Some of the world's leading physicists believe they have found startling new evidence showing the existence of universes other than our own. One possibility is that the universe is so vast that an exact replica of our Solar System, our planet and ourselves exists many times over. These Doppelganger Universes exist within our own Universe; in what scientist now call "The Multiverse." Today, trailblazing experiments by state of the art particle colliders are looking for evidence of higher dimensions and Parallel Universes. If proof is found, it will change our lives, our minds, our planet, our science and our universe.

As man moves to colonize the cosmos, the realities of sexual relationships and reproduction need to be addressed. Probe the physiological, psychological and cultural challenges of sex in space. From the sex act through birth, look at how the extreme environments of space exploration might effect copulation, conception and developing human tissues, as well as how issues around sex might impact the emotional lives of astronauts. Get to the bottom of the rumors to find out if space sex has already happened, and look at how the burgeoning space tourism business may soon lead to a boom in space sex.

Union Pacific's refrigeration train is the coolest train in the world. On its cross-country trip from Wallula, Washington, to Schenectady, New York, it employs the most high-tech mobile refrigeration technology in the world to keep its produce intact and fresh. Even the railcars themselves are stored inside a cooled facility so as not to break the cold chain for this delicate cargo. Also in this episode: how trains and trucks battled for business in the 1950s.

Could North America and parts of Europe be headed for a "big chill?" Many experts fear that an abrupt climate change could have catastrophic effects across the planet, including devastating winters in some northern regions. New research has indicated to scientists that the climate is changing rapidly and unpredictably. In different parts of the world, we could be facing drought, floods, storms and extreme cold. Cataclysmic climate changes, similar to what may happen to us, have happened in the past. The great Mayan civilization was knocked out by drought in a few generations. The Little Ice Age battered Europe. Within a decade, freezing temperatures increased and incessant storms brought starvation, disease, and death to millions. Could this happen again?