Although early metalsmiths learned how to increase the hardness of copper, granite was still over four times as hard. The very hard sand particles imbedded themselves in the copper blade and were ...
On Elephantine Island, researchers have identified clear machining marks carved into hard granite—patterns that resemble ...
Katie has a PhD in maths, specializing in the intersection of dynamical systems and number theory. She reports on topics from maths and history to society and animals. Katie has a PhD in maths, ...