On 7/28/2013 7:12 AM, Warren D Smith wrote:

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From: Gareth McCaughan <gareth.mccaughan@pobox.com> On 27/07/2013 11:18, Warren D Smith wrote: So for example, why do you not experience being in a superposition of living in Paris and Tokyo? Because [...] Why would you expect

a superposition of experiencing being in Paris and experiencing being in Tokyo

to resemble, in any way,

experiencing being in a superposition of Paris and Tokyo?

In default of some reason to expect that, I don't see why the question arises at all. And I know of no such reason, though I'm not a QM expert and maybe there is one that I've never encountered.

--this is an excellent point, and there's plenty of arguments of that vague ilk which may sound good..., but the problem is, these questions don't seem addressable by mathematics or precise reasoning. So when various philoso-physicists (at least those in the Everett camp) are going around saying "the foundational problems of QM are solved" it's all hogwash. It's basically religion, and hopes+dreams, not science. That debate probably would never end and it'd never be clear if it really solves the problem.

However, with my approach to the foundations of QM, the gordian knot is cut. It could really be science.

And not only that, I can kick their asses with more paradoxical issues. For example, why is the "position basis" favored over others?

It isn't in all cases. Atoms, for example, are usually found in energy eigenstates.

Decoherence tends to localize things. Give them precise positions. Why? With pure QM unitary symmetry, no basis favored over any other. Well, my view explains that. And if (say) in the early universe, everything were in a momentum eigenstate, with pure QM, no localization of anything would ever be possible, translation symmetry could never be broken.

It's because the interaction terms in the Lagrangian are position dependent. So even if everything were in a momentum eigenstate (and everything is in a superposition of energy-momentum eigenstates) there would be finite probabilities of localized interaction.

This (in flat spacetime) is a theorem of mathematics. So the physicists who somehow convince themselves that positions being the "pointer basis" is somehow caused by QM, thru mysterious measurement-simulating environmental effects, are full of crap. The true explanation is quantum gravity, I claim via my reasoning.

What about the "direction of time"? QM with measurement features a time direction. QM without features CPT symmetry.

The direction of physical time is determined by expansion of the universe (which allows entropy to increase) - which in a sense is a gravitational effect. Brent

Again, the hogwash camp somehow deduces this is not a paradox, using religious reasoning. My way, gordian knot cut.

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(Warren, would you be willing to teach your email software to handle quoted material better? Because what you're doing at the moment degenerates to total incomprehensibility once there are a couple of levels of nesting.) Warren Smith wrote:

--this is an excellent point, and there's plenty of arguments of that vague ilk which may sound good..., but the problem is, these questions don't seem addressable by mathematics or precise reasoning.

[SNIP: "hogwash", "religion", etc.] It seems to me that when you choose to begin by asking "so why don't I experience being in a superposition of Paris and Tokyo", you are not in a very strong position to complain about *other* people making vague handwavy arguments that sound good but lack mathematical backing.

And not only that, I can kick their asses with more paradoxical issues. For example, why is the "position basis" favored over others?

In what sense do you think it is? (Handwavy partial answer pending clarification of question: the interactions relevant to most of our perceptions are full of terms involving differences of positions, and have little that concerns momenta or differences of momenta.)

Decoherence tends to localize things.

Oh -- was that an explanation of what you mean by the position basis being favoured? OK. This would be a good point to repeat my remark that I'm not a QM expert. But: Is it actually any more true that "decoherence tends to localize things" than that "decoherence tends to pin down the momenta of things"?

Give them precise positions. Why? With pure QM unitary symmetry, no basis favored over any other. Well, my view explains that. And if (say) in the early universe, everything were in a momentum eigenstate, with pure QM, no localization of anything would ever be possible, translation symmetry could never be broken. This (in flat spacetime) is a theorem of mathematics. So the physicists who somehow convince themselves that positions being the "pointer basis" is somehow caused by QM, thru mysterious measurement-simulating environmental effects, are full of crap. The true explanation is quantum gravity, I claim via my reasoning.

What if they claim instead that any preference for one basis over another is the result of the combination of the laws of physics, the initial conditions[1] we happen to have got, and the nature of the apparatus (in which I include eyes, ears, etc.) with which we perceive the world? [1] You could, I think, just as well use "current conditions" or "final conditions" or "conditions on some other lower- -dimensional portion of spacetime"; all I mean is whatever contingent stuff needs to be added to the actual laws to get a complete description of what happens. It seems not especially surprising if the universe did not begin in an exact momentum eigenstate with perfectly flat spacetime.

What about the "direction of time"? QM with measurement features a time direction. QM without features CPT symmetry. Again, the hogwash camp somehow deduces this is not a paradox, using religious reasoning. My way, gordian knot cut.

Of course the "hogwash camp"'s statements are to be ridiculed until they give a complete mathematical analysis with all details filled in (anything else is religion, hogwash, and crap), whereas your way needs only the briefest of handwavy sketches to declare victory. I would enjoy reading your comments more if you would either be more polite, or justify your rudeness by applying the same standards to your own reasoning as to other people's and actually show that yours is better instead of just assuming it. (For the avoidance of doubt: Your way may, in fact, be better. The Everett approach may, in fact, be religion, hogwash, and crap. But you will convince more people by cogent argument than by intimidation, at least in a forum like this one. At any rate, you will more readily convince *me*, which perhaps regrettably happens to be what I care about; of course your concerns may differ.) -- g