Light, despite being massless, is affected by gravity due to the curvature of spacetime around massive objects like black holes. Photons follow the geometry of spacetime, which allows them to be drawn into black holes. The concept of weight (W=mg) does not apply to massless particles, as gravity influences them through their energy and momentum. This interaction leads to the phenomenon where light can be "sucked" into a black hole, contributing to its event horizon. Understanding this principle is crucial for grasping the nature of black holes and general relativity.