Understanding Aether: What is it and What Does It Do?

[peter0302]

peter: look into the casimir effect or hawking radiation as evidence of virtual particles "popping".

Oh, yes indeed I am aware of these effects. What I don't understand is how they don't violate CoE. And more specifically, since a particle existing for a Planck Time in frame A exists for longer than a Planck Time in moving frame A', and we know that CoE cannot be violated in ANY frame or else the laws of physics would not be the same, how is this apparent paradox answered?

 

[matheinste]

Hello mitesh.

There is no paradox. There is a perfectly logical explanation within SR but some say that GR is required.

Matheinste.

 

[mitesh9]

Sure!
But my question is, How is twin paradox (may it not be paradox) different from muon situation? and if they are not different, why do we need to give explanation for the former, while accept the later as it is?

 

[Ken G]

As ehj says the muons age less and so decay later. This of course translates to "from our earthhbound point of view the muon's clock ticks more slowly than ours".

This is indeed a commonly used phrased, and I said above one cannot say that it is "wrong", because it all depends on certain coordinate choices. Nevertheless, I like to point out that this is not a necessary way to say it, nor even the best way in my opinion, for I prefer saying "the time between the events of creation and destruction of the muon, in our earthbound point of view with the Einstein convention, is longer than is that time in the muon frame". There is no need to specify a reason for this fact that has anything to do with what is happening to time, other than a result of the relative velocity between the frames, as any reason you cite will merely be exposing a choice of coordinate.

It is the same as if I asked you why light passing from one rocket to another might be redshifted-- there is no unique reason (in special relativity) other than "they are separating". In the above example, if we say one clock ticks more slowly as viewed from another, we are still exposing a prejudice that the time elapsing in our frame is in any way relevant to the time elapsing in some other frame. An important lesson of relativity is to relax that assumption, so why underscore it with our terminology, even if all we mean by "rate" terminology is dividing some other time by our own time? What is the meaning of such a ratio other than a comparison of two times, one being larger than the other?

 

[mitesh9]

By the way, In addition to my previous post, can anyone tell me what is the perfectly logical explanation for the (so called) "twin paradox" too? And what is the true (may not be logical, like SR), explanation for it?

 

[matheinste]

Hello Ken G.

""the time between the events of creation and destruction of the muon, in our earthbound point of view with the Einstein convention, is longer than is that time in the muon frame".

Apart from not explicitly stating that the Einstein convention process was used ( which i assumed was understood when using SR ) i can't see any meaningful difference in the statements of ehj, you and myself.

Perhaps i misunderstand the difference between a frame and a coordinate system and should not treat them as interchangeable although i did not mention coordinates explicitly.
Again i assumed that it was understood that the standard definition of an inertial frame applied to both Earth and muon frames.

Matheinste.

 

[Ken G]

By the way, In addition to my previous post, can anyone tell me what is the perfectly logical explanation for the (so called) "twin paradox" too? And what is the true (may not be logical, like SR), explanation for it?

I'd say the explanation is that elapsed proper time depends on the spacetime path taken between two events. The inertial path is defined by the path of greatest proper time. The presence of forces coaxes the system to choose some other path, that involves a proper acceleration (that could be measured with an accelerometer). But why it even has the option to choose paths of smaller elapsed proper time is beyond me, I have no idea why that is, or even a good way to talk about it. Mathematicians speak of the Poincare group, but I'm afraid at the moment that adds little to my physical insight.

 

[Ken G]

Apart from not explicitly stating that the Einstein convention process was used ( which i assumed was understood when using SR ) i can't see any meaningful difference in the statements of ehj, you and myself.

It depends on what one means by "meaningful". To be sure, they are just different choices of words to describe calculations that are not going to get a different answer for some observable. But that does not necessarily imply there is no meaningful difference (is there a meaningful difference between the many-worlds and Copenhagen interpretations of quantum mechanics?). There is meaning in a good way of picturing something.

I'm wondering which picture is most true to the core lesson of relativity, which is that a different spacetime path will involve a different elapsed proper time, and the only way to conclude that this time is "slower" is to imply a rate, which is to divide by the other time, and why are we doing that if the other time really isn't relevant in any way? The system didn't take that other path, so what is the relevance of the time you would infer by taking a path the system did not take, and then applying your own simultaneity convention (also not relevant to the system in question)? It seems we are unnecessarily elevating the importance of our own reference frame, rather than the frame of the system in question, so it doesn't sound like the most "objective" stance.

Perhaps i misunderstand the difference between a frame and a coordinate system and should not treat them as interchangeable although i did not mention coordinates explicitly
Again i assumed that it was understood that the standard definition of an inertial frame applied to both Earth and muon frames.

The standard definition of an inertial frame is part of my beef here. I think it's fine that an observer has a clock to reference, and can recognize when he and other observers are not accelerating, but what business does he have extrapolating the concept of what his clock is saying to other places just because he can send light there? The latter is what sounds like pure coordinatization to me. The invariant physics is that I can take my time elapsed and my concept of distance and compute the time elapsed for someone else, and it might be less than mine, without anything having to "run slower".

But above all, I'm not objecting to the latter way of picturing it, as it is an interpretation and is a matter of personal preference. I am more objecting to the way interpretations such as that get taught-- which is that they are part of the reality. If relativity, above all physics, does not teach us to avoid that trap, what does?