Our planetary home is the wrong shape, says SETI Institute’s Seth Shostak. A sphere has less surface area than any other form of the same volume.

Gerald O’Neill’s proposed mammoth, rotating aluminum cylinders in orbit have a very low tonnage-to-terran ratio. Rather than crowding a few billion people onto the moon, for example, where residents will have to contend with such domestic inconveniences as no air, no water, and no going outside without #5,000,000 sun-block, we can take the moon apart and redevelop it as a dream suburbia.