 So the next topic we're going to talk about is mechanics, which is just the rules by which everything moves And this is one of the most foundational elements of modern physics In fact before that people thought that everything had its own rules and after the laws and mechanics were discovered People realized that everything in the entire universe seemed to follow the same rules Rather than rocks being different to planets or stars. It was realized that they actually follow the same universal principles Now if everything follows the same physical principles Then you'd imagine that we'd be able to figure out what they were fairly quickly because everything would be reasonably simple So why did it take literally thousands of years to figure out the laws and mechanics? Well, there's two main reasons the first is that a rock and a waterfall and a feather and a fire and a star all behave extremely differently and The main reason for that is that even though they follow the same rules they're composed of very different things And they have very different environments which means that when they follow those rules they do very different things And the second is the underlying rules are quite different to the apparent behavior of all the things we see around us