= B =
[uncommon; prob. from the nuclear military] An
unexpectedly large quantity of something: a unit of measurement.
"Why is /var/adm taking up so much space?" "The logs have grown
to several barns." The source of this is clear: when physicists
were first studying nuclear interactions, the probability was
thought to be proportional to the cross-sectional area of the
nucleus (this probability is still called the cross-section). Upon
experimenting, they discovered the interactions were far more
probable than expected; the nuclei were `as big as a barn'. The
units for cross-sections were christened Barns, (10^-24 cm^2) and
the book containing cross-sections has a picture
of a barn on the cover.
--The Jargon File version 4.3.1, ed. ESR, autonoded by rescdsk.