James Lackner has done just that. He has spun, done deep knee bends, turned somersaults. It is part of his work as director of the Graybiel Spatial Orientation Laboratory, at Brandeis University. Lackner has learned that, far from our being masters of the universe, ready to boldly go where no one has ever gone, we humans are very much slaves of Earth's gravity. We can adapt to environments other than 1-G, but it's no picnic.
Weightlessness looks like a blast on TV and in the movies.
For astronauts, however, it quickly becomes as hassle. If not for Velcro, foil-packed dinners, and special toilets, the space shuttle would be an even dirtier, more dangerous habitat than it already is. Even the neatest astronaut inadvertently contributes crud to cabin air, where it stays suspended, affecting eyes, lungs and delicate interments. Zero-G causes other problems as well, including calcium loss from bones, atrophy of muscles, and visual disorientation. What a mess that would be.