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« Weird Questions and Weirder Answers Department: Curing Insanity | Main | Anniversary and Thank You »


Ray Girvan

I couldn't resist reconstructing the sum. The decimal point location isn't quite clear, but it's essentially
279808597221212130415979571232933594210766 divided by 67273337308854741368832000
= 4159279268941259.856432900344136492280378

A couple of minutes to transcribe: so little time to compute in Derive that it just registers as 0.000s. How far we've come.

John Ptak

Thanks for this Ray, I do appreciate it. I don't know the Derive site. I wonder how many hours all of this calculation took for this person; unfortunately there is no indicator of time. (I do have some manuscript engineering drawings, 19th c, big, that record the amount of time spent in execution. Very handy insight! Well, I don't know about "handy", but "interesting" will do.) Care to guess on the amount of time it would've taken for a good reckoner (without prodigious mental calculating abilities?)to do that work?

Ray Girvan

I estimate someone very practiced, with no special abilities, could do it in under an hour.

I tried one step. It took me 30 seconds to decide on a multiplier (I think that part could be vastly improved with familiarity); 70 seconds to do the multiplication; 90 seconds for the subtraction; 30 seconds for sundry transcription. Total 220 seconds. Repeat for the 16 digits: 3520 seconds = roughly an hour.

That'd be an ideal-case baseline, assuming no errors, no flagging with boredom, etc. Call it two hours, being realistic and including error-checking (casting out nines, for instance).

Derive isn't a website but a now-defunct symbolic math program.


Hey John,
Feynman was a game guy, very funny and down to earth. My husband works in Graphic Arts at Caltech and from time to time prints the photograph of the chalkboard from his last lecture. He was good buddies with a colorful local character named Zorthian. They swapped art and physics lessons but mostly flirted with women in local bars.

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