur."

This has nothing to do with Doppler. Einstein's 1905 SR paper has nothing to do with Doppler.

I'll say it again: the coordinate transformation equations at the end of Section 3 of "On the Electrodynamics of Moving Bodies (http://www.fourmilab.ch/etexts/einstein/specrel/www/)" are direction dependent.

The consequences of Section 4 are based on the equations in Section 3. You cannot simply ignore them and still claim you're dealing with Einstein's Theory of Special Relativity.

Sam5, you're just making up your own little theory of relativity just to shoot it down.

Sam5
2004-Jun-25, 12:55 AM
Sam5, you're just making up your own little theory of relativity just to shoot it down.

His version of the Doppler numbers are in his Section 7 of the paper. He got this info from Lorentz’s book, but he doesn’t yet understand it in 1905.

He said he got the time dilation idea from Lorentz’s book.

He said he “borrowed” his constancy postulate from Lorentz’s book.

He revoked the “constancy” postulate in 1911-1912.

He revoked geometrical “length contraction” in SR in 1907.

He revoked his “no gravity, no acceleration” rule of SR in 1918.

He removed “balance wheel” clocks in 1918 and replaced them with atomic clocks.

He got rid of the paradox with the first major GR paper in 1911.

He revoked his “no ether” rule in 1918 and again in 1920.

So by 1918, there was no more “SR” theory, because he had stripped it of all its major 1905 features.

Sam5
2004-Jun-25, 12:58 AM
Sam5:
But the clock at the top of the accelerating box is experiencing the same g as the clock at the bottom, so they run at the same rate.
You've said this before, and that is exactly why you are in disagreement with general relativity. What you say here is not true, in general relativity.


You keep saying this over and over and over again, but you never prove it. That’s just your opinion. Give us the quote where he says the A clock will tick faster than the B clock in the accelerating box. What paper, what page, what is the exact quote?

Sam5
2004-Jun-25, 01:11 AM
I'll say it again: the coordinate transformation equations at the end of Section 3 of "On the Electrodynamics of Moving Bodies (http://www.fourmilab.ch/etexts/einstein/specrel/www/)" are direction dependent.




Yeah, so?

So tell me, what is it in non-accelerated straight-line relative motion that causes balance-wheel clocks to slow down their tick rate in SR theory?

milli360
2004-Jun-25, 01:33 AM
Sam5:
So tell me, what is it in non-accelerated straight-line relative motion that causes balance-wheel clocks to slow down their tick rate in SR theory?
It's the way space and time are related. But there are other equivalent ways to put it.

Sam5
2004-Jun-25, 01:47 AM
Sam5:
So tell me, what is it in non-accelerated straight-line relative motion that causes balance-wheel clocks to slow down their tick rate in SR theory?
It's the way space and time are related. But there are other equivalent ways to put it.

Ok, tell me the many ways.

How does relative non-accelerated motion in a straight line at a steady speed slow down a balance-wheel clock?

milli360
2004-Jun-25, 01:49 AM
Sam5:
So tell me, what is it in non-accelerated straight-line relative motion that causes balance-wheel clocks to slow down their tick rate in SR theory?
It's the way space and time are related. But there are other equivalent ways to put it.

Ok, tell me the many ways.
They're all the same way


How does relative non-accelerated motion in a straight line at a steady speed slow down a balance-wheel clock?
It's a relative slow down. But you know that. There's no need to keep including "balance wheel"--the effect is the same for all clocks

Sam5
2004-Jun-25, 02:11 AM
Sam5:
So tell me, what is it in non-accelerated straight-line relative motion that causes balance-wheel clocks to slow down their tick rate in SR theory?
It's the way space and time are related. But there are other equivalent ways to put it.

Ok, tell me the many ways.
They're all the same way


How does relative non-accelerated motion in a straight line at a steady speed slow down a balance-wheel clock?
It's a relative slow down. But you know that. There's no need to keep including "balance wheel"--the effect is the same for all clocks

I use “balance-wheel” clock because the 1905 paper used “balance-wheel” clock.

Lorentz used atomic clocks. After 1911 Einstein used atomic clocks. Airy used pendulum clocks. Harrison used a counter-balance-spring dual rocking rod clocks. The ancient Hebrews and Mayans used a sundial.

