Lorentz Ether Theory

[DryLab]

So you're suggesting that pre-Einstein Lorentz relativity can't handle:

[math]

m^2=E^2-p^2

[/math]

I think Henri Poincare was using that around 1900 to show the momentum of packets of light. I'm a little slow I guess. I can't see the connection.

[Qfwfq]

Why didn't Henri Poincarè beat both Einstein and Minkowski to it, then? Any way in the case of light the equation becomes [imath]E^2=p^2[/imath].

[Erasmus00]

Thanks for the link it was a good read. I understand relativity phenomena and can get my brain around most of it.

 

But then you must see that special relativity requires no distortion of spacetime.

 

Back to the original quest, is there any known relativity phenomena that could not be the result of the way mass is put together.

 

I think you missed my point- Lorentz ether theory overlaps with special relativity. However, Lorentz theory is simply not able to extend to general relativity, and hence special relativity is preferable.

 

Also, Lorentz theory is just a collection of facts (length contraction, time dilation, etc), but Einstein's theory gives you powerful new principles with which to create new theories. QED, QCD, etc are all based on Einstein's powerful principles. For instance, how can one combine quantum mechanics with Lorentz ether?

 

For example, all the binding forces move at the invarient speed of light.

 

You can't establish that the speed of light is invariant without special relativity! This is circular. Saying the invariant speed of light is the cause of length contraction, etc, is the same thing as saying "special relativity is the cause of..." Its the same explanation.

-Will

[DryLab]

Any way in the case of light the equation becomes [math]E^2=p^2[/math].

Agreed; no problem. Also if you choose the right units m = v, or mass = frequency.

[Farsight]

Erasmus: In the original GR translation I read, Einstein never actually mentioned curved spacetime, and from other things I've also read, he didn't seem to think quite the same as people do now. Plus, his ideas evolved over the years. Here's a few interesting quotes:

 

..In his response to Godel's paper in the Schilpp volume, Einstein acknowledged that "the problem here disturbed me at the time of the building up of the general theory of relativity." This problem he described as follows: "Is what remains of temporal connection between world-points in the theory of relativity an asymmetrical relation (like time, intuitively understood, and unlike space), or would one be just as much justified to assert A is before B as to assert that A is after B? The issue could also be put this way: is relativistic space-time in essence a space or a time."

 

..according to the general theory of relativity, space is endowed with physical qualities; in this sense, therefore, there exists an ether. According to the general theory of relativity space without ether is unthinkable; for in such space there not only would be no propagation of light, but also no possibility of existence for standards of space and time (measuring-rods and clocks), nor therefore any space-time intervals in the physical sense. But this ether may not be thought of as endowed with the quality characteristic of ponderable inedia, as consisting of parts which may be tracked through time. The idea of motion may not be applied to it..

 

..In the second place our result shows that, according to the general theory of relativity, the law of the constancy of the velocity of light in vacuo, which constitutes one of the two fundamental assumptions in the special theory of relativity and to which we have already frequently referred, cannot claim any unlimited validity. A curvature of rays of light can only take place when the velocity of propagation of light varies with position. Now we might think that as a consequence of this, the special theory of relativity and with it the whole theory of relativity would be laid in the dust. But in reality this is not the case. We can only conclude that the special theory of relativity cannot claim an unlimited domain of validity; its results hold only so long as we are able to disregard the influences of gravitational fields on the phenomena..

 

We know he was somewhat sidelined in later years with his dream of "pure marble geometry" and grand unification. To get there, I think he was giving up on the invariant speed of light for the sake of time dilation. You end up with something of a horror movie: Aether II, the sequel. It all feels a little "Lorentzian", if you know what I mean. What I'm fairly sure about, is that things aren't quite so black and white.

[DryLab]

But then you must see that special relativity requires no distortion of spacetime.

Yes; I can see that. I'm quite at ease in thinking length contraction and time dilation are experienced by moving objects.

special relativity is preferable.

Ok; no problem.

For instance, how can one combine quantum mechanics with Lorentz ether?

I'll take your word that it can't be done. I can't do it :eek2:

You can't establish that the speed of light is invariant without special relativity!

We can measure it and know it without SR it seems to me. We knew the speed of light before SR. We knew it was invarient before SR.

[Erasmus00]

We can measure it and know it without SR it seems to me. We knew the speed of light before SR. We knew it was invarient before SR.

 

Actually, no. Lorentz ether theory was built around the idea that the speed of light is NOT invariant, and he put together adhoc explanations for why MEASUREMENTS of the speed of light don't vary. The speed of light is different in various reference frames, but we cannot measure it, according to the ether theory.

-Will

[DryLab]

Actually, no. Lorentz ether theory was built around the idea that the speed of light is NOT invariant,

I think we're saying the same thing. With Lorentz the speed of light is invarient relative to a special frame at rest in space. In a moving frame, matter experiences length contraction and time dilation so that speed-of-light measurements are still invarient.

