Re: reverse water sprinkler

[DEVARAKONDA VENKATA NARAYANA SARMA <narayana@HD1.DOT.NET.IN>]

 From "Surely you are joking, Mr.Feynman"
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The answer is perfectly clear at first sight. The trouble was, some guy
would think that it is perfectly clear one way, and the other guy would
think that it is perfectly clear the other way. So everybody was discussing
it. I remember that at one particular seminar, or tea, somebody went up to
Prof. John Wheeler and said "Which way do you think it goes round?"

Wheeler said, "Yesterday, Feynman convinced me that it went backwards.
Today, he convinced me equally well that it goes round the other way.
I do not know what he will convince me of tomorrow!"
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regards,

sarma.
At 04:08 PM 12/7/99 -0500, you wrote:
> Once when I was in college,  a fellow physics major stormed into the
> physics library all fired up about a question about a water sprinkler and
> which way would it spin if you ran it backwards.  Later I found that the
> question was popularized in one of Feynman's books (I think it was _Surely
> You're Joking_) in which Feynman makes a mess in someone's lab trying to
> answer he question.  At the time I remember it as a curious but not
> particularly important puzzle.  Now one of my students has put that puzzle
> back on the front burner for me.