The levitation in air of water, other diamagnetic substances¹ and even living organisms² was recently achieved by using the extremely strong magnetic field provided by a Bitter-type hybrid magnet. We too have succeeded in levitating water, but in the lower fields of an ordinary 10 T superconducting magnet. To achieve this we make use of gravitational and magnetically induced buoyancy forces in the host paramagnetic atmosphere (pressurized air or oxygen), rather than simply the diamagnetic force on the levitating object, to balance the gravitational force. This permits the magnetic levitation in air of paramagnetic as well as diamagnetic substances, which was widely believed to be impossible³. The physics underlying this effect is essentially the same as that of magnetohydrostatic ore separation, where a ferromagnetic fluid is used⁴. Because our process can levitate subtances at a stable position in an atmosphere, we have named it 'magneto-Archimedes levitation'.

1. Department of Applied Chemistry, Department of Superconductivity, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113–8656, Japan
2. Japan Science and Technology Corporation, 4-1-8 Honcho, Kawaguchi, 332-0012 Japan
3. TDK Co., Ltd, Materials Research Center, 570-2 Matsugashita, Minamihatori, Narita, 286–8588 Japan