# Einstein said: NO Absolute Rest

1. Nov 14, 2005

### Macro

This to me means that everything is moving *through space*
in some form or another.

If we can calculate a slowest object it would be like finding a
fastest time. Einstein dared not say it.

If moving through space is what slows time then time can be both absolute and relative. The Fastest time is absolute and moving though space slows it down in a relative.

Relatives owe there existence to the absolutes.

Hope you like this! :tongue:

2. Nov 14, 2005

### Janus

Staff Emeritus
What Einstein meant was that there is no prefered frame by which to judge absolute rest, or absolute motion. Your notion of a "slowest object" violates that as it requires such a prefered frame to which that motion is judged. What you think it means is wrong.

3. Nov 14, 2005

### pervect

Staff Emeritus
It's very hard to follow your line of thought, parts of which are backwards anyway.

Between any two specific events (points in space-time), there is always a timelike path connecting them which has the longest proper time.

This path will always be a geodesic.

There is no path of shortest proper time, by traveling a circuitous route at very high velocities, one can make the proper time as short as desired. It is the direct path, moving as slowly as possible, which maximizes proper time.

In special relativity only, the length of this path (the path of longest time) is a geometric invariant, the Lorentz interval between the two events. The Lorentz interval is invariant in SR, which means it is the same for all observers.

4. Nov 15, 2005

### Macro

You think I am wrong?
Then prove that everything is not moving through space in some way Janus!!! :!!)

Last edited: Nov 15, 2005
5. Nov 15, 2005

### SpaceTiger

Staff Emeritus
This issue was already discussed https://www.physicsforums.com/showthread.php?t=98068". It's basically an extension on what Janus said.

Last edited by a moderator: Apr 21, 2017
6. Nov 15, 2005

### JesseM

Can you think of any experiment that would determine which of two objects is moving more quickly "through space"? If not, then your ideas are philosophy, not science. From a philosophical point of view, I suppose it's possible that there is such a thing as absolute rest and absolute motion but they have no physical consequences whatsoever.

7. Nov 15, 2005

### Janus

Staff Emeritus
The burden of proof is not on me.
But,
It's evidenced everyday in high energy particle labs around the world.

8. Nov 15, 2005

### aaroman

Probably this is the truth:
But for another meaning of the word 'rest': there is an incertitude principle that tells that no matter how hard you look at things, you won't find one with a momentum exactly zero, hence all objects do move. I believe that even if you could freeze an object to absolute zero, there still will be quantum fluctuations, so no object is staying still.

9. Nov 15, 2005

### Staff: Mentor

No need to prove it - I'll just define it that way! You can find your "slowest object" and then I'll simply define a coordinate system that shows that object at rest. Simple!

10. Nov 15, 2005

### pervect

Staff Emeritus
Note that in SR only, the object that russ_watters has just specified, the one that is apparently at rest, will be the object that follows a "timelike geodesic" that connects two points in space-time with the longest proper time.

Imagine a clock on the object that russ_watters has just specified, which we will call the "stationary twin". Imagine another clock that accelerates, leaves the "stationary twin", turns around, and comes back, which we will call the "accelerating twin".

In SR only, the stationary twin will always have the longest elapsed time on his clock, his clock will always read longer than the clock of the accelerating twin.

11. Nov 15, 2005

### Jonny_trigonometry

wouldn't the fastest time in the universe be the place where gravitational energy is the least?

12. Nov 15, 2005

### Macro

The one that is moving more rapidly through space will have a slower clock!!! :!!)

13. Nov 15, 2005

### Macro

Yes. This is my point jonny.

14. Nov 15, 2005

### JesseM

That won't work if the two clocks are moving apart at constant velocity, because different frames will disagree about which one is ticking slower. The only "objective", frame-independent way to compare them is to have one turn around so they can meet up again at a single location, but in that case you will simply find that whichever one you turned around is the one that elapsed less time. So how do I know which clock was ticking slower before either of them turned around?

Say I have two clocks A and A' on earth, and two clocks B and B' flying away from the earth on twin rockets moving alongide each other at constant velocity. After the two sets of clocks have been moving apart for a while, I put A' on a rocket which accelerates in the direction of the B clock, and meanwhile the rocket that B' is riding accelerates in the direction of earth. After some time, B' reunites with A on earth, and we see that B' has elapsed less time since they departed. Also after some time, A' catches up with B in space, and we see that A' has elapsed less time since they departed. So in this case, before either A' or B' accelerated, which set of clocks do you think was ticking slower, A and A' sitting next to each other on earth or B and B' sitting next to each other in twin rockets in space?

(by the way, why do you always put the smiley-with-hearts-in-its-eyes after your comments? Are you in love?)

15. Nov 16, 2005

### pmb_phy

This means that there is no preferred inertial frame of reference so that no inertial observer could detect his state of motion. Only motion relative to something has any meaning. It means nothing more and nothing less that that.

Pete

16. Nov 16, 2005

### Macro

It is simple. There is a doppler effect in moving away. And there is a transverse doppler effect that doesn't depend on direction. Only one is a real clock slowdown the other is only an appearence. The other aint Jesse.

Try Again Jesse! :!!)

17. Nov 16, 2005

### JesseM

No, you are misunderstanding the "transverse doppler effect", which certainly does depend on direction--see the explanation http://www.kineticbooks.com/physics/trialpse/41_Special%20Relativity/21/sp.html [Broken], and note that the equation they give depends on both the velocity and the angle of the object's path relative to the direction of the signal. If two observers are moving apart, at constant velocity, their view of each other will always be completely symmetrical, including how each one sees the other's clocks slowed down or sped up. Would you like me to calculate a numerical example to demonstrate this?

Last edited by a moderator: May 2, 2017
18. Nov 16, 2005

### JesseM

I understand the consequences of relativity just fine, and the "transverse doppler effect" is part of relativity, unless you're talking about a new version of the transverse doppler effect that works differently than the one in relativity. If you're not just here to troll, please answer my question yes or no--do you deny that the relativistic version of the transverse doppler effect means that two observers moving at constant velocity relative to each other will have a completely symmetrical view of how each other's clocks slow down/speed up?

19. Nov 19, 2005

### Jonny_trigonometry

Macro,
The transverse doppler effect is dependant on direction. Suppose I fly circles around you at relavitistic speeds so as to stay a constant distace from you (you're at the center of the circle). You would see a red shift of the light from my space ship due to time dilation. There is no doppler effect caused by moving toward or away from you in this situation.

http://en.wikipedia.org/wiki/Transverse_Doppler_effect

Last edited: Nov 19, 2005
20. Nov 20, 2005

### Son Goku

That doesn't necessarily make it the place with the fastest time, or make it's time the absolute a priori measurement of time, which is then altered by the presence of mass.

Let us take the point in the universe which has the least gravitational energy to be a point which has no gravitational energy.
With no gravitation, it is basically flat space or Minkowski space.
So it is purely special relativistic and in a special relativistic environment time is not absolute but relative between observers.

By getting rid of gravity all you've done is allowed us to just discuss special relativity.