Science: hysicists can't travel to a black hole to see how it ticks, but they have taken a big step toward creating something similar in the lab. Using an optical fiber and laser light, Ulf Leonhardt of the University of St. Andrews in the U.K. and colleagues have simulated a "white hole"—essentially a black hole working in reverse—as they report in more detail in Science magazine. The model might soon mimic perhaps the most tantalizing property of a black hole: the "Hawking radiation" that should emanate from it.