Why is Special Relativity preferred over Lorentz Ether Theory?

Question

Special Relativity and Lorentz Ether Theory make the same predictions, so they cannot be experimentally differentiated. (Are Lorentz aether theory and special relativity fully equivalent?). As such, distinctions between them are conceptual. From what I understand, the key distinction between the two theories are how they assume light moves. In Special Relativity, it is assumed that the two-way speed of light is constant for all observers. In Lorentz Ether Theory, it is assumed that the speed of light moves at a constant speed through some universal ether frame. Most of the arguments I've seen against Lorentz Ether Theory are that it is more conceptually complicated because of the inclusion of this universal ether frame, but from this Lorentz Ether Theory doesn't need the constant two-way speed of light assumption. Neither theory seems to make fewer assumptions than the other. Lorentz Ether Theory also gives (in my opinion) much more satisfying explanations of the mechanics behind time dilation and length contraction.

Given the similarity of the two theories, why is Special Relativity preferred? Also, as far as I know Lorentz Ether Theory has not be analogously extended to something like General Relativity or applied to Quantum Field Theory. Are there fundamental issues with doing this, or has this not been attempted?

Answer 1

About the question of choosing between special relativity and Lorentz Ether theory.

Historically there have been cases with a parallel to that question.

I will first describe one such parallel case, and then I will return to special relavitity.

By the 1930's there was sufficient data from cloud chamber observations that there was something odd with beta decay. With all other forms of decay there was corroboration of conservation of energy, but with beta decay this was not the case.

Historians of science describe that Niels Bohr proposed to relinquish the principle of conservation of energy.

Another proposal was a theory of beta decay in which the missing energy is carried off by an a particle that is invisible to any detection.

In cloud chambers it is charged particles that trigger condensation. By the 1930's time the existence of the neutron was known. By itself a neutron does not trigger condensation in a cloud chamber, but sooner or later the neutron collides with something, in that collision event multiple particles are created, and from the trails of those particles the transient presense of a neutron can be inferred. Even if the probablity of a neutron interaction is low, as long as that probability is non-zero a sufficiently large experiment will eventually generate enough events to get to statistically significant numbers.

So OK, let's say we propose a small neutral particle, and we attribute to it a probability of interacting with other matter far smaller than neutrons.

As the experiments were refined no candidates for the 'little neutral particle' were encountered; the existence of the 'little neutral particle' seemed ever less plausible.

To propose a particle that is created in a decay event and subsequently never ever interacts with any other matter, that seems silly.

On a philosophic level: to propose the existence of a particle that is inherently undetectable: well, if you do that you lose more than you gain. Such a theory isn't ever going to increase your understanding of the physical world.

Now, in the case of the neutrino: eventually the existence of neutrino's was confirmed in the 1950'; the Cowan-Reines neutrino experiment. Neutrino's have an exceedingly low probability of interaction with other particles.

My point is: as long as the purported neutrino particle remained undetected the case against the neutrino particle was strong.

Returning to special relativity:

Lorentz Ether theory requires simultaneous supposition of the following: the existence of a Lorentz Ether, and the existence of a set of physical properties such that the Lorentz Ether is undetectable.

I submit:
To propose a theory with an entity (Lorentz Ether) that is inherently undetectable, such a theory isn't ever going to increase your knowledge of the physical world.

For me that is the reason for preferring the special relativity interpretation over the Lorentz Ether interpretation.

Answer 2

The current dominant interpretation of special relativity isn't actually Einstein's original formulation, but rather Minkowski's geometrical formulation in terms of spacetime. This has a number of conceptual advantages over Lorentz ether theory. As you point out yourself, the geometric interpretation extends naturally to gravity (general relativity) and to quantum field theory. The geometric explanation of time dilation and length contraction is simple, applies to all interactions (not just ones based on electromagnetism), and also explains gravitational time dilation. It also doesn't require hypothesizing an unobservable ether.

The vast majority of working physicists are quite content with the geometric interpretation, and the success of its extension to general relativity means there's very little incentive to pursue an ether based theory of gravity or of QFT.

Answer 3

Lorentz Ether Theory also gives (in my opinion) much more satisfying explanations of the mechanics behind time dilation and length contraction.

I agree. For example, lets say using LET theory, that A is rest with the Ether and B is moving relative to the Ether. B length contracts due to his motion relative to the Ether. B really physically contracts. because of B's motion relative to the Ether his rulers length contract and his clocks run slower and by his measurements, A appears to be length contracted. In SR it the motion relative to A that 'causes' the length contraction of B and if there is a third observer C moving relative to both A and B, then the length contraction of B from C's point of view is caused by B's motion relative to C. If C is not a huge gravitational body, then the motion of B relative to C should have no physical effect on B, so the fact that B length contracts by a factor that is function of B's velocity relative to C is just a mathematical outcome, not a physical effect. In SR there is no common cause for the length contraction and it appears to be an phantom property - just an appearance. I am convinced this is why many people even here on this forum are confused by the Ehrenfest paradox, Bell's rocket paradox and the twins' paradox, because they cannot accept the physical reality of length contraction and time dilation.

Let's examine the twins' paradox. Lets say The earth is stationary and twin B flies away and returns later. Since B has been moving relative to the Ether and A has not there is no no question that B should have aged the least. Let's reverse the situation. If the Earth is initially moving relative to the Ether, and B is at rest relative to the Ether, then the twin on Earth is initially aging slower. In order for B to return to the Earth, B has to return to Earth faster than A was initially moving away from B. B has on average the highest velocity relative to the Ether and B obviously ages the least. There is no question of anyone getting confused and saying the situation is symmetrical and the twins should age the same amount.

let's analyse Bell's rocket paradox using LET. Let's say the rockets are initially at rest with the Ether. if there is a string connecting the rockets and they accelerate in such a way that the distance between them remains constant relative to an observer at rest in the initial reference frame, then the connecting string connecting the two rockets must be length contracting because it is moving relative to the ether and since the rockets maintain a constant separation, the string must be getting stretched and eventually break. If LET had been the accepted interpretation, Bell's rocket paradox would not exist. When Bell announced the connecting string must break it would not have been controversial. Everyone would have just said "of course it does!" Where's the paradox?" That is exactly what LET predicts! If LET had been accepted, there probably would have been no confusion and no relativistic paradoxes. Relativity would have been much easier to understand, but perhaps that is boring. We would not have thousands of book, blogs and videos about the mysteries of relativity and perhaps that is why the SR interpretation is better because it creates a whole industry, based on confusion. The case against LET is that the Ether is undetectable. It is only logically there. The same could be said for Dark matter. Scientists argue it is logically there, but they have ever been able to determine what is made of or directly detect it. When we talk about the expanding universe and people ask what is expanding, the answer is 'space' which is made of nothing. In the LET interpretation we could argue that it is the Ether that is expanding. Objects far away from us are moving at appar3ently relativistic speeds, but they do not experience time dilation due to their relative motion to us, because they are at rest with the local Ether. Superluminal recession velocities are not a problem because its not the galaxies that are receding superluminally, but the ether. In "The river model of black holes" by Andrew J. S. Hamilton and Jason P. Lisle published in the American Journal of Physics) and "the river model of space" by S. Braeck, O. Gron, spacetime is described as flowing into the the black hole with a velocity of c at the event horizon and a velocity greater than c below the event horizon. If we ask what exactly is flowing, the Ether is an obvious candidate.