# Observational evidence for many worlds (by Don N. Page)?

• Demystifier

#### Demystifier

Gold Member
In a recent paper
http://xxx.lanl.gov/abs/1101.1083
Don N. Page presents a very interesting statistical anthropic argument for the reality of many worlds. It is not only an argument against the collapse hypothesis, but also against (my favoured) Bohmian interpretation.

What do you think?

## Answers and Replies

My first thoughts...

There are an awful lot of "If"s in the hypothesis. Also I'd hardly call his argument "statistical evidence" since he's using a statistic of 1 sample.

Saying "biophilic values" of coupling constants are unlikely requires some assumption that they could have been otherwise and yet that they do not vary after the fact (whereby the weak anthropic principle simply argues that we are in the domain/epoc of biophilic values because it is the only domain/epoch in which we might manifest to ponder their values.)

Finally I see some problem with false alternatives in his argument in that there is a third alternative to physically collapsing Bohmian pilot waves and Everett many worlds, namely non-objective CI. (My preferred interperetation ;)

I'd say it is premature to make such an argument until a better synthesis of GR and QM is achieved which might shed better light on the manifestation of and possible variation thereof of the coupling constants.

I don't need to read it. Many Worlds Interpretation is equivalent to Copenhagen Interpretation. There is a theorem proving equivalence. The theorem is sound. Any argument proving MWI over Copenhagen is based on flawed assumptions. Thus is the difference between a theorem and theory. If something contradicts a sound theorem, it needs not be considered.

I don't need to read it. Many Worlds Interpretation is equivalent to Copenhagen Interpretation. There is a theorem proving equivalence.
There is such theorem, but every theorem rests on certain assumptions. Here some assumptions are relaxed, which avoids the theorem.

Jambaugh is right that there are many "if's" in the argument, but the mere fact that there ARE such if's that may lead to a distinction between the interpretations - deserves attention.

Finally I see some problem with false alternatives in his argument in that there is a third alternative to physically collapsing Bohmian pilot waves and Everett many worlds, namely non-objective CI. (My preferred interperetation ;)
Hm, let me try to translate it to a language that might make sense from the Page's anthropic point of view: Assume that collapse is purely subjective. But there is no subjectiveness without life, so, for the sake of self-consistency, a collapse may only occur to a "biophilic" state. Therefore, we don't need many worlds to explain life. Would that make sense to you?

I'd say it is premature to make such an argument until a better synthesis of GR and QM is achieved which might shed better light on the manifestation of and possible variation thereof of the coupling constants.
Well, it's never premature to make an argument, provided that you are aware that it is still only a provisional argument.

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There is such theorem, but every theorem rests on certain assumptions. Here some assumptions are relaxed, which avoids the theorem.
These assumptions are basis of Quantum Mechanics. If QM is wrong, then yes, we might be able to distinguish, but if QM is wrong, we have no basis for assuming Many World in the first place. We'd be needing a completely new theory and a completely new discussion.

The argument does not deserve any attention.

These assumptions are basis of Quantum Mechanics.
Well, not exactly. The crucial assumption here is that the ONLY goal of QM is:
To predict probabilities for experiments that can be repeated many times.

If we accept that assumption, then standard QM and many-world QM are indeed equivalent.

However, Page does NOT accept that assumption. Instead, he also wants QM to explain why the physical constants have the values they have, in the context in which they are also subject to quantum probabilistic laws. Clearly, since they appear constant to us, we cannot perform experiments which would measure such a probability distribution. And in that context, Page argues that many-world QM can explain why the physical constants have the values they have, while the standard QM can't.

In a recent paper
http://xxx.lanl.gov/abs/1101.1083
Don N. Page presents a very interesting statistical anthropic argument for the reality of many worlds. It is not only an argument against the collapse hypothesis, but also against (my favoured) Bohmian interpretation.

What do you think?

Well, David Deutsch seems to think the MW idea is correct because how else can you account for the processing of information in parallel as proposed in quantum computing?

http://en.wikipedia.org/wiki/David_Deutsch#The_Fabric_of_Reality