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0 pointsSharlin11y ago0 comments

The Standard Model does not concern itself with the various interpretations of quantum mechanics. It can, as of now, neither verify or falsify any of the interpretations which, consequently, are not scientific theories or even hypotheses, but firmly on the side of philosophy of physics. The interpretations are attempts to answer why Nature works as it does, within the framework of the Standard Model which only appears to answer the question how.

Yudkowsky certainly hasn't invented the many worlds interpretation, which was originally formulated by the physicist Hugh Everett in 1957. Even though originally scorned, in the more recent times it has gained popularity among physicists. The series of blog posts by Yudkowsky are (in my opinion, at least) a persuasive argument in its favor against the competing interpretations, and are very much recommended reading for anyone who would like to better understand the issue.

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acqq11y ago

> the interpretations which, consequently, are not scientific theories or even hypotheses, but firmly on the side of philosophy of physics.

Thanks, that's exactly what I wanted to know.

I'm completely satisfied with the "shut up and calculate" approach. For me, until somebody shows that he/she can calculate (that is, predict) more than what physicists achieve, they are the ones the closest to "the truth" and not the "interpreter."

spacehome11y ago

Bring it back to the scientific method. The way to differentiate between competing hypotheses is by devising experiments that falsify some of them, and then running the experiments and either falsifying or failing to falsify them.

The issue here is subtle, and it's that the most popular interpretation, Copenhagen, isn't a complete theory because it doesn't tell you algorithmically when collapse occurs. For any possible algorithmic way to handle collapse, there's a corresponding experiment that could (at least in theory) differentiate between Copenhagen and Many Worlds. But the Copenhagen is inordinately slippery in that collapse is defined to occur ex post facto in whatever way is needed to make the experimental results match the theoretical results.

It's perhaps not so surprising that this shortcoming was overlooked in the beginning because Copenhagen was hypothesized before we really had a clear handle on the study of algorithms. But the fact that Copenhagen is still as popular as it is means that Yudkowski needs to spend a lot of time on philosophy of science, because that's what's holding back most people from seeing the problems with Copenhagen, and why at first glance it looks like philosophy.

sriku11y ago

spacehome suggested reading Elizer's posts on quantum physics precisely to not bother to deal with outdated statements like "the most popular interpretation, Copenhagen". Afaik, no serious physicist uses this any more, not even to explain quantum theory. To use wavefunction collapse to "explain" QM is like invoking "God" to explain the universe - i.e. it is not much of an explanation, and it raises more questions than it answers.

Text books ought to be rewritten to teach decoherence instead of outdated stuff like wave-particle duality, wavefunction collapse and such. That is the history of the development of QM and not QM as it is known today, in my limited knowledge.

If you get decoherence, much of the "mysteriousness" and "spookiness" that's talked about in such magazines just disappears and you find them all, every one of them, shallow.

acqq11y ago

I think I can agree with your first paragraph, even if I'd phrase it somewhat differently, but I don't see the connection between it and the next two.

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scott_s11y ago

Last week, I wrote a comment replying to someone asking, if we can't use experiments to determine which interpretation is better, what's the point? Rather than repeat myself, I'll just link to it: https://news.ycombinator.com/item?id=7940647

acqq11y ago

You say there: "How they lean will influence what sort of questions they investigate, how they investigate it, and what sort of outcomes they will look for."

If I understand you, we can expect that somebody is maybe going to be the first to discover something new thanks to the way he's used to think about the subject. Still, before that happens, what do we have?

Edit: Only real hard science. The discoverer we expect of course must decide from which side to attack the matter to reach the new discoveries.

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GregBuchholz11y ago

If you can get the same answers, with a simpler or more elegant theory, you might consider that a "better" theory. IIRC, initially the heliocentric theory of the solar system gave worse approximations of planetary positions than the highly refined epicycles of the geocentric models.

danbruc11y ago

IMHO the many worlds interpretation is one of the least appealing interpretation - millions of millions of millions of universes for nothing. What do you think about the following similar argument? Why are the laws of physics and the physical constants the way they are? There is a universe for every possible set of laws and constants and our universe just happens to be compatible with life. You can just render almost every interesting question moot with similar arguments - I would really prefer something more interesting at the heart of the universe.

acqq11y ago

On that level I don't have any problem with "many worlds" as it can be seen just a one more extrapolation of "we're not in the designed special position" principle: first we're not the center around which the planets circle, then our Sun also isn't the center of our set of stars, then our set of stars is one of many other galaxies... if our physical universe is just a lucky variant of other possible (and mostly uninteresting) universes, it at least doesn't appear surprising.

danbruc11y ago

But there is an important difference - you can observe the other stuff in our universe and therefore know that we are not (exceptionally) special in our universe. Other universes are usually per definition completely outside of our reach, as hard to grab as a god or Russell's teapot.

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DavidPlumpton11y ago

What's more likely? That quantum interference appears because many worlds perpetually exist, or because they seem to exist but somehow don't, or because they sometimes briefly come into existence, hang around for a bit and then randomly collapse breaking all sorts of laws (Liouville thereom, CPT invariance etc.)?

Many Worlds is much tidier than all the alternatives.hh

eli_gottlieb11y ago

Actually, I'd say the "illusion" option is the simplest and tidiest. It is more likely that we interpret a complicated reality from incomplete information than that reality truly is complicated.

j / k navigate · click thread line to collapse

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acqq11y ago

> the interpretations which, consequently, are not scientific theories or even hypotheses, but firmly on the side of philosophy of physics.

Thanks, that's exactly what I wanted to know.

spacehome11y ago

sriku11y ago

If you get decoherence, much of the "mysteriousness" and "spookiness" that's talked about in such magazines just disappears and you find them all, every one of them, shallow.

acqq11y ago

I think I can agree with your first paragraph, even if I'd phrase it somewhat differently, but I don't see the connection between it and the next two.

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scott_s11y ago

acqq11y ago

You say there: "How they lean will influence what sort of questions they investigate, how they investigate it, and what sort of outcomes they will look for."

Edit: Only real hard science. The discoverer we expect of course must decide from which side to attack the matter to reach the new discoveries.

1 more reply

GregBuchholz11y ago

danbruc11y ago

acqq11y ago

danbruc11y ago

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DavidPlumpton11y ago

Many Worlds is much tidier than all the alternatives.hh

eli_gottlieb11y ago

Actually, I'd say the "illusion" option is the simplest and tidiest. It is more likely that we interpret a complicated reality from incomplete information than that reality truly is complicated.

j / k navigate · click thread line to collapse