Balance-wheel clocks don’t work by the same laws of physics as atomic clocks. You can slow down an atomic clock where you can’t slow down a blance wheel clock, and you can slow down an atomic clock where you can speed up a pendulum clock.

So, tell me, in the 1905 theory, what causes his balance-wheel clocks to slow down when they are moving in a straight line at a steady speed?

Sam5
2004-Jun-25, 02:14 AM
It's a relative slow down.
All clock slow-downs are “relative”. Everybody already knew that. Ancient Egyptians knew that. Even sundial time-of-day is “relative”, depending on where you are located.

Grey
2004-Jun-25, 03:33 AM
Why don’t you go right ahead and explain your thought experiment, and stop trying to get me to make a commitment about what will happen in your thought experiment.
It's really just a slight variation on the one we started with, and I wanted to know whether you understood the relationship in general relativity between a box experiencing constant acceleration and one that's at rest in a constant gravitational field. In fact, I don't think that it's possible to understand the significance of the results for the accelerating box in general relativity without comparing these two circumstances. I was hoping to start from elementary levels of discussion that I was sure we would all understand before moving on, rather than get bogged down in unrelated matters, as we've seemed to.


I’ve already said I don’t think there is any such thing as a “uniform gravitational field” in which “1 g” acceleration can be experienced at several “elevations”.
Are you sure you don't want to retract that statement, now that I've shown you that there is? Well, barring the fact that we can't make a plane that's truly infinite in size, but we can make it as close as we'd like if we make a big enough slab of material. So that's just an engineering problem. :D If you still disagree, can you show the flaw in the derivation of the gravitational field for such a plane? Would it help you if I worked through the derivation here and explained the steps?

Sam5
2004-Jun-25, 03:40 AM
It's exactly what I mean by the "potential box". The clocks at the top of the accelerating box are at a higher potential than the clocks at the bottom. They tick at different rates, even though they experience the same acceleration.

So, I’m still waiting for you to give me some quotes from any of the GR papers where it says that the A clock resting on a platform above the B clock will tick faster than the B clock in the accelerating box. What paper, what page, what is the exact quote? So far, you’ve only given your opinion that the A clock will tick faster, and you’ve never given any GR reference to your opinon. It’s just your opinon.

I’ve aready shown you that if the A clock ejects one marble per second, and the box accelerates at 1 g, the B clock 16 feet below will receive one marble per second.

I’ve asked you several times to give me some references to GR theory, but you’ve never done it.

milli360
2004-Jun-25, 06:37 AM
It's a relative slow down.
All clock slow-downs are “relative”. Everybody already knew that.
Well, my next sentence, that you snipped, was "But you know that." So, oddly enough, I'm going to agree--I'm just not certain that "everybody" does. :)

Sam5:
I’ve aready shown you that if the A clock ejects one marble per second, and the box accelerates at 1 g, the B clock 16 feet below will receive one marble per second.

You've claimed it, but you've ignored the questions about your setup. It doesn't work the way you say it does.


I’ve asked you several times to give me some references to GR theory, but you’ve never done it.
What do you consider references? In this post (http://www.badastronomy.com/phpBB/viewtopic.php?p=277243#277243) as well as dozens others, I linked you to my webpage (http://mentock.home.mindspring.com/twin2.htm), which I know you've seen because you've quoted from it. There are references at the bottom of it.

Sam5
2004-Jun-25, 11:05 AM
I linked you to my webpage...

You said your acellerating box idea is supported by GR, and I asked you to show me in GR where your idea is supported. You've posted links to your own quotes many times, but you've never posted any links to GR to support your claim.

If you don’t know, just say, “I don’t know”.

milli360
2004-Jun-25, 12:48 PM
I linked you to my webpage...

You said your acellerating box idea is supported by GR, and I asked you to show me in GR where your idea is supported. You've posted links to your own quotes many times, but you've never posted any links to GR to support your claim.

If you don’t know, just say, “I don’t know”.
I just clicked on the sci.physics faq link, and it doesn't seem to be supported anymore, at that site.

I found it here (http://math.ucr.edu/home/baez/physics/Relativity/SR/TwinParadox/twin_gr.html).

