I think Sarma's quote from Ziman might ring truer with astronomers
than with biologists. Astronomers can't do experiments to test
hypotheses. I think it is fair to say that in atronomy the making
of hypotheses is so unimportant that little attention is given to
it. Almost all hypotheses are implicit.
I thought John Denker's subject line (above) related to the silly
practice of putting puzzles on exams, something I detest, but from
which I profitted as a student. The diagonal resistance of a cube
of one ohm resistors is the example that comes to mind.