[asa] The Multiverse - Physics or Metaphysics?

Lawrence Johnston posted a link to a paper by Eugene Koonin about the
transition from chance to biological evolution in the history of life:

http://www.biology-direct.com/content/2/1/15

These thoughts were prompted by reading this paper (and also having recently
taken delivery of Martin Rees's book "Just six numbers" concerning the fine
tuning of the universe). Both Koonin's paper and Rees's book invoke the
idea of a multiverse to sidestep the problems without recourse to an
Intelligent Designer, or Creator.

The essence of Koonin's paper, as I understand it is that in order for
biological evolution to get started, a primitive replication/translation
system had to emerge by chance. He performs some toy calculations to work
out the probability that such a system could emerge by chance in our
universe (given number of stars, planets, age of the universe, number of
nucleotides needed for such a system etc). He arrives at this vanishingly
small number less than 10^(-1000).

His resolution to this paradox is to invoke the "Many Words from One" (MWO)
hypothesis, which I think is essentially the same as the Many Worlds
interpretation of Quantum Mechanics. This means that all possible Quantum
outcomes actually occur in different universes at every instant in time, and
so at each point, the universe splits into parallel versions, with the
different outcomes happening in the different universes.

In the MWO hypothesis, even the most incredibly unlikely things are bound to
happen in some, very rare universes, with probability 1. A radioactive atom
with a half life of 1 second can carry on undecayed indefinitely, because
there will always be universes in which it did not decay. [ This also leads
to the "Quantum Immortality" paradox that you never actually experience
death, because the event that causes your death will not happen in some
universes, and it is these universes in which your consciousness continues
to exist].

Hence the emergence of the primitive replication/translation system is bound
to occur in some versions of the universe, and those universes are the ones
in which eventually people evolve to ask the question about how it all
started up. Koonin calls this "anthropic selection" - ie our universe is
one where this incredibly unlikely event occurred because we are here (the
anthropic principle).

The final sentence in Koonin's paper is telling:

A final comment on "irreducible complexity" and "intelligent design". By
showing that highly complex systems, actually, can emerge by chance and,
moreover, are inevitable, if extremely rare, in the universe, the present
model sidesteps the issue of irreducibility and leaves no room whatsoever
for any form of intelligent design.

It is my view that Koonin hasn't sidestepped the problem of intelligent
design at all - in effect he has replaced one unprovable assumption (God)
with another equally unprovable assumption (the multiverse).

I wonder if people on the list would agree with me that "God did it" and
"The multiverse did it" appear to be equivalent statements, and neither is
satisfactory from a scientific viewpoint?

God is omnipotent and can do anything. So when you can't explain something
you could invoke God's intervention to explain something apparently
miraculous.

But the multiverse - where anything can happen with a finite probability, is
also omnipotent - and can also be invoked to explain something apparently
miraculous (such as the appearance of Koonin's first replicator).

It seems to me that Koonin's paper suffers from precisely the same failing
as Intelligent Design, namely that when you can't find a way of explaining
something, you invoke something else that is omnipotent in order to explain
it. To do this is to give up doing science, it seems to me.

I'll finish with a humorous scenario that occurred to me.

One of the bizarre paradoxes of the Many Worlds Interpretation of Quantum
Mechanics is the so-called "Quantum Suicide" thought experiment (look it up
on Wikipedia). It is proposed as a thought experiment that would
distinguish between Many Worlds and the Copenhagen interpretations. The
experiment resembles Schrodinger's cat, except that the physicist himself
replaces the cat. A device measures the spin state of an electron, and
fires a gun or not with 50% probability according to the result. The
experiment is then repeated a large number of times (say 1000). At the end
of this there will be 999 dead physicists whose consciousness is terminated
when the gun went off, and one left alive in the universe where the spin
state corresponded to "no fire" every time. If the physicist emerges at the
end of this conscious, then he "knows" that the MWI is true.

Or does he? Suppose he now goes home to his devoutly religious wife, and
says "Honey I'm home - guess what we're going to be famous because I've
proved the Many Worlds Interpretation is true". But his wife, who knows
there is no chance she'll end up in the same universe as him has prayed to
her God to intervene and save his life. She will reply "No, I've just
proved that God answers prayer".

What should the physicist do:

(a) Divorce his religious nutter of a wife & go ahead and publish?
(b) Start believing in the God his wife prayed to?
(c) Go back and figure out what went wrong with the experimental apparatus?

I think it should be clear which one I think is the most sensible :-)

Iain

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Received on Fri Sep 7 15:27:29 2007