Peter once told me that when he was a kid, he left a note on a slip of paper in a library book for a future reader to find. The note said, “I’ll be a pie-eyed emu,” and added something like “If you understand this, contact me” and his address or possibly phone number.
He explained to me that he had at the time just discovered the equation
eiπ + 1 = 0
which he was delighted by: it combined the numbers e, i, pi, 1, and 0 in one equation.
And he wanted to find other like-minded people. So he figured that anyone who understood that his note was a reference to that equation would be a like-minded person. Kind of a message in a bottle, tossed out to the world in hope of finding kindred spirits.
(It reminds me of the Wilmar Shiras stories “In Hiding” and “Opening Doors,” which Peter introduced me to, in which at one point a super-bright boy posts a cryptic ad in hopes of finding others like him. In fact, it’s possible Peter wrote the note after reading those stories; I’m not sure. He probably would’ve read them around age ten or eleven.)
But I never quite understood Peter’s anecdote about leaving that note; in particular, although I could see the I and the pi and that the equals sign could be read as “be,” I never understood why “e” would become “emu.”
It turns out that the phrase comes from a 1942 Alfred Bester story, “The Push of a Finger.” Peter must have been reading back issues of Astounding, because he was only two and a half years old when the story was published there.
I haven’t read the story, but various people’s vague online memories of it suggest that the equation in the story did contain the Greek letter μ, and thus was not the equation that Peter was referring to.
I don’t know whether he was just conflating the memory of the phrase from the story with the equation he liked, or whether he misunderstood when he read the phrase as a kid, or what.