Monday, October 15, 2007

Health on Luna

Many space advocates see the establishment of lunar bases as the first steps towards full-fledged lunar settlements, much as cities in the American West grew up around Army forts, tradiing posts, harbors, and railroad routes. It's an attractive argument to many, but it ignores at least one fundamental factor. People in nineteenth century America knew humans could survive in the plains, mountains, and deserts of the West. Today, it's not yet clear humans can live indefinitely on the Moon.

Radiation and the effect of low gravity on the human body over an extended period seem to pose the biggest health concerns. As we get into such a project, however, we may well find other negative factors. Building habitats in free space and controlling every aspect of the environment-- including radiation levels and the strength of gravity-- may be the only way humans can live lifetimes beyond Earth.

On the other hand, blocking radiation from reaching lunar settlement areas in thoroughly possible, and low gravity has its benefits. Falling on Luna, for example, would be a much slower affair. Most people could easily catch themselves. In any case, landing would not be the thump it is on Earth. Stress on the heart on Earth comes from requiring the heart to constantly, rhythmically push blood from the feet up against the pull of Earth's gravity. Lunar gravity is only one-sixth as strong. All else being equal, therefore, a human heart could last many times as long on Luna as it does on Earth. Throw in advanced medical care and a calm, functioning, fulfilling society and Lumans might enjoy absolutely Old Testament lifespans.

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