How Time Passes Differently for Twins Traveling at Light Speed

[Ich]

there are 3 spacetime events involved.

 

[JesseM]

Don't add other factors

Those "other factors" are what our debate is about, since we both agree that in the scenario you proposed as a poll, A will read a lesser time than B when they meet. So now please address the two questions in my last post, which I think will clarify what it is we actually disagree about:

This is clear in the numerical example I give in my last post, where A accelerates towards B, and all frames agree that when they meet, A will read 2006.73 while B will read 2007. But you see that in B's frame, A ages 1.73 years and B ages 2 years between the time A accelerates and the time they meet; but in C's frame, A ages 1.73 years but B only ages 1.5 years between the time A accelerates and the time they meet. Are you saying that the description of the situation from C's perspective is any less valid than B's, or aren't you?

and

To pin down what you mean here, let's imagine that A and B were out-of-sync in their own rest frame--at the same moment B read 2005, A already read 3164. Then A accelerates, and when they come together, B reads 2007 and A reads 3165.73. Would you say that A has "logged more time" simply because it reads a greater time when they meet, ignoring the question of whether they were in sync to begin with? Or would you say that the question of whether they were initially in sync is relevant to the question of which clock "logged more time"?

I am saying that, in the example I proposed as a PF poll question in post 64, between a first spacetime event defined as A and B at rest in the same frame and both set to read zero in the frame in which they are at rest

As Ich says, this is not a "spacetime event". A spacetime event is something that happens at a single point in space and a single moment in time--any description of two clocks separated in space cannot qualify as a single event. But this is just an issue of your using incorrect terminology, I understand the scenario you are describing and as I've said practically every time we discussed this scenario, I agree that the clock that accelerates will read a lesser time when they meet. If you ever thought I disagreed about this, you haven't been reading my posts very carefully.

 

[yogi]

No Ich says there are three events - which is correct - however I am only concerned with the reading of clocks in the rest frame starting at the time B begins to move and the time both clocks are stopped. Tell me Ich - would you agree that it makes no difference whether A and B are initally separated and then B moves to A - or If A and B were initally together and B moves the same distance as he did in the first case - and when he stops at the same point and simultaneously stops his stopwatch (clock) - if he sends a signal back to A - would you that in this case the transmiited signal would indicated the same time - e.g. B would send "my clock reads 40 minutes at the time I reached the destination. And A, Knowing the distance, could then calculate the time that passed on his clock from the time B left up until B signalled - and would he conclude that his clock read 50 minutes as before.

Jesse - the way you frame the problem always leads to diversionary tangents - I know how most SR types like to transform from one frame to another - blindly using the formulas - but not keeping in mind the limitations that - measurements of space and time in another relatively reference frame are illusory - and this leads to the abstruse analysis that colminates in shifting hyper planes and Earth clocks jumping ahead by thousand of years because the traveler turns around and so on. When you are all done, that type of analyis leaves one not knowing reality from squat. No wonder Einstein said "Now that the mathematicians have gotten involved in relativity, I am not sure I still understand it myself "

 

[JesseM]

Jesse - the way you frame the problem always leads to diversionary tangents

So do you refuse to answer my questions?

but not keeping in mind the limitations that - measurements of space and time in another relatively reference frame are illusory

Illusory? What the hell does that mean? If A and B are out-of-sync in C's frame, is this somehow more "illusory" than the fact that A and B are in sync in B's frame. If so, then it seems you do indeed think the description in B's frame is more valid than the description in C's frame, even if you are not willing to be straight with me and come out and say it in response to my question about this.

and this leads to the abstruse analysis that colminates in shifting hyper planes and Earth clocks jumping ahead by thousand of years because the traveler turns around and so on.

Not if you are consistent about which inertial frame you use throughout the problem. The shifting hyperplanes only happens if you insist on trying to understand what things look like from the perspective of a non-inertial observer, meaning you have to switch from one frame to another in the middle of the problem. But really, the theory of SR was never meant to tell you anything about the "reference frame" of a non-inertial observer, it is just supposed to tell you how a given physical situation can be understood if you analyze it from beginning to end in one inertial frame or another. In the case of the A-B scenario, if you analyze the whole thing from the perspective of B's frame, or if you analyze the whole thing from the perspective of C's frame, there is no shifting of hyperplanes or sudden jumps in clock readings whatsoever.

