The "questions you have always wanted to ask, but you thought it&#

[Rickshaw]

Why is light affected by gravity forces? Is it because photons have a theoretical mass?

[Guest]

Gravity is a distortion of spacetime caused by mass. The path of light through spacetime is susceptible to these distortions, regardless of its own mass. See the wikipedia articles on gravitational lensing and the geodesic equation describing the Kepler problem in General Relativity for more information.

Edited January 8, 2011 by 5eraph