Isaac Newton invented the mathematical branch known as calculus. However, legend says that he also invented the cat door, although there are two sides to this story. In the first, Isaac Newton was a genius and created a cat door so cats could go in and out at will.

However the other story about Isaac Newton says that he was like many geniuses who are so smart in abstract matters that they’re actually stupid in practical life. In this other story, Isaac Newton supposedly cut a hole in a door so a cat could go in and out. When this cat had kittens, Isaac Newton cut a second, smaller hole in the door so the kittens could go in and out, not realizing that the kittens could just have gone through the much bigger hole that their mother used.

Whether you want to believe Isaac Newton was a genius or a genius/idiot depends on which story you want to believe. The main point is that would Isaac Newton had discovered as many facts of life if he didn’t have cats around to inspire him?

Click here to read about Isaac Newton and the legend of the cat door.