PDA

View Full Version : Time Dialation Is'nt Possible



LockedInThisHell
2004-Jul-06, 01:22 AM
I don't see how Einsteins theory of time dialation can be possible.Time is simply a man made tool(of the mind),it makes no sense to me that someone travelling at high speeds would age slower than someone who is'nt.

Ilya
2004-Jul-06, 01:48 AM
That only proves limitations of your mind.

Which is not a slur - human mind simply did not evolve to deal with relativistic (or quantum) phenomena. Nonethelss they are quite real. Slowed-down aging has been demonstrated for subatomic particles many times.

Musashi
2004-Jul-06, 01:51 AM
A watch or a clock is a tool.. one that measures time. Time is not a tool.

Wingnut Ninja
2004-Jul-06, 02:05 AM
Time is simply a man made tool(of the mind)

Not according to Einstein. It's just as much a part of the real universe as gravity and energy.

Bozola
2004-Jul-06, 02:35 AM
I don't see how Einsteins theory of time dialation can be possible.Time is simply a man made tool(of the mind),it makes no sense to me that someone travelling at high speeds would age slower than someone who is'nt.

It is stress related. Have you ever been stuck in a traffic jam? The slow you move the angrier you get. The more stress you develop in a slow traffic jam, the quicker your body ages.

Easy to understand, no?

Simply put, Einstein's "time dilation effect", i.e., special relativity in this case, is nothing like what I just described.

Gullible Jones
2004-Jul-06, 02:41 AM
I don't see how Einsteins theory of time dialation can be possible.Time is simply a man made tool(of the mind),it makes no sense to me that someone travelling at high speeds would age slower than someone who is'nt.

Well, tough, because it's been observed in relativistic particles for quite a while.

Okay, sorry if that was rude. I'll be blunt: it doesn't quite "make sense" to me, either. As Ilya said, we didn't evolve under circumstances in which we had to deal with relativistic phenomena; therefore, our minds can't "know" such phenomena.

Eta C
2004-Jul-06, 03:50 AM
To quote someone's quote line (I forget who's, and who the quote is from) There is no requirement for the universe to comply with your expectations.

Actually, SR is a conservative theory. Early in the 20th century physics was faced with a choice: abandon the principle of relativity (that the laws of nature are the same everywhere) or abandon Maxwell's new theory of electrodynamics (which was incompatible with the traditional Galilean principle of relativity). What Einstein did was to abandon neither and create a theory that included a principle of relativity that is consistent with Maxwell's theory. This came at the cost of abandoning the notion that time and space were absolutes. Well, so it is. SR and GR have been proven consistent with all experimental tests so far, which is what one expects from a successful theory.

freddo
2004-Jul-06, 04:14 AM
I don't see how Einsteins theory of time dialation can be possible.Time is simply a man made tool(of the mind),it makes no sense to me that someone travelling at high speeds would age slower than someone who is'nt.

Hi, welcome to the Board...

Black holes, time dilation through relative motion, the big bang, a finite but unbounded universe, expansion of space-time... All of these things are extremely, amazingly, frustratingly difficult to conceptualise. It's nobody's fault if they find it impossible. However, using an inability to believe as a basis for counterargument is a known logical fallacy. Particularly when there is plenty of evidence to demonstrate time dilation through relative motion is real.

As Gullible Jones said, its tough, really.

freddo
2004-Jul-06, 04:29 AM
To quote someone's quote line (I forget who's, and who the quote is from) There is no requirement for the universe to comply with your expectations.


The universe is not required to conform to the expectations of the ignorant.

Ut
2004-Jul-06, 01:13 PM
I don't remember where I picked up this visualization tool, but I find it works for me, even if it isn't accurate.

Think of time as a 4th spacial dimension, t. Now, pretend you have a constant speed of c through the 4 dimensions. If you're travelling in only the t direction, your velocity in the x, y, and z directions will be 0. If you're travelling in the x direction, your velocity in the y, z, and t directions will be 0. That is, you won't be travelling through time. Any deviation from the t direction results in time dialation.

Of course, this is relative to some arbitrary origin.

It works for me...

