Newton’s law of gravity determines the force of gravitational attraction between two bodies regarding their masses and the distance between them. It can be applied to any system of bodies interacting through the force of gravity, such as the solar system. It tells us that their motion is determined by a simple mathematical law. Newton’s law of gravity led us to accurately predict eclipses, planetary orbits, the return of comets, the rotation of galaxies, artificial satellites, surveys of the Earth, the Hubble telescope, observations of solar flares, and the global positioning system (GPS).

## The Formula to Get 42 Billion Digits of π

While writing "7 Utterly Well-written Math Books About Pi," I found a very interesting math formula that will give you 42 consecutive digits of π accurately but is still wrong.