There is a model airplane discipline that has been around a very long=20 time. They use a type of rubber for their motors that is optimized and=20 standardized for competition. They achieve some amazing flight times. I=20 will leave it to those interested to pursue. On 9/9/2012 4:41 PM, Isaac Marino Bavaresco wrote: > I think that when the rubber band is stretched, the individual atoms > inside the molecules have less freedom to "jiggle" and need to do so in > a lesser amount of ways than when the molecules are un-stretched. > It may be similar to when a gas is compressed. Its molecules get closer > and collide a lot more. > > > Isaac > > > > > Em 9/9/2012 17:08, Sean Breheny escreveu: >> Yes, but they jiggle regardless of whether the band is stretched or >> not so I don't see how the jiggling provides any means of energy >> storage (other than normal thermal energy storage). >> >> Sean >> >> >> On Sat, Sep 8, 2012 at 11:02 PM, Paul Anderson wrot= e: >>> But they do jiggle faster and slower, depending on the temperature. >>> >>> -------- >>> Paul Anderson -- VE3HOP >>> >>> On 2012-09-08, at 7:45 PM, Sean Breheny wrote: >>> >>>> I think he is just talking about the thermal vibration of the >>>> molecules in the material. They are jiggling all the time, regardless >>>> of whether the rubber is stretched or not. His point is that the >>>> jiggling tends to kink the long-chain molecules so that their natural >>>> (at rest) length is shorter than their max possible (un-kinked) >>>> length. >>>> >>>> Sean >>>> >>>> >>>> On Sat, Sep 8, 2012 at 3:09 PM, Tamas Rudnai = wrote: >>>>> These "jiggling things" are very interesting. On that video Feynman c= laims >>>>> that when you tie some paper together with a rubber band particles in= side >>>>> keep "jiggling" as long as you keep it like that (except that rubber = does >>>>> not last forever). It seems to me that it is a very good way to store >>>>> energy for a longer period of time. >>>>> >>>>> Tamas >>>>> >>>>> >>>>> On 8 September 2012 10:51, Sean Breheny wrote: >>>>> >>>>>> Thanks! I had not found such a simple explanation before! >>>>>> >>>>>> On Sat, Sep 8, 2012 at 11:53 AM, Peter Johansson >>>>>> wrote: >>>>>>> On Sat, Sep 8, 2012 at 3:23 AM, Sean Breheny wro= te: >>>>>>> >>>>>>>> A long time ago I noticed that a rubber band feels cool after it i= s >>>>>>>> stretched and released. >>>>>>> The physics, as described by Feynman: >>>>>>> >>>>>>> http://www.youtube.com/watch?v=3DXRxAn2DRzgI >>>>>>> >>>>>>> -p. >>>>>>> -- >>>>>>> http://www.piclist.com PIC/SX FAQ & list archive >>>>>>> View/change your membership options at >>>>>>> http://mailman.mit.edu/mailman/listinfo/piclist >>>>>> -- >>>>>> http://www.piclist.com PIC/SX FAQ & list archive >>>>>> View/change your membership options at >>>>>> http://mailman.mit.edu/mailman/listinfo/piclist >>>>>> >>>>> >>>>> -- >>>>> int main() { char *a,*s,*q; printf(s=3D"int main() { char *a,*s,*q; >>>>> printf(s=3D%s%s%s, q=3D%s%s%s%s,s,q,q,a=3D%s%s%s%s,q,q,q,a,a,q); }", >>>>> q=3D"\"",s,q,q,a=3D"\\",q,q,q,a,a,q); } >>>>> -- >>>>> http://www.piclist.com PIC/SX FAQ & list archive >>>>> View/change your membership options at >>>>> http://mailman.mit.edu/mailman/listinfo/piclist >>>> -- >>>> http://www.piclist.com PIC/SX FAQ & list archive >>>> View/change your membership options at >>>> http://mailman.mit.edu/mailman/listinfo/piclist >>> -- >>> http://www.piclist.com PIC/SX FAQ & list archive >>> View/change your membership options at >>> http://mailman.mit.edu/mailman/listinfo/piclist --=20 John Ferrell W8CCW =93During times of universal deceit, Telling the TRUTH becomes a revolutionary act=94 George Orwell --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .