Incredibly huge inconsistency of modern physics

[Darwin123]

Wrong- learn about the MWI interpretation which is actually becoming more poplar!
Irrelevant to the fantasy about "pure chance" in QM or the actual mathematical treatment of randomness.

The multiworlds interpretation (MWI) is more popular with who?

I much prefer the Quantum Darwinsm (QD) interpretation to MWI. QD has been used to make predictions that have been verified by experiments.

I am not sure. However, I think that QD is better than MWI in terms of falsifiability. There are actually some experiments where the results COULD HAVE falsified QD. The experimental results were consistent with QD. QD wasn't falsified, but that doesn't mean it couldn't be falsified.

So maybe QD isn't really an 'interpretation'. QD is more like a model. I hesitate to call it a theory, though. QD includes some hypotheses on how the environment of the system is structured. The novel feature in QD is a formal definition of a 'measurement' process. The measurement apparatus is now longer classical in nature as in Copenhagen interpretation.

The experiments involve using thermal radiation to collapse the wave function. I think several such experiments have been performed. The results were that as the temperature of the thermal radiation increases, the rate of wave function collapse increases.

I heard there is at least one experimental prediction MWI in principle. However, I didn't really understand the suggested experiment. Something about repeating an experiment in such a way that the wave function doesn't collapse for an unexpectedly long time. I haven't heard of anyone trying it.

I also looked into another interpretation of quantum mechanics called stochastic electrodynamics (SED). I know that an experiment has been performed involving multiphoton emission that has falsified SED. However, I don't think this experiment has been repeated many times.

Maybe the results that contradict SED represent a statistical fluke. I will continue my subscription to Physics Today, Scientific American and Discover. Eventually, someone will write a summary article. I hope!

I don't know whether QD or MWI are correct. Maybe there is another interpretation that I haven't heard of. However, there are no shortages of alternative interpretations to Copenhagen interpretation.

So there are at three three interpretations other than the Copenhagen interpretation: MWI, QD and SED. A true skeptic of quantum mechanics should know a little about all three plus the Copenhagen interpretation.

I come from a background of an education that included science: high school science, undergraduate science, postgraduate physics.

Yes, me too! What a coincidence!

 

[TheAdversary]

+Reality Check I get the idea you're not listening to what I'm saying. But here goes ...

Can you perform an experiment to determine the truth or falsehood of the MWI? This is different from performing an experiment that determines the validity of the
mathematical framework of QM; We know that works or else ultimately the tech wouldn't be there allowing me to write this message in the first place.
But determining the validity of the MWI requires access to those supposed other dimensions. Otherwise it's just Russel's teapot.
As said, I can just as well put forth a theory about Angels and Demons, or perhaps the Flying Spaghetti Monster causing the collapse of the wave-function
with His Noodly Appendage.
Can I strike up a conversation with one of my alter egos? But that probably wouldn't end well ...

Quantum Darwinism??!!?? Ugh ... Survival of the Fittest Particle. The Struggle to be Measured.

Stochastic, as in, requires probability?

There's no experimental verification for any of those fantasies, and they just keep getting worse. God help us.

 

[Reality Check]

+Reality Check I get the idea you're not listening to what I'm saying. But here goes ...
....

I know that you are not listening to explanations of QM, TheAdversary. The answer is no for the simple reason that you should know if you were able to click on links and read Wikipedia pages, TheAdversary: the MWI interpretation has the same predictions as the Copenhagen interpretation
Interpretations of quantum mechanics

Lots of gibberish ignored.

 

[Reality Check]

The multiworlds interpretation (MWI) is more popular with who?

Scientists. And becoming more popular. I suspect the majority are still sticking with the Copenhagen interpretation or my favorite - the rather pragmatic "shut up and calculate", instrumentalist interpretation!

 

[TheAdversary]

'the MWI interpretation has the same predictions as the Copenhagen interpretation'

Same predictions, but more complicated. Occam's Razor. I already explained it in a previous post.

 

[Reality Check]

Same predictions, but more complicated. Occam's Razor.