No wonder Einstein said "Now that the mathematicians have gotten involved in relativity, I am not sure I still understand it myself "

Yogi, you sound like a creationist taking quotes by scientists out-of-context to make it sound like they're supporting positions they obviously don't. If you notice, the only mathematical ideas I'm using in discussing how things would look in B's frame vs. C's frame are the Lorentz transformation equations, which Einstein himself derived in section 3 of his 1905 paper! And the whole concept of the Lorentz transformation is not that they represent some arbitrary mathematical transformation, they are the formulas for relating physical measurements made on systems of measuring-rods and synchronized clocks of different observers. If observer B has a system of measuring-rods spread throughout space which are at rest relative to him, with clocks mounted along them that are synchronized using the assumption that light travels at a constant velocity relative to B, and C also has a system of measuring rods at rest relative to him, with clocks mounted on them that are synchronized using the assumption that light travels at a constant velocity relative to him, then what the position and time coordinates they get by reading off their respective measuring-rod/clock systems will be exactly the ones I gave in my numerical example earlier. For example, if C sees that the clock in his system that was next to A when it accelerated read 2005 at that moment (at which moment A's own clock also read 2005), then if he looks at the moment that B was next to a different clock in his system that also read 2005, he will see that B's own clock read 2005.5 at that moment. This shows the physical meaning of the statement that in C's frame, the event of A accelerating, and of A's clock reading 2005, happened at the same moment that B's clock read 2005.5. So don't give me that nonsense about this being just a matter of abstract mathematics, Einstein explains in detail the physical meaning of the coordinates of different inertial observers in section 1 of his 1905 paper.

 

[yogi]

Its not abstract math - it is measurement math - the measurements made in a relatively moving frame are only apparent - they are true in the sense that the measurements are true - but to introduce additional clocks and frames is not necessary for the situation involved in the simple example Einstein gave - at no time in his explanation of the physical meaning of the equations does Einstein make any claim about what the moving (B clock) measures in the A frame. (Its not important) The reciprocity of the frames is not discussed by Einstein in part 4 when he describes the physical meaning. So why consider anything other than the simple fact that the clocks don't agree when the one way journey is completed. As you say "SR is meant to explain what happens from beginning to end in one inertial system" dido to that.

Me a Creationist...In the beginning there was nothing, and God said let there be light. And still there was nothing, but you could see it.

 

[JesseM]

Its not abstract math - it is measurement math - the measurements made in a relatively moving frame are only apparent

All frames are "relatively moving" relative to something--for example, the frame where B is at rest is moving relative to C. Again, are you saying there's some reason to believe the measurements in B's frame are any less "illusory" or "apparent" than the ones made in C's frame?

but to introduce additional clocks and frames is not necessary for the situation involved in the simple example Einstein gave - at no time in his explanation of the physical meaning of the equations does Einstein make any claim about what the moving (B clock) measures in the A frame. (Its not important)

Just a quibble--in Einstein's example it's the B clock that is the inertial one, the A clock is the one that accelerates. But even if you switch the letters, I'm not sure I understand your point--he certainly talks about what the clock that was moved measures, he says that it lags behind the clock that didn't move by (1/2)t(v/c)^2. Maybe that's not what you meant by "what the moving clock measures in the clocks' frame", but if so, what did you mean? Did you mean that Einstein doesn't talk about how things look in the frame of the clock that was moved? Well, I don't either, since the clock that was moved (A) moved non-inertially and thus doesn't have a "frame" in SR. I did talk about how the whole situation would look from the frame of a third observer C who is moving inertially at velocity v relative to the inertial observer B. So is your point just that Einstein didn't talk about how the whole situation would look in a different frame? No, he didn't, but anyone who comprehended the previous sections of the paper would understand that Einstein believed it's an arbitrary choice which frame you use to describe a given physical situation, no inertial frame is more valid than any other. Would you disagree that this is clearly Einstein's view?

