The discussion centers on the constancy of the speed of light and the implications of time dilation as described by Einstein's theory of relativity. Two observers, one stationary and the other traveling at half the speed of light (0.5c), measure the time it takes for a beam of light to travel a distance of 200 units. Despite the stationary observer recording 2 seconds, the moving observer records only 1 second due to time dilation. The conversation reveals misunderstandings about frame of reference, the role of the Lorentz Transform, and the relativity of simultaneity, emphasizing that both observers measure the speed of light as constant when accounting for their relative motion.
PREREQUISITESPhysics students, educators, and anyone interested in understanding the principles of special relativity and the behavior of light in different frames of reference.
"Moving through space" is a nonsense phrase. The Earth is moving at 0 in its rest frame and at 7500 in some other frame (e.g. the rest frame of the local CMB radiation). There is no "rest frame of space".John15 said:The Earth is moving through space at a minimum of 7500kps.
That is not only not "obvious", it is untrue. Light does not "reach" the speed of light is at c from the instant it is created. Light always travels at "c".John15 said:Light obviously reaches the speed of light.
Question is then what happens to it at this speed that stops it going any faster?
Yes, everything is governed by the same rules and those rules say that something traveling at c in one inertial frame is traveling at c in all frames. This implies that it is not traveling at 0 in any inertial frame.John15 said:If the Earth can have a rest frame of 0 whilst moving through space then that must apply to all including wavelengths of energy, everything is governed by the same rules.