Everyone had his or her favorite drink in hand. There were bubbles and deep reds, and the sound of ice clinking in cocktail glasses underlay the hum of contented chatter. Gracing the room were slender women with long hair and men dressed in black suits, with glints of gold necklaces and cuff links. But it was no Gatsby affair. It was the annual Imperial College quantum gravity cocktail hour.
The host was dressed down in black from head to toe—black turtleneck, jeans, and trench coat. On my first day as a postdoctoral student at Imperial College, I had spotted him at the end of a long hallway in the theoretical physics wing of Blackett Lab. With jet-black wild hair, beard, and glasses, he definitely stood out. I said, “Hi,” as he walked by, curious who he was, and with his “How’s it going?” response, I had him pegged. “You from New York?” I asked. He was.
Smolin, one of the fathers of a theory known as loop quantum gravity, and he was in town considering a permanent job at Imperial. Along with string theory, loop quantum gravity is one of the most compelling approaches to unifying Einstein’s general relativity with quantum mechanics. As opposed to string theory, which says that the stuff in our universe is made up of fundamental vibrating strings, loop quantum gravity focuses on space itself as a woven network of loops of the same size as the strings in string theory. Lee had just finished his third book, Three Roads to Quantum Gravity, and was on a mad rush to mail out the manuscript to his editor. I accompanied him through the drizzle to the post office and for a celebratory espresso—the first coffee of hundreds we’d share in the future.