Time translation symmetry

Alright kiddo, have you ever played with a toy where you turn it around and it looks the same no matter which way it is facing? That's kind of like time translation symmetry. It means that if you were to look at something happening in a video, it would look the same if you watched it at different times.

Let's say you're watching a video of someone bouncing a ball. If you watch it from the beginning or the middle or the end, the ball would still be bouncing the same way. That's time translation symmetry. It doesn't matter when you start watching or how long you watch, the video will always look exactly the same.

Scientists use time translation symmetry to help them understand things like the laws of physics. They know that if time translation symmetry is present, then certain things aren't changing over time. For example, the laws of physics are the same today as they were yesterday and will still be the same tomorrow. That's because time translation symmetry is present.

So, time translation symmetry is just a fancy way of saying that something looks the same no matter when you look at it. Cool, huh?