A cura di @GiMa.

Il giornalista Ferris Jabr ripercorre la storia della corda e di come nella storia della civiltà abbia svolto un ruolo forse più importante della ruota:

The void opened suddenly—a negative space where there had once been sand. Kathryn Bard stuck her hand straight through the gap and felt nothing but air. It just kept going. She considered her surroundings: a slope of windblown sand near a terrace of fossilized coral 700 meters inland from the modern-day Egyptian coast. The recess in front of her, Bard realized, was probably not a result of geological processes; it was too deep. This was something else, something deliberate. Perhaps a tomb. Or a gateway.

Immagine da Wikimedia.