How Does Crepuscular & Anticrepuscular Rays Work?

Crepuscular and anticrepuscular rays are light beams that look like sunbeams coming from or going to the sun, but they happen when clouds are in the way.

Imagine you're playing with a flashlight in a dark room. When you turn it on, the light shines straight ahead, that’s like crepuscular rays. But if there are pieces of paper (like clouds) blocking some parts of the light, the shadows around them look like they’re coming from the sun, even though the sun is behind you.

Now imagine you're in a room with a window on one side and a door on the opposite side. When you shine your flashlight through the window, the light comes in, that’s crepuscular rays again. But if there are pieces of paper (clouds) blocking some parts of the light, the shadows cast on the other side of the room look like they’re going away from the sun, and that’s anticrepuscular rays.

It's just like when you're in a hallway with lights above, sometimes the light looks like it's coming from one end (crepuscular), and sometimes it looks like it's disappearing at the other end (anticrepuscular).