Does Ether Exist? 19th Century Evidence

[bjacoby]

We never do physics and accept something as valid based on quotes. Einstein also made many other "blunders" (would you also like quotes for those?). You need to supply valid peer-reviewed publications.

Zz.

You are spouting nonsense! Are you saying that to discuss what might be in a given scientist's mind is of no relevance? Are you saying that historical facts are of no relevance to understanding the thinking in a given historical period? Are you saying only peer-reviewed papers contain truth and all others are false? Sorry you are spouting nonsense of no significance to science or the discussion here.

Einstein's views on the aether and aether theory of the age ARE relevant to this discussion. No, they certainly don't "prove" that an aether does or does not exist. And I doubt very much that any "peer-reviewed" paper will do that either at this time. And I would hardly characterize Einstein's various opinions as "blunders". To do that one would have to be God and therefore know the "correct" theory for everything. The best we can say is that Einstein had some ideas that proved to not be accepted according to what we know at present.

So let's discuss Einstein's view of the Aether in 1920:

In a speech (May 5, 1920) at the University of Leiden Holland , he stated:

"There are weighty arguments to be adduced in favor of the aether hypothesis. To deny the aether is ultimately to assume that physical space has no physical qualities whatever. The fundamental facts of mechanics do not harmonize with this view...According to the General Theory of Relativity, space is endowed with physical qualities; in this sense, therefore, there exists an aether. According to the General Theory of Relativity space without aether is unthinkable."

Obviously, Einstein HAD considered the problem of "empty space having properties" and his view in 1920 pretty much agrees with mine today.

Thus if one would wish to define a "modern" aether, one would surmise that the aether is that which gives empty space it's properties! What that means exactly is a MUCH bigger problem!

 

[Dale]

So, DaleSpam, are you saying that empty space has no properties?

I certainly never said that. Empty space has geometrical properties (e.g. distance, curvature), not material properties (e.g. density, velocity).

But logically one must assert that in physics in any phenomenon where there are waves propagated there must be media for them to propagate in.

This is demonstrably wrong. The wave equation is
$$\left(\frac{\partial^2}{\partial x^2}+\frac{\partial^2}{\partial y^2}+\frac{\partial^2}{\partial z^2}-\frac{1}{c^2}\frac{\partial^2}{\partial t^2}\right)A=0$$
This logically requires time, space, speed, and A (e.g. in the case of an electromagnetic A is the electric field). Nothing else is logically required by the mere existence of a wave. Most familiar examples of waves do have a medium, but it is certainly not logically implied by the wave equation.

To deny that is to deny logic and create a religious dogma. Which is what it seems you are trying to do.

This type of comment seems to be the last refuge of all crackpots.

 

[ZapperZ]

You are spouting nonsense! Are you saying that to discuss what might be in a given scientist's mind is of no relevance? Are you saying that historical facts are of no relevance to understanding the thinking in a given historical period? Are you saying only peer-reviewed papers contain truth and all others are false? Sorry you are spouting nonsense of no significance to science or the discussion here.

It is relevant ONLY if that is the context! If this is a historical discussion on what Einstein was thinking at that time, then yes. If this is a question on the validity of the ether, then NO! Nothing in physics is validated or invalidated just because of some quote. Cite me an example to falsify that!

And if this is such a discussion about the historical context of the ether, then it belongs in a different forum than the physics subforums!

Zz.

 

[Phrak]

I only provided that particular 1920 address to illustrate that Einstein still had the 'ether' very much in his thought processes. I was just defending myself against Cepheid (post 47)

Actually, he didn't. The 'ether' is the so called luminiferous ether. Einstein was proposing an ether of his own. This was no more and no less than the properties of empty spacetime.

Perhaps he simply asked "what is waving?" An obvious question. The answer cannot be 'nothing' and still be physics. Should there be something in the properties of spacetime that would sustain something such as eletromagnetic waves? If this should not be natural behavior of empty spacetime, then what else should sustain it?

Maybe it's just Photons--stuff, superimposed upon spacetime. This is a very un-unified state of afairs. How is stuff unified with spacetime? Einstein talks about wood and marble.

 

[ervinn]

If we assume Ether exists the strange think is lot of unknown could be explained by the Ether.
If we knew what Ether is, we could explain Dark Matter. It is not really a matter out there it is the Ether property.

Also Ether could explain Quantum Theory. We would be not surprised that in the smaller scale things are different than in bugger scale. The same way we are not surprised that a stone reach the ground faster than a leaves, the air is there. In Quantum Physic we would say the Ether is there.

With Ether we could explain why the speed of light is as it is. As we can explain why the speed of sounds is as it is. In the speed of sounds depends on the molecular movement...
Why we can not know the reason why the speed of light is what it is?

With Ether we could explain and understand the Relativity Theory. One of the Ether property could be that when greater mass is present all activities slows down. The same why when an object travels in higher (close to the light) speed, all activities slows down with the light emissions as well.

With Ether we do not need time to exists. In that case time is not exists in the physical world. Time is only invented by our mind to measure duration physical activities.

Physical activities taken place, but Ether influences them somehow. Physical activity slower when close to high mass, and slower when an object travel fast inside the Ether.

To find out the properties of the Ether and understand them, may help to join the different theories out there and come up with a Standard Unified Theory.

 

[Neandethal00]

During the 19th century, it was proposed that light travels through vacuum in the presence of a pseudo medium known as ether. But does it really exist? Is there any evidence whether it exists or not?

The ether conceived in the 19th century probably does not exist. But empty space is most likely a medium. A medium that does not interact with anything we know of yet, not even light. This medium is more evasive than neutrino, which has a mass. Experiments using light to prove or disprove existence of this medium will always fail. Only things that interact with space medium are fields, electric/magnetic/gravitational fields. Inverse square laws are an indication.

 

[DaveC426913]

The ether conceived in the 19th century probably does not exist. But empty space is most likely a medium. A medium that does not interact with anything we know of yet, not even light. This medium is more evasive than neutrino, which has a mass. Experiments using light to prove or disprove existence of this medium will always fail. Only things that interact with space medium are fields, electric/magnetic/gravitational fields. Inverse square laws are an indication.

Unless you can provide citations for this, you are asserting it as a personal theory, which is forbidden.

 

[Dale]

If we assume Ether exists the strange think is lot of unknown could be explained by the Ether.

I disagree. I think that the aether has less explanatory power than Einstein's postulates. With Einstein's postulates time dilation of EM, weak, and strong interactions is explained, and it easily generalizes to gravity. With aether the time dilation of EM can be explained, but weak and strong interactions have to be added as ad hoc assumptions, and gravity is not an obvious generalization to me.