[Qfwfq]

In the original GR translation I read, Einstein never actually mentioned curved spacetime

Perhaps he mentioned it in a way that you didn't recognize.

[Farsight]

No, check for yourself. This interpretation of "curved spacetime" is something that's grown up over the years, and is not in accord with what Einstein actually said.

 

http://www.alberteinstein.info/gallery/pdf/CP6Doc30_English_pp146-200.pdf

 

What's interesting is that when you ask yourself "What is curved spacetime?", you realise that you don't actually know. Also see Pete Brown's interesting paper:

 

http://xxx.lanl.gov/ftp/physics/papers/0204/0204044.pdf.

[Qfwfq]

Popular I've already seen those and I don't have to check for myself. In the first pages of Die Grundlagen Einstein shows that, in order to generalize the principle of relativity, we cannot consider the spacetime continuum to be flat (Euclidean) and he proceeds to a very summary introduction of differential geometry including the Riemann tensor. To describe the non-uniform field, intrinsic curvature is necessary.

 

If you read a paper by an eminent botanist and it talks about malus rosaceae, would you keep on insisting it has nothing to do with apples?

[Farsight]

Qfwfq: you mean this?

 

http://www.physik.fu-berlin.de/~kleinert/files/1916_49_769-822.pdf

 

Did you read the original, or a translation? If the latter, you wouldn't have a link to it would you? In the paper I referred to there was plenty of tensors, gradients, and curvature, but not one mention of curved spacetime. I was surprised.

[Erasmus00]

Did you read the original, or a translation? If the latter, you wouldn't have a link to it would you? In the paper I referred to there was plenty of tensors, gradients, and curvature, but not one mention of curved spacetime. I was surprised.

 

 

So they mention CURVATURE but don't use the phrase "curved space-time." What do you think curvature is in reference to?

-Will

[Qfwfq]

Qfwfq: you mean this?

 

http://www.physik.fu-berlin.de/~kleinert/files/1916_49_769-822.pdf

 

Did you read the original, or a translation? If the latter, you wouldn't have a link to it would you?

This one is the original, the one you've linked to in the past is an English translation. Therefore one may have a link to either. :hihi:

 

In the paper I referred to there was plenty of tensors, gradients, and curvature, but not one mention of curved spacetime. I was surprised.

Would you like a cup of camelia sinensis? You might prefer it blended with camelia assamica....

 

Right on, Will. :hihi:

[Farsight]

So they mention CURVATURE but don't use the phrase "curved space-time." What do you think curvature is in reference to?

-Will

 

A mathematical "space" describing measurements of motion. I used to think of this like everybody else does, and like you do, until I read up on what Einstein was doing from 1949.

[Erasmus00]

A mathematical "space" describing measurements of motion. I used to think of this like everybody else does, and like you do, until I read up on what Einstein was doing from 1949.

 

This "mathematical space" is what we refer to as space-time!

-Will

[Farsight]

The difference is subtle, yet moot. You end up with this:

 

Actually, no. Lorentz ether theory was built around the idea that the speed of light is NOT invariant, and he put together adhoc explanations for why MEASUREMENTS of the speed of light don't vary. The speed of light is different in various reference frames, but we cannot measure it, according to the ether theory.

 

That's where Einstein was going. You might not believe me, but I assure you I am sincere about this. Here's a quote from the man himself:

 

"In the second place our result shows that, according to the general theory of relativity, the law of the constancy of the velocity of light in vacuo, which constitutes one of the two fundamental assumptions in the special theory of relativity and to which we have already frequently referred, cannot claim any unlimited validity. A curvature of rays of light can only take place when the velocity of propagation of light varies with position. Now we might think that as a consequence of this, the special theory of relativity and with it the whole theory of relativity would be laid in the dust. But in reality this is not the case. We can only conclude that the special theory of relativity cannot claim an unlimited domain of validity; its results hold only so long as we are able to disregard the influences of gravitational fields on the phenomena (eg of light)".

 

We can talk about interpretation, and what this means, just like we can talk about "curved spacetime". But I've read other stuff too. I know what he was saying above. He wasn’t talking about velocity as a vector quantity. He didn’t mean the curvature of light was there because the light changed direction. He meant that the curvature was there because the speed changes. He meant c varies. He was talking about what you would call an aether theory. Here's another quote from Einstein:

 

"According to the general theory of relativity, space is endowed with physical qualities; in this sense, therefore, there exists an ether. According to the general theory of relativity space without ether is unthinkable; for in such space there not only would be no propagation of light, but also no possibility of existence for standards of space and time (measuring-rods and clocks), nor therefore any space-time intervals in the physical sense. But this ether may not be thought of as endowed with the quality characteristic of ponderable inedia, as consisting of parts which may be tracked through time. The idea of motion may not be applied to it".

 

This aether is not the old aether that "flows", or blows like some wind. This is something different. It's space. Note that it's space, not spacetime. Because, as Einstein always said, time is suspect.

 

Dryad, are you there? How does this respond to your OP? Sorry if it looks like I'm drifting off the point here.