Astronomy Cast-Observations 2

http://www.astronomycast.com/astronomy/ep-79-how-big-is-the-universe/
This episode is the sequel to the episode that I last listened to. It discusses how big the universe is. It starts by discussing how much of the universe we can actually see and we get a distance of somewhere between 70 and 80 billion light-years, although the universe has only existed for a fraction of this time. This is because of the rapidly expanding universe due to dark energy. It then talked about how large we think the universe is and the relatively small amount of the universe that is visible to us.