I Many Worlds Interpretation and Coffee

[secur]

Actually theoretical physics also has many worthwhile aspects. It's very simple: the worth of a theory is proportional to the amount of data, experimental and observational, it encompasses. And inversely proportional to the publicity.

How does this relate to OP? MWI as a mathematical tool is justified, almost, by all QM data. (Except for the unresolved issue of Born's rule.) However MWI as reality has no contact with experiment, or observation, at all. We (almost certainly) can never detect those "many worlds". So as a convenient mathematical formulation - somewhat analogous to Hamilton and Lagrange formulations - it's fine. But it's extremely pointless to worry about cups of coffee, twins becoming president, twins murdering or committing suicide, etc, in those many worlds. Very much like angels dancing on pins.

Not surprisingly the worthwhile aspect of MWI - just as a mathematical tool - gets almost no publicity. Everett's original idea is ignored. Instead the useless aspect appears often in pop-sci. That's why many members of the public interested in physics, such as OP, ask about that so often.

Of course very few physicists concern themselves with theory that has no contact with data. Perhaps, 1%. That's not much, and after all, some good may come of string theory, etc - who knows? The only problem concerns the public. There's only a limited "bandwidth" for physics in popular media, and I guess more than half of it is completely wasted. This has many negative ramifications for society. It's a major factor in the decline in STEM disciplines in the US (I don't really know about elsewhere). Physics could be charging ahead, attracting the best and brightest, receiving great respect from non-physicists, if the public image was presented well. Basically, just stick to the data, and almost ignore theory. (Astronomical imagery is a good example of the right kind of publicity.) Instead ...

 

[Zafa Pi]

All QM interpretations are ridiculous in one way or another. Looks like people pick ones they like based on which kind of "ridiculous" is more tolerable to them.

I am mathematician by education, so infinities and infinitesimals of various kinds are not a problem for me, hence MWI with its infinite branching and very low probabilities of "almost anything happening" does not sound especially problematic to me (evidently, some people are finding *that part* "ridiculous").

The Tarsi-Banach Theorem is a mathematical result that I've proved in lectures several times, but would never accept as a result of physics.

 

[Demystifier]

How do you interpret that?

I interpret it as a special case of another quote:
"Truth and clarity are complementary." - Niels Bohr

 

[Demystifier]

The Tarsi-Banach Theorem is a mathematical result that I've proved in lectures several times, but would never accept as a result of physics.

Is it just because of the existence of atoms, or because you don't think that the axiom of choice represents a physical choice?

 

[Zafa Pi]

I interpret it as a special case of another quote:
"Truth and clarity are complementary." - Niels Bohr

Oh, I get it, the truth and clarity operators don't commute, they work at home.
Don't you think it's about time you changed your moniker to Mystifier?

 

[Demystifier]

Don't you think it's about time you changed your moniker to Mystifier?

There is no demystification without prior mystification. In most of my posts I do my best to demistify things. But sometimes I go in the opposite direction, as in https://www.physicsforums.com/threads/what-is-quantum-theory-about.767672/ .

 

[vanhees71]

I interpret it as a special case of another quote:
"Truth and clarity are complementary." - Niels Bohr

Well, then Bohr definitely wrote only about true things.

 

[Zafa Pi]

Is it just because of the existence of atoms, or because you don't think that the axiom of choice represents a physical choice?

Atoms?? I thought your view of reality was continuous. I don't accept the T-B Thm for physics because by now some alchemist would have the would's weight in gold.
The axiom of choice is not a sufficiently well ordered topic for QM , and should be maximally filtered out using the Zorn rule.

 

[Zafa Pi]

There is no demystification without prior mystification. In most of my posts I do my best to demistify things. But sometimes I go in the opposite direction, as in https://www.physicsforums.com/threads/what-is-quantum-theory-about.767672/ .

OMG, that referenced post of yours is more depressing than Donald Trump.

 

[Demystifier]

OMG, that referenced post of yours is more depressing than Donald Trump.

What if I tell you that I have a theory that solves all these questions at once?

 

[Demystifier]

Well, then Bohr definitely wrote only about true things.

Except the Bohr model of atom (with the so called "old QM"), which is clear but not true.

 

[Zafa Pi]

What if I tell you that I have a theory that solves all these questions at once?

Oh sure, butter me up with something I won't be able to follow. I'm holding out for comprehension.
OK. let's see it, maybe it will work as a soporific.

 

[PeroK]

Is it just because of the existence of atoms, or because you don't think that the axiom of choice represents a physical choice?

I tend to view physics as finite, in the sense that any experiment only has a finite number of outcomes. The mathematics and theoretical physics extrapolates this to countable and uncountable infinities. A classical example is modelling a body as a continuous mass distribution, even though the physics is a large, finite number of particles.

In QM you can practically only carry out a finite number of measurements, so there is always a mathematical extrapolation to a continuous wave function defined on an uncountable set of points.

The extent to which the underlying reality is infinite is perhaps unknowable, as we will only ever have a finite set of data.

In particular, I can't see that the axiom of choice would be relevant in a physical situation.