eieken writes "The physics of Superman mostly belong in the realm of comic books, but some scientists decided to give their input on the matter. The article tells of 'a scientific experiment in which a researcher put several chickens in a centrifuge and raised them in twice-normal gravity for months at a time. When they emerged, the chickens were stronger and had larger bones and muscles, and greater endurance. In other words, they were superchickens.' Do they have human sized centrifuges?"