"The Green Flash", number 148 of 188 from Robert Aitken's book Miniatures of a Zen Master.

Life is full of practical jokes and Aitken's grandfather perpetrated one on unsuspecting visitors to his workplace. He worked as a astronomer
at the Lick Observatory. He would tell visitors that the best way to see the green flash of the setting sun was to "turn your back on the sunset and bend over and watch for the flash there between your legs."

What a silly sight that must have been. Whole families lined up all bent over watching the sun set. An astronomer's practical joke. At the same time, those bent over were willing participants, giggling at themselves all along.