The reciprocity of the frames is not discussed by Einstein in part 4 when he describes the physical meaning.

Yes he does. He first talks about how objects look in a reference frame K (which he has labeled 'the stationary system') when they are moving relative to K, then he says "It is clear that the same results hold good of bodies at rest in the 'stationary' system, viewed from a system in uniform motion".

So why consider anything other than the simple fact that the clocks don't agree when the one way journey is completed.

Because that's not all that you consider. You also say that the clock which moved "logged less time" than the other clock, or that it "aged less". And you also seem to think it is somehow more valid to say that the two clocks were initially in sync than it is to say they were initially out-of-sync. If you want to renounce all such statements and just say that in Einstein's scenario, the clock that accelerated will be behind the clock that didn't when they meet, then I certainly agree with that much, but if you continue to make statements which go beyond that and seem to implicitly privilege B's frame over other frames, then I still say you're wrong.

As you say "SR is meant to explain what happens from beginning to end in one inertial system" dido to that.

Yes, but SR also says that the only truly physical facts are the ones that would be true in every inertial frame. The fact that A is behind B when they meet will be predicted in every frame, but the statement that A and B were initially synchronized is not a frame-independent truth, nor is the statement that A's clock was ticking more slowly as A and B approached each other.

Me a Creationist...In the beginning there was nothing, and God said let there be light. And still there was nothing, but you could see it.

I wasn't accusing you of being a creationist, just of taking quotes out of context like a creationist.

 

[yogi]

What I have attempted to say - many times - is that the A frame is the frame where the clocks are brought in sync - we never do any syncing in the B frame (I am calling B the traveling clock) - everything is determined in A frame - once B is up to speed it is also a valid inertial frame - but it is different than the A frame

To restate: B is initially at rest in the A frame and in sync with A clock - B leaves the A frame (via acceleration that produces a relative velocity) and returns to a different spatial point in the A frame (or B could return to the same location as A). I am saying that this return does not have to be a physical pulling up to a stop in the A frame adjacent to A - it can be passing any known spatial point that was measured off (a proper distance in the A frame) and B's clock will be read by A either because B physically stops at one of these points or passes by and transmits a radio signal to A.

In contrast to venturing to a distant star and returning to effect real age difference (classical twin paradox) - real age difference is brought about whenever one clock leaves the frame in which it has been calibrated and later returns to any point in the frame in which it was calibrated. That is the essence of Einstien's explanation in part 4

If you do not agree - that is ok - but then show me a single experiment that disproves my interpretation (don't give me the mainstream authority argument - give me an experiment)

 

[jdavel]

yogi and JesseM,

Two clocks, A1 and A2, at rest wrt each other, separated by a distance L, synchronized as defined by SR.

A third clock, B, moving at v wrt A1 and A2, passes A1 (on his way to A2) and, at the instant he passes A1 he synchs with A1.

Do you guys disagree on what B and A2 read when B passes A2?

 

[JesseM]

What I have attempted to say - many times - is that the A frame is the frame where the clocks are brought in sync - we never do any syncing in the B frame (I am calling B the traveling clock)

OK, I have been calling A the traveling clock since that's how Einstein wrote it in his example. But I'll switch from now on so we're using the same convention.

- everything is determined in A frame - once B is up to speed it is also a valid inertial frame - but it is different than the A frame

To restate: B is initially at rest in the A frame and in sync with A clock - B leaves the A frame (via acceleration that produces a relative velocity) and returns to a different spatial point in the A frame (or B could return to the same location as A). I am saying that this return does not have to be a physical pulling up to a stop in the A frame adjacent to A - it can be passing any known spatial point that was measured off (a proper distance in the A frame) and B's clock will be read by A either because B physically stops at one of these points or passes by and transmits a radio signal to A.

Sure. Or this other point could have a clock that was synchronized with A's clock in A's rest frame, and then you could compare what B's clock reads at the moment it passes this clock, and you'd see B was behind this other clock. This would be the idea described in section 1 of Einstein's paper, where the coordinates of an event (in this case, the event of B's clock reading a certain time) are determined by local readings on a network of measuring-rods and clocks spread throughout space which are all at rest relative to the observer and with the clocks synchronized according to Einstein's procedure.

