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Infinitenight2093
2010-Nov-12, 12:53 AM
Assuming that time does not have to flow forward in the fourth dimension, could we not just use the fourth dimension as a gateway to the past by somehow following the backwards path within it? or possibly going to an "event" in the past through the fourth dimension?

Jens
2010-Nov-12, 01:36 AM
Assuming that time does not have to flow forward in the fourth dimension, could we not just use the fourth dimension as a gateway to the past by somehow following the backwards path within it? or possibly going to an "event" in the past through the fourth dimension?

It all depends on whether the assumption is correct, doesn't it? If the assumption is correct, then I suppose we might be able to find a way to do that. If the assumption is wrong, then surely we cannot.

caveman1917
2010-Nov-12, 01:48 AM
Yes, if you define the time dimension as allowing you to go backwards then you can go backwards ;)
Thing is that nature doesn't seem to agree with that definition - but one never knows of course.

Cougar
2010-Nov-12, 03:35 AM
Assuming that time does not have to flow forward in the fourth dimension, could we not just use the fourth dimension as a gateway to the past by somehow following the backwards path within it? or possibly going to an "event" in the past through the fourth dimension?

Oddly, the equations of quantum physics don’t require or imply any difference between past and present. They’re time-invariant. They’re reversible in principle. In the macro world, we 'always' see an ice cube melt in a glass of water - an example of the so-called arrow of time. But that's just because that is a more likely eventuality. There is nothing in the laws of physics that prohibits a cube of ice from emerging in a glass of water. It's just greatly less probable (by a huge degree). This always bothered me - and still does. But of course the universe cares not about my sensibilities. If you want an in depth analysis of what's going on here, which is also accessible to the average reader, pick up Sean Carroll's From Eternity to Here: The Quest for the Ultimate Theory of Time [2010].

Infinitenight2093
2010-Nov-12, 05:49 AM
Oddly, the equations of quantum physics don’t require or imply any difference between past and present. They’re time-invariant. They’re reversible in principle. In the macro world, we 'always' see an ice cube melt in a glass of water - an example of the so-called arrow of time. But that's just because that is a more likely eventuality. There is nothing in the laws of physics that prohibits a cube of ice from emerging in a glass of water. It's just greatly less probable (by a huge degree). This always bothered me - and still does. But of course the universe cares not about my sensibilities. If you want an in depth analysis of what's going on here, which is also accessible to the average reader, pick up Sean Carroll's From Eternity to Here: The Quest for the Ultimate Theory of Time [2010].

yes, so assuming that I'm correct, how would one go about using the fourth dimension as a time machine to reach events in either the past or the future?
is it even possible to enter the fourth dimension?
and, are there any theories that use this idea?

astromark
2010-Nov-12, 08:40 AM
Quote; "yes, so assuming that I'm correct, how would one go about using the fourth dimension as a time machine to reach events in either the past or the future?
is it even possible to enter the fourth dimension?
and, are there any theories that use this idea? " End quote...

To the best of my understanding there is not any method or proposed model that would allow time travel...

As best as I can. I have no method available to test the idea of entering the forth dimension.

So I turn my back on all that science and go with the idea... No. I can not.

Space needs time in order to exist.. It has taken time to simply exist... and time needed some space to happen in...

Those two are inseparable... time and space. Known as 'Space time'.

You can travel both across and through space. As it takes some time to do this you can travel in time.

A long time. A life time. Back and forward do not seem to be available for reasons as you can imagine...

' If a event is in the future... Its time has not yet arrived.' ... and so on...

astromark
2010-Nov-12, 08:57 AM
Assuming that time does not have to flow forward in the fourth dimension, could we not just use the fourth dimension as a gateway to the past by somehow following the backwards path within it? or possibly going to an "event" in the past through the fourth dimension?

Trying not to drift away from the science and astronomy of this question... You start this with 'Assuming' and you can not.
If you want for philosophy.. then I can not add to that., but will anyway.
Only to add that the method and manor of time and its relentless progression
Is a man made construct... by man, for man. The universe does not keep a record or care for what little time we have...

Jens
2010-Nov-12, 09:38 AM
yes, so assuming that I'm correct, how would one go about using the fourth dimension as a time machine to reach events in either the past or the future?
is it even possible to enter the fourth dimension?
and, are there any theories that use this idea?

I think the answer is that nobody knows. The problem is, if somebody knew, then they could try it, and by doing so find out if it's possible or not. I'm not aware of any way to either speed up or slow down time (other than being in math class, of course), and I don't think there is any mainstream theory that would allow it. By the way, "enter the fourth dimension" is a bit meaningless, because we are already within it. I think you mean "navigate within the fourth dimension." You must be aware, just as I am, that everything around you travels with you along the fourth dimension into the future. So I don't see any reason to assume it's not a universal phenomenon.

