Everything we know about our universe is through the medium of light, or more generally, electromagnetic radiation. Light also gives us a yardstick for measuring distance as well as giving us the unique advantage of being able to look back in time as we look deep into space. With today’s telescopes we can examine the universe the way it was when it was about 1/20th of its present age. Our earliest view of the universe is the so called microwave background radiation, recently studied by the Planck satellite, which reveals the conditions in our universe when it was about 270,000 years old and 1/1000 its present size.
Although there are many details still to be understood, this is a good time for such a review because we stand at a unique moment in the history of astronomy when we can tell the story of the evolution of the Universe from when it was a fraction of a second old to the present day and even look into the future.
This series of five lectures starts a brief overview of the contents of our Universe from the point of view of an astronomer. They reveal that our Universe contains not just the familiar, planets, stars and galaxies but that clusters of galaxies are immersed in giant haloes of gas so hot they emit X rays as well as haloes of mysterious dark matter that outweigh all other matter. On the very largest scale the evolution of the universe is dominated by the even stranger vacuum energy, about which we know even less.
Closer to home, we will see how stars manufacture all the elements that make up our bodies and everything we see around us. We will then take a closer look at our own star, the Sun, and see how it works and how it influences our climate. From there we will tour the planets in our solar system and see the great variety of landscape they offer, as well as how we think they were formed. Finally, we will consider the possibility that we might be the only conscious observers of our Universe. If this is true it may have a bearing on how we see and even manage our own future.
