[net.space] ET's and Simple Explanations

mclean@NRL-CSS@sri-unix (10/21/82)

From: mclean at NRL-CSS (John McLean)


         It seems to me the simplest explanation consistent with 
         the available evidence is that there is no other intelligent
         civilization in the galaxy.

Two comments:

   (1)  The cannon of simplicity is notoriously difficult to apply .
        Although the simplest explanation as to why I don't see an
        elephant in front of me is that there is no elephant in front
        of me to see, the extra terrestial example is not so clear-cut.
        The simplicity of the "no elephant" explanation rests on the 
        fact that I do not have to go on to explain why there is no 
        elephant in front of me.  An advocate of extra terrestial life
        would want an explanation of why there is none, or similarly,
        why the earth is so special.  This leads to my second point.

   (2)  "Facts" do not exist in a vacuum.  It is folly to gain a small
        amount of simplicity in explaining X by greatly increasing
        the complexity of my explanation of Y (assuming that I want
        eventually to explain both).  The advocate of extra terrestial
        life wants to explain, not merely why we haven't seen any
        signs of such life, but also why the same circumstances that
        gave life to this planet shouldn't arise elsewhere with
        similar results.

john

REM@MIT-MC@sri-unix (10/22/82)

From: Robert Elton Maas <REM at MIT-MC>
My explanation is rather simple and consistent:
 (1) The same forces that caused life on Earth, cause it everywhere
  else too, anyplace there's a long-lived star with planets containing
  lots of random elements from earlier supernovas and stellar-winds.
 (2) The same forces that drive us toward suicide hee on Earth, have
  driven technological civilizations towards suicide elsewhere.
 (3) The same forces that cause life on Earth to adapt to every nook
  and cranny in our biosphere, even places where we think no creature
  would want to live, occurs elsehere. Whenever the means to inhabit a
  biosphere exists, that biosphere will be totally inhabited to the
  limit of the energy materials and room available.
We don't see the Galaxy thriving with live at every bend in the road,
in particular we don't see it thriving around our neck of the woods,
so probably nobody has made it fully into space yet, although the
galaxy abounds with pre-space life.

Anything of the type "making A simple at the expense of making B very
complex" in that argument?