[cbr]

> ended up learning which days were sunny and which were overcast.

The earliest source I can find for this is https://neil.fraser.name/writing/tank/ but it says it "might be apocryphal".

[cbr]

Actually, there's also the 1992 paper "What Artificial Experts Can and Cannot Do" [1] which gives this anecdote and calls it a "legend".

[1] http://www.jefftk.com/dreyfus92.pdf

[rrmm]

Nice sleuthing! I don't even recall where I first heard this story myself. The paper was an interesting read and still largely applicable even now in this 3rd or 4th coming of NN's.

[cbr]

Expanded this into a post: http://www.jefftk.com/p/detecting-tanks