How does gravity bend light

Question

Assuming photons have no mass, as I believe they don't, how does gravity affect photons in order to bend them?

Answer 1

The idea that gravity is specifically a force that masses exert on each other is actually false, although it works as a very good model for many applications. But actually, (as far as we can tell) the way that gravity works is it actually causes the space-time to bend. So gravity isn't causing light to bend, rather the light is travelling on a straight path through curved space, and so it appears to bend.

Think of it as like a car in a hot wheels track - hot wheels cars can't turn, they really only go straight, but adding bends to the track itself, the car's path is bent.