Introduction To Cosmology Guide

One of the most surprising realizations in cosmology is that the atoms that make up stars, planets, and people account for only about 5% of the universe. The rest is composed of two mysterious substances:

The ultimate fate of the cosmos depends on the battle between gravity and dark energy. Current data suggests we live in a "flat" universe dominated by dark energy, leading to a scenario known as the In this future, galaxies will move so far apart they become invisible to one other, stars will run out of fuel, and the universe will eventually become a cold, dark, and empty void. Conclusion Introduction to Cosmology

An invisible form of matter that does not emit light but exerts gravitational pull, holding galaxies together. One of the most surprising realizations in cosmology