Geometry Reveals How the World Is Made of Cubes

Plato was right: On average, the world is made out of cubes. On a mild autumn day in 2016, the Hungarian mathematician Gábor Domokos arrived on the geophysicist Douglas Jerolmack’s doorstep in Philadelphia. “What if I told you that the number was always somewhere around six?” Then he asked a bigger question, one that he hoped would worm its way into his colleague’s brain. “It was geometry with an exact prediction that was borne out in the natural world, with essentially no physics involved,” said Jerolmack, a professor at the University of Pennsylvania. “How in the hell does nature let this happen?” Over the next few years, the pair chased their geometric vision from microscopic fragments to rock outcrops to planetary surfaces and even to Plato’s Timaeus, suffusing the project with an additional air of mysticism.