Gravitational-wave astronomy

Gravity-wave astronomy is like regular astronomy, but instead of looking at light from stars, we look for ripples of gravity that come from the universe.
These ripples happen when things like stars and black holes suddenly move around and make big movements.
The ripples are very small and hard to find, but if we can detect them using special detectors then we can learn more about how the universe works.
We can learn things like how many black holes and stars are in certain galaxies and how they're moving around.
We can also use gravity-waves to look back to the very beginnings of the universe and learn more about how it all started.