Ignorance about the MWI interpretation. MWI is simpler than the Copenhagen interpretation because it replaces a vast number (infinite in infinite universe) of collapsing wave functions with 1 universal wave function. MWI is more complex than the Copenhagen interpretation because it replaces 1 universe with (maybe an infinite) number of universes. The net effect is basically equal complexity, i.e. the same number of entities are postulated.
Ignorance of Occam's Razor: It does not say which competing scientific theories are correct. It is a guide for the development of theoretical models.

 

[TheAdversary]

Is the math of the MWI simpler then in practice? Or is it the same? Otherwise, it's just a statement about philosophical complexity, whatever that means.
Then I can just as well posit a singular omnipotent God. Nice and simple.

 

[TheAdversary]

It's the same theory, right? You should then use Occam's Razor to remove the philosophical noodling!

 

[Darwin123]

'the MWI interpretation has the same predictions as the Copenhagen interpretation'

Same predictions, but more complicated. Occam's Razor. I already explained it in a previous post.

I thought that Occams's Razor only applied to the predictions. That is, I interpreted the 'complexity' of a theory pretty much as the difference between the number of predictions provided by the theory and the number of physical measurements needed to make one prediction.


I don't think the picture one visualizes in the intermediate steps matters, really. If I need 10,000 measurements to predict one number in one experiment, then it is complicated theory no matter how complicated the intermediate picture.

Compare two theories. If the precise same inputs is used to make the precise same predictions, then I consider both theories to be the same. Each theory is equally true, at least to me. I would consider two pictures leading to the same predictions to be REPRESENTATIONS of the same theory. So if the predictions are the same, Copenhagen interpretation and MWI are different representations of the same theory.

Quantum Darwinism and stochastic electrodynamics give predictions different from Copenhagen interpretation, and different from each other. So I don't consider them mere representations of the same theory. They are both refinements of a larger theory called quantum mechanics.

This is not assurance that either of them are right

 

[Reality Check]

Is the math of the MWI simpler then in practice?

No one who knows about Occam's Razor would ask that, TheAdversary .
ETA: Occam's Razor is not about math. Occam's Razor is not about calculations ("practice").

 

[TheAdversary]

I think it's an informal, organic, pragmatic principle. A theory is an attempt to understand our Universe. Since people throughout the ages have tried this and came
up with all sorts of different fantasies that turned out to be incorrect and even damaging, science dictates that the truth of a theory should be tested by experiment.
That assumptions should be experimentally verified. This is not a perfect method; Some uncertainty always remains.
But if a theory is tested over and over, or even silently proclaimed by the technology and innovations that came from it, it will rise in stature. That is, it's a
filtering process whereby wrong ideas should leave the mind, and correct ideas come in. Occam's Razor is simply a part of this filter.
Let's say we have two theories. All of the assumptions of both have been experimentally verified; They make the same predictions.
But if one of them is more complicated than the other, why not choose the simpler one? Sure, you could choose the more complicated one but why? It's pragmatic.
In the end, we need to reason about science in ways that cannot themselves be tested. Self-evident pragmatism. Like you just know you don't want to be kicked in the balls
That's where Occam's Razor comes from, for me.

 

[Reality Check]

I think it's an informal, organic, pragmatic principle. ....

Your post is largely not about the actual Occam's Razor and its usage in science, TheAdversary.
It is the scientific method that requires theories to be tested by experiment. If a theory is tested over and over then it "will rise in stature" to become a physical law (still capable of being overturned though). Occam's Razor has nothing to do with this filter.

Occam's Razor is more about judging where to expend effort in developing theoretical models. If we have multiple theoretical models that make the same predictions (no experiments are needed!) then it is the theoretical model that postulates the few entities that can be selected for further development.

It is not ease of calculations that determines the number of postulated entities. It is not your knowledge of mathematics that determines the number of postulated entities, TheAdversary !

 

[TheAdversary]

'Occam's Razor has nothing to do with this filter.'