Well maybe sitting in front of a really boring math teacher could stop and eventually reverse time. Worth an experiment, no? :)

apolloman
2010-Nov-12, 11:46 AM
I'm not aware of any way to either speed up or slow down time :)

Jens, how about orbiting a black hole ? That would slow down time albeit in a relativistic manner (i.e. wrt somebody not orbiting the BH) wouldn't it ?

WayneFrancis
2010-Nov-12, 11:56 AM
Jens, how about orbiting a black hole ? That would slow down time albeit in a relativistic manner (i.e. wrt somebody not orbiting the BH) wouldn't it ?

I think, but could be wrong, that what Jen's meaning was that your local (proper) time will always click forward at a rate of 1 sec/sec. All orbiting a black hole will do is speed up other peoples time but never your own.

apolloman
2010-Nov-12, 01:27 PM
yep, thats what I was getting at as well.

Cougar
2010-Nov-12, 02:14 PM
how would one go about using the fourth dimension as a time machine to reach events in either the past or the future?

You should not be expecting an answer to this.

caveman1917
2010-Nov-12, 05:10 PM
how would one go about using the fourth dimension as a time machine to reach events in either the past or the future?

The latter part we are already doing right now. For the former part, reaching the past, you could use closed timelike curves (http://en.wikipedia.org/wiki/Closed_timelike_curve). Though you'll have to assume the chronology protection conjecture (http://en.wikipedia.org/wiki/Chronology_protection_conjecture) to be false (it is widely expected to be true), and note that closed timelike curves stand on the same footing as wormholes and white holes, theoretically valid solutions but no physical evidence at all.

Infinitenight2093
2010-Nov-12, 06:14 PM
The latter part we are already doing right now. For the former part, reaching the past, you could use closed timelike curves (http://en.wikipedia.org/wiki/Closed_timelike_curve). Though you'll have to assume the chronology protection conjecture (http://en.wikipedia.org/wiki/Chronology_protection_conjecture) to be false (it is widely expected to be true), and note that closed timelike curves stand on the same footing as wormholes and white holes, theoretically valid solutions but no physical evidence at all.

Cougar yes, I didn't have high hopes for an definite answer just some thoughts...And Jens, yes we may already be in the fourth dimension, as well as the fifth, sixth...but we cannot mentally comprehend these higher dimensions, only see their effects on our three dimensional perspective. So yes, I was looking for a way to navigate the fourth dimension as a means of time travel.

Herkfixer
2010-Nov-12, 08:33 PM
The "Fourth Dimension" Time, is not a physical dimension. It cannot be navigated. Time is linear. Time is not a place, or a thing. It is a measurement that only measures things at a positive integer. You cannot step outside of time since it is not a manifestation. Even if it was a manifestation of an actual "dimension", you still would not be able to control it. It would be tantamount to a historian recording an event in your life. Then you saying, after the story is written, I will remove all parts that have anything to do with me. Then you have nothing. No story. To remove time would be to undo everything and the only way to move through something linear is to have the ability to remove yourself from it in order to move in the opposite direction.

And since no one else said it yet. As the quote says, "Time travel into the future is possible. You are already doing it, one second per second at a time."

And Einstein said, "The only reason for time is so that everything doesn't happen at once."

Infinitenight2093
2010-Nov-12, 09:05 PM
The "Fourth Dimension" Time, is not a physical dimension. It cannot be navigated. Time is linear. Time is not a place, or a thing.
Time is only linear to we who perceive it to be so, a forward flow of time is the only way events would make sense in our brains. There is no law or statement in all of physics that prevents the backwards flow of time, we just haven't figured out how to do that yet...also, what makes you say that the fourth dimension can not be navigated? by your quote from an unknown source "Time travel into the future is possible. You are already doing it, one second per second at a time", we are already navigating time. I am simply addressing the problem of navigating backwards in time using the fourth dimension.

It is a measurement that only measures things at a positive integer. You cannot step outside of time since it is not a manifestation. Even if it was a manifestation of an actual "dimension", you still would not be able to control it. It would be tantamount to a historian recording an event in your life. Then you saying, after the story is written, I will remove all parts that have anything to do with me. Then you have nothing. No story. To remove time would be to undo everything and the only way to move through something linear is to have the ability to remove yourself from it in order to move in the opposite direction.
I have said nothing about removing myself from time, only using time to its fullest.

And Einstein said, "The only reason for time is so that everything doesn't happen at once."
I would like to rephrase that quote to better fit my OP, "the only reason we perceive the 3rd dimension is so that everything doesn't happen at once." Time will always be here as long as there is space for it to occupy, but the reason for time is still a shady subject.

tommac
2010-Nov-12, 09:37 PM
yes, so assuming that I'm correct, how would one go about using the fourth dimension as a time machine to reach events in either the past or the future?
is it even possible to enter the fourth dimension?
and, are there any theories that use this idea?

