There is a demonstration of the Feynman
sprinkler puzzle somewhere at MIT.

the link was posted last night. the guy who hijacked the professor's email
addy should have taken greater care in whose address he grabbed, for it would
seem the real professor at MIT would have long ago known of the demo that any
student -- or his mother or even little sisten in grade school -- could walk up
to and push the button to see for himself.