Maybe I lobbed it in too quickly there, but you need to read the whole thing. What I'm saying is that Occam's Razor cannot be anything else than an informal,
pragmatic device. When two theories both have been verified by experiment, the scientific method cannot decide between them. So what then?
Common sense remains. Nothing else.
And so it's best explained by an example :
Let's say we have two mathematical descriptions that perfectly predict the motions of the objects in the Solar System, but one has the Earth as the centre,
and the other the Sun. Both can be made to comply to observation perfectly. One describes the motions as ellipses that seem to follow a simple law,
the Heliocentric one, but the Geocentric one describes the motions as weird spirals and no simple, common law is evident.
Strictly, the scientific method cannot make the decision which one is correct, as they both predict the same things when looking at the night sky.
But that one simple law that describes all the motions, equal areas during equal intervals of time, seems to have merit. And led to the development of Mechanics, historically.
Geocentricism had no such merits, and was consequently abandoned. In other words, Occam's Razor was applied.
If this is not the way modern science approaches nature, remember me to cancel my subscription to modern science.

 

[TheAdversary]

Don't modern students get courses on Philosophy of Science, Scepticism, the Demarcation problem etc. at universities any more? Or is it considered suspect because of the
dirty word 'Philosophy'? Or is it just rushed because of financial priorities? Or maybe just offered as an extra?
This should be the backbone of a scientific education! And a lot of it is simple enough to be taught to children already at an early age ...

 

[W.D.Clinger]

Don't modern students get courses on Philosophy of Science, Scepticism, the Demarcation problem etc. at universities any more?

Philosophy of Science is almost always offered as an elective. Few universities offer courses devoted entirely to scepticism or to the demarcation problem, although those topics may come up in less specialized courses.

This should be the backbone of a scientific education!

I doubt that. I took four philosophy courses as electives, and thought they were worthwhile given my peculiar interests, but they were not essential to a scientific education.

And a lot of it is simple enough to be taught to children already at an early age ...

If philosophy is simple enough for children, why do so many who post here understand it so poorly? And why is that poor understanding of philosophy so conspicuous among those who make a habit of suggesting philosophy is on their side?

 

[TheAdversary]

I don't mean to imply that Philosophy is simple; Far from it, as this thread has shown. And I'm talking specifically about Philosophy of Science; That should be the backbone
of a scientific education, even if it's not explicitly taught in a class. Feynman describes it quite well in Cargo Cult Science.
And basic principles of science like finding out how something actually works, instead of coming up with some fantasy, is something you can teach children quite well, even
in a playful manner. I do this all the time with my nephew; Show him the cars don't work without batteries etc.
I think most modern educators care more about ADD and Autism and pills than passing on knowledge these days, but maybe I'm being cynical here.

 

[TheAdversary]

I like to mention Technical Lego here. They're excellent in teaching children basic principles of mechanics. You can show the child that when the big gear drives the small gear,
the small gear will go really fast. But the other way round, the small one driving the big one, makes the big one turn slowly. And by just asking him to try to stop one of the axles,
you can make him understand that the force (torque, but for the sake of argument) is very small when the (angular, ...) velocity is high, and vice versa.
This will give him an intuitive idea already about the rather abstract notion of energy. And then later the Work Energy Theorem will fall into place, when he's older.

 

[schrodingasdawg]

... a vast number (infinite in infinite universe) of collapsing wave functions with 1 universal wave function.

In the Copenhagen interpretation, the wave function doesn't have any physical reality. It's a book-keeping device used by humans to predict experimental outcomes given experimental preparations. It's a generalization of a probability distribution which uses complex numbers (allowing for interference) instead of positive real numbers. Collapse isn't, accordingly, a physical process; you replace the wave function when a measurement is made because you learn something new about the system, just as you'd replace an assessment of odds when you learn something new classically.

The wave function as a real physical object which collapses upon measurement (especially by a conscious observer) is part of von Neumann and Wigner's interpretation of QM, rather than of Bohr's and Heisenberg's.

 

[Daylightstar]

...
The wave function ... which collapses upon measurement (especially by a conscious observer) ...

^{Hilite by Daylightstar}
Except of course, he did not actually establish this, he simply 'concluded' it.

 

[Reality Check]

What I'm saying is that Occam's Razor cannot be anything else than an informal, pragmatic device.

We agree: Occam's Razor is an informal, pragmatic device for judging theoretical models, TheAdversary.
Where we disagree is that you are insisting Occam's Razor can be used to pick between the interpretations of QM.
I gave the example of the deterministic MWI interpretation which does not violate Occam's Razor.