There is no evidence that it is the least bit harmful. It is often annoying to those who don’t crack their own knuckles, and perhaps that is partly where the myth that it is harmful started. What is happening is that when you seperate two bones by pulling or sharply bending, you are creating a […]
The principle factor affecting a moving (and spinning) baseball is air drag. Imagine a standard fastball thrown with a straight overhead motion. The ball will be spinning naturally on a horizontal axis (with the top of the ball rotating back toward the pitcher). This spin causes the magnitude of the drag vectors to be different […]
First, the simplest definition of density: it is how heavy something is relative to its size. A pound of rocks weighs the same as a pound of ping pong balls. But the ping pong balls take up a lot more space. Hence, the rocks are much more dense. Another way to look at density is […]