gedanken

/g@dahnkn/ , 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 apparatus. 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 , DWIM.

