Well, according to Sir Isaac Newton (the guy who invented calculus), gravity is the force that pulls objects towards each other. And by “objects,” we mean everything from planets and moons to tiny particles floating around in space.

But how does it work? Let’s break it down.

First, you need two things: mass (the amount of matter an object has) and distance (how far apart the objects are). The formula for calculating gravitational force is F = Gm1m2r2, where “F” stands for force, “G” is a constant value that represents gravity’s strength (6.67 x 10-11 Nm2/kg2), and “m1” and “m2” are the masses of the two objects in question. The distance between them is represented by “r.”

So, let’s say we have our trusty Milky Way galaxy (which has a mass of 2 x 1030 kg) and another nearby galaxy called Andromeda (with a mass of 800 billion times that of the sun). If they were both sitting right next to each other, the gravitational force between them would be pretty intense. But since they’re actually about 2.5 million light-years apart, their acceleration towards each other is incredibly small (about 1.9 x 10-13 m/s2).

But don’t let that fool you! Even though the force between these two galaxies might seem tiny, it’s still enough to keep them from flying off into space forever. And over time, their gravitational dance will eventually lead to a collision (which is expected to happen in about 4 billion years).

It may not be the most exciting topic out there, but it sure does help us understand how our universe works.