In contrast to venturing to a distant star and returning to effect real age difference (classical twin paradox) - real age difference is brought about whenever one clock leaves the frame in which it has been calibrated and later returns to any point in the frame in which it was calibrated. That is the essence of Einstien's explanation in part 4

What I am saying is that this is not a "real age difference" unless they meet, because nothing is physically "real" in relativity unless it is agreed upon in all frames. It's true that if B reads 2010 at the same moment he's passing a clock in A's network which reads 2015, then at that moment B is five years younger than A, in A's frame. But in C's network of clocks, at the moment B reads 2015 he may be passing a clock in C's network that reads 2020, and at the moment that A passes a clock in C's network that reads 2020, A may read 2014. This would mean that in C's frame, A is one year younger than B. Since the question of whether B is older or younger than A at the moment that B reads 2015 cannot be decided in a way that doesn't depend upon an arbitrary choice of reference frame, there is no physically real age difference between them until they meet at a single point in space.

If you do not agree - that is ok - but then show me a single experiment that disproves my interpretation (don't give me the mainstream authority argument - give me an experiment)

I am not sure what your interpretation actually is. Why is it, exactly, that your interpretation tells you that the age difference in A's frame is more "real" than the age difference in some other frame? Is it simply because Einstein chose to describe this example from the point of view of this frame? Or is it because they were initially brought into sync in this frame? If they had been initially brought into sync in some frame other than their rest frame, would you say that the "real age difference" would be the one in this other frame, or would you say that their real age difference should still be viewed in terms of their initial rest frame, but that it would no longer match the difference in their clock-readings since they were out-of-sync in their initial rest frame? If you want me to try to find an experiment that shows why your interpretation doesn't make sense, then please answer these questions about how your interpretation works.

 

[JesseM]

yogi and JesseM,

Two clocks, A1 and A2, at rest wrt each other, separated by a distance L, synchronized as defined by SR.

Synchronized in their rest frame, presumably?

A third clock, B, moving at v wrt A1 and A2, passes A1 (on his way to A2) and, at the instant he passes A1 he synchs with A1.

Do you guys disagree on what B and A2 read when B passes A2?

No, I'm pretty sure we both agree that B would be behind A2. But I think yogi would say this means that B really aged less than A2 did between the time it passed A1 and the time it passed A2, while I would point out that in B's frame, A2 aged less than B between the times of these two events, and I'd say that no inertial frame should be preferred over any other.

 

[jdavel]

So,

Two clocks, A1 and A2, both at rest in S, separated by a distance L, synchronized as defined by SR.

A third clock, B, at rest in S' which is moving at v wrt S, passes A1 (on his way to A2) and, at the instant he passes A1 he synchs with A1.

Suppose you define 3 events, E1, E2, and E3 and use the notation:
event: En[x, t, x', t']
gamma = Y

Then the three events and their S and S' coordinates are:

E1[0, 0, 0, 0] "B passes A1"

E2[0, L, YL, -YLV/C^2] "A2 is set to 0"

E3[L, L/v, 0, (L/v)/Y] "B passes A2"

JesseM, when you say "...in B's frame, A2 aged less than B between the times of these two events" which two events do you mean?

 

[JesseM]

So,

Two clocks, A1 and A2, both at rest in S, separated by a distance L, synchronized as defined by SR.

A third clock, B, at rest in S' which is moving at v wrt S, passes A1 (on his way to A2) and, at the instant he passes A1 he synchs with A1.

Suppose you define 3 events, E1, E2, and E3 and use the notation:
event: En[x, t, x', t']
gamma = Y

Then the three events and their S and S' coordinates are:

E1[0, 0, 0, 0] "B passes A1"

E2[0, L, YL, -YLV/C^2] "A2 is set to 0"

E3[L, L/v, 0, (L/v)/Y] "B passes A2"

JesseM, when you say "...in B's frame, A2 aged less than B between the times of these two events" which two events do you mean?

