A Skeptical Look At The Multiverse

sjanich writes "The NY Times has a short, interesting article on multiverse theory. The author, Paul Davies, writes: 'This idea of multiple universes, or multiple realities, has been around in philosophical circles for centuries. The scientific justification for it, however, is new.' It is quite an interesting read. The author is a Physicist and pretty good science writer." Davies is not kind to the multiverse theory.

Comments

theory that makes no predictions is meaningless

[obtuse]

Davies refers to, but never explicitly states one particular point: Most of the multiverse theories are inherently untestable, because we're completely isolated from the other universes. These are theories that don't predict or even suggest anything. How meaningless can you get?

This is a good general point. Solipsism is uninteresting. Subjectivism & deconstructivism are often taken to similar absurd extremes by stupid people, including respected critics.

He makes the analogy between theology & these scientific non-explanations. Religion is personally very meaningful, but metaphysics isn't science. Consequently a classic metaphysical question, "How many angels can dance on the head of a pin?" is the canonical meaningless question.

The word that springs to mind is sophomoric. It reminds me of High School, when one friend asked another "What if you're really insane & just dreaming all of this?" The answer was of course, "So what? You've gotta pretty much live your life the same way anyway."

Everett interpretation

[aminorex]

It is worthwhile to point out that cosmological
diversity is only one kind of "multiverse" theory.
In it, all of the various universes are embedded
in a larger space. Such theories are not therefore
unscientific, in the sense of being intrinsically
unfalsifiable, or unverifiable: Because the various
universes have topological relation to one another,
there is a continuum of existence connecting them,
and they may interact in yet unforseen ways. Our
current inability to design experiments to detect
such interactions is merely an artifact of
ignorance.

But there are many other forms of ontological
multiplicity which do not involve topological
continuum. The outstanding example is the
Everett interpretation of quantum mechanics.
In that theory, rather than the actual state of
affairs in the universe being the sole real
instantiation of the phi wavefunction, created
by the act of observation (as in the classical
Copenhagen interpretation of Bohr et al), the
quantum wave function is considered to be a
representation of the distribution of an infinite
multiplicity of alternatives, all equally "real".

I find the Everett interpretation to be much
preferrable, on several grounds, not the least
of which is that it is consistent with the
mathematical concept of probability distribution
in a way which the Copenhagen interpretation is
not, but others disdain
it because it implies the real existence of
entities which are not, so they say, in principle,
detectable. Again, this complaint fails because
it is an argument from ignorance: The current
inability, at a given level of human understanding
and technology, to design a verifying or falsifying
experiment, does not relate to the truth or falsity
of the hypothesis. Cophenhagenists are quite
comfortable supposing that unseen cats are undead,
and any truth not currently known is not yet true.
I think this is a much larger leap of faith than
is needed to create a working understanding.