It says:


Uniform "gravitational" time dilation: Say you have two identically constructed clocks. One is deep down in a uniform "gravitational" potential well (or "pseudo-potential" well, if you prefer); the other is higher up. If the two clocks compare rates by sending light signals back and forth, then both will agree that the lower clock runs slower than the higher clock.

Sam5
2004-Jun-25, 01:05 PM
I found it here (http://math.ucr.edu/home/baez/physics/Relativity/SR/TwinParadox/twin_gr.html).

It says:


Uniform "gravitational" time dilation: Say you have two identically constructed clocks. One is deep down in a uniform "gravitational" potential well (or "pseudo-potential" well, if you prefer); the other is higher up. If the two clocks compare rates by sending light signals back and forth, then both will agree that the lower clock runs slower than the higher clock.



Thanks. Now I know two of you who are wrong. I’m trying to find the information stated by Einstein or some other notable scientist, not random internet SR/GR gurus or self-appointed “twin paradox resolution” pundits.

Sam5
2004-Jun-25, 01:10 PM
According to my understanding of what Einstein says in his 1911 paper, as published in the bottom paragraph on page 106 of “The Principle of Relativity”, he is saying that you are not correct and that there is a difference between the accelerating box in space and the box resting on earth. He recognizes a difference because the two are not equivalent.

In the accelerating box, the A clock doesn't know it is "above" the B clock.

In the box resting on earth, the A clock DOES know it is "above" the B clock.

milli360
2004-Jun-25, 01:17 PM
According to my understanding of what Einstein says in his 1911 paper, as published in the bottom paragraph on page 106 of “The Principle of Relativity”, he is saying that you are not correct and that there is a difference between the accelerating box in space and the box resting on earth. He recognizes a difference because the two are not equivalent.

In the accelerating box, the A clock doesn't know it is "above" the B clock.

In the box resting on earth, the A clock DOES know it is "above" the B clock.
So your theory is based upon pre-general relativity?

Tensor
2004-Jun-25, 01:21 PM
According to my understanding of what Einstein says in his 1911 paper, as published in the bottom paragraph on page 106 of “The Principle of Relativity”, he is saying that you are not correct and that there is a difference between the accelerating box in space and the box resting on earth. He recognizes a difference because the two are not equivalent.

It doesn't matter what your understanding of the 1911 paper is. Go through "The Principle of Relativity" and study the 1916 paper (though since you have trouble with the SR math, you'll never get the GR math). It is GR and the potential box problem can be understood through GR, not his 1911 paper.


In the accelerating box, the A clock doesn't know it is "above" the B clock.

In GR is does. The A clock is in a higher potential.

Sam5
2004-Jun-25, 01:24 PM
Milli, please. Go out and buy some of the Volumes of “The Collected Papers of Albert Einstein”. The 1911 paper is a general relativity paper. See also, “Outline of a Generalized Theory of Relativity and of a Theory of Gravitation,” 1913.

Sam5
2004-Jun-25, 01:52 PM
“Thus, given sufficiently sensitive instruments we can tell the difference between being on the rocket and being on the Earth. Does this mean that the Equivalence Principle is wrong? No. It does mean, though, that it is only strictly true in an infinitesimally small region of space. The word for this property is local, and we conclude that the Equivalence Principle is only truly locally.”


SOURCE (http://66.102.7.104/search?q=cache:dgjDxK8T3S8J:www.upscale.utoronto.c a/GeneralInterest/Harrison/GenRel/TimeDilation.html+einstein+accelerating+room+clock s&hl=en&ie=UTF-8)

The accelerating box in space is NOT exactly the same as the box resting on earth.

milli360
2004-Jun-25, 02:34 PM
Milli, please. Go out and buy some of the Volumes of “The Collected Papers of Albert Einstein”. The 1911 paper is a general relativity paper. See also, “Outline of a Generalized Theory of Relativity and of a Theory of Gravitation,” 1913.
It doesn't matter what the title is, Sam5, the theory of general relativity wasn't established until late in 1915. Einstein had thoughts about general relativity when he was 16 years old, but that doesn't make them relevant to a discussion of general relativity.

He tried a lot of different things. He even thought he'd found a proof that a generally covariant form was impossible--but then, he realized he'd made a mistake, and he did find a covariant form that he liked.

