(I'm 14 and still learning physics so I obviously don't know as much as you smart guys yet :P) E=MC^2, is that saying that If you take energy (I'm guessing the electrons) out of a particle or (I forgot the name but it's a group of particles) your also losing matter, if so does that mean electrons have mass? how much? Sorry I'm a bit confused, this probably sounds dumb :L Edit: And what does he mean by C^2 (I know its the speed of light squared, but what does it actually mean within the equation)? I'm also wondering, what is energy itself. There is different kinds, like kinetic and so forth but what actually is energy?