### From Evolution of Physics by Einstein

### III. FIELD, RELATIVITY – Ether and motion

*The situation grows more and more serious. Two assumptions have been tried. The first, that moving bodies carry ether along. The fact that the velocity of light does not depend on the motion of the source contradicts this assumption. The second, that there exists one distinguished c.s. and that moving bodies do not carry the ether but travel through an ever calm ether-sea. If this is so, then the Galilean relativity principle is not valid and the speed of light cannot be the same in every c.s. Again we are in contradiction with experiment.*

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I do not think that moving bodies carry ether along. When a disturbance moves through a medium it does not carry the medium along. According to the wave theory, light would be a disturbance in ether. Therefore, the motion of light would not carry ether along. Light has no mass, but it has some inertia that is proportional to its frequency. This inertia manifests as momentum. So light moves through ether at a great but finite speed.

Please note that we are viewing ether as a “field” with zero inertia. It does not have motion, or lack of motion, in some absolute sense.

According to the Disturbance hypothesis, matter is also a disturbance moving through ether. The inertia of a body, such as earth, manifests as mass because it is several orders of magnitude greater than the inertia of light. So a body is expected to move through ether at a speed several orders of magnitude slower than the speed of light.

Current estimates put the speed of earth to be about 10^{4} times slower than the speed of light, but it assumes the inertial basis for light to be the same as that for earth. When we use the inertial basis to be ether, the speed of earth is estimated to be 2^{50} or 10^{15} times slower than the speed of light. This is a very rough estimate but it is enough to show that the motion of earth relative to ether would be virtually undetectable. Experiments, even more accurate than Michelson-Morley experiment, shall be incapable of detecting earth’s motion relative to ether. It is then no surprise that the motion of source will have no effect on the velocity of light.

Einstein’s conclusion that moving bodies do not carry ether along is correct because even solid bodies move as disturbance in ether per the Disturbance Hypothesis. But to Einstein this meant that the Galilean relativity principle was not valid and the speed of light could not be the same in every coordinate system.

But this contradiction can explained by the Disturbance Hypothesis. Experimentally, the speed of light appears to be same in every cordinate system because any difference is virtually impossible to detect. Furthermore, Galilean relativity principle needs to be expanded to account for the differences in inertia per the disturbance levels.

#### The famous Michelson-Morley experiment is fully understandable, without contradiction, in the light of Disturbance Hypothesis.

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