Joshua Sokol in Quanta:
On a mild autumn day in 2016, the Hungarian mathematician Gábor Domokos arrived on the geophysicist Douglas Jerolmack’s doorstep in Philadelphia. Domokos carried with him his suitcases, a bad cold and a burning secret.
The two men walked across a gravel lot behind the house, where Jerolmack’s wife ran a taco cart. Their feet crunched over crushed limestone. Domokos pointed down.
“How many facets do each of these gravel pieces have?” he said. Then he grinned. “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. What if the world is made of cubes?