Cosmology Audio

This class is an introduction to the modern extragalactic astronomy and cosmology, i.e., the part of astrophysics that deals with the structure and evolution of the universe as a whole, and its major constituents: dark matter, dark energy, galaxies, quasars, large-scale structure, and intergalactic gas.

Ever since we discovered that distant galaxies are racing away from us, there has been a heated debate over just how fast the Universe is expanding. At the beginning of the 21st century, we thought we knew the answer. But now, two very different viewpoints have emerged. And they are dividing the scientific community. The Sky at Night meets leading astronomers and cosmologists on both sides of the debate. Which team has the right answer? Or could both teams be right? If so, we may need to rethink everything we think we know about the Universe.

About 100,000 to 60,000 years ago, a species of hominines—bipedal ape-like creatures—began to move out of its home territory in Africa and into the Asian continent. Today, homo sapiens, the descendants of those first hominines—live in nearly every ecological niche. We fly through the air in planes, communicate instantaneously over immense distances, and develop theories about the creation of the Universe.