Since we’ve touched down some points on General Relativity down pat, it’s time we apply them on to the biggest canvas available — outer space.
Being the incredible mind that Albert undoubtedly is, he had the most amazing idea. Matter curves space, correct? Then what would happen if you place millions and millions of matter in an area — like the stars and planets in space, for example. Space would curve and curve until it closes in on itself. That is, if you make a light ray travel into outer space, it would eventually run out of things to see and will go back to its starting point.
With this brilliant idea in mind, Albert figured out an equation for the whole universe. This equation is really long and scary so I won’t dare show it to you. Besides, he realized a part of it (the cosmological constant, or the force that prevented the universe from collapsing) was a mistake after Edwin Hubble pointed out that the universe is expanding.