In a funny 'interview' of Rajan Mahadevan, champion mnemonist, a famous humorist of the Usenet generation (whose name eludes me at the moment), described how Mahadevan attempted to prove to him that he could memorise any string of numbers he was shown. It went something like this:
"What's your credit card number?" said Mahadevan.
"5413, ..." said the humorist. "Yeah, real smooth. You nearly got me there."
Now Mahadevan is famous for his recital of several tens of thousand digits of p from memory. He is exceptional in this regard, of course. I can barely hold ten digits of a phone number in my head: by the time I dial the first few, I've forgotten the last. It's possible that my short-term memory is all shot to pieces, because I still recall our home phone number in Moscow (2320960) - and that was from 30 years ago. Thus, garbage accumulates in the brain.
I remember reading about the mathematicians at Princeton's Institute of Advanced Studies in the 1930s who played chess with each other - mentally. Of course, I have no recollection of where exactly I read this. Possibly some biography of Einstein. Or was it of Feynman? At any rate, they would swap moves verbally, and follow the progress of their game in their heads, without recourse to a board. Their visual imagination was so powerful that they couldn't be cheated by illegal plays.
Isn't that a neat trick?
I was reminded of Mahadevan and the humorist and the mathematicians when I read what the wife of that brilliant polymath Joseph Needham said about his eidetic recall. This is a quote from Simon Winchester's biography of Needham, reviewed in the International Herald Tribune:
Formidable.“She recalled watching him lying awake in bed, mentally visualizing the book’s page proofs, and then correcting in a notebook any errors or infelicities. Once this activity became too humdrum for him, she said, he further occupied himself by translating the selfsame pages from English into French, also in his head, and then correcting any errors that he fancied he could also see in this new translated text.”