SeanF
2004-Jun-25, 02:36 PM
According to my understanding of what Einstein says in his 1911 paper, as published in the bottom paragraph on page 106 of “The Principle of Relativity”, he is saying that you are not correct and that there is a difference between the accelerating box in space and the box resting on earth. He recognizes a difference because the two are not equivalent.

In the accelerating box, the A clock doesn't know it is "above" the B clock.

In the box resting on earth, the A clock DOES know it is "above" the B clock.
Okay, now, this is funny! The very paragraph that you refused to talk about publicly before, insisting that you would only talk about in PM, and then refused to talk about in PM, insisting that you were too busy talking publicly, now you want to talk about it publicly! Wow! =D>

At any rate, that paragraph says exactly what milli360 said. The two clocks in an accelerating, non-gravitational system tick at different rates if they're at different "heights" in the system.

But you have to understand the whole thing . . .

milli360
2004-Jun-25, 02:39 PM
Sam5:SOURCE (http://66.102.7.104/search?q=cache:dgjDxK8T3S8J:www.upscale.utoronto.c a/GeneralInterest/Harrison/GenRel/TimeDilation.html+einstein+accelerating+room+clock s&hl=en&ie=UTF-8)

The accelerating box in space is NOT exactly the same as the box resting on earth.
No one ever said it was, but I'm glad you posted that link. Notice that the little experiment at the end can be run exactly the same in the potential box. Do you concede?

Tranquility
2004-Jun-25, 02:39 PM
Why is it that every thread titled "relativity" have to be a minimum of 6 pages long :)

SeanF
2004-Jun-25, 02:42 PM
“Thus, given sufficiently sensitive instruments we can tell the difference between being on the rocket and being on the Earth. Does this mean that the Equivalence Principle is wrong? No. It does mean, though, that it is only strictly true in an infinitesimally small region of space. The word for this property is local, and we conclude that the Equivalence Principle is only truly locally.”

SOURCE (http://66.102.7.104/search?q=cache:dgjDxK8T3S8J:www.upscale.utoronto.c a/GeneralInterest/Harrison/GenRel/TimeDilation.html+einstein+accelerating+room+clock s&hl=en&ie=UTF-8)
Your source says, "Einstein's Equivalence Principle states that accelerations are equivalent to gravitational fields." He left out the word "homogenous," which makes the entire following treatment invalid. He's using his own "Equivalence Principle," not Einstein's. Kind of similar to what you do.

Tensor
2004-Jun-25, 02:43 PM
At any rate, that paragraph says exactly what milli360 said. The two clocks in an accelerating, non-gravitational system tick at different rates if they're at different "heights" in the system.

You mean Sam5 posted a link that, not only doesn't support his position, it refutes his position? I'm shocked, I tell you, shocked. :wink:


But you have to understand the whole thing . . .

Yeah, including the math.....

milli360
2004-Jun-25, 02:43 PM
Why is it that every thread titled "relativity" have to be a minimum of 6 pages long
Everybody has to get their two cents in. And relativity is a buck two ninety-five problem. :)

Tensor
2004-Jun-25, 02:45 PM
Why is it that every thread titled "relativity" have to be a minimum of 6 pages long :)

I thought the FAQ required at least six pages. :-?

Tensor
2004-Jun-25, 02:51 PM
...is a buck two ninety-five problem. :)

Wow, I had forgotten that phrase. Used to use it a lot ... a few years ago. :wink:

Sam5
2004-Jun-25, 03:03 PM
The very paragraph that you refused to talk about publicly before, . .

I posted excerpts from the paragraph just a few weeks ago. That’s when you said it wasn’t on the website. That’s when I suggested you go out and buy the book.

I posted the excerpts months ago and suggested you could order the book from a mall book store or get it through an inter-library loan system.

Some of us even discussed the paragraph being missing from the website, months ago. I also pointed out that the website changed some of his equations and they are not the same as in Einstein’s original paper.

When I talked about it months ago, all I got was “doh” in response.

You do not see him describing the two situations differently in that paragraph, one situation in an accelerated "gravitational free" system, and the other at places with differing gravitational potential in a gravity field?

milli360
2004-Jun-25, 03:08 PM
Sam5:
SOURCE (http://66.102.7.104/search?q=cache:dgjDxK8T3S8J:www.upscale.utoronto.c a/GeneralInterest/Harrison/GenRel/TimeDilation.html+einstein+accelerating+room+clock s&hl=en&ie=UTF-8)

The accelerating box in space is NOT exactly the same as the box resting on earth.
No one ever said it was, but I'm glad you posted that link. Notice that the little experiment at the end can be run exactly the same in the potential box. Do you concede?

