Hello! I'm doing a school project, where I am writing about Infinity in Math and Physics. I've got the math part settled, but it's the physics part that has begun to bother me. One part of my task is to write about some of the mathematical expressions in physics, where we use infinity - but the only real thing I've been able to find about infinity in physics, is when we are talking mass and density of black holes, which is fine, I think I have a pretty basic understanding of it, but can anyone tell me about other things in physics where we have something that gets "infinitely big", or where we use infinity? If you've got some sources for it, I would be forever thankful!