Who needs billiard balls when you have soldier crabs? http://www.technologyreview.com/view/427494/computer-scientists-build-comput... A billiard-ball computer was on display in the lobby of MIT's Stata Center a couple of weeks ago. It was fun to run it once, but we didn't have time to learn to reset it. Feeding the balls through a second time was boring, as the machine was in, and stayed in, the halt state. Who can beat elephants pulling on ropes 1200 years ago to calculate navigation parameters in binary? It must be true, it was in Scientific American. http://ftp.math.utah.edu/pub/tex/bib/sciam1980.html#Anonymous:1988:ARP The full article isn't as easily found online as it was years ago. "An ancient rope-and-pulley computer is unearthed in the jungle of Apraphul By A. K. Dewdney" (v 258 no. 4, April, 1988) On Thu, Sep 11, 2014 at 4:49 PM, Bill Gosper <billgosper@gmail.com> wrote:
HGB>I guess the Galton box qualifies as a mechanical calculator for a Gaussian: https://en.wikipedia.org/wiki/Bean_machine
Also, Fredkin's billiard ball computer: https://en.wikipedia.org/wiki/Billiard-ball_computer
And then there's those wonderful 1960's mechanical desktop "calculators"; I recall seeing one in the 1950's multiply two large numbers; they were amazing to watch! <HGB
Even from a distance. The Friden (and I think, Marchant) machines had a column of 10 togglable keys for each of 10 digit positions, and a 20 digit accumulator carriage that chugged back and forth. The Friden I used in 1961 to Monte-Carlo submarine kill probabilities(!) could also take the 10 digit square root of the 20 digits in the accumulator. Unless the carriage was too close to an immovable object, whereupon you enjoyed the screech of stripping gears, and a multihundred dollar, multiday repair job.
HGB> Some of IBM's early punch card machines were deliciously electromechanical, < and LOUD (and plugboard programmable) HGB> with grease everywhere. Also, some of their disk drives and printers I used in the 1960's had _hydraulic_ mechanisms; the IBM CE's looked more like car mechanics than computer engineers!
And UNIVAC CEs were more like shipyard workers than car mechanics. UNIVAC tape drives were frightening.
And the 1206 CPU, built like a bank vault, though solid state, required such
deafeningly ferocious cooling that you could Bernoulli-levitate a football
in the vertical exhaust.
--rwg
Also, selected Stanford AI alumni have coffee tables made from Librascope
disk platters.
At 11:39 AM 9/11/2014, Dave Dyer wrote:
I nominate Turing's analog computer to find zeta function zeros, described in the Hodges biography.
Also, obviously, the concept of physically realizing Turing machines using punched tape and mechanical reader/writer mechanisms.
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