Art Bell returned for an in-depth conversation with scientist and author Michio Kaku, covering such topics as atomic weapons, the environment, genetic experimentation, future technology, parallel worlds, and cosmology. We've already passed one point of no return-- the melting of the North Pole; this will change the way our descendants experience the planet, Kaku declared. The polar melting will cause more release of methane, possibly setting up a "positive feedback loop" that will further warm up tundras, he explained.

The genome of Neanderthals has been mostly mapped out, and an egg created from their DNA could potentially be gestated in a chimpanzee, in order to recreate a Neanderthal, Kaku noted, adding that no laws are in place yet to guide this kind of mind-boggling experimentation. On the technology front, he pointed out that by 2020 when Moore's Law of computing power has reached its peak, the subsequent stagnation could lead to an economic depression. However, if quantum computing is successfully developed, it could offer a leap forward in sophistication and ability.

Nanotechnology, he said, holds out promise to revolutionize medicine. For instance, nanobots could be injected to kill individual cancer cells. Parallel universes could co-exist with us, such as in our own living rooms, said Kaku, though there is an astronomically small chance we would ever enter into one of these worlds. More and more, cosmologists and physicists are warming to the multiverse idea, and the notion that our universe may have been created by a collision with another bubble universe, he shared.