How Do Light Cones Get Tilted?

We can see light getting bent out there in space by heavy objects. It's called gravitational lensing. If it's like a really big, heavy object between us and some source of light,. then those photons come towards earth, they gat bent around that massive object. And this is one way we can detect, for example, the existence of dark matter - try to figure out roughly where it is based on how it distorts Light.