In B's frame, the event of E1 does not happen simultaneously with E2--instead, at the moment B passes A1 and both read 0, A2 reads vL/c^2. So, define the event E2b: "A2 reads vL/c^2". If you want to compare how much A2 ages vs. how much B ages in B's own rest frame, then you must compare how much time elapses on B between events E1 and E3 with how much time elapses on A2 between events E2b and E3. Saying that event E2 is somehow more important than E2b is equivalent to saying that one inertial frame's definition of simultaneity (the A1/A2 rest frame) should be preferred over another inertial frame's definition of simultaneity (B's rest frame).

 

[jdavel]

Ok, how's this?

Two clocks, A1 and A2, both at rest in S, separated by a distance L, synchronized as defined by SR.

A third clock, B, at rest in S' which is moving at v wrt S, passes A1 (on his way to A2) and, at the instant he passes A1 he synchs with A1.

Suppose you define 4 events, E1, E2a, E2b and E3 and use the notation:
event: En[x, t, x', t']
gamma = Y

Then the four events and their S and S' coordinates are:

E1[0, 0, 0, 0] "B passes A1"

E2a[L, 0, YL, -YLv/C^2] "A2 is set to 0"

E2b[L, vL/c^2, L/Y, 0] "A2 reads vL/c^2"

E3[L, L/v, 0, (L/v)/Y] "B passes A2"

 

[yogi]

djavel - I do not know what is meant by syncing a clock that flies by - we can read its instantaneous value, but we do not have a way of determining that the flyby clock is actually running at the same speed as the two clocks that were in the same rest frame. For example a GPS clock that flies over the North Pole will not be in sync with a clock at the North Pole unless it had been preset to run at the same rate as the clock in the non rotating Earth centered reference frame located at the same height as the satellite

Jesse - I do not understand why the B clock has to be adjacent (physically return to the same point occupied by the A clock) for a real time difference to have elapsed.

 

[JesseM]

Jesse - I do not understand why the B clock has to be adjacent (physically return to the same point occupied by the A clock) for a real time difference to have elapsed.

As I said, because I'd say the only "real" physical quantities are those that all frames agree on. Do you agree that as long as the two clocks are separated in space, different frames will disagree on the time difference between them? Are you saying the time difference in A's frame is more "real" than the time difference in C's frame?

 

[JesseM]

Then the four events and their S and S' coordinates are:

E1[0, 0, 0, 0] "B passes A1"

E2a[L, 0, YL, -YLv/C^2] "A2 is set to 0"

E2b[L, vL/c^2, L/Y, 0] "A2 reads vL/c^2"

E3[L, L/v, 0, (L/v)/Y] "B passes A2"

Yes, this looks fine to me.

 

[Dragongod]

the problem is that Einstein never actually proved his special relativity theory. Its based on his assumption that in space-time, which according to him is some kind of forth dimension, time isn't universal. He just merely stated that. He never proved it with logical reasoning. So according to his assumptions, if you have twin at point A and twin at point B if one moves faster than the other over, automatically because time isn't universal, one will have to be older. It doesn't actually make sense. Whether you travel at the speed of light or not, and i can say at the speed of light because it hasn't been proven that the speed of light is actually some kind of cosmic speed limit, the distance you travel over in no way should effect time. Time within a system (the Universe) should be constant. According to Einstein its not but that is irrevelent because who is to say he is right - it is not proven that time isn't constant. And logically, it should be. All that changes, within a system where time is constant, is the distance traveled by the body in that period of time. It doens't destort time itself. Special Relativity Theory is based on Einstein's assumptions about Spacetime.

 

[Dragongod]

According to Einstein Time is a subjective thing. Time according to me is not. Time exist whether we do or not and always moves forward at an instanteous rate that we cannot measure. For example, the second you try to measure an instant, you are already too late. Time is always moving forward and cannot be distorted, especially by different frames of reference. Whether i am at point A or you at point B or C or D or F it has no baring on the time that is constantly moving forward regardless of anything.

