The History of Mathematics

Set theory is a relatively new idea as a foundation of math in terms of the overall history of math wouldn't you say? Yeah I mean well modern mathematics as we know it's about somewhere between 100 and 150 years old. But yeah so this gives us a common language for all different parts of math. Right. Okay so why don't we have a few examples could you tell me some examples of things that are infinite sets? Well like the real numbers where you know anything that you can express with a decimal including things like pie and e. So they could have infinitely many digits after the decimal point. And what about things like shapes or points or you know geometric things not just numerical things.