system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: If photons are massless, why does gravity affect light?

Edit: All answers point to the distortion of the space time fabric by the mass of objects as the reason why.

However, an addendum to my original question then : Why does mass/energy distort space time?
gpt
While photons are massless, gravity still affects them because gravity distorts space-time. Photons are not immune to this distortion.

Essentially, photons still need to travel the uneven ‘surface’ of space. You can’t walk in a truly straight line between New York and LA, because you need to cross over the Rocky Mountains. Light is sort of the same way.