Source : Free On-Line Dictionary of Computing

Gedanken
     
        John Reynolds, 1970.  "GEDANKEN - A Simple Typeless Language
        Based on the Principle of Completeness and the Reference
        Concept", J.C.  Reynolds, CACM 13(5):308-319 (May 1970).
     
        [{Jargon File}]

gedanken
     
        /g*-dahn'kn/ 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 idealise 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}.