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As much as yawaramin's comment about him poking fun at programmers is probably correct, Feynman wasn't a total stranger to computer science: > Feynman worked o

by stolio 12y ago

As much as yawaramin's comment about him poking fun at programmers is probably correct, Feynman wasn't a total stranger to computer science: > Feynman worked out the program for computing Hopfield's network on the Connection Machine in some detail. The part that he was proudest of was the subroutine for computing logarithms. I mention it here not only because it is a clever algorithm, but also because it is a specific contribution Richard made to the mainstream of computer science. He invented it at Los Alamos. http://longnow.org/essays/richard-feynman-connection-machine/ http://longnow.org/essays/richard-feynman-connection-machine...

bane 12y ago
If you read his books (which he dictates) he also appears to have come up with a basic concept of parallelism and pipelining which he managed to do on punchcard machines of the time by mixing up groups of different computations in the punchchard stacks based on dependent variables in the computations they were doing. Here's another telling of the story http://www.mphpa.org/classic/HISTORY/H-06c18.htm http://www.mphpa.org/classic/HISTORY/H-06c18.htm The new IBM punched-card machines were devoted to calculations to simulate implosion, and Metropolis and Feynman organized a race between them and the hand-computing group. "We set up a room with girls in it. Each one had a Marchant. But one was the multiplier, and another was the adder, and this one cubed, and all she did was cube this number and send it to the next one," said Feynmann. For one day, the hand computers kept up: "The only difference was that the IBM machines didn't get tired and could work three shifts. But the girls got tired after a while." Feynmann worked out a technique to run several calculations in parallel on the punched-card machines that reduced the time required. "The problems consisted of a bunch of cards that had to go through a cycle. First add, then multiply, and so it went through the cycle of machines in this room - slowly - as it went around and around. So we figured a way to put a different colored set of cards through a cycle too, but out of phase. We'd do two or three problems at a time," explained Feynman. Three months were required for the first calculation, and Feynman's technique reduced it to two or three weeks.

by stolio 12y ago

bane 12y ago

If you read his books (which he dictates) he also appears to have come up with a basic concept of parallelism and pipelining which he managed to do on punchcard machines of the time by mixing up groups of different computations in the punchchard stacks based on dependent variables in the computations they were doing. Here's another telling of the story http://www.mphpa.org/classic/HISTORY/H-06c18.htm http://www.mphpa.org/classic/HISTORY/H-06c18.htm The new IBM punched-card machines were devoted to calculations to simulate implosion, and Metropolis and Feynman organized a race between them and the hand-computing group. "We set up a room with girls in it. Each one had a Marchant. But one was the multiplier, and another was the adder, and this one cubed, and all she did was cube this number and send it to the next one," said Feynmann. For one day, the hand computers kept up: "The only difference was that the IBM machines didn't get tired and could work three shifts. But the girls got tired after a while." Feynmann worked out a technique to run several calculations in parallel on the punched-card machines that reduced the time required. "The problems consisted of a bunch of cards that had to go through a cycle. First add, then multiply, and so it went through the cycle of machines in this room - slowly - as it went around and around. So we figured a way to put a different colored set of cards through a cycle too, but out of phase. We'd do two or three problems at a time," explained Feynman. Three months were required for the first calculation, and Feynman's technique reduced it to two or three weeks.