Did you know…that Sir Isaac Newton (1/4/1643 ― 3/31/1727) writer and scientist who first described the principle of gravity, is also known to have invented the swinging cat door for the convenience of his cats?
Though there has been some disagreement about Sir Isaac Newton inventing the first cat door, sources do claim that he cut a cat-sized hole in a door and hung a black cloth over it to keep out the light while he concentrated on scientific experiments so his cat(s) could come and go as they pleased!