help me lrn2physics

Hey /sci/,

How the hell can something be massless? Someone told me that light is a massless energy particle or some shit like that but that can't be possible because in order for something to actually exist, it must be made of something, and that something has to have mass, regardless of how minute it is right? Or is this correct since light is suppose to have duality? Please edumacate me.

>>21
>>19
You actually can't accellerate a photon.  When a photon goes through something with a non-unity index of refraction, it still goes at the speed of light in that material.  When it "bounces off" a reflective surface, what comes back is actually a new photon.  When it's "bent" by gravity, it's still following geodesics, and therefore following a straight path through _curved_space_.