Flow of superfluid 3He.

To push some of the newly discovered superfluid 3He through a fine tube, in order to see how it behaved, might seem a particularly obvious experiment, were it not for the daunting difficulties inherent in working at temperatures near 2 mK. In fact, it is a quite remarkable achievement in terms of experimental design and technique that has enabled R. M. Mueller, E. B. Flint and E. D. Adams to report (Phys. Rev. Lett., 36, 1460; 1976) the first studies of equilibrium flow phenomena, only four years after observation of the superfluid phases was first suspected. Their experiments were carried out in the Physics Department at the University of Florida