According to current theory; mass and energy are equivalent; associated through the equation E=Mc^2. A derivation from this equation leads to the relationship M=1/(1-v/c)^2. As the velocity of an object approached c, the mass approaches infinity. This prevents anything with mass from reaching the speed of light.

The speed of light likewise tops out at c, and it is due to the same relationship: Since mass and energy are equivalent, accelerating even a single photon beyond the speed of light is kinetically impossible.

There are better reasons and explanations, but I think this is about as simple as it gets.

__________________
jwj

It's a big universe out there...is it really unwinding, really burning out?