Eta C
2004-Jul-06, 01:39 PM
To quote someone's quote line (I forget who's, and who the quote is from) There is no requirement for the universe to comply with your expectations.


The universe is not required to conform to the expectations of the ignorant.

Thanks for the correction. Jay's version is, perhaps, a bit more trenchant. Either way, the sentiment's the same.

Argos
2004-Jul-06, 02:30 PM
I don't see how Einsteins theory of time dialation can be possible.Time is simply a man made tool(of the mind),it makes no sense to me that someone travelling at high speeds would age slower than someone who is'nt.

Most large scale natural laws and phenomena donīt seem to make sense. They must be approached in a positivist way. They have to be accepted as mathematical truths. Time dilation is a necessary consequence from the fact that the speed of light is finite, and it is expressed in very consistent formal terms.

Added: You can see for yourself (http://www.fourmilab.ch/etexts/einstein/specrel/www/)

toolazytotypemyname
2004-Jul-07, 12:51 AM
I don't remember where I picked up this visualization tool, but I find it works for me, even if it isn't accurate.

Think of time as a 4th spacial dimension, t. Now, pretend you have a constant speed of c through the 4 dimensions. If you're travelling in only the t direction, your velocity in the x, y, and z directions will be 0. If you're travelling in the x direction, your velocity in the y, z, and t directions will be 0. That is, you won't be travelling through time. Any deviation from the t direction results in time dialation.

Of course, this is relative to some arbitrary origin.

It works for me...


I think that comes from Brian Greene's book, the Elegant universe perhaps. It is the best explanation I have ever heard. When I had physics in college, they briefly covered relativity but I could never quite grasp how it worked. By the way this explanation was early in the book, once he got into multidimensional strings and such, I was totally lost.

Master258
2004-Jul-07, 12:57 AM
A watch or a clock is a tool.. one that measures time. Time is not a tool.
Yes, Time=real

Ut
2004-Jul-07, 01:39 AM
I think that comes from Brian Greene's book, the Elegant universe perhaps. It is the best explanation I have ever heard. When I had physics in college, they briefly covered relativity but I could never quite grasp how it worked. By the way this explanation was early in the book, once he got into multidimensional strings and such, I was totally lost.

Yeah, I couldn't remember if it was Greene or Hawking, and since I don't actually own anything by either of them (I've managed to talk my friends into buying their books for me, on occasion, though :D), I didn't care to speculate. Thanks for clearing that up.

Matt McIrvin
2004-Jul-07, 02:39 AM
Think of time as a 4th spacial dimension, t. Now, pretend you have a constant speed of c through the 4 dimensions. If you're travelling in only the t direction, your velocity in the x, y, and z directions will be 0. If you're travelling in the x direction, your velocity in the y, z, and t directions will be 0. That is, you won't be travelling through time. Any deviation from the t direction results in time dialation.

That's right, except there's one more strange thing about it... the "Pythagorean" law in space-time has funny minus signs in it. To calculate the elapsed proper time, tau-- that is, the time you'd experience traveling along some straight path-- you use this formula:

tau^2 = t^2 - x^2 - y^2 - z^2

where we use space and time units such that the speed of light is 1, that is, say, measure time in seconds and space in light-seconds.

At the speed of light the distance in the time direction equals the distance in some space direction (say the x direction), and proper time is zero. The closer you are to the speed of light, the more cancellation there is.

Celestial Mechanic
2004-Jul-07, 03:43 AM
Where have I seen this peculiar style of punctuation? "Is'nt" instead of "isn't", "have'nt" instead of "haven't"? Oriel36 punctuated his contractions that way.

LockedInThisHell
2004-Jul-08, 05:13 AM
That only proves limitations of your mind.

Which is not a slur - human mind simply did not evolve to deal with relativistic (or quantum) phenomena. Nonethelss they are quite real.
Oh really,speek for your self !Your mind did'nt evolve to deal with thinking on it's own obviously,which is'nt a slur, I'm just pointing out that your statement above was useless and un-original.
Time is a creation of our minds,a tool used to measure change,nothing more.
Slowed-down aging has been demonstrated for subatomic particles many times.
Thats better a statement that has to do with the topic,and yes I've examined a few of those "demonstrations" my self,but why do you think speed plays a role in effecting the rate at which they deteriorate(don't tell me that it has to do with stress and traffic).

