= G =
gedanken /g*-dahn'kn/ adj.
Ungrounded; impractical; not
well-thought-out; untried; untested.
`Gedanken' is a German word for `thought'. A thought
experiment is one you carry out in your head. In physics, the term
`gedanken experiment' is used to refer to an experiment that is
impractical to carry out, but useful to consider because it can
be reasoned about theoretically. (A classic gedanken experiment of
relativity theory involves thinking about a man in an elevator
accelerating through space.) Gedanken experiments are very useful
in physics, but must be used with care. It's too easy to idealize
away some important aspect of the real world in constructing the
Among hackers, accordingly, the word has a pejorative connotation.
It is typically used of a project, especially one in artificial
intelligence research, that is written up in grand detail
(typically as a Ph.D. thesis) without ever being implemented to
any great extent. Such a project is usually perpetrated by people
who aren't very good hackers or find programming distasteful or are
just in a hurry. A `gedanken thesis' is usually marked by an
obvious lack of intuition about what is programmable and what is
not, and about what does and does not constitute a clear
specification of an algorithm. See also AI-complete,
--The Jargon File version 4.3.1, ed. ESR, autonoded by rescdsk.