> On 12 September 2012 05:50, Barry Gershenfeld wrote: > I then worked out, on my own, that if I let it return to room > temperature, and then relax it, it would take up that same heat and get > cold. I think this is a fundamental thing most non-technical people don'= t > understand. They get that things can be made cold, but they don't > understand the "taking heat from surroundings" thing. So, the rubber ban= d > is an excellent demonstration of this, and then could be extended (heh) t= o > the trick of absorbing heat in one place, transporting it somewhere else, > and releasing it (the Refrigeration trick). I kind of doubt it would be > an efficient method, but for demonstration purposes it would be quite an > interesting thing. And you explain the principle of refrigeration withou= t > cans of Freon--you just hand out some rubber bands. Yes. I mentioned the idea of refrigeration in an earlier post. Imagine an exercise powered cooling machine! Or a pedestrian or vehicle way that cooled 'stuff' as a byproduct of "waste" energy. Or exercise equipment that cools the user. A backpack that pumps heat away from your back etc. Synchronising heat/cool cycles may allow net heat flow in one direction without any mechanical valving per se. If adjacent strips can be neutral (N) or cool (C), then with a heat source at left, by cycling strips NNN CNN CCN NCN NCC NNC NNN .... or similar, heat flow may be able to be promoted left to right, The process need not be overly efficient as long as any heat generation occurs away from the cooled area. Such a flow on zones may be able to be created within the laers of a stretch fabric or similar so as a person moves their clothing pumps heat away from the body or equipment. Worth a thought :-) I have now a year to patent this, no ? :-) Russell --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .