Lawrence M. Krauss

Neutrinos alone, among all the known particles, have ethereal properties that are striking and romantic enough both to have inspired a poem by John Updike and to have sent teams of scientists deep underground for 50 years to build huge science-fiction-like contraptions to unravel their mysteries.

The toughest trail I ever ran was the Escarpment in the Catskills of New York State. This was an 18-mile race through Rip Van Winkle country, routed through boulder fields, across angular juttings of granite and along a path with an unrelenting barrage of roots, rocks and mud, all of it hidden under slick leaves and dangling nettles.