The Story of Rubik's Cube, the World’s Most Popular Toy

A perennial puzzle turns 40

The event, in case you missed it, was called the Zonhoven Open. It took place in Belgium last March, and it witnessed 18-year-old Mats Valk do something remarkable. The lanky teen picked up a color-scrambled Rubik's Cube, whirred it around in his fingers and slammed it down—solved—in 5.55 seconds. It was a world's record—and still is.