LockedInThisHell
2004-Jul-08, 03:10 PM
A watch or a clock is a tool.. one that measures time. Time is not a tool.
No?Then what is it ?

LockedInThisHell
2004-Jul-08, 03:15 PM
Time is simply a man made tool(of the mind)

Not according to Einstein. It's just as much a part of the real universe as gravity and energy.
There is only the "now" and the changes that occur within it.As I said,time is a tool created by us.

Musashi
2004-Jul-08, 03:18 PM
No, time is not a tool.

LockedInThisHell
2004-Jul-08, 03:25 PM
I don't see how Einsteins theory of time dialation can be possible.Time is simply a man made tool(of the mind),it makes no sense to me that someone travelling at high speeds would age slower than someone who is'nt.

Hi, welcome to the Board...

Black holes, time dilation through relative motion, the big bang, a finite but unbounded universe, expansion of space-time... All of these things are extremely, amazingly, frustratingly difficult to conceptualise. It's nobody's fault if they find it impossible. However, using an inability to believe as a basis for counterargument is a known logical fallacy. Particularly when there is plenty of evidence to demonstrate time dilation through relative motion is real.

As Gullible Jones said, its tough, really.
They arn't hard to concepualize,actually they are quite simpl,it's just that I can see beyond some theories that we're created by others in the past,hence einstein and his idea of what time is and or is not.

LockedInThisHell
2004-Jul-08, 03:39 PM
I don't remember where I picked up this visualization tool, but I find it works for me, even if it isn't accurate.

Think of time as a 4th spacial dimension, t. Now, pretend you have a constant speed of c through the 4 dimensions. If you're travelling in only the t direction, your velocity in the x, y, and z directions will be 0. If you're travelling in the x direction, your velocity in the y, z, and t directions will be 0. That is, you won't be travelling through time. Any deviation from the t direction results in time dialation.

Of course, this is relative to some arbitrary origin.

It works for me...
3 spacial dimensions - up/down, left/right, front/back,and one time dimension - future/past, 1+3 dimensionality,unless you are speaking of some kind of hyperdimentionality,otherwise the above visualization tool can not work.

Ricimer
2004-Jul-08, 04:19 PM
locked:

Time is as real as distance is. The units are arbitrary, but so is the size of a meter or yard. However, it is still a real physical quantity that can be measured, just as the distance bettween two cities can be measured.

Have you looked at the logical proof/derivation that gives us time dilation? Quite fascinating, simple and..airtight (assuming the base assumptions are valid...which is only the relativity principle and constant speed of light... so they're as solid as can get).

RadioMike
2004-Jul-08, 05:16 PM
Locked:

How about this: Its perfectly OK for you not to accept Time Dialation as valid and I totally appreciate that as a non-scientist myself, "visualizing" it is problematic based upon my own perceptions of space and time.

I also don't know jack about GR or SR and I'd be wasting everyone's time to argue the point with those more knowledgeable on this board. Remember Occam's Razor.

Your style of expressing your viewpoint may very well lead to fruitless exposition resulting in a locked thread.

May I suggest framing your comments as to solicit better models and examples? That is to say, examples more comprehensible to laymen such as me? #-o

Thanks!

TravisM
2004-Jul-08, 05:27 PM
Did anyone ever figure out why tau is calculated with those minus signs instead of the addition so familiar?

Why does s = t^2 - ( x / c ) ^ 2 - ( y / c ) ^ 2 - ( z / c ) ^ 2 ???
Why not s = t^2 + ( x / c ) ^ 2 + ( y / c ) ^ 2 + ( z / c ) ^ 2

Is it because we're using different types of measurements on different dimensions? t being time and s being tau...

The bottom equation has no s = 0... I think...

Lt. Rico
2004-Jul-08, 06:35 PM
Time is a tricky thing because we can only talk about it in our human-brain-limited conceptual terms, but it is not simply a tool invented by humans - it is a very real thing.

One way to look at it is to try to imagine a world where time does not exist. If there is no time, then either everything that ever happens, happens all at once, or nothing ever happens at all. In either case, those are pretty clearly not the universes we live in.