SeanF
2004-Jun-25, 03:22 PM
I posted the excerpts months ago and suggested you could order the book from a mall book store or get it through an inter-library loan system.
And as soon as I got my hands on it, you decided you didn't "have time" to talk about it anymore. I wonder why that could be?


You do not see him describing the two situations differently in that paragraph, one situation in an accelerated "gravitational free" system, and the other at places with differing gravitational potential in a gravity field?
Nope. First, the equivalence principle says the accelerating non-gravitational system and the homogenous gravitational system are both the same - they are the same "system" - to the extent that you can refer to different points in an accelerating system as having different "gravitational potential". That's why later on he simply refers to the clocks S1 and S2 without specifying whether he's talking about "accelerating" or "gravity." They're the same thing.

Now, what the specific paragraph in question is distinguishing between is measuring the velocity of light at different points in the system as opposed to measuring time at different points in the system.

The velocity of light will be the same throughout the system. Time will be different at two different points if they're at different potentials (time will be the same at two different points if the two points are at the same potential - ie, they're both on the floor).

Again, this is true regardless of whether the system is "accelerating" or "homogenously gravitational."

Sam5
2004-Jun-25, 03:23 PM
Okay, now, this is funny! The very paragraph that you refused to talk about publicly before, :^o . .

You don’t remember our discussion here?

LINK, see last post on page (http://www.badastronomy.com/phpBB/viewtopic.php?t=9731&postdays=0&postorder=asc&high light=constitution&start=1475)

And here:

LINK (http://www.badastronomy.com/phpBB/viewtopic.php?t=9731&postdays=0&postorder=asc&high light=constitution&start=1500)


Don’t you remember when I said, “I told you that you can buy the whole book and the entire theory for $10, so I'm not going to sit here and type the whole thing,” Jan 16, 2004?

SeanF
2004-Jun-25, 03:56 PM
Okay, now, this is funny! The very paragraph that you refused to talk about publicly before, :^o . .
You don’t remember our discussion here?

Watch the ad hominens, Sam. Do you remember this (http://www.badastronomy.com/phpBB/viewtopic.php?t=14183&postdays=0&postorder=asc&sta rt=109), only ten days ago?


Because I don’t want 5-6 guys to jump in and tell me I’m wrong before I hear your opinion. Maybe we can exchange opinions by PM. I just want your opinion. I don’t know if yours will be different from mine or not.
. . .
Ok, when I have time, I'll copy the part that is not online, and I'll send it to you by PM. Then we can discuss it without any interference.
That certainly validates my claim that you refused to talk about it publicly, preferring PM.

You didn't even need to take the time to copy it, Tensor did that for you.

Then you didn't want to talk about it at all anymore (http://www.badastronomy.com/phpBB/viewtopic.php?t=14284&postdays=0&postorder=asc&sta rt=401).

Don't call people liars, especially when they're telling the truth.

Sam5
2004-Jun-25, 04:21 PM
Okay, now, this is funny! The very paragraph that you refused to talk about publicly before, :^o . .
You don’t remember our discussion here?

LINK (http://www.badastronomy.com/phpBB/viewtopic.php?t=9731&postdays=0&postorder=asc&high light=constitution&start=1475)

And here:

LINK (http://www.badastronomy.com/phpBB/viewtopic.php?t=9731&postdays=0&postorder=asc&high light=constitution&start=1500)




Watch the ad hominens, Sam.
Huh?

What ad hominems?

We already talked about it publicly, last January, but you indicated you didn’t know anything about it. I was going to try to take some time to send you the paragraph in a PM and explain it to you, but I never had the time.

We are discussing it now, again.

In the paragraph in question, E notes a difference between clocks inside an accelerating box in space, away from gravity fields, and inside a box in a gravity field. That’s what I explained last January.



He recognized the difference between the two types of systems.

Some people get the big box in deep space confused with his small elevator falling in a gravity field.