You may want to read the papers from:
http://www.phys.uconn.edu/~mallett/main/time_travel.htm
although it seems that his work stopped in 2007 which would seem to me that he either gave up on it or got debunked.

Also you may also do a quick read on quantum entanglement which is a spontaneous transmision of data between two particles. The problem however is that the change in data would be difficult or impossible to distinguish between sample data.

cosmocrazy
2010-Nov-13, 05:24 PM
Assuming that time does not have to flow forward in the fourth dimension, could we not just use the fourth dimension as a gateway to the past by somehow following the backwards path within it? or possibly going to an "event" in the past through the fourth dimension?

Other than the paradoxes arising from causality , i.e The Grandfather Paradox, then the direction of time is really not an issue. As mentioned by Cougar in quantum physics time doesn't have meaning to flow in any particular direction. A particle's history (like a photon or electron) is probabilistic until its particular position is measured, until then it could be said to have followed all possible paths simultaneously. So in effect its history is not determined until its present is observed. Direction of time seems to be most applicable to the macroscopic world and its rate is always relative between reference frames but is experienced by each observer's own personal clock to run along at 1 sec per sec. It appears time is the mechanism/ dimension that allows definitive change that can be measured or experienced in the macroscopic world we observe. Without it we'd not exist as we experience to, but only as quantum probabilities. Why its directional arrow points only one way I have no idea other than as I mentioned, Causality.

tommac
2010-Nov-13, 05:26 PM
The one thought i had was would all quantum probability reset if any information was able to be transmitted and interpreted back in time.

Other than the paradoxes arising from causality , i.e The Grandfather Paradox, then the direction of time is really not an issue. As mentioned by Cougar in quantum physics time doesn't have meaning to flow in any particular direction. A particle's history (like a photon or electron) is probabilistic until its particular position is measured, until then it could be said to have followed all possible paths simultaneously. So in effect its history is not determined until its present is observed. Direction of time seems to be most applicable to the macroscopic world and its rate is always relative between reference frames but is experienced by each observer's own personal clock to run along at 1 sec per sec. It appears time is the mechanism/ dimension that allows definitive change that can be measured or experienced in the macroscopic world we observe. Without it we'd not exist, but only as quantum probabilities. Why its directional arrow points only one way I have no idea other than as I mentioned, Causality.

Herkfixer
2010-Nov-13, 05:35 PM
There is no law or statement in all of physics that prevents the backwards flow of time, we just haven't figured out how to do that yet...also, what makes you say that the fourth dimension can not be navigated? by your quote from an unknown source "Time travel into the future is possible. You are already doing it, one second per second at a time", we are already navigating time. I am simply addressing the problem of navigating backwards in time using the fourth dimension.

There is no law that prevents the backwards flowing of time because one is unnecessary. Time isn't something that "flows" in the physical sense. The "flow" of time is metaphoric. We are not navigating time, because to do so would mean that you can alter something about what you are navigating through and we cannot because there isn't anything to navigate through.

Time is only linear to we who perceive it to be so, a forward flow of time is the only way events would make sense in our brains.
Again. Time is not an actual dimension that is sperate and apart from anything. It is a form of MEASUREMENT. Any reference to time as a Dimension is purely arbitrary. Dimensions 1-3 are physical constructs that are difined by how many coordinates it takes to describe a position within that space.

1st Dimension - A dot
2nd Dimension - A line
3rd Dimension - A Cube

The "4th Dimension" Time, is not a spatial dimension like 1-3, it is a temporal dimension. A temporal dimension is one way to measure physical change. It is perceived differently from the three spatial dimensions in that there is only one of it, and that we cannot move freely in time but subjectively move in one direction. Period. Because it is not a physical dimension, it cannot be "moved" through. Just because you can verbalize, "I will move from now, to then." has no bearing on the possibility of it being so.

I would like to rephrase that quote to better fit my OP, "the only reason we perceive the 3rd dimension is so that everything doesn't happen at once." Time will always be here as long as there is space for it to occupy, but the reason for time is still a shady subject
We don't "perceive" the 3rd Dimension, we exist inside of it and can interact with it. It is not a construct that exists just to me able measure something else. You can not compare the 3rd Dimension to Time, because they are unrelated in every way. Apples to Oranges. Time will always be here even if there is not a space to occupy because time will always exist to an outside observer. And the "reason" for time is not a shady subject, time exists as a measurement, and that is all.

caveman1917
2010-Nov-13, 06:29 PM
There is no law or statement in all of physics that prevents the backwards flow of time, we just haven't figured out how to do that yet

There is the second law of thermodynamics. While it doesn't strictly prevent a momentarily backwards flow, it does prevent this as a statistical law - so time could be seen as a statistical phenomenon with such high probability of flowing forwards that you'd about never get to have it go backwards. What it does prevent completely is us 'making' it go backwards, or "how to do that", since any work we do with the system will make entropy increase without even a recourse to some statistical blip.

I would like to rephrase that quote to better fit my OP, "the only reason we perceive the 3rd dimension is so that everything doesn't happen at once." Time will always be here as long as there is space for it to occupy, but the reason for time is still a shady subject.

I think you meant the 4th dimension. How about turning that phrase upside-down?
"The only reason we perceive the (1-3)dimensions is so that everything doesn't happen at the same place". Space will always be here as long as there is time for it to exist in, but the reason for space is still a shady subject.

caveman1917
2010-Nov-13, 06:55 PM
Time is not an actual dimension that is sperate and apart from anything. It is a form of MEASUREMENT.

Time is as much a dimension as each spatial one is.

Any reference to time as a Dimension is purely arbitrary.

Technically that is correct, but so is any reference to a spatial dimension. The only invariant is the 4d spacetime construct. How you decide to cut that up into spatial dimensions and timelike dimensions is indeed arbitrary (though it has to be consistent), but this holds as much for the spatial dimensions as it does for the time dimension (and it must be so).

Dimensions 1-3 are physical constructs that are difined by how many coordinates it takes to describe a position within that space.

Wether you can call them "physical" or not could be open to interpretation. But how is this different from a time dimension, with 4 coordinates necessary to unambiguously define any event?

1st Dimension - A dot
2nd Dimension - A line
3rd Dimension - A Cube

I think you meant:
0th dimension: point
1th dimension: line
2nd dimension: square
3rd dimension: cube
(4th dimension: hypercube)

It [time dimension] is perceived differently from the three spatial dimensions in that there is only one of it

Untrue, there is nothing in principle to prevent you from creating metrics with any number of spatial or timelike dimensions.

Because it is not a physical dimension, it cannot be "moved" through.

Sure it can. At least in the same sense as one can "move" through a spatial dimension. Take a 1+1dimensional coordinate system. For some equation of motion, instead of differentiating with respect to t (as you would when you're considering it the "moving" through space with respect to time), differentiate with respect to x.

time exists as a measurement, and that is all.

As does space.

Herkfixer
2010-Nov-13, 09:13 PM
Time is as much a dimension as each spatial one is.

Apparently to you, but as much as I've read, reality doesn't agree with you. At least not our definitions of it, as well as Algebra, Geometry, Physics, and just real science in general. Your points are philosophical ones not grounded in reality.

Here is a short list of different definitions of the word "Time".

"Merriam Webster Online Dictionary". 2010. http://www.merriam-webster.com/dictionary/time. "1a: the measured or measurable period during which an action, process, or condition exists or continues : duration; 1b: a non-spatial continuum that is measured in terms of events which succeed one another from past through present to future; 2: the point or period when something occurs : occasion"

"Encarta Online Dictionary". Encarta Online Dictionary. 2010. http://encarta.msn.com/encnet/features/dictionary/DictionaryResults.aspx?refid=1861720331. "1. system of distinguishing events: a dimension that enables two identical events occurring at the same point in space to be distinguished, measured by the interval between the events.".

"Webster's New World College Dictionary". 2010. http://www.yourdictionary.com/time. "1.indefinite, unlimited duration in which things are considered as happening in the past, present, or future; every moment there has ever been or ever will be... a system of measuring duration 2.the period between two events or during which something exists, happens, or acts; measured or measurable interval"

"Dictionary.com Unabridged, based on Random House Dictionary". 2010. http://dictionary.reference.com/browse/time?r=66. "1. the system of those sequential relations that any event has to any other, as past, present, or future; indefinite and continuous duration regarded as that in which events succeed one another.... 3. ( sometimes initial capital letter ) a system or method of measuring or reckoning the passage of time: mean time; apparent time; Greenwich Time. 4. a limited period or interval, as between two successive events: a long time.... 14. a particular or definite point in time, as indicated by a clock: What time is it? ... 18. an indefinite, frequently prolonged period or duration in the future: Time will tell if what we have done here today was right."

"The American Heritage® Stedman's Medical Dictionary @dictionary.com". 2002. http://dictionary.reference.com/browse/time?r=66. "A duration or relation of events expressed in terms of past, present, and future, and measured in units such as minutes, hours, days, months, or years."

"Collins Language.com". HarperCollins. 2010. http://www.collinslanguage.com/results.aspx?context=3&reversed=False&action=define&homonym=-1&text=time. "1. the past, present, and future regarded as a continuous whole,... 2. (Physics) a quantity measuring duration, measured with reference to the rotation of the earth or from the vibrations of certain atoms"

"Britannica Concise Encyclopedia". 2010. http://www.britannica.com/EBchecked/topic/596034/time. "Measured or measurable period. More broadly, it is a continuum that lacks spatial dimensions."

None of these definitions have anything to do with time being a physical construct. Time is a means of measuring how long something takes or when something happened. In order to move "through" something, you have to be able to manipulate it. In order to be able to manipulate it, you must be able to "see" it (seeing meaning quantitatively be able to measure its properties, not just say that it exists).

As for time being as much a dimension as a spatial one, it is not. The definition of a Dimension itself is, a topological measure of the size of its covering properties. Roughly speaking, it is the number of coordinates needed to specify a point on the object. For example, a rectangle is two-dimensional, while a cube is three-dimensional." You cannot use coordinates to specify a point on time. It does not have a topology. Which brings me to:

Whether you can call them "physical" or not could be open to interpretation. But how is this different from a time dimension, with 4 coordinates necessary to unambiguously define any event?

There is no interpretation to physical. I can touch it, its physical. I cannot touch it, it is not physical. Most of your points are philosophical points, not scientific ones. Well YOU call it physical, but are you really touching it... bah.. whatever... its real and its physical. Each "dimension" requires the number of coordinates specified in its dimension number in order to exist. Yes, I got them wrong earlier and thank you for pointing it out... I forgot the square. But to my point. It does not take 4 coordinates to specify time. Time is "one dimensional" if you want to get down to it. In order to specify when something happened all I need is to give you the arbitrary notation (seconds, minutes, hours, days, etc) of when it happened.

And the "4th-dimension" already exists in a spatial dimension, the hyper-cube or tessaract. Time would not be considered the 4th dimension even if it did exist because it wouldn't fit the definition of a dimension.

Untrue, there is nothing in principle to prevent you from creating metrics with any number of spatial or time-like dimensions.

Again.. philosophical, not science. There aren't even any theories that there are more than one "dimensions" of time. Time is time, you can speed it up, or slow it down, but it is still time. Using your argument I could say there are an infinite number of candy dimensions where each dimension is a different flavor of candy. Doesn't make it true and is a fun thought experiment, but the science stopped when you started that thought.

Sure it can. At least in the same sense as one can "move" through a spatial dimension. Take a 1+1dimensional coordinate system. For some equation of motion, instead of differentiating with respect to t (as you would when you're considering it the "moving" through space with respect to time), differentiate with respect to x.

Your making stuff up now. t would be a constant. When "figuring" your motion in respect to x, that is the only number you could move relative to. Thats why we call it a constant. You can't change it. The coodinate system of a 1-dimensional object isn't 1+1 because that would make it two dimensional and then we use a different coordinate system. Your trying to force time to be a physical construct. You cannot interject it into physical reality.

Nothing about Euclidean n-space (reality) or the Cartesian coordinate system requires time for a position to be known. Moving from one point in space to another, does not require time to exist either. But if we want to know how long it took to make that journey, it is only our curiosity that creates the measurement of time to tell us how long that took. This is a subjective number based on the observer, not the actual events.

Time "appears" to move slower to the man that got sucked into a black hole. It "appears" to him that time stopped. 1,000 years goes by and he escapes the black hole but it only "felt" like a few days. Does that mean that 1,000 years had not passed? No... that just means his perception of that time was altered based on the events that he witnessed. (Yes I know he would be dead, and he could never escape, and that there are a lot of other things at play in this scenario but I'm only giving this as a rough example).

caveman1917
2010-Nov-13, 11:05 PM
Time is as much a dimension as each spatial one is.Apparently to you, but as much as I've read, reality doesn't agree with you. At least not our definitions of it, as well as Algebra, Geometry, Physics, and just real science in general. Your points are philosophical ones not grounded in reality.

Ever heard of Minkowski space?

You cannot use coordinates to specify a point on time.

3h20m45s. Oops.

There is no interpretation to physical. I can touch it, its physical. I cannot touch it, it is not physical.

I think you'll find it is a tad more complicated than that, unless you'd like to say neutrino's aren't physical.

Well YOU call it physical

No i do not, please don't misrepresent what i said. I said a timelike dimension is just as physical as space-like dimension.

It does not take 4 coordinates to specify time.

While i agree i phrased that perhaps unclearly, what i meant was that it takes 4 coordinates to specify an event (a 4vector) in standard minkowski spacetime. One of those is a coordinate in a timelike dimension.

Time would not be considered the 4th dimension even if it did exist because it wouldn't fit the definition of a dimension.

Once again, ever heard of minkowski space? You know, the one where science is done in.

There aren't even any theories that there are more than one "dimensions" of time.

Yes there are. The one that could be most considered is 1+3, where things go in reverse and c becomes a lower bound. In essence everything would be tachyons.
Though one could even construct ultrahyperbolic ones such as 5+7 at the cost of predictability.

Time is time, you can speed it up, or slow it down, but it is still time.

No you can not. Time is proper time and it does neither of those.

Using your argument I could say there are an infinite number of candy dimensions where each dimension is a different flavor of candy. Doesn't make it true and is a fun thought experiment, but the science stopped when you started that thought.

Wrong. A metric tensor defined on some manifold has a signature that can be expressed as (p,q,0). There are only two different "flavours of candy", conveniently giving the spacelike or timelike distinction to the underlying dimensions.

Your making stuff up now. t would be a constant. When "figuring" your motion in respect to x, that is the only number you could move relative to. Thats why we call it a constant. You can't change it. The coodinate system of a 1-dimensional object isn't 1+1 because that would make it two dimensional and then we use a different coordinate system. Your trying to force time to be a physical construct. You cannot interject it into physical reality.

I never said anything about a 1-dimensional object, not sure where you gotten that from. I clearly defined the geometry as 1+1.

Nothing about Euclidean n-space (reality) or the Cartesian coordinate system requires time for a position to be known.

Again, ever heard of minkowski space?
And you should read up on what a cartesian coordinate system is.

Moving from one point in space to another, does not require time to exist either.

Do you think all those t's and τ's in the equations are only there for aesthetics?

Time "appears" to move slower to the man that got sucked into a black hole. It "appears" to him that time stopped. 1,000 years goes by and he escapes the black hole but it only "felt" like a few days. Does that mean that 1,000 years had not passed? No... that just means his perception of that time was altered based on the events that he witnessed. (Yes I know he would be dead, and he could never escape, and that there are a lot of other things at play in this scenario but I'm only giving this as a rough example).

This is just plain wrong. You should read up on the difference between proper time and coordinate time. Though you'd probably be better of with a good introductory text on special relativity in general.

Herkfixer
2010-Nov-14, 06:41 PM
I had a 5 page response to this but my head is starting to hurt. I'll just say we'll have to agree to disagree. Minkowski created "his universe" to "Mathematically" explain time. It was not a basis to actually manipulate it. It has no basis in reality other that the piece of paper its written on.

Relativity exists to explain why the standard measurement of time changes based on factors like gravity and velocity. And no matter which theory you look at time exists separate from the physical universe as a means of measurement, not a physical manifestation. Look up the definition or physical if you want to argue about what physical means.

Take care and have a great day. If you can change time itself, prove it and I'll change my mind. Come back from the future with the winning score of this years Superbowl as proof and post it here. In January, after I'm a millionaire, then I'll say you were right.

astromark
2010-Nov-14, 07:18 PM
This is a good example of a wast of time...
Something we as human beings have a limited amount of...
So we sit about discussing the points of merit of all sorts of papers regarding the measuring and recollection of time...
or is that a recollection of events prior to this moment...
What time is and how you might say it seems to be the pivotal argument... It changes nothing. Only we care.
The passage of time is what stops everything happening at once... Good old 'Albert' had a way with words.

This discussion of attempting to move forward or backward through time as if that might be possible is a mistake.
Its not possible now and as I have no proof of fact of it ever being so can reasonably conclude it never will be.
As I notice my cat is chasing its tail... nature has told me something.
Can you see the science fiction writers assembly of disappointment ?

Substantia Innominata
2010-Nov-14, 09:02 PM
Minkowski created "his universe" to "Mathematically" explain time. It was not a basis to actually manipulate it. It has no basis in reality other that the piece of paper its written on.

In a strict sense, this is true of any model whatsoever. And this, of course, is all science is about.

And no matter which theory you look at time exists separate from the physical universe as a means of measurement, not a physical manifestation.

One really can over-abstract anything. How can something like time exist 'seperate from the physical universe'? Where then does it exist? What else is there? Do you have knowledge about an unphysical universe? Or about a different physical universe? Or a metaphysical universe? I'd say nearly everybody will agree that at least in some sense, time is real. It is real, at least in form of a human concept. Just like space. And as such, I'd have a hard time imagining it being located anywhere else than, ultimately, in the human brain itself?! Well it has to be somewhere. It is a concept, arising out of our nature of perceiving the world. Again, just like space. We happen to perceive 3 spatial dimensions, so we call this aggregate (and experience it as) 'space'. Henceforth we make use of it in our theories too. We also happen to perceive stuff, well, happening, in sequence and as such enfolding in one direction only. We call this aspect of reality 'time'. And there it is. Like anything we can think about, it must be, in some fashion, set and realized in our brains -- something similar might well hold for certain animals, as well as, apparently, some plants. One might generalize this physical equivalent under the term 'biological clock'?! The only difference, I'd say, lying in the respective order of additional abstraction. So our concept of time, indeed, seems highly abstracted. While that of, say, plants isn't abstracted at all, and how could it be -- you'll need a brain for that.

