The Earth and the Moon have existed for more than 4.5 billion years. And during that time, the Moon has been orbiting the Earth in a choreographed, circular dance.

What is not so evident is that the Earth and the Moon are in a violent game of tug-of-war, each aggressively pulling on each other.

The Moon’s pull is evident in the rise and fall of tides in Earth’s oceans. But what dictates this relationship?

Sir Isaac Newton mathematically modeled this relationship and it is called Newton’s Universal Law of Gravitation.

the universal gravitational constant times the mass of each object all divided by the square of the distance between the two objects. Fg = G*m1*m2 / r2

G represents the Universal Gravitational Constant M1 and M2 are the masses of the two objects. R is the straight line distance between the centers of the two objects.

The gravitational force is proportional to the product of their masses. So as the product increases, so does the gravitational force. Likewise, as the product decreases, so does the gravitational force.

The gravitational force is inversely proportional to the square of the distance. Thus, as the distance increases, the gravitational force decreases. And vice-versa.

Newton’s Universal Law of Gravitational.