Wednesday word: thalweg

[trellia-chan.livejournal.com]

thalweg: [tahl-veg or tahl-veyk]

Noun:

1. In geography and fluvial geomorphology:

a : A line following the lowest part of a valley whether under water (as in a river) or not. When underwater, the thalweg is

the longitudinal outline of a riverbed from source to mouth, measured from the deepest part of the river.

b : The line of continuous maximum descent from any point on a land surface or one crossing all contour lines at right angles. c : Subterranean water flowing beneath and in the same direction as a surface stream course.

2.  In international law:
The middle of the chief navigable channel of a waterway which constitutes a boundary line between states and countries.

Origin: 1831.  An English loan word from German. Thal meaning "valley" and weg meaning "way."  In German, the modern spelling of the word is Talweg.

Thursday word: heisenbug

[prettygoodword.livejournal.com]

heisenbug (HAI-zen-bug) - n., (computing) a software defect that alters its behavior or disappears when one attempts to isolate it.


Named by analogy from the Heisenberg Uncertainty Principle, as a metaphoric extension that misses the point of the original but never mind that. That heisenbugs exist is not as farfetched as it might seem, given that debugging tools alter the computing environment -- such as initializing variables that were not being initialized by the buggy code. The term is sometimes attributed to Jim Gray because of his use in a widely read 1985 article on software defects, but it appears at least two years earlier in the proceedings from a 1983 ACM conference.

Heisenbugs are usually resolved through very careful debugging.

---L.