High-G Life

In a basement at the College of Medicine of State University of Iowa, a centrifuge whirligigs at 95 r.p.m. From 14 cages spinning about on the centrifuge come the squeaks of mice and hamsters that have spent most or all of their lives under conditions of high gravitation. Last week Physiology Professor Charles C. Wunder, who conducts the experiments, announced that his centrifuged mice have conceived, delivered and raised nine litters at up to 2Gs (the gravitational force at the earth's surface is figured at 1G; at more than 1G. earth's creatures feel heavier; at less than 1G, lighter). Neither parents nor offspring were seriously bothered by the twice-normal weight of their bodies. "We weren't really studying breeding," said Dr. Wunder. "It just happened. For some reason, every spring there seems to be an upsurge in the centrifuge."

An obvious problem of the space age is how humans will exist under high or low gravitation conditions. Men have been tested on centrifuges that simulate high gravitation, but only for short periods. For experiments extending over months and years, laboratory animals must be used, and some of the results have been fascinating.

Elephant Walk. "Under increased gravity," says Wunder, after studying motion pictures of his high-G hamsters, "the hamsters walk around and seem to adapt very nicely, but their walking pattern is more like an elephant than a hamster. They're a bit perturbed about having to carry a bigger load." When young mice or hamsters are put on a centrifuge, they usually lose considerable weight for three or four days. "Apparently they have trouble digesting their food," says Dr. Wunder. "They level off and gain back their original weight, but they never get as big as ordinary mice."

After as little as one week, the femurs (leg bones) of young mice get rounder in cross section than normal femurs. Dr. Wunder believes that this change is an adaptation to strengthen the bone and allow it to support the abnormal weight of the high-G mouse. Chickens react in somewhat the same way: Dr. Alfred Smith of the University of California has found that when they are centrifuged, the anti-gravity muscles of their drumsticks grow to as much as seven times normal. But chickens are not so successful as mice at high-G reproduction. They try--but tend to lay flat, infertile eggs.

Elephant Legs? California's Smith has also noticed that when his chickens have got used to living at 4Gs, they have a good deal of trouble when taken off the centrifuge and forced to live like other chickens in the earth's normal 1-G field. "It looks as if they get a stoppage of the gut," he says. "After all, at 4-Gs their hearts were pumping fluid with the normal density of molten iron." At the present point in their experiments, neither Wunder nor Smith cares to predict the effect on the human body of space-age gravitational changes. But the logical extension of the test results so far would indicate that a child growing up on the moon, with its .16-G force, would have light bones. And the legs of a lady on Jupiter, with its 2.65-G surface, might be as thick as an elephant's.

This file is automatically generated by a robot program, so reader's discretion is required.