The Fate of the Universe
One of the biggest questions in science is "What will happen to the Universe"?
We think that the Universe started with a Big Bang. We know galaxies are still moving apart as the Universe expands. But we are not sure what will happen in the distant future.
The fate of the Universe is a balance between these things:
- Its continued expansion
- Gravity trying to pull things together and slow down the expansion
- An unknown force that may be increasing the rate of expansion, called dark energy
So, the Universe could:
- Continue to expand forever and cool down.
- Stop expanding and collapse back in on itself.
- Expand at an increasing rate until everything rips apart.
Astronomers are trying to find out what will happen. To do this, they need to work out how much mass there is in the Universe. The more mass, the more likely it is that gravity will win. This mass includes stuff we can see, but also dark matter. They also need to understand if there is such a thing called dark energy, and what it is.