 

[DaveC426913]

Dragongod, are you aware of the countless experiments that have demonstrated beyond a shadow of a doubt that objects traveling at relativistic speeds experience time at a different rate?

We don't need spaceships and distant planets and thought experiments. This is real laboratory experimentation. Particles fired at relativistic speeds in accelarators die at a different rate than if they were not moving. Those rates are predicted with exquisite accuracy, time and time and time again, by Einstien's theory.

Relativity is one of the most tested theories in the history of science, and it has passed spectacularly every time.

Einstein's relativity is not merely the best theory going, it is the only theory that even makes the trip downtown, let alone into the ballpark.

 

[Dragongod]

That doesn't prove that the particles are somehow not governed by the same dimension of time. The fact that that happens (particles moving at a faster and rate and living longer than those that are not moving as fast) could be due to the fact that as particles move over a DISTANCE not TIME, they gain more mass and therefore gain more energy. That experiment doesn't necessaritly prove what Einstein was proving - that it is due to different TIMES.

 

[Dragongod]

The experiment doesn't necessarily prove that time is relative. It just proves that F=ma and that an increase in force would mean an increase in mass and acceleration. you can't increase acceleration without increasing mass. As something moves over a particular distance it gains more energy. Thats all it shows. If mass and energy could somehow stay constant regardless of acceleration, i don't see how it could, but if it did, neither twin would be older than the other. According to Einstein, one of the twins would still age more. No proof.

My theory (post #88) would still hold up just as Einstein's has. It would be consistant with the experiments thus far because of the reasons I gave in posts #89 and #90. Time exist as dimension that does not exist in the physical realm. The only things we can affect are those that deal with (matter, mass, energy). Time has none of those qualities and therefore cannot be affected. It is not a tangle entity. We can't touch it. It does not change with space, or mass. Time has no mass. It is just a constant that has to exist because we can conceptionally understand it.

Einstein thought Time and Space existed as single entity together. And that is the backbone of all his reasoning for Special Relativity. He arrived at this answer only because he foolishly concluded that space (emptiness according to him) can somehow bend to bodies that have mass or rather large mass. He gave the example of a ball falling on a matress to show this. True the matress bends to the ball but that's only because the matress has mass. Something has no mass cannot bend or curve. Thats like saying that width and depth can exist without taking up space, basically saying without mass. It can't it doesn't make sense. Einstein concluded wrongly.

 

[Janus]

That doesn't prove that the particles are somehow not governed by the same dimension of time. The fact that that happens (particles moving at a faster and rate and living longer than those that are not moving as fast) could be due to the fact that as particles move over a DISTANCE not TIME, they gain more mass and therefore gain more energy. That experiment doesn't necessaritly prove what Einstein was proving - that it is due to different TIMES.

I would strongly suggest that you actually study Relativity before discussing it or trying to rebut it.

 

[DaveC426913]

as particles move over a DISTANCE not TIME, they gain more mass and therefore gain more energy. That experiment doesn't necessaritly prove what Einstein was proving - that it is due to different TIMES.

What does gaining more energy have to do them living longer?



The lifespan of particles before decay are known to many decimal places. If, under whatever circumstances you want, they decay in a longer time, they are, in any way you care to define it, experiencing time dilation.

It's not like particles have a rich life happening in there that we can see how fast their tea goes cold. They are created, they last a time, they die. If we record that they take 25% longer time to die, it's because the time they experienced was dilated.

There *isn't* a better definition of time than that. In fact, particle decay is how we measure time. There simply is no more fundamental measurement than subatomic particles by which we could rate this event.

 

[jdavel]

yogi

"djavel - I do not know what is meant by syncing a clock that flies by - we can read its instantaneous value, but we do not have a way of determining that the flyby clock is actually running at the same speed as the two clocks that were in the same rest frame."

Well, I'm beginning to see why you get so confused about relativity!

"Synching" clock B and A1 as B passes A1 simply means that t' = t for the event "B passes A1". Of course at any later (or earlier) time they won't be equal. Just at that one instant. You can do the same thing with the spatial coordinate, setting x = x' for exactly one event. In fact the Lorentz transforms in their familiar, simple form require that t' = t = 0 and x' = x = 0 for the same single event. In other words, the clocks are synched to zero when the spatial origins coincide.