LawBeefaroni
2004-Jul-08, 08:29 PM
Now I'm going at 1.3 times the speed of light. You see, time slows down approaching light speed and actually goes backwards beyond it. I hit LS around T+0:00:30 but for you it was about 10 years. Since you obviously wouldn't wait that long for my quick demonstration I had to exceed the speed of light to get to the right moment to post. I will now continue back to around 1994 and to prove it, I will stop the World Series(!!), then accelerate to light speed for 30 seconds and I will be back in good old 2004.

I'm not sure what other proof you need.

LawBeefaroni
2004-Jul-08, 08:31 PM
Would a practical demonstration convince you, Locked?
I will hit the speed of light and post into the past.

Swift
2004-Jul-08, 09:40 PM
Now I'm going at 1.3 times the speed of light. You see, time slows down approaching light speed and actually goes backwards beyond it. I hit LS around T+0:00:30 but for you it was about 10 years. Since you obviously wouldn't wait that long for my quick demonstration I had to exceed the speed of light to get to the right moment to post. I will now continue back to around 1994 and to prove it, I will stop the World Series(!!), then accelerate to light speed for 30 seconds and I will be back in good old 2004.

I'm not sure what other proof you need.
:o
Hey, while you're going back, could you stop at the 1997 World Series and make sure that Mesa retires the side in the 9th inning of the last game and the Indians win the series. Thanks, I owe you one. :D

Extravoice
2004-Jul-09, 02:27 AM
Maybe this question belongs in anothe forum, but this discussion got me thinking....

Time is often described as the fourth dimension. Under "normal" conditions we can move freely in the other three dimensions, but seem to be locked into a constant forward "rate" along the time axis.

Any guesses what things would be like if we were locked into a constant "rate" along one of the Euclidean dimensions, but could move freely along the other two as well as time?

The more I think about this, the more my brain hurts. After all, the term rate implies a relationship to time. So our "rate" along the time axis is one second per second? Ouch, ouch! :cry:

Ricimer
2004-Jul-09, 04:08 AM
actually, you'd probably pin it down compared to that spatial dimension, so one second per meter that-a-way.

gritmonger
2004-Jul-09, 05:32 AM
Okay- since this is technically close to topic, I'll ask: Who ever thought too hard and too long about the "What happens if you turn on a flashlight at lightspeed?" question? My answer ended up being "nothing" because time dilation at lightspeed means eternity is not long enough for you to even begin thinking about sending a signal to your arm. Instant at point "A" is the same instant at point "B."

Essentially, subjectively, a photon is a purely three-dimensional object. Odd conclusion, yes- but I don't often think like a photon. But this is puzzling too- if it is all the same instance, then to the photon there is no beginning or end, really- it has a three dimensional existence that is branched based on all of its possible paths. Subjectively, to the photon, all paths are real and exist. It can interfere with itself, and "spooky action at a distance" is all the same instant to a photon.

Now brain hurt. Me go lie down. This line of thought brought to you by three weeks of 115 degree heat 25 miles from Death Valley.

Normandy6644
2004-Jul-09, 06:00 AM
Okay- since this is technically close to topic, I'll ask: Who ever thought too hard and too long about the "What happens if you turn on a flashlight at lightspeed?"

Special relativity says that you will see the light at c, regardless of your motion. There is an equation for the relative addition of velocities that says this:

w=(u+v)/(1+uv/c^2)

where v is the velocity of an observer with rest frame x' as measured by an observer with rest frame x, u is the velocity of that same object but now as measured by the observer with rest frame x', and w is the velocity of a third object as measured by the observer with rest frame x. In English, this means that if you are on a ship travelling at the speed of light and you throw a baseball at a certain velocity, u is the ship's velocity, v is the velocity of the baseball, and w is the velocity of the ball measured by an observer. If v=c, then

w=(u+c)/(1+uc/c^2)=c(c+v)/(c+v)=c.

So all observers measure the ball (or light beam, or anything) as travelling at c.

gritmonger
2004-Jul-09, 06:07 AM
But if you are travelling at c, does any time pass at all?
Yes, you might see the photons from the flashlight travelling at lightspeed; but no time is passing in which to observe it.

