When I was deployed to Aviano in 1998, I happened upon a chat site at JPL where the scientists were debating the cat/buttered toast issue. They had all sorts of analytical data and supposition depending upon the type of cat, induced and parasitical friction, even down to which type of bread and butter. The best theory had to do with a hairless cat covered in goats butter, which lead to the discovery of perpetual motion and endless energy supplies.