If light has no mass, how does gravitational force bend light inwards

Question

In the case of black holes, lights are pulled into by great gravitational force exerted by the dying stars (which forms into a black hole). If light has no mass, how is light affected by gravity?

In: 784

Answer 1

ELI5 best effort….

Draw a straight line on a piece of paper, that’s your light.

Now bend the paper, that’s space time bending due to being in the proximity of a mass.

Your line is still straight.