Gullible Jones
2004-Jul-09, 06:19 AM
Technically, you can't reach the speed of light. Supposing you could, yes, you'd be in complete stasis.

gritmonger
2004-Jul-09, 06:30 AM
Then, subjectively, if I were a hypothetical photon, would I have a beginning or end, or just a long three-dimensional continuum of existence?

TravisM
2004-Jul-09, 11:59 AM
I can think of the 'flashlight' problem with light-cones. I like light cones, sherbert ones.. :D
A light cone depicts the maximum distance a particle can travel in a given time from some event that occured at the apex of the cone. If we follow a photon from an explosion along the edge of a light cone, or better yet if we are the photon, and we have a photon-sized flash light ( ;) ) any light cones that originate from the tiny flash light will still propogate away from it in a light cone, at the speed of light. So the realativity explanation holds up when you graph it out! Neat. 8)
[edit to add]
When viewed from a 'stationary' frame of reference, none of those photons are going any speed other than c.

Disinfo Agent
2004-Jul-09, 12:03 PM
Okay- since this is technically close to topic, I'll ask: Who ever thought too hard and too long about the "What happens if you turn on a flashlight at lightspeed?" question?
I am driving my car at the speed of light and I turn on my headlights. What do I see? (http://math.ucr.edu/home/baez/physics/Relativity/SpeedOfLight/headlights.html)

There are no inertial reference frames in which the photon is at rest so it is hopeless to try to imagine what it would be like in one. Photons do not have experiences. There is no sense in saying that time stops when you go at the speed of light. This is not a failing of the theory of relativity. There are no inconsistencies revealed by these questions. They just don't make sense.

Despite these empty answers, nobody should feel too put down for asking such questions. They are exactly the kind of question that Einstein often asked himself from the age of 16 until he discovered special relativity ten years later. Einstein reported that in 1896 he thought,

"If I pursue a beam of light with the velocity c (velocity of light in a vacuum), I should observe such a beam of light as a spatially oscillatory electromagnetic field at rest. However, there seems to be no such thing, whether on the basis of experience or according to Maxwell's equations. From the very beginning it appeared to me intuitively clear that, judged from the standpoint of such an observer, everything would have to happen according to the same laws as for an observer who, relative to the earth, was at rest. For how, otherwise, should the first observer know, i.e., be able to determine, that he is in a state of fast uniform motion? One sees that in this paradox the germ of the special relativity theory is already contained. Today everyone knows, of course, that all attempts to clarify this paradox satisfactorily were condemned to failure as long as the axiom of the absolute character of time, viz., of a simultaneous, unrecognizedly was anchored in the unconscious. Clearly to recognize this axiom and its arbitrary character really implies already the solution to the problem.''

Wally
2004-Jul-09, 01:12 PM
But if you are travelling at c, does any time pass at all?
Yes, you might see the photons from the flashlight travelling at lightspeed; but no time is passing in which to observe it.

speed and motion are relative (hense the name of Einstein's theories). To you, time passes at a "normal" rate, and the light from the flashlight takes off from you at c. Time to someone in another reference frame, moving at c compared to you, see's your time as standing still (and you see the same for him).

Disinfo Agent
2004-Jul-09, 01:25 PM
Time is simply a man made tool(of the mind),it makes no sense to me that someone travelling at high speeds would age slower than someone who is'nt.
The German philosopher Immanuel Kant also thought that time and space were just 'categories' with which the human mind organised the information from the senses.
But he lived at a time when everyone thought Newtonian mechanics was the correct picture of the universe. Relativity has certainly put Kant's ideas into question, if not to rest.

gritmonger
2004-Jul-09, 04:09 PM
Disinfo Agent: I understand all of that- but then what would be the experience of somebody travelling faster than c?

The paradox arises - and I don't quite think it's solved - because while the light seen by an observer travelling at c will appear to still be travelling at c, time dilation is infinite. It is not other objects or referencial frames that matter anymore: t = 0 for the hypothetical photon. For an observed object, the apparent velocity will be v = d/t. If t=0, you have a divide by zero error- and can you then have an observed velocity? Any distance travelled by any observed object amounts to infinite speed to an observer travelling at c.