SeanF
2004-Jun-25, 04:34 PM
Huh?

What ad hominems?
Placing the "growing nose" smilie in my post is calling me a liar. The smilie's name is "Liar" for crying out loud. And I wasn't even lying!


We are discussing it now, again.
And publicly, too, which you didn't want to do ten days ago. Oh, well.


In the paragraph in question, E notes a difference between clocks inside an accelerating box in space, away from gravity fields, and inside a box in a gravity field.
Nope. He notes the difference between measuring the speed of light and measuring time. That's all. There's no difference in either case between the accelerating system and the gravitational.

milli360
2004-Jun-25, 04:40 PM
Sam5:
Huh?

What ad hominems?

I had to ask too. I used search and tried to find any of your posts that used the words "liar" or "liars" and I could only find one, and it was just quoting someone else.

So, I PMed SeanF, and he answered back. You've inserted the growing nose smilie into a quote of his post. I should have figured that out, because the post I'd found was about Diamond accusing you of calling him a liar, because you inserted the growing nose smilie into his posts.

PS: not only is that an ad hominem, it's a deliberate misquote

Sam5
2004-Jun-25, 05:08 PM
So, I PMed SeanF, and he answered back.

Hey, I knew what he was talking about.

What is the Pinocchio nose Emoticon to be used for, other as this kind of joke? Surely no one here would insert it into their own post?

This is just a joke. It’s a funny joke. Ha Ha.

I think probably Sean forgot that we talked about this same subject and this same 1911 paragraph back in January.

He accused me of not wanting to talk about it in public, and I pointed out that we had already talked about it.

Sometimes you guys let yourself get too stressed out over nothing. Just relax. Geepers. :D

Sam5
2004-Jun-25, 05:10 PM
Anyway, I think it is a metaphor, not a simile, but whatever it is, I intended it as a joke.

milli360
2004-Jun-25, 05:24 PM
Sam5:
Hey, I knew what he was talking about.

That's not what you said.

:^o :^o :^o :^o :^o :^o :^o :^o


What is the Pinocchio nose Emoticon to be used for, other as this kind of joke? Surely no one here would insert it into their own post?
Why not? I just did, for fun. :)

This is just a joke. It’s a funny joke. Ha Ha.

PS: The misquoting by inserting stuff still squicks me out, even more than quoting out of context

Sam5
2004-Jun-25, 07:54 PM
Sam5:
Hey, I knew what he was talking about.

That's not what you said.

:^o :^o :^o :^o :^o :^o :^o :^o

ROTFLMAO!!

LOL, now you’ve got it!! :lol: :lol: :lol:

swansont
2004-Jun-25, 08:29 PM
Why is it that every thread titled "relativity" have to be a minimum of 6 pages long :)

They're a lot shorter if you move through them at a speed approaching c.

swansont
2004-Jun-25, 08:35 PM
The equivalence is the same when atomic clocks experience the same g force, whether achieved by gravity or accelerated motion. Two clocks at sea level experience 1 g and tick at the same rate. The clock on the mountain does not experience the same g force as the clock at sea level, so the mountain clock runs fast. But the clock at the top of the accelerating box is experiencing the same g as the clock at the bottom, so they run at the same rate.

But would two clocks that experience the same acceleration, moving at different speeds (with respect to an inertial observer) run at the same or different rates?

Normandy6644
2004-Jun-25, 08:35 PM
Why is it that every thread titled "relativity" have to be a minimum of 6 pages long :)

They're a lot shorter if you move through them at a speed approaching c.

or c+v :roll: :lol:

Sam5
2004-Jun-25, 08:47 PM
The equivalence is the same when atomic clocks experience the same g force, whether achieved by gravity or accelerated motion. Two clocks at sea level experience 1 g and tick at the same rate. The clock on the mountain does not experience the same g force as the clock at sea level, so the mountain clock runs fast. But the clock at the top of the accelerating box is experiencing the same g as the clock at the bottom, so they run at the same rate.

But would two clocks that experience the same acceleration, moving at different speeds (with respect to an inertial observer) run at the same or different rates?

That question mixes three relativity theories, Lorentz, SR, GR.

