Black holes 'attracting' light?

[Ithaca]

Black holes 'attracting' light?

I'm puzzled. If light is made up of photons and photons have no mass, how can black holes 'attract' light into themselves - surely gravity only acts on things with mass? I can't see how thinking of light as a wave would help with this either...

Sorry if the answer is very simple - I think I must be missing something obvious but it's annoying me!

Thanks!

 

[Farsight]

They don't. They kinda bend spacetime. The light goes straight, like light does. But the space is bent. That's basically what's going on for anything with gravity. Search Google and you'll find something that'll tell you all about it and give you a simple concept.

http://en.wikipedia.org/wiki/Black_hole

 

[Ithaca]

Ahhh, thank you for the link - that makes it clear!