Thirteen years after Melissa Lavasani emerged from Macalester College as a star on her tennis team, she was crawling up her stairs at the end of every day. It was then that Lavasani, who was suffering...

“What if I had not taken LSD ever; would I have still invented PCR? I don’t know. I doubt it. I seriously doubt it.” In 1986, biochemist Kary Mullis invented the polymerase chain reaction, a technique...