it's a little more confusing than that, because while he does link to a proof, the proof does not claim to be new, the guy says "A favourite proof of mine: fir

it's a little more confusing than that, because while he does link to a proof, the proof does not claim to be new, the guy says "A favourite proof of mine: first demonstrated to me by my professor in number theory. I think its beauty stems from the fact that it requires no knowledge of mathematics above the definition of what it means for a number to be rational, and can be written almost in one line."