Self-interacting dark matter

Alright, kiddo. Do you know what dark matter is?

No? Well, scientists believe that there's a special kind of matter out there that we can't see with our eyes or telescopes, but we know it's there because it has gravity and affects the movement of stars and galaxies. We call it "dark" because we don't really know what it is or what it's made of.

Now, self-interacting dark matter is when this mysterious stuff interacts with itself. Imagine a room full of toys where everyone is playing nice with each other, but suddenly some toys start bumping into each other and pushing each other around. That's kind of what self-interacting dark matter is like.

Scientists think that if dark matter does interact with itself, it could explain some strange things they've observed in the universe, like giant clumps of dark matter that seem to have formed in unexpected ways.

But the tricky part is that we still don't know for sure if dark matter really does self-interact, and if it does, how strong that interaction is. So we have to keep doing experiments and observations to try to unlock this mystery of the universe.