Do photons "carry momentum"? I was just reading this article in the NY Times,.. http://www.nytimes.com/2007/03/13/s...tml?ex=1175918400&en=d898bf8d246a0844&ei=5070 And THIS sentence just doesn't make ANY sense to me... "Particles of light, or photons, have no mass, but they carry momentum." What? P=mv. If m=0, P=0. If something is massless, how in the hell could it possibly carry ANY momentum - at all?