X-Message-Number: 3596 Date: 04 Jan 95 23:27:15 EST From: "Steven B. Harris" <> Subject: SCI.CRYONICS Flash Cooling Thomas Donaldson says: >>As for the Peltier effect, we might step back a bit from what Coetzee is saying ask the question he is trying to answer: is there a fast way to cool someone down? Here is a SPECULATION: let's suppose we could find some nano- device which would convert, alone or with other devices of its kind, the heat in a patient's body into (say) x-rays (which will pass through the body and dissipate that heat elsewhere). Heat goes with infrared, ie. low frequency light waves. To detect that heat the nanodevices would (I think) need to have a lower temperature than the body they are attempting to cool. And for those who worry about spectral lengths, I did point out that more than one such device may be involved. << As I'm sure Brian will point out, with X-rays the problem here is inefficiencies made necessary by the 2nd law of thermodynamics. If you convert heat (low temp energy) to X-rays (very high temp energy), you are effectively pumping heat up a temp gradient with a heat pump. This is permitted, BUT the efficiencies of going up a gradient that large are so bad that you end up dumping 10's or 100's of thousands of times as much energy into the body as you need to take out in initial heat, and it ALL has to come out as X-ray (not just the heat there was at first, but all the energy you dumped in, too). No way to do this with photons, as X-ray absorption of one kind or another in normal electron-containing matter is going to deposit enough of that energy going out, to get you. What you really need is to run the heat pump and convert all your heat and refrigerator energy input into high temp NEUTRINOS. No law in thermo against that, and you really could theoretically then get all that electric refrigeration energy you put in, back *out* without it being deposited, sort of like in the last stages of a star before it supernovas. Of course you don't want new elements in the body, so you have to cycle between nuclear reactions that make neutrinos, and those that make antineutrinos, so your lepton number is conserved. Use little accelerators to make short-lived neutron-rich isotopes and then let them decay again, or something. You have to catch all the decay energy to recycle it into electricity again, of course, but that design will be done for nanoatomic batteries anyway. Details left to the engineering student to work out <g>. Steve Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=3596