What I'm driving at is that even if time is a mere figment of (maybe) living organisms, it still has a basis in the physical world. Otherwise there wouldn't be any figment in the first place.

This is a good example of a wast of time...

But then you could say this about nearly anything, couldn't you? In the end, all you achieve as a result will be.. a waste of time?

This discussion of attempting to move forward or backward through time as if that might be possible is a mistake.

Is there something wrong with your wristwatch? Run-down battery, perhaps? Mine actually is and keeps steadily ticking on.

Its not possible now and as I have no proof of fact of it ever being so can reasonably conclude it never will be.

As regards moving backward: Sound, reasonable.

Can you see the science fiction writers assembly of disappointment ?

Why? They ain't science-fiction writers for nothing. Plus there's certainly a reason it's called 'fiction'. Consider a time-machine becoming actually possible. And realized! What is there, they (SF authors) could go on write about, in a sense of fiction? The sole fact of possibilities in the real world being limited is, no doubt, the raison d'ętre of all fictional literature. Isn't it great then that there still is a place for time-machines, alien-invasions, and all these sort of things? As long as we don't confuse literature with the real world, there'll be all right. Yet when science fiction writers are disappointed it has more than often to do with poor stories of colleagues, or with the fact of their own stories being regarded as poor -- and the low sales resulting. But the more scientific, as well as technological, boundaries there remain in the real world, the better, the easier for them?? The oldfashioned, rattling time-machine will still do, perfect! And who doesn't love the FICTION?

Herkfixer
2010-Nov-14, 10:00 PM
One really can over-abstract anything. How can something like time exist 'seperate from the physical universe'? Where then does it exist? What else is there? Do you have knowledge about an unphysical universe? Or about a different physical universe? Or a metaphysical universe? I'd say nearly everybody will agree that at least in some sense, time is real. It is real, at least in form of a human concept. Just like space. And as such, I'd have a hard time imagining it being located anywhere else than, ultimately, in the human brain itself?! Well it has to be somewhere. It is a concept, arising out of our nature of perceiving the world. Again, just like space. We happen to perceive 3 spatial dimensions, so we call this aggregate (and experience it as) 'space'. Henceforth we make use of it in our theories too. We also happen to perceive stuff, well, happening, in sequence and as such enfolding in one direction only. We call this aspect of reality 'time'. And there it is. Like anything we can think about, it must be, in some fashion, set and realized in our brains -- something similar might well hold for certain animals, as well as, apparently, some plants. One might generalize this physical equivalent under the term 'biological clock'?! The only difference, I'd say, lying in the respective order of additional abstraction. So our concept of time, indeed, seems highly abstracted. While that of, say, plants isn't abstracted at all, and how could it be -- you'll need a brain for that.

What I'm driving at is that even if time is a mere figment of (maybe) living organisms, it still has a basis in the physical world. Otherwise there wouldn't be any figment in the first place.

You make half my point then backtrack and contradict it. My point isn't that there is no such thing as time, whether as a concept or as a construct, but that it is not something. It is, as you said, a concept our brains invent in order to put events in order. Without time we wouldn't be able to accurately describe events to someone who wasn't there. Even concepts such as after and before are concepts of time. They don't need to be in a numerical format. Space on the other hand, whether we could describe it or not, whether we knew it existed or not, whether we existed or not, would still exist. Time is not such a necessity.

True events will always happen in a perceived order, but to say that something like time is required for that to happen would be naive. You might as well say that time drives events. What is the actual purpose of time. In order to say time must exist and that it is navigable, you must be able to say what the purpose of time is or what its constituency or parameters are.

If we approach a river and wish to navigate it we must understand it. If we wish to build a boat to sail it, we need to know that wood floats on it. If we wish to swim across it, we must know how to swim and to stay afloat. In order to do both we must know that people do not already float. If without these developments we just try to walk across the water we sink and drown.

But this analogy only works if time were a physical, navigable construct. Everyone keeps saying that time is about perception just as space is just a perception. That is like saying, if our brains didn't exist, neither would the universe. No... the universe would still exist, but time would not. There would be no need for time because there is no outside observer that would require any sort of measurement.

Gravity holds things down, it exists without human brains Electromagnetism holds the electron to the nucleus of an atom together, and bonds them together to create complex molecules, it exists without human brains. The Strong Force holds together the gluons and quarks together to make protons and neutrons and also holds the protons and neutrons together to make the atom, it exists without human brains. The Weak Force is responsible for some flavor changes, weak decay and emission of neutrinos, it exists without the human brains.

