"Parallel Universe" explains one of the most exciting and speculative areas in physics, parallel universes. The special, originally airing on the BBC in the UK in 2002, describes how the theory of parallel universes resulted from the esoteric battle to find a "theory of everything".
The Origin of a Revolution
The show explains the current scientific perspective on parallel universes through a historical context. Parallel universes are not a new idea. The idea has lurked in various cultures for millennia, in religion, superstition, and fiction, which is precisely why scientists tried to avoid and ignore it when in popped up early in the field of quantum mechanics. Quantum superposition, a phenomena exhibited by particles, meant that objects can be in more than one place at once, suggested that parallel universes exist.
Decades later, the development of string theory promised to explain the interactions of all the forces, but competing theories showed that no one theory was correct. In the mid-nineties this discrepancy was resolved when mathematical physicist Edward Witten showed that all of the theories were the same, if viewed in eleven dimensions.
A Maverick Idea
The new idea that Witten came up with was M Theory, and a major implication is that our universe exists in a multiverse filled with an infinite number of parallel universes.
Another result of M Theory is that it showed just what was banging in the Big Bang that originated our universe. Our universe exists on a brane (essentially a stretched out string), as do parallel universes. Occasionally, branes collide releasing enormous amounts of energy that explode into a separate space.
An Engaging Introduction
Parallel Universe explains this story clearly and enthrallingly. Beautiful, imaginative animated graphics help to explain the odd concepts. The pace is quick, perhaps a bit too quick for some not already familiar with the very basics of quantum mechanics and the Big Bang. String theory, however, is covered well for the neophyte. The interviews are interesting, and include pop physicists Michio Kaku (one of the co-founders of string theory) and Neil deGrasse Tyson (astrophysicist). Both ooze charisma and are frequently filmed.
The only drawback is that the show spends only a small amount of time on the future and philosophical implications of parallel universes. To be fair though, this is a reflection of the reserved facade of science, reticent to state officially pure speculation.
The hour long special is not currently released on DVD, but look for it on the Science Channel. A related program that airs as a NOVA special on PBS is Brian Greene's "The Elegant Universe". Of the two, Parallel Universe is a more straight forward and concise introduction, but both are good for anyone intrigued by parallel universes.
