How does light get affected by gravity?

Question

If photons don't have mass, how come gravity can bend light? Because if photons have no weight, wouldn't they not be affected by the fabric of spacetime?

Answer 1

Any massless particle, like a photon or gluon, can only travel at c. It can never have zero speed or exist at zero speed. So there is no acceleration and it is not appropriate to think about acceleration in the normal sense.