Fine Tuning
Recently,
many physicists and cosmologists have argued that there is quite a problem in
how our cosmic environment manages to be one in which Darwinian evolution can
operate over long ages to produce living beings. The cosmic period known to us
began with a Big Bang. It looks as if the early cosmic density, and the
associated expansion speed, needed tuning with immense accuracy for there to be
gas clouds able to condense into stars: tuning to perhaps one part in a
trillion trillion trillion trillion trillion. Further, the strength of the
nuclear weak force had to fall inside narrow limits for the Big Bang to
generate any hydrogen (which was needed for making water and for long-lived,
stable stars like the sun) and for the creation of all elements heavier than
helium. Also the strength ratio between electromagnetism and gravity needed
extremely accurate tuning, perhaps to one part in many trillion trillion, for
there to be sun-like stars. Again, the existence of chemistry seemingly
demanded very precise adjustment of the masses of the neutron, the proton and
the electron.
In a
book of mine, Universes (1989), I
made a long list of such claims about fine tuning. No doubt some of the claims
will turn out to be wrong. For instance, it might be that the early cosmic
expansion speed was more or less forced to be what it was, because of a process
known as “inflation”, and the people who think that inflation itself needed
very precise tuning could be mistaken. What is impressive, I suggest, is not
any particular one of the claims about fine tuning, but the large number of
claims which seem plausible, and the consequent implausibility of thinking that
every single claim is erroneous. Here, then, we might be thought to have
evidence of design, provided we judged that such design would have been
directed towards producing living beings in a non-miraculous fashion through
making the world obey physical laws which led to the existence of stable stars,
planets, and an environment with a rich chemistry in which life could evolve.
Contributed by: Dr. John Leslie
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