In the
physics
Physics is the natural science that studies matter, its fundamental constituents, its motion and behavior through space and time, and the related entities of energy and force. "Physical science is that department of knowledge which r ...
of
superfluidity
Superfluidity is the characteristic property of a fluid with zero viscosity which therefore flows without any loss of kinetic energy. When stirred, a superfluid forms vortices that continue to rotate indefinitely. Superfluidity occurs in two ...
, 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. Although superfluid helium-3 only exists within a few thousandths of a degree of
absolute zero, boojums have also been observed forming in various
liquid crystals, which exist at a far broader range of temperatures.
The boojum was named by
N. David Mermin
Nathaniel David Mermin (; born 30 March 1935) is a solid-state physicist at Cornell University best known for the eponymous Mermin–Wagner theorem, his application of the term " boojum" to superfluidity, his textbook with Neil Ashcroft on sol ...
of
Cornell University
Cornell University is a private statutory land-grant research university based in Ithaca, New York. It is a member of the Ivy League. Founded in 1865 by Ezra Cornell and Andrew Dickson White, Cornell was founded with the intention to tea ...
in 1976. He was inspired by
Lewis Carroll
Charles Lutwidge Dodgson (; 27 January 1832 – 14 January 1898), better known by his pen name Lewis Carroll, was an English author, poet and mathematician. His most notable works are '' Alice's Adventures in Wonderland'' (1865) and its sequ ...
's poem ''
The Hunting of the Snark
''The Hunting of the Snark'', subtitled ''An Agony in 8 Fits'', is a poem by the English writer Lewis Carroll. It is typically categorised as a nonsense poem. Written between 1874 and 1876, it borrows the setting, some creatures, and eight por ...
''. As in the poem, the appearance of a boojum can cause something (in this case, the supercurrent) to "''softly and suddenly vanish away''". Other, less whimsical names had already been suggested for the phenomenon, but Mermin was persistent. After an exchange of letters that Mermin describes as both "lengthy and hilarious",
the editors of ''
Physical Review Letters
''Physical Review Letters'' (''PRL''), established in 1958, is a peer-reviewed, scientific journal that is published 52 times per year by the American Physical Society. As also confirmed by various measurement standards, which include the ''Journa ...
'' agreed to his terminology. Research using the term "boojum" in a superfluid context was first published in 1977, and the term has since gained widespread acceptance in broader areas of physics. Its Russian phonetic equivalent is "budzhum", which is also well accepted by physicists.
The plural of the term is "boojums", a word initially disliked by Mermin (who at first used "booja") but one which is defined unambiguously by Carroll in his poem.
References
* A collection of articles by David Mermin, including "''E pluribus boojum''".
External links
* (5.4 MB).
** Reprinted here by Univ of Southampton, dept of Economics:
*Transcript of Mermin's 1999 lecture, in which he describes how he made "boojum" an internationally accepted scientific term: {{cite web, url=http://www.lassp.cornell.edu/~cew2/KnightLecture.html , title=Writing Physics , last=Mermin , first=N. David , date=April 19, 1999 , website=Knight Distinguished Lecture in Writing in the Disciplines , publisher=Cornell , accessdate=16 January 2014 , archiveurl=https://web.archive.org/web/20120828183555/http://www.lassp.cornell.edu/~cew2/KnightLecture.html , archivedate=August 28, 2012 , url-status=dead
Fluid dynamics
Superfluidity