152 Cosmological models
Supposing these technical difficulties can be overcome in each case, it is still
unclear that these proposals avoid the real problem of origins. It can be claimed
they simply postpone facing it, for one now has to ask all the same questions of
origins and uniqueness about the supposed prior state to the present hot big bang
expansion phase: Why did this previous state have the properties it had? (whether
or not it had a classical analogue)? This ‘pre-state’ should be added to one’s
cosmology, and then the same basic questions as before now arise regarding this
completed model.
3.9.2.2 Explanation of initial conditions from ‘nothing’
Attempts at an ‘explanation’ of a true origin, i.e. not arising from some pre-
existing state (whether it has a classical analogue or not), are difficult even to
formulate.
They may depend onassuming a pre-existing set of physical lawsthat are
similar to those that exist once spacetime exists, for they rely on an array of
properties of quantum field theory and of fields (existence of Hilbert spaces
and operators, validity of variational principles and symmetry principles, and
so on) that seem to hold sway independently of the existence of the universe
and of space and time (for the universe itself, and so space and time, is to arise
out of their validity). This issue arises, for example, in the case of Vilenkin’s
tunnelling universes: not only do they come from a pre-existent state, as remarked
previously, but they also take the whole apparatus of quantum theory for granted.
This is far from ‘nothing’—it is a very complex structure; but there is no clear
locus for those laws to exist in or material for them to act on. The manner of
their existence or other grounds for their validity in this context are unclear—and
we run into the problems noted before: there are problems with the concepts of
‘occurred’, ‘circumstances’ and even ‘when’—for we are talkinginter aliaabout
the existence of spacetime. Our language can hardly deal with this. Given the
feature that no spacetime exists before such a beginning, brave attempts to define
a ‘physics of creation’ stretch the meaning of ‘physics’. There cannot be a prior
physical explanation, precisely because physics and the causality associated with
physics does not exist there/then.
Perhaps the most radical proposal is that
order arises out of nothing: all order, including the laws of physics,
somehow arises out of chaos,in the true sense of that word—namely a total lack of order and structure of any
kind (e.g. [1]). However, this does not seem fully coherent as a proposal. If
the pre-ordered state is truly chaotic and without form, I do not see how order
can arise therefrom when physical action is as yet unable to take place, or even
how we can meaningfully contemplate that situation. We cannot assume any
statistical properties would hold in that regime, for example; even formulating
a description of states seems well nigh impossible, for that can only be done in