One of the Universe's most enduring mysteries is Time Travel. In this episode, we explore the possibilities. Discover why Time Travel into the future is unavoidable in the Einsteinian world of Relativity. As for the past... the laws of physics do not tell us it's impossible, but the bizarre consequences of going into the past and altering the future make for mind-bending science. Finally, we go for the future by traveling to the nearest star, 4.3 light years away... in only 45 days. Our destination may be an Earth-like planet; a planet scientists are now hunting for, and may find in the next 3 to 4 years.
In the last few years, the Red Planet has yielded up many new clues that life may have once existed there...and may even exist there today. There is now have proof that water once flowed on the surface, that Mars once had lakes, and that the frozen poles are mostly water, not carbon dioxide as previously thought. Mars has snow--an aurora--and lightning generated by dust storms. Most intriguing of all are the seasonal plumes of methane that just may point to bacteria living below the surface.
Take a tour through the Art Gallery of the Galaxy and view what are considered the "crown jewels" of the heavens. Nebulas are mysterious clouds of gas that aren't classified as stars, planets, moons or asteroids. Astronomers use the most sophisticated techniques to view them since they are practically invisible to the naked eye. Nothing less than stunning, nebulas glow, reflect or obscure the galaxy's light with amazing swirls of color. Nebulas mark the regions where the nothingness of space first coalesces, where stars are born and where stars die. Cutting-edge computer graphics are used to bring the universe down to earth.
Black Holes are one of the most destructive forces in the universe, capable of tearing a planet apart and swallowing an entire star. Yet scientists now believe they could hold the key to answering the ultimate question - what was there before the Big Bang? The trouble is that researching them is next to impossible. Black holes are by definition invisible and there's no scientific theory able to explain them. Meet the astronomers attempting to image a black hole for the very first time and the theoretical physicists getting ever closer to unlocking their mysteries. It's a story that takes us into the heart of a black hole and to the very edge of what we think we know about the universe.
The Universe as we know it is condemned to death. Space, matter and even time will one day cease to exist and there's nothing we can do about it. Harsh realities are revealed about the future of our Universe; it may collapse and burn or it might be gripped by a galactic ice age. Either of these scenarios might be a long way off. However, our Universe could suddenly be destroyed by a "random quantum fluctuation", a bubble of destruction that can obliterate the entire cosmos in the blink of an eye. No matter how it ends, life in our Universe is doomed.