Does that clear up some of your confusion?

 

[Dragongod]

Janus if i am wrong about anything please correct, i came to this site to learn. Also DaveC426913 that means that u are using a different definition than time than i am. U justify time being relative by saying "They are created, they last a time, they die. If we record that they take 25% longer time to die, it's because the time they experienced was dilated." "There *isn't* a better definition of time than that. In fact, particle decay is how we measure time."
---- this shows that, BY DEFINITION, if I say the electrons LIVE LONGER BECAUSE they gain more mass and energy, you are argreeing with me because you also say that particles can live longer due to particular factors. We have the same definition for two different labels. I define something living longer due to particular factors as having a LONGER LIFESPAN while you define something that lives longer due to particular factors as having MORE TIME. The way I define time has nothing to do with the concept you are speaking concerning time. We are talking about two different concepts using the same label (time). Hopefully i am getting my point across, i know it sounds a little "iffy." The problem here is semantics as it is in most cases.

 

[yogi]

djavel - that is exactly what I said - if that is what you are defining as synchronize - ok - you can do that - a single reading - but synchronized can also mean running together - like synchronous motors, See a dictionary: 1) To render synchronous in operation 2) Having the same period 3) Having the same period and phase

DragonGod - it is true Einstein did not prove SR - he did suggest some types of experiments that he felt would reveal the truth of time differences between moving clocks ...and later as experimental technology developed his predictions were found to be in agreement therewith. But Einstein did not proffer a physical reason as to why age differences occur - your questions in this regard are not outrageous - it is natural to want to relate time dilation to some physical source - your approach is very much like that of Curt Renshaw http://renshaw.teleinc.com/index.asp - who has developed a number of equations that are somewhat consistent with the notion that time dilation in SR is energy related. There are also some energy theories that correlate gravitational time dilation with SR. Tom Martin http://www.gravityresearch.org/ and others have developed this notion in connection with inflow theory

 

[yogi]

Jesse - your post 85 - in theory all observers agree upon the proper length and proper time - distance and time measured in the frame where the clocks are at rest and the rulers are at rest. And yes - if the two clocks are separted in space (e.g. the A frame) - an observer in another frame B moving wrt to A will not see the two clocks as running in sync, nor will this B frame observer be able to correctly measure the distance between the two clocks.

Example: I can agree with the fact that the muon has a 2usec lifetime (a proper time of 2 usec) in every frame, but when it is moving at 0.99c wrt to the earth, I measure it to be greater.

 

[Ich]

Jesse - your post 85 - in theory all observers agree upon the proper length and proper time - distance and time measured in the frame where the clocks are at rest and the rulers are at rest. And yes - if the two clocks are separted in space (e.g. the A frame) - an observer in another frame B moving wrt to A will not see the two clocks as running in sync, nor will this B frame observer be able to correctly measure the distance between the two clocks.

Example: I can agree with the fact that the muon has a 2usec lifetime (a proper time of 2 usec) in every frame, but when it is moving at 0.99c wrt to the earth, I measure it to be greater.

So you think the Lorentz equations are correct, even with this -vx/c² term?

 

[JesseM]

Jesse - your post 85 - in theory all observers agree upon the proper length and proper time - distance and time measured in the frame where the clocks are at rest and the rulers are at rest. And yes - if the two clocks are separted in space (e.g. the A frame) - an observer in another frame B moving wrt to A will not see the two clocks as running in sync, nor will this B frame observer be able to correctly measure the distance between the two clocks.

So are you saying that the "real" answer to the time difference between two clocks separated in space can be found by using length and time measurements in their own rest frame? Does that mean that if two clocks are in motion relative to each other, you think there's no real answer to the time difference between them at any given moment, that only when they come to rest relative to each other can a real time difference be found?

