Seemed like a good idea at the time. Last week in Copenhagen, 1,000 people gathered in a public square to participate in a collective act that some might call idiotic and others brave. Together, bound in solidarity, they each ate one ghost chili pepper — one of the spiciest chili peppers on Earth. Also called the "bhut jolokia," the ghost pepper grows in the Indian states of Assam and Nagland and, from 2007 till it was dethroned in 2012 by the Trinidad moruga scorpion, it was certified as the hottest pepper in the world by Guinness World Records. It measures...