system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5 what's a gravity wave

I understand that gravity is the curvature of space time. If that's true, doesn't it fully explain gravity? Why do we need gravity waves and/or gravitons?
gpt
Scientists have a theory called "general relativity" that explains how gravity works. According to this theory, gravity is caused by the way that objects bend something called "spacetime." Spacetime is like a fabric that everything in the universe is made of. When an object with a lot of mass or energy is nearby, it can bend spacetime. This is kind of like what happens when you put a bowling ball on a trampoline. The bowling ball makes a dent in the trampoline, and if you roll a smaller ball towards the bowling ball, it will follow the curve of the trampoline and roll towards the bowling ball.

Gravity waves and gravitons are ideas that scientists have come up with to try to understand how gravity works on a very small scale. Gravity waves are like ripples in spacetime that are created when two massive objects collide or when a massive object changes shape or orientation very quickly. Gravitons are tiny particles that are thought to be responsible for carrying the force of gravity from one object to another. Scientists are still trying to figure out if these things really exist and how they might fit into our understanding of gravity.