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 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: Introduction to Cosmology

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 An invisible form of matter that does not

Evidence for this theory is overwhelming, most notably the radiation. Discovered in 1964, the CMB is the "afterglow" of the Big Bang—faint radio signals coming from every direction in the sky, representing the moment the universe cooled enough for light to travel freely. 3. The Composition of the Cosmos Current data suggests we live in a "flat"

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.

A repulsive force that appears to be accelerating the expansion of the universe, pushing galaxies apart at an increasing rate. 4. The Fate of the Universe

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.