Weightless

The ease with which man adapts to weightlessness is a fascinating mystery. Considering that for many people travel by sea or even by car can cause bouts of nausea, one can’t help feeling perplexed. During month-long spells in space the astronauts complained only of passing discomforts, and doctors who examined them afterwards discovered a light decalcification of the bones and a transitory atrophy of the heart muscles: the same effects, in other words, produced by a period of confinement to bed. Yet nothing in our long history of evolution could have prepared us for a condition as unnatural as non-gravity.