- Boojum (superfluidity)
In the
physics ofsuperfluidity , a boojum is ageometric pattern on the surface of one of the phases ofsuperfluid helium-3 , whose motion can result in the decay of asupercurrent . A boojum can result from amonopole 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 ofabsolute zero , boojums have also been observed forming in variousliquid crystal s at room temperature.The boojum was named by
David Mermin ofCornell University in1976 . He was inspired byLewis Carroll 's poem "The Hunting of the Snark ". 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" [http://www.cornell.edu/academics/faculty/dmermin.cfm] , the editors of "Physical Review Letters " agreed to his terminology. Research using the term "boojum" in a superfluid context was first published in1977 , 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.
External links
* [http://www.physicstoday.com/pt/vol-34/iss-4/vol34no4p46-53.pdf "E pluribus boojum": the physicist as neologist", Physics Today, Vol. 34, April 1981, pp. 46–53] (5.4 MB).
* [http://www.lassp.cornell.edu/~cew2/KnightLecture.html Transcript of Mermin's 1999 lecture, in which he describes how he made "boojum" an internationally-accepted scientific term.]
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