 

[yogi]

Ich: The LT are correct if the postulates are correct since they follow straightaway - but other postulates like those posed by Selleri recogonize two way isotropy (round trip velocity of c constant) but they do not share Einstein's postulate of one way isotrophy - consequently Selleri transforms predict the same time dilation in terms of the correctness of the interval, but they do not include the vx/c^2 factor. Ironically, because of the methodology used in the physical experiments that seek to measure time dilation, this term doesn't get measured (no clock displacement in the relatively moving frame). So, my above statement is based upon the correctness of the LT, which is why I prefaced it with "In Theory"

 

[Ich]

Ich: The LT are correct if the postulates are correct since they follow straightaway - but other postulates like those posed by Selleri recogonize two way isotropy (round trip velocity of c constant) but they do not share Einstein's postulate of one way isotrophy - consequently Selleri transforms predict the same time dilation in terms of the correctness of the interval, but they do not include the vx/c^2 factor. Ironically, because of the methodology used in the physical experiments that seek to measure time dilation, this term doesn't get measured (no clock displacement in the relatively moving frame). So, my above statement is based upon the correctness of the LT, which is why I prefaced it with "In Theory"

So those transforms that you prefer are just the LT without vx/c^2?

 

[jdavel]

yogi,

"...consequently Selleri transforms predict the same time dilation in terms of the correctness of the interval, but they do not include the vx/c^2 factor..."

This is great!

I Googled 'Selleri transforms' and the first hit I tried sent me to one of your posts on physicsforums!

So I tried the next one. That took me to another one of your posts!

At that point I was laughing too hard to try any of the others.

 

[yogi]

Well - what can I say. I assure you selleri transforms exist independent of yogi and google. Below I will give you a link

http://redshift.vif.com/JournalFiles/V11NO1PDF/V11N1SEL.pdf.

 

[jdavel]

JesseM and yogi,

Sorry about not finishing this; I got side tracked. Let's try it once more.

This time, to avoid confusion about English terminology, let's START by just labeling events (E1, E2...) and giving their coordinates. Then make sure that all events that either of you think are relevant have been included Then make sure we agree that (according to the Lorentz transforms) the coordinates are correct. Only then do we discuss in English what the events correspond to and what their coordinates are telling us.

Terminology:

Two frames S and S' with S' moving at v relative to S
Y = gamma
c2 = c*c
The coordinates of an event En are xn, tn, xn', tn'

So (no earth, no stars, no clocks, no english at all; just some events and their coordinates!)

En...xn...tn...xn'...tn'


E1...0...0...0...0

E2...L...Lv/c2...L/Y...0

E3...L...L/v...0...(L/v)/Y


Are these all the events we need?

Are the coordinates all correct?

 

[JesseM]

JesseM and yogi,

Sorry about not finishing this; I got side tracked. Let's try it once more.

This time, to avoid confusion about English terminology, let's START by just labeling events (E1, E2...) and giving their coordinates. Then make sure that all events that either of you think are relevant have been included Then make sure we agree that (according to the Lorentz transforms) the coordinates are correct. Only then do we discuss in English what the events correspond to and what their coordinates are telling us.

Terminology:

Two frames S and S' with S' moving at v relative to S
Y = gamma
c2 = c*c
The coordinates of an event En are xn, tn, xn', tn'

So (no earth, no stars, no clocks, no english at all; just some events and their coordinates!)

En...xn...tn...xn'...tn'


E1...0...0...0...0

E2...L...Lv/c2...L/Y...0

E3...L...L/v...0...(L/v)/Y


Are these all the events we need?

If you don't discuss what these events mean in english, and what you want to find in english, then we can't really say whether these are all the events you "need." (what do you need them for?) But if we say as before that there are two clocks A1 and A2 at rest in S and synchronized in S, and another clock B moving at v relative to them (at rest in S'), and B first passes A1 (with both reading 0 at that moment) and then passes A2, then these three events will tell you how much time elapses on both B and A2 between the moment when B passes A1 and the moment when B passes A2, in the S' frame. If you want to know how much time elapses on both clocks between the times of these events in the S frame, then instead of E2 you need this event:

E2a...L...0...YL...-YLv/C^2

Since yogi now says he doesn't even agree with the Lorentz transform, I don't see him agreeing with the events you chose.