Thread: Special Relativity Error?

In Einstein's theory of Special Relativity, he assumed he was dealing with a system in uniform motion. If EVERYTHING in the system is in uniform motion, that would include light. Therefore his conclusion contradicts his premise.

Originally Posted by Raggedjoe

In Einstein's theory of Special Relativity, he assumed he was dealing with a system in uniform motion. If EVERYTHING in the system is in uniform motion, that would include light. Therefore his conclusion contradicts his premise.

No. He considered two reference frams in uniform motion with respect to one another. He made no assumptions about the things that were moving with respect to those reference frames, except for light.

Special relativity and the Lorentz transformation can be derived from two assumptions. 1) The speed of light is the same in all inertial reference frames. 2)
The laws of physics are the same in all inertial reference frames.

Note that the notion of uniform motion with respect to reference frames includes the condition that the direction of that motion is also fixed. But special relativity allows one to transform velocities (vector quantities) between reference frames and not just speeds in the direction of the uniform motion.