The answer depends on how fast the clocks are moving through a field and how strong the field strength is at the clocks.

swansont
2004-Jun-25, 11:48 PM
The equivalence is the same when atomic clocks experience the same g force, whether achieved by gravity or accelerated motion. Two clocks at sea level experience 1 g and tick at the same rate. The clock on the mountain does not experience the same g force as the clock at sea level, so the mountain clock runs fast. But the clock at the top of the accelerating box is experiencing the same g as the clock at the bottom, so they run at the same rate.

But would two clocks that experience the same acceleration, moving at different speeds (with respect to an inertial observer) run at the same or different rates?

That question mixes three relativity theories, Lorentz, SR, GR.

The answer depends on how fast the clocks are moving through a field and how strong the field strength is at the clocks.

Again, you have to define what "moving through a field" means. They are in outer space, not a wheat field, if that helps.

Is an object at the surface of the earth, unmoving with respect to it, moving through a field? What about a satellite in geosynchronous orbit, which is moving at the same angular speed?

Sam5
2004-Jun-26, 12:52 AM
Is an object at the surface of the earth, unmoving with respect to it, moving through a field? What about a satellite in geosynchronous orbit, which is moving at the same angular speed?

I’ve been trying to find out. What do you think?

I think I’ve got a big electric field moving over my house right now, spitting out big long jagged bolts of electricity or something really bright and white.

swansont
2004-Jun-26, 05:53 PM
Is an object at the surface of the earth, unmoving with respect to it, moving through a field? What about a satellite in geosynchronous orbit, which is moving at the same angular speed?

I’ve been trying to find out. What do you think?


It's your hypothesis. I think it's bogus. I'm just waiting for you to make some actual predictions.

Lorentz
2004-Jul-17, 01:06 AM
You seem to think that two clocks at different places in an accelerating box will experience different tick rates. Am I right about this? And if so, why?
[Sam5 quote]


Yes, Sam5, that is exactly what happens. Two clocks at different places in an accelerating box will experience different tick rates. However, the difference between the two tick rates will be proportional to the distance between the clocks.

Lorentz equations
x'=g(x-vt)
y'=y
z'=z
t'=g[t+(vx/c^2)]
where
g=1/sqrt[1-(v/c)^2]

Please look at the time equation.
t'=g[t+(vx/c^2)]

Do you see the "vx/c^2" term? For every one value of time, t, in the K frame, there are many different values for time, t', in the K' frame. There is a different value of t' for every different value of x.

In a frame that isn't accelerating, the time between ticks has only one value per frame regardless of the position of the clock. Look at two ticks (they are called events) 1 and 2. In the K frame, the time between ticks is dt where
dt=t_2 - t_1
In the K' frame, the time between ticks is dt' where
dt'=t'_2 - t'_1 where x is any value at all.

Using algebra, substitution into the Lorentz equation results in a cancellation of "vx/c^2" term.
dt' = g dt

That is the time contraction. But the x term only cancels out if v doesn't change. Suppose K' is an accelerating frame but K is an inertial reference frame. If v changes

dt' = g dt (1+ax/c^2)

Where a is the acceleration in the K frame, i.e.,
a=(v_2-v_1)/(t_2-t_1).

So the tick rate does change with position. Note that if both a and x are small, the tick rates are independent of acceleration


Ultimately, the time between ticks are determined by forces. The forces that hold the clock together, that make them work. However, these forces change with velocity. Anyway, by definition, any explicit discussion of forces takes the subject out of "kinematic physics" into "dynamic physics." Your claim that the kinematic part of relativity is inconsistent has been shown wrong. Now analyze the dynamics.

epictetus
2011-May-20, 12:47 AM
Indeed. I've got another wrinkle to possibly crunch. (Is that even English?)
Ok, I gather that mass is greater on top of Olympus (Ok, Everest) than at the equator, because of their relative distance from the earth's core.
Originally I was inclined to ask how much slower passes for an equivalent mass weighed at the equator than at either of the poles; but I don't dare pose it now in so plain and unnuanced a form.
I'm left with a simple (har har!) but related question. Objects at the equator would weigh less owing to the centrifugal force. But what about their great speed compared to bodies of the same mass placed at the poles? (I'm ignoring for now whether at the poles rotation in one spot counts for movement in relativity theory). Would this accelerate the passage of time as they experience it on the equator? Would it equal or overcome the deceleration of time entailed by their position on the equator? And are there equations to figure out such discrepancies?
Anyone caring to respond has my gratitude.

loglo
2011-May-26, 02:25 AM
Hi Epictetus,
Welcome to BAUT. A hint:- generally you will get quicker responses if you open your own new thread rather than appending to an existing very old thread.

