More than six thousand light years from the surface of the earth, a rapidly spinning neutron star called the Black Widow pulsar blasts its companion brown dwarf star with radiation as the two orbit each other every 9 hours.
Standing on our own planet, you might think you’re just an observer of this violent ballet.
But in fact, both stars are pulling you towards them.
And you’re pulling back, connected across trillions of kilometers by gravity.
Gravity is the attractive force between two objects with mass— any two objects with mass.
Which means that every object in the universe attracts every other object: every star, black hole, human being, smartphone, and atom are all constantly pulling on each other.
So why don’t we feel pulled in billions of different directions?
Two reasons: mass and distance.
The original equation describing the gravitational force between two objects was written by Isaac Newton in 1687.
Scientists’ understanding of gravity has evolved since then, but Newton’s Law of Universal Gravitation is still a good approximation in most situations.
