Posted: Sep 12, 2011 2:10 am
eric8476 wrote:how can something with no mass have energy? how is a particle associating with energy and how can particles be observable if they have no mass?
Particles with no mass, like the photon, can still interact with ordinary matter, changing their velocity, because they have momentum.
So in simple words, a photon colliding with an atom at rest will make the atom move.