phase
1. n. The offset of one's waking-sleeping schedule with
respect to the standard 24-hour cycle; a useful concept among
people who often work at night and/or according to no fixed
schedule. It is not uncommon to change one's phase by as much as
6 hours per day on a regular basis. "What's your phase?" "I've
been getting in about 8 P.M. lately, but I'm going
to wrap around to the day
schedule by Friday." A person who is roughly 12 hours out of
phase is sometimes said to be in `night mode'. (The term `day
mode' is also (but less frequently) used, meaning you're working
9 to 5 (or, more likely, 10 to 6).) The act of altering one's
cycle is called `changing phase'; `phase shifting' has also been
recently reported from Caltech. 2. `change phase the hard way':
To stay awake for a very long time in order to get into a
different phase. 3. `change phase the easy way': To stay asleep,
etc. However, some claim that either staying awake longer or
sleeping longer is easy, and that it is shortening your
day or night that is really hard (see wrap around). The `jet lag' that
afflicts travelers who cross many time-zone boundaries may be
attributed to two distinct causes: the strain of travel per se,
and the strain of changing phase. Hackers who suddenly find that
they must change phase drastically in a short period of time,
particularly the hard way, experience something very like jet lag
without traveling.
Node:phase of the moon,
Next:phase-wrapping,
Previous:phase, Up:= P =
phase of the moon n.
Used humorously as a random parameter on which something is
said to depend. Sometimes implies unreliability of whatever is
dependent, or that reliability seems to be dependent on
conditions nobody has been able to determine. "This feature
depends on having the channel open in mumble mode, having the foo
switch set, and on the phase of the moon." See also heisenbug.
True story: Once upon a time there was a program bug that
really did depend on the phase of the moon. There was a little
subroutine that had traditionally been used in various programs
at MIT to calculate an approximation to the moon's true phase.
GLS incorporated this routine into a LISP program that, when it
wrote out a file, would print a timestamp line almost 80
characters long. Very occasionally the first line of the message
would be too long and would overflow onto the next line, and when
the file was later read back in the program would barf. The length of the first line depended on
both the precise date and time and the length of the phase
specification when the timestamp was printed, and so the bug
literally depended on the phase of the moon!
The first paper edition of the Jargon File (Steele-1983)
included an example of one of the timestamp lines that exhibited
this bug, but the typesetter `corrected' it. This has since been
described as the phase-of-the-moon-bug bug.
However, beware of assumptions. A few years ago, engineers of
CERN (European Center for Nuclear Research) were baffled by some
errors in experiments conducted with the LEP particle
accelerator. As the formidable amount of data generated by such
devices is heavily processed by computers before being seen by
humans, many people suggested the software was somehow sensitive
to the phase of the moon. A few desperate engineers discovered
the truth; the error turned out to be the result of a tiny change
in the geometry of the 27km circumference ring, physically caused
by the deformation of the Earth by the passage of the Moon! This
story has entered physics folklore as a Newtonian vengeance on
particle physics and as an example of the relevance of the
simplest and oldest physical laws to the most modern science.