Well, sure any celestial body in the solar system has one side that is hit by sun light and the other that is not. But usually people talk about the 'dark side of the moon' as the side that is not visible of the moon and my point was that is a misnomer. But yes there are regions of the moon that are at any given moment in darkness but this side is always changing as the moon moves around the earth and moon and earth move around the sun. This region is cold but so any shaded area, even one created by a rock formation lighted by the sun.
About mirror matter, I have a PhD in Physics and never heard of it, sorry. I know of course about supersymmetric particles and not sure if they are the same concept or just related. I read the wiki article and I understand now the basic concept, not sure we need mirror matter because even if Parity is violated as it is in the weak force we know in the end CPT (charge, parity and time reversal) is conserved. But I will look into it further, it is an interesting topic. Giovanni On Tue, Jan 24, 2012 at 3:09 AM, Rich Murray <[email protected]> wrote: > Thanks for clarification re Moon -- has a two-week night, while one > of its poles is always dark -- so surface temperatures get low > anyplace it's dark for over a day -- that's how it can hold plenty of > H2O as ice within the highly insulating dusk on the surface. > > I saw a reference to a paper by an expert that proposed energy flow > from 300 degree Kelvin to much colder solar system mirror matter could > run a practical heat engine -- apparently there is enough heat > transfer for it to work -- if the cold mirror matter was at 20 degrees > Kelvin, even if it was mirror CO2 or mirror H2O, it could have a > strong fractal microstructure, like a ceramic, with a bit of C > impurity, and be placed as a thin layer on a thin metal surface of > ordinary matter, so then it is possible that there will be useful > thermal transfer from the ordinary metal to the much colder mirror > matter layer, which would radiate its mirror IR into the very cold > mirror dust and gas, still bound by gravity to orbit around the Sun, > but not heated by the Sun's IR and light output. > The very interesting mirror matter web sites will lead you to it: > http://en.wikipedia.org/wiki/Mirror_matter > > I'm now imagining creatures that evolved as floaters in the organic > clouds of gas giants, gradually evolving to absorb and use mirror > matter with their normal matter nanostructures, using the mirror > matter as heat sinks to allow their metabolism to be driven by light > from the distant Sun, and even the galactic background IR, as their > balloons become larger and very thin, filled with normal H2 at just a > little over the pressure of the supporting gas layers, until they are > actually able to sail on the solar wind and light pressure to slowly > build up speed, becoming living spacecraft -- not so unlikely, when we > watch a bird that can fly, float on water, dive, walk on land, and > sleep in nests on trees, changing its shape radically when flying. > >
