How did special relativity replace the aether theory?

Question

I was reading up on it last night, but I dont understand how they are even the same comcept for one to replace the other. Can somebody explain it to me in detail. Thanks in advance. Im just really wondering how Nikola Tesla and Albert Einstein shared similarities in their theories and differences in explaining the cosmos.

Answer 1

It was argued in analogy with ocean waves that if light is a wave, then there must be a ponderable medium by which the wave travels. Hence the notion of the aether.

That the aether is not dragged along by the planet in its motion is proved by the existence of abberation of light coming from the stars which checks within the limits of observational accuracy, the kinematic results of compounding the velocity of light in a vacuum with the velocity of the earth in its orbit. This means that there is an apparent aether wind which blows opposite the direction of the motion of the earth. There was therefore one thing to do, To prove that there is an aether wind.

The interferometer used in the Mickelson - Morley experiment was capable of resolving to an accuracy of 0.002 fringe shift. The predicted fringe shift was about 0. 2. The result was nul.

In view of the nul result of the Mickelson - Morley experiment, Fitzgrald proposed a hypothesis that the linear dimension of a moving body contracts in the order of

l' = l( 1- v^2/C^2) ^(1/2). By  separate approach Lorentz, who was the professor of Einstein, arrived at the famous Lorentz transform m' = mo(1- v^2/c^2)^(-1/2). But Lorentz did not accept the implications of his work and dismissed it as just a mathematical curousity, but not without a valid reason. The equation will yield an infinite value of mass when v = c.

It took sometime until Einstein came up with a new idea. This new theory was based on the postulate that the velocity of light is constant. Thus he arrived at the special theory of relativity. But he adopted the Lorentz transform as the equation of the change in mass due to the change in velocity which resulted in the equation E = m'c^2.

Eintein's relativity does not in any way disproves the validity of Classical Newtonian Physics. It must be remembered that Newtonian Physics is capable almost without any exception  of accounting the motion of all planetary bodies. Its one outstanding anomaly is its failure to account for the advance in the perihelion of the planet mercury where the result of the equation does not agree with that obtained by actual observation. Neither could Einstein's relativity account for this as the equation of the advance in perihelion obtained using relativistic approach is also identical with that obtained by clasical physics approach. The idea of the aether was therefore replaced in relativistic theory by the idea of the curving of the fabric of space and time. But Einstein's relativity can not explain the behavior of light without getting out from the implications of the Lorentz transform.

Quantum mechanics can account for this in the equation

E = h/c where h is Plancks constant. The ambiguity of the notion of an increasing mass simply is not existent in Quantum Mechanics. But for Quantum Mechanics to explain the phenomenon of quantum tunneling, it needs to adopt the notion of an aether although this aether is not necessarily the same as  the pre- Mickelson- Morley aether. Her however Physics had a complete turn around.

Answer 2

The aether theory arose because science believed that some medium must exist for light to propagate through, at that time they believed that light travelled in the form of a wave. They concluded that the aether was a frictionless solid that permeated space. In an effort to find absolute motion the famous Michelson Morley experiment was carried out, the designed a very sensitive instrument called an interferometer, it was so sensitive it could detect the growth of leaf from second to second. The experiment could detect no difference in the speed of light regardless of any reference frame. Einstein realized that the results of this experiment could be used to show that time dilated at light speeds.