Cosmology

Cosmology is the branch of astronomy on the start, evolution, and of course the eventual fate of the universe.

Big Bang Theory

The Big Bang Theory is a theory that states that the universe 13.8 billion years ago was a point with infinite density, and that it expanded and evolved into the current universe. It went through the Radiation and is going through the Matter era.

Radiation era

The radiation era lasted around 50000 years. It consisted of the Planck Epoch, the Grand Unified Theory Epoch, the Quark Epoch, the Lepton Epoch and the Nuclear Epoch. During this time, protons and neutrons were formed. During the Nuclear Epoch, protons and neutrons fused into nuclei, producing the first element, helium.

Matter era

The matter era is still going on. It consists of the atomic, galactic and stellar epochs. In the atomic epoch, the cosmic microwave background appears and atoms of helium and hydrogen form. The Galactic epoch had large gas clouds of hydrogen form and turn into galaxies. This resulted in the Stellar epoch, where stars form from hydrogen and helium.

Dark energy era

The dark energy era is the current era. Dark energy is accelerating the expansion of the universe, which could end it.

Black Hole Mirage theory

The black hole mirage theory theorises that the universe formed from debris that were ejected by the collapse of a four-dimensional black hole. It states that the three-dimensional universe we live in is simply a brane of a black hole. It explains the universe's uniformity as there would've been ample time for the four-dimensional universe to reach a state of equilibrium.

End of the universe

The end of the universe depends on whether dark energy or gravity dominates the universe. It could end with the big freeze, if dark energy wins against gravity and acceleration stops, the big rip, which could happen if dark energy wins against not only gravity but the other fundamental forces, and the Big Crunch if gravity wins.

Epic reflection

This lesson seems to be ok. It was definitely a bit rushed, but the presenters were able to come up with filler at the last minute. I learnt about the epochs that led to today.