Yorkshireman
2004-Jul-09, 04:20 PM
If you're travelling faster than c, you're not made of hadrons or photons - you're a tachyon particle and all the rules are different anyway - i.e. a tachyon 'rests' at infinite velocity and can't be slowed down to c without infinite expenditure of energy.

AFAIK, Tachyons are allowed by theory but are unobservable by the hadron universe.

I think the paradox is resolved by Disinfo's quote: a photon cannot 'observe' and does not have an 'age', so it makes no sense to frame the question.

gritmonger
2004-Jul-09, 04:37 PM
I think the paradox is resolved by Disinfo's quote: a photon cannot 'observe' and does not have an 'age', so it makes no sense to frame the question.

But if that's true, about no observation, how could entangled photons ever exchange information? If there is no way to pass information, how could entangled photons ever collapse to similar states upon observation?

Yorkshireman
2004-Jul-09, 04:48 PM
how could entangled photons ever exchange information? If there is no way to pass information, how could entangled photons ever collapse to similar states upon observation?

If I knew the answer to that, I'd have a Nobel Prize! But actually - is there not an essential difference between a photon 'observing' and 'being observed'?

Quantum entanglement is the wierdest thing in physics. Discuss...

Disinfo Agent
2004-Jul-09, 04:56 PM
Disinfo Agent: I understand all of that-
Then you're more intelligent than I. :D


[...] but then what would be the experience of somebody travelling faster than c?
Weird (http://math.ucr.edu/home/baez/physics/ParticleAndNuclear/tachyons.html).
We've had some threads that touched that here, too, like this (http://www.badastronomy.com/phpBB/viewtopic.php?p=148022#148022) one.


The paradox arises - and I don't quite think it's solved - because while the light seen by an observer travelling at c will appear to still be travelling at c, time dilation is infinite. It is not other objects or referencial frames that matter anymore: t = 0 for the hypothetical photon. For an observed object, the apparent velocity will be v = d/t. If t=0, you have a divide by zero error- and can you then have an observed velocity? Any distance travelled by any observed object amounts to infinite speed to an observer travelling at c.
You are forgetting that not only does time dilate as one approaches the speed of light, but space contracts. So (in the limit) the distance travelled is zero, and you have v=0/0, and indeterminate form, which can be regarded as standing for... c, as it should be! :)

gritmonger
2004-Jul-09, 06:03 PM
Disinfo Agent: I understand all of that-
Then you're more intelligent than I. :D
I meant to say, I get it or grasp the gist. :-?




The paradox arises - and I don't quite think it's solved - because while the light seen by an observer travelling at c will appear to still be travelling at c, time dilation is infinite. It is not other objects or referencial frames that matter anymore: t = 0 for the hypothetical photon. For an observed object, the apparent velocity will be v = d/t. If t=0, you have a divide by zero error- and can you then have an observed velocity? Any distance travelled by any observed object amounts to infinite speed to an observer travelling at c.
You are forgetting that not only does time dilate as one approaches the speed of light, but space contracts. So (in the limit) the distance travelled is zero, and you have v=0/0, and indeterminate form, which can be regarded as standing for... c, as it should be! :)

So both distance and time are zero... to a photon. It is dimensionless, subjectively? All points are at all times simultaneously? Well, then spooky action at a distance makes a lot more sense. No distance or time involved to a photon: both are the same instance of a photon because they "are?"

Disinfo Agent
2004-Jul-09, 08:59 PM
A miracle or two may have occurred during my derivation. :wink:

gritmonger
2004-Jul-09, 09:15 PM
Disinfo - I'm sorry if I seem a bit slow in coming along in following the logic of relativity - all of my learning has been secondhand and through analogy.

But is that essentially correct - a photon is subjectively dimensionless?

Disinfo Agent
2004-Jul-09, 09:24 PM
Disinfo - I'm sorry if I seem a bit slow in coming along in following the logic of relativity - all of my learning has been secondhand and through analogy.
So has mine. I'm sorry, gritmonger, I was just thinking out loud in my post, really. I'm not versed in relativity. But a few of the posters here do seem to have a grasp on it. Hopefully, one of them will answer your question. :)