[Physics] Constant light speed

[Ilja Schmelzer]

2017-06-12 22:05 GMT+02:00, Tufail Abbas <tufail.abbas at gmail.com>:
>>Note that above solutions are clearly physically different. The source
>> is, in the first solution, at rest, while it moves in the second solution.
>> And if the first solution has spherical symmetry. The second solution does
>> no longer have such a symmetry
>
> Is the stare of rest associated with spherical symmetry,  and is state of
> motion associated with deformation of spherical symmetry . May be still the
> equations remains under coordinate transformation,  as possibly  body in
> motion is still symmetric on a larger scale ( say universal scale) , though
> locally they have some assyemtry over the local sphere.

A solution with the source of sound in rest relative to the medium has
spherical symmetry, the one where the source moves relative to the
medium does not have it. Once there is no symmetry locally, none will
appear on the larger scale too.  This is not the type of asymmetry
which goes away in the large distance limit.

I will not comment your ring electron model.

>>For other wave equations, like sound waves or water waves, the name
>> "Lorentz transformation" is not used, and the Lorentz transformations are
>> seldom used. But, nonetheless, the mathematics of the Lorentz
>> transformation works in the same way for these equations
>> too................If
>> the train moves in your direction, you hear a different sound than if the
>> train move away.
>
> Mathematics may possibly work in the same manner but I don't know what
> physical meaning you are trying to derive out from this.

You have an equation, and you have a method to find a lot of new,
different solutions if you have one solution.  These are real
solutions of real wave equations.

> Though the speed
> of sound is same wrt respect to medium, but if the receiver is moving at
> some velocity wrt source toward the source then the velocity of receiver
> gets added to velocity of sound and time taken by impulse to reach the
> receiver is reduced. This is not the case with light. Such is not the case
> with light as velocities does not add due to some strange reasons. I think
> that you would agree with that.

No.  The mathematics is the same. Light waves move in a light cone
independent of the speed of the source.

The strange reason is that clocks and rulers made out of things
following the wave equation show time dilation and length contraction.
This would be the same for sound waves, if you would build clocks out
of sound waves, these clocks would be similarly time-dilated, by a
formula with the speed of sound instead of c.

>>Despite these differences, some properties remain unchanged an
>> symmetric - namely the speed of the wave.

> Can you explain this a bit. I am not sure what do you mean by unchanged an
> symmetric - namely the speed of the wave. If space has a direction then
> what is then what is the physical meaning of speed being symmetric.

You throw a stone into the water, the result will be waves which look
like a circle.

If your stone had a velocity relative to the surface, the resulting
waves will be a superposition of waves emitted at slightly different
moments at slightly different places. This makes the resulting wave
asymmetric, the frequency of the wave will be higher in forward
direction than in backward direction.   But nonetheless, the speed of
this wave will not be influenced by this, it is the same speed of
water waves as usual.

This is the speed which is independent - it is the speed of the wave
itself, which is independent of the speed of the cause of the wave.