Mastodawn

The Mountain That Weighed the Earth. How scientists in 1774 used a Scottish mountain to estimate the mass of the Earth to within 20% of the modern number by measuring the mountain’s gravitational effect on a precision plumb line. https://signoregalilei.com/2026/01/18/the-mountain-that-weighed-the-earth/

The mountain that weighed the Earth

Suppose you want to find out how much you weigh. It’s easy enough – get a scale, stand on it, and read the number. Now suppose you want to know how much the Earth weighs. You get out a scale and…hm…

Signore Galilei