Hawkins's computer was too literal. But his instinct — that Stonehenge handled information — survives every test the sixty years since have thrown at it. An investigation through stone provenance, isotopes, ancient DNA and landscape archaeology, ending with a named, testable hypothesis: the Gathering Engine.
Riyadh is planting 7.5m trees and running a new metro against an Expo 2030 deadline. A look at the water, heat and money behind the desert city's greening