I was reading in one of my books today. It brought up an answered that I had when I was talking Modern PHysics over a year ago. Sadly our curriculum didn't really allow for us to do modern physics but our class flew through all the old physics for grade 12. Basically I had read alot of modern physics off of This Site So first day We did Wave-PArtice duality. HE wrote Wave on one side of the board and Particle on the otherside. Then asked which is light? People were like guessing answers. But he would ask why, howcome. I was then able to give an answer for both side. Light is a wave because it can defract and interfere. Light is a particle because it has relative mass, as blackholes and gravity affects the direction of light. Then after that I read about how gravity actually warps space. Also that say Starship A, when approaching the speed of light, the relative mass increases. Therefore to be moving at c you need infinite amount of energy. Now what my question is. If light has no rest mass. but relative mass. But Starship A does have rest mass and inifinity relative mass. What makes light not become infinte relative mass when Starship A does? Photon is a boson, a fundamental particle. How can a fundamental particle exist but not have any mass. What would it be made of? How could it exist? I haven't done string theory all that much, I think Imight get the gist of what its about. If you need to explain this with string theory.