Scientists working on behalf of NASA built a device to simulate variable levels of gravity. It consists of a superconducting magnet that generates a field powerful enough to levitate the water inside living animals, with a space inside warm enough at room temperature and large enough at 2.6 inches wide for tiny creatures to float comfortably in during experiments.

The researchers first levitated a young mouse, just three-week-old and weighing 10 grams. It appeared agitated and disoriented, seemingly trying to hold on to something.

"It actually kicked around and started to spin, and without friction, it could spin faster and faster, and we think that made it even more disoriented," said researcher Yuanming Liu, a physicist at the Jet Propulsion Laboratory in Pasadena, Calif. They decided to mildly sedate the next mouse they levitated, which seemed content with floating.

I wonder if this would actually feel like freefall? I guess it would, since all of your tissues would be being lifted simultaneously, including in the fluid and hairs inside your semicircular canals.