Max Born's Reflections on the Non-Existent Ether

[khil_phys]

Max Born, in his book "Einstein's Theory of Relativity", keeps referring to the luminiferous ether repeatedly, as if it were real. The book was published in 1920, it had been definitively proved by 1890 that no such thing as the ether existed. Can anyone tell why does Born keep going on with it?

 

[Passionflower]

Old habits die hard.

 

[ghwellsjr]

Max Born, in his book "Einstein's Theory of Relativity", keeps referring to the luminiferous ether repeatedly, as if it were real. The book was published in 1920, it had been definitively proved by 1890 that no such thing as the ether existed. Can anyone tell why does Born keep going on with it?

If Special Relativity comports with reality, and since the second postulate states that any frame of reference you choose will have all the characteristics of an absolute ether rest state, then Special Relativity cannot be incompatible with Lorentz Ether Theory which merely states that such an absolute ether rest state exists. Both theories share the same first postulate which is the principle of relativity.

Maybe Max Born recognizes this fact and uses it to transition from the ideas of LET to the ideas of SR as a teaching aid. Do you find his development sensible?

 

[Bill_K]

khil_phys, Born's book is online at archive.org, and from what I can see his reference to the ether is historical and dismissive. For example on p.161 he says, "Even nowadays there are some people who regard the mechanical explanation of the electromagnetic ether as a postulate of reason. Such theories still continue to crop up, and, naturally, they become more and more abstruse since the abundance of the facts to be explained grows, and hence the difficulty of the task increases without cessation."

 

[khil_phys]

khil_phys, Born's book is online at archive.org, and from what I can see his reference to the ether is historical and dismissive. For example on p.161 he says, "Even nowadays there are some people who regard the mechanical explanation of the electromagnetic ether as a postulate of reason. Such theories still continue to crop up, and, naturally, they become more and more abstruse since the abundance of the facts to be explained grows, and hence the difficulty of the task increases without cessation."

If Special Relativity comports with reality, and since the second postulate states that any frame of reference you choose will have all the characteristics of an absolute ether rest state, then Special Relativity cannot be incompatible with Lorentz Ether Theory which merely states that such an absolute ether rest state exists. Both theories share the same first postulate which is the principle of relativity.

Maybe Max Born recognizes this fact and uses it to transition from the ideas of LET to the ideas of SR as a teaching aid. Do you find his development sensible?

I get what you mean. And considering the time when this book was written, it is completely sensible.

But still, Born assumes the existence of the ether as real, as is implicitly stated in these words on pg. 106 - "The Doppler effect does not only depend on the relative
motion of the source of light and of the observer, but also to a slight extent on the motions of both with respect to the ether. But this influence is so small that it escapes observation; moreover, in the case of a common translation of the source of light and of the observer it is
rigorously equal to zero.

 

[Bill_K]

Born assumes the existence of the ether, analyzes the possibility in great detail, and finally dismisses it on p 191. This book is a really good historical survey of the theories that were advanced as alternatives to Einstein's relativity, and the experiments that resolved the issue.

 

[khil_phys]

I agree with you.

Also, please explain this statement - But this influence is so small that it escapes observation; moreover, in the case of a common translation of the source of light and of the observer it is rigorously equal to zero.