From: henry@spsystems.net   
      
   In article ,   
   Gordon D. Pusch  wrote:   
   >All known life is water-based. There are practical limits to how far an   
   >"antifreeze" can depress the freezing point of water, before it it is more   
   >antifreeze than water. Martian night-time temperatures plummet to -140 C;   
   >they are so cold that CO2 can freeze out of the atmosphere. Good luck   
   >trying to find an "antifreeze" that will keep water frome freezing solid   
   >at those temperatures. I think you will find that you will need to base   
   >martian life on something other than water...   
      
   Not necessarily.  There is no fundamental reason why you can't have   
   warm-blooded plants, which use metabolic heat (and insulation) to keep   
   their interiors warm and whose fluids thus don't have to handle the full   
   range of ambient temperatures.  (It's marginally conceivable to use   
   passive heat storage to the same effect, given really good insulation --   
   biological aerogels, anyone?)   
      
   This would, mind you, require much more radical genetic engineering than   
   anything done to date.   
      
   >> It would be difficult. But not impossible. Nothing is impossible when humans   
   >> are put to the challenge.   
   >   
   >That oft-repeated claim is quite bluntly bull$#!+. There are numerous   
   >things than are _PROVABLY IMPOSSIBLE_, e.g., solving the "Halting Problem"   
   >or squaring a circle and trisecting an angle using only a compass and a   
   >straightedge...   
      
   However, most of those provably-impossible feats require very strict   
   problem definitions.  It actually *is* possible to trisect an angle with   
   compass and straightedge... by cheating, using a real straightedge in ways   
   that violate the strict classical definition.  Moreover, even under the   
   classical definition, while it is not possible to exactly trisect an   
   angle, it *is* possible to trisect one to any desired finite accuracy.   
   When we're discussing real engineering as opposed to mathematical   
   problems, rather often the problem definition is imprecise enough to   
   permit creative solutions, if you don't let yourself be shackled by the   
   arbitrary constraints of an oversimplified model.   
   --   
   MOST launched 1015 EDT 30 June, separated 1046,         | Henry Spencer   
   first ground-station pass 1651, all nominal!            | henry@spsystems.net   
      
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