Pick up a rock on the beach in Dahab and you're holding something 600 million years old — formed before Africa and Arabia even existed as separate continents.

Joseph and Annet pick up a piece of red granite and a smooth black basalt on the beach and unpack what makes them different, why one lets water through and the other doesn't, and how that knowledge was used to find wells in the desert. You'll also learn why the Red Sea might have gotten its name — and it's not what most people think.

Chapters:

00:00 — Episode intro & disclaimer

00:55 — Welcome to Dahab

01:09 — The rock in Joseph's hand

01:19 — Red granite: hundreds of millions of years old

02:17 — How the rock got smooth: wadis and floods

03:15 — What's inside granite (minerals)

04:03 — The tiny white circles  ...