An error in an Special Theory of Relativity?

Question

Let a ray of ligth is moving along the z axis away from origin of some inertial frame of reference 'S'. The frame 'S' is moving with speed of light along z axis w.r.t stationary Frame 'T'.Then the ligth should appear stationery to the observer in the S. Then why einstien called speed of light universal constant. Why the speed of light is not relative?. Also we can put this phenomena in a way that time is runing slower. But what when 'S' is moving alog -z axis.Then the ray of ligth should appear at 2c speed or the time is runing faster is it so?

Answer 1

Special Relativity (SR) does not conclude that the speed of light is constant. Instead, it STARTS with the OBSERVATION that the speed of light is constant in all reference frames and then derives how such an observation would impact the rest of physics.

In 1887, Michelson and Morley used an inferometer to measure the effect of the movement on earth on the perceived speed of light from the sun. That is, they were expecting that as the earth rushed away from the sun, the speed would decrease and as the earth rushed toward the sun the speed would increase. The inferometer was setup to detect these differences in speed and, if those differences existed, should have provided an interference pattern allowing for calculations of how the speed is changed by earth's movement.

However, when they turned the experiment on, they found no intereference pattern. They found that the speed of light was constant in every reference frame.

In 1905, Einstein published a paper which assumed that the results of this experiment were not a fluke. It then took that assumption and derived the impact on space AND TIME. The result was that when objects are in motion, the space around them and the time that they move through are actually changed to compensate for their speed. This change is what "lets" light travel the same speed everywhere.

Einstein's theory predicted other things that were completely different from classical/Newtonian mechanics and since then many of those predictions have been tested.

General Relativity (GR) added the effects of gravity (or rather, the effects of mass and energy on spacetime) to this model. Both because of the earth's gravity and because of the speed of the orbiting object, an orbiting clock should tick slower as it orbits the earth. Scientists have synchronized very precise atomic clocks on earth and then sent one clock up in space to orbit the earth and then later land and be compared to the other clock which has been on the ground at all time. Classical mechanics suggest that they should continue to be in sync. However, relativistic mechanics predicts that the one that was sent into space should be slowed down by a particular amount. In fact, in the actual experiment the clocks *ARE* slowed down by exactly that amount. This is strong evidence that Einstein's predictions are correct.

Again, Einstein did not PREDICT that light should travel at a constant speed. OBSERVATIONS suggest that that is true. Einstein just derived various results of those observations.

Answer 2

in the original Initial-system every thing is labeled with o
In the moving Initial-system every thing is labeled with 1
you have a light beam travelling along the z-axis
to a certain time to it has been travelling c*to

The other Initial-system is moving in the opposite direction also with the speed of light, and have therefore been travelling -cto

the distance between the light front and the second initial-system to a certain time will be
l cto - (-cto)l =2cto

from the initial-system moving in -z direction the the time can be calculated by use of this
2cto=t1*c => t1=2toc/c=2to you see the time in the second initial-system is run twice so fast as in the first.

Answer 3

The speed of light is invariant under frame transformation.

Answer 4

this is why the theory of relativity is still only a theory. that is one of some kinks that have to be worked out.

Answer 5

no