>Hilmar, from what I have read the speed of light appears as a constant because the tools used to measure the speed of light, eg a clock and a fixed ruler, change with motion. As you approach the speed of light your clock slows down and your ruler shortens so the speed of light appears to be constant. The relationship between the measuring ruler and time for each observer however remains constant.
Yes, that is my understanding, too. Both the distances (along the direction of the movement) and the time scales get distorted. This "Lorenz contraction" was known before the Special Theory of Relativity; Einstein put knowledge which was already available at his time, into a consistent framework.
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