Several millennia ago, a Greek ship sank off the coast of an island in the Aegean Sea called Antikythera. When sponge divers eventually discovered the shipwreck in 1900, they called that small, corroded hunk of bronze the “Antikythera Mechanism”—and soon realized that it was a shockingly advanced astronomical calculator. The Antikythera Mechanism tracked planetary motion, predicted eclipses, and even included a dial for the Olympics—all centuries before gears were even supposed to exist. Andrew and Jamie also talk about why no other versions of the device have ever been found, and how that’s kept the debate alive for so long. Was this the pinnacle of ancient engineering, or something much stranger?