Well Answer this. If a train is moving at the speed of light and you walk from the back of the train to the front of the train, wouldn't that be faster than the speed of light?

Physicists in the 20th century performed a famous experiment to see if Einstein's Theory of Relativity was correct. According to classical physics, light has no mass. It moves in straight lines from point A to point B without being affected by forces like gravity. However, Einstein said that this wasn't exactly true. Gravity actually "bends" space in such a way that light will curve around bodies of large mass (well, of any particular mass, but it's only noticeable with large mass) like stars. In particular, Einstein said that if you look at the sun, the light from the stars in the background will be curved around the sun to look like they're further apart than they usually are. The problem with this is that looking at the sun usually entails a whole lot of sunlight, which makes it impossible to see stars. So the physicists of the 20th century waited until a solar eclipse (where the moon passes between the earth and the sun) so the moon would block out the excess sunlight. What did they see? Exactly what Einstein predicted: that the stars seemed to be "moved" by the gravitational effect the sun has on light. Afterwords, someone asked Einstein what he would have done if the universe didn't work the way Einstein had predicted. Einstein replied "Then I would have felt sorry for God, for the theory IS correct." Relativity also explained why Mercury's "perihelion" (that is, the major axis of its elliptical orbit around the sun) would "process" (that is, move to a different point) every mercurial year. Physicists before Einstein could not explain this phenomenon. With the development of atomic clocks late in the 20th century, physicists were able to directly observe the contraction of time. Two atomic clocks were synchronized, and then one was placed in an airplane and flown around the world for a few days. When the clock was compared with the stationary clock, it was found to be slightly behind the stationary clock, since time had slowed down for the mobile clock while it was flying. Granted, they were only off by fractions of microseconds, but the point is that atomic clocks are accurate enough to measure such a small discrepancy. Of course, Relativity might not be correct at all. Someday, someone might observe a phenomenon that is in direct opposition to Relativity. For instance, everyone thought running a mile in under 4 minutes was impossible for the human body. But in 1954, Roger Bannister ran a mile in 3'59.4" Hence, Relativity is only "correct" because it accurately predicts things we observe about the universe.

I don't know...I do know that Scientific American in one of its latest issues has asked the same question.