Stephen Hawking: Think Beyond the Planet
Stating the obvious, perhaps. The idea for space colonization dates back at least a century, when the Russian rocket pioneer Konstantin Eduardovich Tsiolkovsky said, "Earth is the cradle of mankind... but one cannot live in the cradle forever!" But Hawking took his argument a step further: Before we simply pack up and move to Mars or some other planet, we should consider what kind of structure is truly best for us.
As spheres, Hawking says, planets have less surface space than many other geometric shapes, and have a hard time accommodating rapidly growing populations. Artificial habitats such as rotating cylinders proposed by Gerald O'Neill and Tom Heppenheimer in the 1970s would be a more efficient and cost-effective way to go. Completely artificial space colonies might make their inhabitants feel a bit like hamsters, but at least those folks wouldn't have to terraform a planet with a hostile environment. Even asteroids might be preferable habitats, as their asymmetrical shapes offer higher ratios of surface area to volume.
To space enthusiasts, much of what Dr. Hawking said is not new, but his endorsement of space colonization only adds to its credibility. Unfortunately, any such endeavor would take a colossal worldwide commitment of time and money, as well as an abundance of visionary leadership -- resources not readily found in either the public or private sector these days. Just as it took the authority of Albert Einstein to alert Washington to the power and danger of nuclear energy during World War II, some current or future world leader might be listening to what Stephen Hawking has to say.