It's widely believed Sir Isaac Newton invented the cat flap. Whether true or not, I wouldn't know, but I'd like to think this bit of Newton information entirely factual. The story goes that Newton, working on laboratory light experiments, was repeatedly foiled by unwanted light from a cat pushed open door. Not wanting to banish the cat, Newton cut a hole in the door, and attached a piece of felt to block out unwanted light. Since Newton and the cat were now happy, the world's first cat flap solved the light problem nicely. Later, when the cat had kittens, Newton cut several more kitten sized holes in the door. Though the kittens could have used the larger cat flap, Newton provided the extra doors anyway. This just shows no matter how giant your brain is, logic can still escape you. Alternately, maybe he just found all those little cat flaps amusing.
Sir Isaac Newton