Scientists have now levitated mice using magnetic fields. 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 (6.6 cm) for tiny creatures to float comfortably in during experiments. Repeated levitation tests showed the mice, even when not sedated, could quickly acclimate to levitation inside the cage. The strong magnetic fields did not seem to have any negative impacts on the mice in the short term, and past studies have shown that rats did not suffer from adverse effects after 10 weeks of strong, non-levitating magnetic fields. The researchers also levitated water drops up to 2 inches wide (5 cm). This suggests the variable gravity simulator could be used to study how liquids behave under reduced gravity, such as how heat is transferred or how bubbles behave.