ELI5: Explain Like I'm 5

Accelerating expansion of the universe

So, you know how when you blow up a balloon and it gets bigger and bigger? Well, scientists have found out that the universe is kind of like a giant balloon that is getting bigger too. But, they have also discovered something strange - the universe is not just getting bigger, it is getting bigger faster and faster all the time.

Imagine you have a ball in your hand and you throw it. The ball goes faster and faster until it finally hits something and stops. The same thing is happening with the universe - it is like the universe is throwing all the planets and stars away from each other and they are getting faster and faster. But, we don't really know why this is happening. It could be some mysterious force that we don't understand yet.

This accelerating expansion can have some pretty big consequences for the future of the universe. It means that eventually, distant galaxies will be moving away from us so fast that we won't be able to see them anymore. It also means that in billions of years, the stars and galaxies we see in the sky today will be so far away from each other that they will be like little islands in an empty sea.

Scientists are still trying to figure out the mysteries of the universe, but for now, we know that it is getting bigger at an increasingly faster rate.