Feynman and Pauling Video Snippets. . .
Feynman's Interest in SpaghettiIn a 1993 Nova program (by film-maker Sykes) and the 1994 book "No Ordinary Genuis" (edited by Sykes) Daniel W. Hillis fondly recalls an evening with Feynman breaking spaghetti, unsuccessfully trying to discover why it breaks in three pieces. Here is a video snippet of the interview:
Spaghetti Stumps The Chief. 150KB, 60 secs
The seemingly simple problem was succinctly posed by Hillis as "Why does spaghetti break in 3 pieces?" Well, it doesn't always break in exactly 3 peices, but it happens often enough that many children and adults have probably wondered about it. Such a simple observation defying explanation from a great physicist sparked interest from many people - especially Feynman fans. At the bottom of this page you can see newsgroup posts from 1993 wondering about it in response to the Nova program. An illucidation of the spaghetti solution was provided in 2005 by a January 2005 research paper followed by an August 2005 paper, both in Physical Review Letters. This sparked media coverage, the best of which was in Science News.
A similar problem asking which way a sprinkler turns when run backwards in a tank of water was also presented without solution in his "Surely You're Joking Mr. Feynman" and in the popular Feynman biography "Genuis". The latter states John Wheeler said Feynman had absolutely convinced him it would turn one way on one day, then the other way the next day, and that he didn't know what Feynman would convince him of the next day. Feynman conducted the experiment and found the solution, but he and Wheeler would never reveal the solution so that others could have fun pondering it. It is often referred to as a Feynman Sprinkler.
Other Feynman Videos
Linus PaulingPauling wrote a letter to Feynman to try to get him to try vitamin C for his stomach cancer, right after the first surgery. Pauling's research indicated those with stomach cancer (although not necessarily Feynman's particular rare type) would live 4 times longer on 10 g a day. For several reasonable reasons, Feynman politely rejected Pauling's request but wrote that he would nevertheless give the research data over to the talented doctor Feynman trusted.
==================== Benjamin J. Tilly Dec 26 1993, 1:59 pm Newsgroups: sci.physics Subject: Spaghetti? There was a problem mentioned on the NOVA program about Feynman which is why spaghetti breaks into three pieces when you snap it. Feynman and a friend of his were not able to come up with a good answer despite several hours and a lot of broken spaghetti. Well I began thinking about it and I have no real idea what the answer is either, but I have noticed that if I bend it slowly then it breaks in two *unequal* pieces instead of three. So what I would guess is that it breaks in two unequal pieces and then the recoil of the longer piece snaps that in two. Or it could have something to do with the position of the hands when you break it. But I do not know. So would anyone out there like to take a highspeed camera and some spaghetti and run some quick experiments? Any other theories out there? Ben Tilly ============ Matt Heavner Dec 27 1993, 2:49 am show options Newsgroups: sci.physics Subject: Re: Spaghetti? I also tried to do some spaghetti experiments after watching the Feynman special on Nova. I was using the long spaghetti (twice the length of 'normal' spaghetti--or about 2/3 meter instead of 1/3 meter). When I held it at each end, it split into two pieces. Then when I took one of those two pieces (nearly the same size) and broke it, it split into three pieces. I could take some of the smaller pieces and break them--either into two or three pieces. It seems that the length of the spaghetti is important... I didn't get lots of data however, the sauce also had to be made.... Matt Heavner ================== Nov 16, 1999, sci.physics.research I would think about shockwaves being created at the first break up. I bet if one measures the process you'll find two peaks separated by a split of a second. And they might have opposite signs also. BTW: The equipment to use would be a camera, a flashlight and an acoustic sensor. -- Lorenz Borsche http://www.borsche.de =================== Dr. Michael Albert wrote: > strands tend to break into three pieces instead of two, > with the central pieces being ejected with considerable If you bend a single spaghetti, there are two points where the curvature is maximal, so it will break at one of them, thus removing the tension from the other one. If you have a bundle, the ones broken e.g. at the right point are kept in place by the non-broken ones, so they still fell the tension at the left point and break there too. Those who break only at one point will act as springs and eject the central pieces of the doubly-broken ones. Ralf ========================= Charles Francis Nov 18 1999, 3:00 am >If you bend a single spaghetti, there are two points where the >curvature is maximal, so it will break at one of them, thus >removing the tension from the other one. I thought this was not my experience, so I tested it, on six individual strands. In each case the spaghetti broke first at the point of maximum curvature, creating a whiplash effect in each of the pieces, which broke again at least once, ejecting the pieces with some speed. In no instance did I obtain less than four pieces, only twice did I obtain four pieces, and on one occaision there seemed to be seven pieces. The experiment may depend on who is holding the ends of the spaghetti, and also the brand. -- Charles Francis ===================== Well, now, this is interesting. I always thought this odd-fracturing rule reflected some pretty deep topology. I'll have to check my fallible memory and report back, though. Meanwhile, someone please get a bunch of identical paper soda straws. Stand one on end and press until it buckles. Repeat until you see a pattern. I think you should almost always fractures into three pieces in zig-zag fashion, never two or four, but sometimes five pieces. Next, try the same thing with single sphagetti strands. If you are careful to press vertically, I'd guess you get three piece fracturing. Experimentalists, to your lab benches! :-) Chris Hillman