Harvard professor and best-selling author, Dr. Lisa Randall, simplifies and expounds upon some of modern physics' most basic questions. What is dark matter and dark energy? What is the fundamental nature of space and time? What do we not know yet about the universe and its fundamental properties?
Today Phil helps keep you from ticking off an astronomer in your life by making sure you know the difference between a meteor, meteorite, and meteoroid. When the Earth plows through the stream emitted by a comet we get a meteor shower. Meteors burn up about 100 km above the Earth, but some survive to hit the ground. Most of these meteorites are rocky, some are metallic, and a few are a mix of the two. Very big meteorites can be a very big problem, but there are plans in the works to prevent us from going the way of the dinosaurs.
Where and how are we going into space post Space Shuttle? Further travel in space is inhibited by the challenges of gravity wells and the science and cost of developing vehicles that can transcend them. How can the moon possibly help with this problem and move space exploration to the next level?
Ideas about time and space are explored in the changes that constellations undergo over time, the redshift and blue shift measured in interstellar objects, time dilation in Albert Einstein's theory of relativity, the designs of both Leonardo da Vinci and spacecraft that could travel near light speed, time travel and its hypothetical effects on human history, the origins of the Solar System, the history of life, and the immensity of space. In Cosmos Update, the idea of faster-than-light travel by wormholes (researched by Kip Thorne and shown in Sagan’s novel Contact) is discussed.