Introduction To Cosmology -

The foundation of modern cosmology was laid in the early 20th century. Before this, most scientists—including Albert Einstein—assumed the universe was static and eternal. However, in 1929, Edwin Hubble observed that distant galaxies are moving away from us. More importantly, the further away a galaxy is, the faster it recedes. This discovery of proved that the universe is expanding, implying it must have had a beginning. 2. The Big Bang Theory

The study of cosmology is our attempt to understand the universe as a single, physical entity. While early humans looked at the stars and created myths to explain the heavens, modern cosmology uses the rigorous tools of physics and mathematics to answer the "big questions": Where did we come from, how is the universe structured, and how will it end? 1. The Expanding Universe Introduction to Cosmology

If the universe is expanding today, it must have been smaller and denser in the past. The suggests that approximately 13.8 billion years ago, the entire observable universe was concentrated in a state of infinite density and heat called a singularity. The foundation of modern cosmology was laid in

An invisible form of matter that does not emit light but exerts gravitational pull, holding galaxies together. More importantly, the further away a galaxy is,

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

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:

Cosmology shifts our perspective from the local to the infinite. It reveals a universe that is dynamic, evolving, and largely invisible. While we have mapped the history of the cosmos back to its earliest seconds, the nature of dark energy and the exact mechanism of the Big Bang remain the great frontiers of modern science.