Hey I have thought of a little paradox in my head that I would like some clarity on. Through E=MC^2 we know that mass can be converted into energy and energy into mass. They are "convertable" and energy is in the form of photons which travel at the speed of light, C, because they have no mass. But I have also been told that matter can't reach the speed of light because of general relativity. That as an object approaches the speed of light length contraction occurs and the mass of the object goes up. I was told matter can't reach C because it would need 0 mass but the mass goes up as it goes faster. This is where I am confused. In one case it says mass and energy are interchangable, in the other it says it's impossible. This could easily be a misinterpretation of mine, but could someone please help me out. Thanks