Relativity holds a rather curious place in physics, as I see it. Other branches – nuclear, mechanics, E&M, so forth, all seem firmly based in the study of physical objects, systems, and principles. Relativity is, in point of fact, much more of a math than a physics. It starts with simple axioms about our understanding of the universe and derives conclusions from them about the way the universe must work. The tools of relativity are not physical laws, but rather logic.
Now, as I said, relativity starts with simple axioms, and works from them to derive its conclusions. The axiom in question in this case is that the speed of light is finite, and constant. No matter who is measuring it, how fast they are going, what they are doing, who else is measuring, all observers always measure the same speed of light. That speed we’ll call c here, though more traditionally it is 299 792 458 meters per second.Now to the experiment.
(more…)
