E=MC2 The reason that nothing can exceed the speed of light is that energy and matter are the same thing in different forms. E=MC2.
This means that just as matter has mass, and causes gravity, so does energy. The greater the energy the more mass an object has and, there for more gravity.
As an object gains speed it also gains energy (kinetic) and so gains in mass. This increase in mass grows on a curve. At the flat end of the curve, at just a few percent of the speed of light, there is almost no gain in mass at all. As it approaches the speed of light it becomes more massive and takes larger amounts of energy for it to accelerate. Once an object gets close to the speed of light its mass starts climbing up the vertical part of the curve. Upon reaching the speed of light it becomes infinitely massive and needs infinite quantities of energy to accelerate it.
I imagine at some point before reaching such speeds the object would be crushed under its own gravitational field, and become a singularity.
