Primordial gravitational wave

So you know how when you throw a ball it moves through the air and makes waves? Well, imagine if the whole universe was the air and something much bigger than a ball made waves in it a very, very long time ago. Those waves are called primordial gravitational waves.

These waves happened soon after the universe began, when it was just a big ball of hot, dense stuff. Scientists aren't exactly sure what caused them, but they think it might have been a crazy event called cosmic inflation. This is when the universe suddenly expanded very quickly, making everything stretch and change.

The waves themselves are ripples in the fabric of space and time, caused by huge amounts of energy rushing through the universe. They are super tricky to detect, but scientists have been trying really hard to find them because they can give us clues about what the universe was like right after the Big Bang.

If we can figure out more about these waves, we might be able to solve one of the biggest mysteries in science: how our universe came to be.