To answer your question, centrifugal forces will not affect any time dilation. It is simply a matter of how deep in the gravity well you are located.
The other point that to make is that relativity is about comparing measurements from different places. So time will always flow at the same rate to you no matter where you are. However, when you look at someone else who is deeper in a gravity well or who is moving at a different speed than you are then you will see their time flowing differently to yours, just as they will see your time different to theirs, both will think the others clock is running slow.

Your question turns out to be important for the GPS system as the satellites are both higher in the Earth's gravity well and moving a different speeds. The effect of these are opposite to each other but of a different size so careful calculations need to be done to keep all the clocks in sync.

minitrue noram
2011-May-27, 03:53 PM
And another thing. I'd like to see Sam5's arguments heard. How do scientists define time and with what type of clock.

hi, my idea will not likely be accepted here, but...

i won't rehash what has been said about the current concept of time as practice in contemporary science. we know time is relative, in that it flows differently based on gravitational context affecting the viewer's perception. but let me tell you what is currently considered in Theoretical Physics.

step one: maybe its weirder than anyone has thought to measure yet.
step two: it is possible that Time, like photons, can be measured as a wave or a particle. (with tachyons as the hypothetical particle version).
step three: it's possible that Time exists in a comfortable duality as wave/particle. one half of which is evident in the material four-dimensional world, and the other half which operates across the dimensional barrier.
step four: it is also possible that Time is not connected to space as conventionally thought.
step four: once watching for the quantum version of time, it becomes likely that it is itself derived through multiple interactions at various depths of quantum dimensionality which through their actions conflate into a version which then affects the four-dimensional world.

tl/dr: Time (as we see it) is the result of a waveform collapse which echoes into our world.

Ken G
2011-May-28, 05:14 AM
The problem with that is that it isn't really saying much of anything specific. Removing the undefined parts, it really just boils down to the suggestion that time is an emergent property of something deeper. Given that all physics concepts, after enough study, are eventually found to be emergent properties of something deeper, I'd say that's not really much of a stretch. Still, it does at least entreat us to look underneath time, a process that we should bear in mind even if we are not anywhere close to ready to actually do it.

captain swoop
2011-May-28, 10:07 AM
hi, my idea will not likely be accepted here, but...

i won't rehash what has been said about the current concept of time as practice in contemporary science. we know time is relative, in that it flows differently based on gravitational context affecting the viewer's perception. but let me tell you what is currently considered in Theoretical Physics.

step one: maybe its weirder than anyone has thought to measure yet.
step two: it is possible that Time, like photons, can be measured as a wave or a particle. (with tachyons as the hypothetical particle version).
step three: it's possible that Time exists in a comfortable duality as wave/particle. one half of which is evident in the material four-dimensional world, and the other half which operates across the dimensional barrier.
step four: it is also possible that Time is not connected to space as conventionally thought.
step four: once watching for the quantum version of time, it becomes likely that it is itself derived through multiple interactions at various depths of quantum dimensionality which through their actions conflate into a version which then affects the four-dimensional world.

tl/dr: Time (as we see it) is the result of a waveform collapse which echoes into our world.

This is as you indicate at the start of the post not a 'mainstream' view. If you want to promote your own ideas and 'theories' it must only be done in the 'Against the Mainstream Forum.
Please take some time to read the rules for posting and advice for ATM Posters linked at the bottom of this post.

noncryptic
2011-May-28, 11:28 AM
I explained to a friend of mine an experiment conducted to go about proving realitivity.
Two atomic clocks, both sychronized, ...He then countered it would act different in space than on Earth. I didn't think so.

In a sense you friend is correct; clocks act different in space than on Earth because of the difference in gravity between the Earth's surface and orbit in space.

Regardless of what exactly the cause of the difference is, it is perfectly quantifiable by means of Einstein's theory of Relativity.

http://en.wikipedia.org/wiki/Global_Positioning_System
To achieve accuracy requirements, GPS uses principles of general relativity to correct the satellites' atomic clocks.