All  

calcite

Cave stalactites and stalagmites. Credit: Santi Rodríguez / Adobe Stock

Ancient Cave Crystals Reveal Sea Levels Were 50 Feet Higher in Warmer Climate

Scientist studying ancient crystals in a Spanish cave have discovered disconcerting evidence that shows just how high sea levels can rise in a warmer climate. 4.4 million years ago, one of your...
Megalithic Money - Yap Micronesia

The Megalithic Money of Yap

The tiny island of Yap in the western Pacific holds a strange attraction for economists, because it cuts to the heart of a very basic question “what is money?” For centuries the Yap islanders have...