My point is those are the 4 Fundamental Interactions of the Universe. All of these happen whether or not we can perceive them. Time on the other hand causes no interactions, causes no forces, and has no part in the actual operation of the Universe. It only exists as a means to measure these changes. In order to be able to "use" time as suggested by time travel (use as in manipulate it to flow backwards are forwards at a faster rate than it already flows), it must have a causal relationship to something. It does not. Nothing is caused by time.

caveman1917
2010-Nov-14, 11:45 PM
Relativity exists to explain why the standard measurement of time changes based on factors like gravity and velocity.

What relativity teaches us is actually that there is no "standard" measurement of time. The main lesson is that each observer has his own time (ie proper time) and it will neither slow down nor speed up as you claimed earlier.

And no matter which theory you look at time exists separate from the physical universe as a means of measurement, not a physical manifestation. Look up the definition or physical if you want to argue about what physical means.

If you read my replies carefully you'll see i wasn't arguing for time to be physical. My argument was against your claim that space is but time isn't, that there is a difference between the two. Either they are both physical or they are both not (and this is open to interpretation on philosophical grounds), but not one is and the other isn't, that was my argument. Time is as much a dimension as space, and does fit "the definition of dimension", counter to your claim.

If you can change time itself, prove it and I'll change my mind.

This is quite a bit of a strawman, isn't it? I have actually been claiming the opposite, proper time is immutable - but each observer has his own proper time, that's the important bit.

caveman1917
2010-Nov-14, 11:48 PM
My point isn't that there is no such thing as time, whether as a concept or as a construct, but that it is not something.

Herkfixer
2010-Nov-15, 01:31 AM
If you read my replies carefully you'll see i wasn't arguing for time to be physical. My argument was against your claim that space is but time isn't, that there is a difference between the two. Either they are both physical or they are both not (and this is open to interpretation on philosophical grounds), but not one is and the other isn't, that was my argument. Time is as much a dimension as space, and does fit "the definition of dimension", counter to your claim.
So I see you aren't even reading my replies caveman. Space has physical characteristics. It holds to the very definition of such. Time does not. Time is not a thing. It is a concept that is made up to describe how long it took for something to happen. There is no philosophical grounds to argue this. There is nothing to support anything you say. Physical means physical... you can't redefine it to fit your own philosophical desires to be "different" or whatever your reason. Saying to prove that time has the same physical characteristics as space is not a straw-man, it was supposed to be a metaphorical analogy to the Minkowski space/m-theory/string theory argument. You tried to tell me that if i don't use Minkowski space, I must not understand this stuff. But it is a total hypothetical space. You can't prove it because it doesn't exist. So if you can believe in Minkowski space, why can't you believe other stuff.

What relativity teaches us is actually that there is no "standard" measurement of time. The main lesson is that each observer has his own time (ie proper time) and it will neither slow down nor speed up as you claimed earlier.
My point is that there is a "standard" of time. But it is all relativistic based on your viewpoint. Its relativity...

caveman1917
2010-Nov-15, 02:12 AM
Space has physical characteristics. It holds to the very definition of such.

Then please define, unambiguously, what characteristics something must have to be physical?
Show how space has those characterics.
Show how time hasn't.

And yes, your starting point must be minkowski space. Whichever way you choose to go beyond strict science, it must be consistent with it. [ETA if the OP wants to know about ways for time travel, it can be assumed he means 'time' as it is used in current science. Granted, at the quantum level things get more complicated, but i suppose our OP isn't a microscopic entity :)]

Time is not a thing. It is a concept that is made up to describe how long it took for something to happen. There is no philosophical grounds to argue this.

There have been some threads around on "what really is time or space" (do a search for those terms and you should find them).
My argument is that this is beyond science, and are philosophical considerations - with many grounds to argue either way.

I don't see how you would argue that time is made up to describe the temporal distance between events whilst at the same time stating that space isn't made up to describe the spatial distance between those events.

Saying to prove that time has the same physical characteristics as space is not a straw-man, it was supposed to be a metaphorical analogy to the Minkowski space/m-theory/string theory argument. You tried to tell me that if i don't use Minkowski space, I must not understand this stuff. But it is a total hypothetical space.

Current science uses minkowski as its standard background, and defines 'space' and 'time' according to that model. In this mainstream model both are dimensions and are interchangeable with eachother. Of course it is a hypothetical model, that is what science does.

My point is that there is a "standard" of time. But it is all relativistic based on your viewpoint. Its relativity...

Not to sound condescending, but i think reading up on some introductory textbook on special relativity would help you along a lot concerning this point (you should even be able to find some online). All that's required is some knowledge of high school math and an afternoon of free time, it's really not that hard.