In the physics of superfluidity, a boojum is a geometric pattern on the surface of one of the phases of superfluid helium-3, whose motion can result in the decay of a supercurrent. A boojum can result from a monopole singularity in the bulk of the liquid being drawn to, and then "pinned" on a surface.

What does boojum mean in English?

: a tall spiny long-lived desert tree (Fouquieria columnaris synonym Idria columnaris) native to northwestern Mexico and related to the ocotillo.

How did the boojum get its name?

The plant's English name, Boojum, was given by Godfrey Sykes of the Desert Laboratory in Tucson, Arizona and is taken from Lewis Carroll's poem "The Hunting of the Snark".