The sweat pours down like rain even when you're just standing still. You chug down ice water, but it's not enough to cool you down. Ah, what you desperately need is a bowl of Pyeongyang naengmyeon ...

History is full of backstabbing rivalries: Edison and Tesla, Harding and Kerrigan, Tupac and Biggie. No less dramatic was a 16th-century conflict between Italian mathematicians Gerolamo Cardano, a ...