Warm dark matter

Imagine you live in a room with a bunch of toys scattered around the floor. Some of these toys are big and heavy, like a bowling ball, and some of them are really small and light, like a ping pong ball. If you were to try and pick up all the toys at once, you might have trouble because some of them are just too heavy or too light to easily grab.

Now, think about the universe as one big room filled with a bunch of stuff, including dark matter. Dark matter is like a toy that we can’t see or touch, but we know it’s there because we can see its effects on other things in the universe, like how galaxies move and interact with each other.

There are two popular theories about what dark matter is made of: cold dark matter and warm dark matter. Cold dark matter is like a big, heavy toy that's difficult to move around. Warm dark matter, on the other hand, is like a smaller, lighter toy that moves more easily.

Scientists think that warm dark matter particles would have been moving very quickly in the early universe, but over time they would have slowed down. This means that they would have been able to interact with light particles more easily, which could have affected how galaxies formed and evolved.

So, to sum it up: Warm dark matter is like a small, light toy that moves more easily than a big, heavy toy. Scientists think it could have affected how galaxies formed and interacted with each other because it was able to interact with light particles more easily.