Mirror matter

Okay, kiddo! So, you know how you have a reflection in a mirror, right? Well, scientists think that there might be stuff in the universe that acts like our regular matter, but is kind of like a reflection of it, almost like a mirror image. That's why they call it "mirror matter."

Now, you probably know that everything in the world is made up of tiny things called atoms, right? These atoms have even tinier things called particles inside them, like protons, neutrons, and electrons. Mirror matter works in a similar way, but instead of our regular atoms and particles, it has its own set of atoms and particles that are almost exactly the same, except that they're kind of like a mirror image.

Scientists think that mirror matter could be out there in the universe, but we haven't found it yet because it doesn't interact with our regular matter very much. It's like trying to find a friend in a big busy park when you're both wearing camouflage – it's really hard to spot them!

Some scientists think that mirror matter could make up a lot of the universe, maybe even more than our regular matter. That could mean there's a whole other world out there that we haven't even discovered yet! But we'll have to keep looking for clues to find out.