Space Physiology: Gravity, More or Less

One way to longer life may be higher gravity—at least for rats. That is the "very tentative suggestion" of experiments performed by NASA Physiologist Jiro Oyama, who has been raising mice and rats under artificial gravities created by centrifuges at Ames Research Center in California. Whirling on an 8½-ft. centrifuge, two female rats survived for 47 months, a year longer than their normal three-year life span.

The answer to their longevity may well be the depletion of body fat. In other centrifuge experiments, Oyama subjected weanling rats (three to four weeks old) to 4.7 G. for three to six months. Within...