When an earthquake knocked out the power in Los Angeles in 1994, people were puzzled by the starry sky. Ed Krupp, director of Griffith Observatory, recalls, “People saw something they’d never seen before in an urban environment—or never in their lives. We got two or three dozen calls. They wanted to know, Did the earthquake cause it?”
“The skies are very much a part of our intellectual survival. But people have lost touch with the sky,” says Krupp. It’s a loss felt across the industrialized world as light pollution has increasingly brightened the night sky. Already, for one-fifth of the world’s population—in the US, it’s more than two-thirds and in Europe, half—the Milky Way is no longer visible, according to Italy’s Pierantonio Cinzano of the Light Pollution Science and Technology Institute in Thiene and the University of Padua. Artificial sky glow comes from light that shines upward—from roadways and...
