Re: Non-DNA life (was Testing in historical science)

John Leslie (
Wed, 19 Nov 1997 09:29:02 -0500 ()

Thanks, Glenn, for the message discussing the probabilities of life not
based on DNA. Two suggestions: 1) Some people speculate about life in the
weirdest environments: you might like to look at Feinberg, G., and
Shapiro, R., 1980, "Life Beyond Earth", publisher William Morrow, New
York, 1980, for life on neutron stars, in frozen hydrogen, etcetera. A
short paper by these two is reprinted in my edited volume "Physical
Cosmology and Philosophy", Macmillan, 1990, which also contains a
bibliography on extraterrestrial life. 2) There is, however, an
anthropic-principle argument tending to favour the belief that all
intelligent life, or at least a fair proportion, is chemically based. If,
for instance, intelligent life were possible on neutron stars, evolving
(some suggest) in minutes or less (because of being based on the strong
nuclear force, not on electromagnetism which underlies chemistry) then one
might expect there to be vastly many more observers on neutron stars than
on planets (because the observers would be so tiny, hence so closely
packed, and because every neutron star would presumably have had them
almost from the moment of its formation, and because their lives are so
close packed in time so that civilizations can rise and fall in mere
twinklings of an eye); why, then, do you as an observer not find that you
are a neutron star being? This way of thought may be unfamiliar to you,
perhaps? It stems from Brandon Carter, and gets much attention in my "The
End of the World: the science and ethics of human extinction", published
by Routledge, London and New York, 1996. Compare the case, if you have
amnesia in a closed room, of tending to prefer the view that you are in a
large city rather than in a tiny village, because there are so many more
people in the large city.
All the best: John Leslie