Introduction to Astronomy November 2023

What is the Universe made of?

Guest Speaker: Jonathan Park

The main components of our Universe have been identified as ordinary matter, radiation, dark matter, and dark energy. Matter is the atoms of which everything we see is made, while radiation includes starlight and the cosmic microwave background in the universe. Dark matter is an invisible matter identified from many observations, including the speed at which stars orbit in spiral galaxies. Dark energy is the best explanation for why the expansion of the universe is speeding up rather than slowing down. In this talk, we learn about each of these. We will look at the evidence for dark matter and dark energy, what they might be, and how they affect the geometry and expansion of the universe.

This is an introduction to the topic, so it should be suitable for everyone, but we can go into more detail during the questions and answers after the talk for anyone who wants to know a little bit more.