Do all waves apply to special relativity?

Question

I know that when light is sent out of a moving object, its speed still remains the same as if it was sent out of a stationary object. Keep in mind that there is red-shift and blue-shift in light waves though. Now, my question is: Do other waves follow the same principle as light waves? If I hit a metal pole with a hammer, would the sound waves traveling through it move faster if the pole was on a moving object versus the pole just sitting still in a stationary position? Or would the speed of sound remain the same, and instead the doppler effect would occur. Also note to yourself that the speed of light changes through mediums (it slows), and the speed of sound can change through mediums as well.

I can't test my question since I'm only 17, but It would be nice for someone to tell me so I can get it off of my mind.
I also wonder, if special relativity doesn't apply to other waves, then how do we know it does to light? Would we notice a change in 30 mph added to lights speed already?

Answer 1

When something moves at constant speed ist usually a wave.This is inertial motion as opposed to gravitational motion, where the speed changes with changing distance and time.

Special Relativity does not apply to gravitational motion at all.
So the Only thing it could apply to is wave motion since it moves at constant velocity..The reason is that a wavelenght can be shorten and time of period dilated. The speed of the wave is medium dependent .And a wave is a disturbance in the medium. If light moves as foloowing the rules of a wave and it moves at constant velocity than special relativity would applly to the motion of light.
A wave by definition cannot exist without a medium . If a medium does not exist then the wave doesnot exist.
So if it is believed that a wave propagation can take place without a medium it would go against the definiton of what constitutes a wave.
The responce to the disturbance in the medium is based on the density of the medium. If Space is a medium for a wave and the density is not homogenous,then the speed of the wave is not the same thruout the medium.
In real life motion takes place in a gravity field no matter what the density of the field. So all motion are basically gravitational.However if the density of the gravity field is weak ,that we can aproximate the motion as being inertial.

Answer 2

special relativity applies to all inertial frames. The first postulate is the main fundamental. the second postulate is in fact derived from the first postulate itself. the first postulate says that you can not conduct any experiment which can tell u whether u r moving with constant velocity, or are at rest.
hence relativity applies to all things in the universe, not only light. However the rest of the things move very slowly, compared to c, hence the effects of relativity are not noticeable. If a sound wave is moving with a speed of, say 20m/s, an obvserver moving with 10m/s in the opp direction will see it move with 30m/s. Actually, the speed observed is slightly less than 30, but the difference just cant be measured.

Answer 3

SR is based on the observation that in vacuum the speed of light is the same regarless of the movement of the observer. SR applies to inertial frames (ie ones that are not acclerating) but by extension the principle of the constancy of the speed of light must apply to non-inertial frames (can you see why this is obvious? - imagine creating momentarily comoving frames to describe a non-inertial frame instantaneously).

In fact, this speed constancy applies not only to light but to all zero rest mass particles. In particular it applies to all gauge bosons - these are the particles that mediate all of the forces of nature.

Sound does not fall into this category. Sound is a propagating distortion of a medium, and the distortion is actually mediated by the electrostatic force between atoms, and that is mediated of course by photons and they do indeed move at the speed of light. But the distortion (sounds) does not - it moves at a speed determined by the response time of the atoms.