RE: Anthropic Principle IS a probability argument (long)

Gary Collins (
Fri, 15 Jan 1999 08:35:14 GMT

David Bowman wrote:

> My main objection to
> Glenn's probability calculations is based on the observation that the
> parameters describing the laws of nature at the more phenomenological
> levels are themselves determined by the deeper level theories and are,
> thus, not freely adjustable to take on just any old value one supposes.
> Since we currently do not have a worked out viable Theory of Everything
> we do not know which of the 1 1/2 dozen or so remaining parameters (of
> the so-called Standard Model of physics) are themselves determined and
> calculable by that theory which is not yet in hand. Presumably if such
> a theory exists and it is found that it is unique in that it is
> eventually proved that there can be no other theory which is both
> internally logically consistent and also accurately describes all the
> facts then we would expect that all of the residual parameters of the
> Standard Model would be, at least in principle, calculable from the
> unique TOE. This would indicate that the would could not be any
> different than it is in terms of the laws of nature describing it. As
> things stand now the non-calculable parameters of the Standard Model are
> just adjusted agree with experiment and there is no a priori reason for
> one set of these parameters over another set. A functioning in hand TOE
> would presumably change this situation drastically.
> Even though I expect that a unique TOE may tend to fix all the parameters
> of all the laws of physics, I think that it would still not necessarily
> fix the exact state or appearance of the universe. This is because of
> the built-in indeterminism in the outcomes of events and processes
> described by those laws coming from a combination of fundamental quantum
> uncertainty in the outcomes of measurement-like interactions and the
> amplifying effect of tiny microscopic changes to huge macroscopic ones
> produced by the sensitive dependence on the initial conditions of the
> classical limit of some of the relevant classical phenomenological
> theories (i.e. chaos effects). It is also entirely conceivable that the
> same fundamental TOE can describe a universe (or many universes) with a
> wildly different structure including the phase domain structure of the
> vacuum than the one we have resulting in wildly different
> phenomenological behaviors than the ones seen in our universe. A
> different vacuum phase domain for the TOE may possibly result in
> different low energy (relative to the TOE) Standard Model parameters and
> gauge interactions and thus completely different phenomenological
> theories describing the universe on more everyday energy and distance
> scales.
> So it seems that there is still may be a lot of slack in the necessary
> appearance(s) of the universe or at least in our vacuum phase domain of
> the universe. Therefore I do not completely discount anthropic
> arguments. I just don't think that they are necessarily very
> convincing. The naive applications of them, such as a priori probability
> calculations based on changing the parameters of low energy
> phenomenological theories, are incorrect because the considered
> parameters are determined by the deeper level theories. And more
> sophisticated applications involving deep-level (high energy scale)
> theories tend to be fraught with uncertainties caused by the lack of a
> useful in-hand TOE. In spite of my pessimism concerning these kind of
> arguments I still do get the feeling (and I think it is mostly just a
> feeling) that the universe seems to be made with the likes of us in mind.
> Of course this feeling may result ultimately more from my prior religious
> disposition than from the bare physical evidence. I'm not sure.
Hi David,

'Scuse me for butting in, especially since I really don't know much about this
at all (but I do find it all very interesting). What I would like to ask is
along the lines of: if the parameters were different, couldn't that just mean
that there were different 'underlying rules of nature?' Is there any reason
why these rules have to be the way they are, or indeeed that there should be
any at all? How much is really 'fixed and unalterable' and how much simply
appears to be so because we live in the particular universe that we do?
If a TOE is eventually found, I would ask the same kind of question - would it
be conceivable for there to have been a different TOE, different laws,
different parameters? If the universe were not 'made for us' but just came
into being of its own accord, as atheists bust believe (either that or the
universe itself is somehow eternal) would it still be constrained to be much
the way it is (in terms of the 'deep laws; however deep you want to go) or
could everything have been very different?

This is probably very philosophical and possibly unanswerable, I don't know.
But I would be interested to hear what you have to say on it.