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Comment by vehemenz | Hacker News Reader

When you say "actually scientists" and "boundaries of human knowledge," you seem to be taking for granted naive views about metaphysical realism, scientific realism, and truth that are not trivial to defend, even for experienced philosophers.

If you want to relegate philosophy to obfuscation and trivialities, a good starting place would be to demonstrate that you've made it past the undergraduate, foot stomping "science" phase that, honestly, not enough "actual" scientists seem to have made it past, bringing us mystical nonsense such as the many-worlds interpretation of quantum mechanics.

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> you seem to be taking for granted naive views about metaphysical realism, scientific realism, and truth that are not trivial to defend, even for experienced philosophers.

No, I'm not taking these things for granted. I am simply making the empirical observation that the scientific method has produced vastly more tangible progress than other methods, and it has produced this progress in areas that were previously believed to be inaccessible to science. Science works in ways that no other method does.

> mystical nonsense such as the many-worlds interpretation of quantum mechanics

It's not mystical nonsense, it's a logical consequence of the mathematics of quantum mechanics. You may find it distasteful, but it's the way the world appears to be. You may not like the idea that clocks in space run faster than clocks on earth, but that is also manifestly how the world behaves.

> > mystical nonsense such as the many-worlds interpretation of quantum mechanics

> It's not mystical nonsense, it's a logical consequence of the mathematics of quantum mechanics.

It's an interpretation of the mathematics of quantum mechanics. It's not the only possible interpretation.

> You may find it distasteful, but it's the way the world appears to be.

Yeah? I agree that quantum appears to be the way the world works; show me your concrete evidence for many worlds. You can't do it.

> show me your concrete evidence for many worlds. You can't do it.

Most people would agree that the sun emits light in all directions, but there is no way to prove it with concrete evidence. The only thing you can prove with concrete evidence is that the sun emits light in the direction of objects in our solar system that we can see. We infer that the sun emits light in all directions because that is the best explanation that accounts for the data that we have.

Many-worlds is the same. We can't demonstrate their existence, we infer it from the current-best explanation that accounts for the data that we have.

> current-best explanation

Many-worlds is by far not accepted to be the "current-best explanation".

It's a candidate. It's not clear it's right.

Sorry, I wasn't clear. The current-best explanation is not many worlds, it's the mathematical formalism of QM. Many-worlds is a logical consequence of that.

Many worlds is one possible interpretation of the logical consequences of that. It's not nearly as definite or clear-cut as you're making it sound.

It seems pretty clear cut to me. I've seen no argument against it that doesn't involve some logical fallacy. If you think you know of one please enlighten me.

Well, I'm not an expert. But I know that, among those who are experts, many-worlds is not the consensus or even the majority view. So, while it may seem clear cut to you, it doesn't to everyone. That's why I keep saying that no, it's not clear.

I realize that's argument by authority, and that's considered a fallacy...

I'm not an expert either. I'm a computer scientist, not a physicist. But the math behind QM -- at least the parts that matter for this discussion -- is pretty straightforward linear algebra. Really, anyone can learn it. So don't take my word for it, look into it and decide for yourself. You can start here:

https://www.amazon.com/Philosophy-Physics-Princeton-Foundati...

https://www.amazon.com/Quantum-Mechanics-Experience-David-Al...

Or, if you don't feel like buying a book:

https://flownet.com/ron/QM.pdf

Or, if you prefer a video:

https://www.youtube.com/watch?v=dEaecUuEqfc

BTW, it may come as a surprise to learn that I am actually not a big proponent of many-worlds despite recognizing that it is in fact a logical consequence of the math. If so, you may find this interesting too:

https://blog.rongarret.info/2009/04/on-shadow-photons-and-re...

and a follow-up written ten years later:

https://blog.rongarret.info/2019/07/the-trouble-with-many-wo...

>QM is pretty straightforward linear algebra

The chasm between my grades in linear algebra and my grades in quantum begs to differ... :(

There are two different ways of approaching QM: the physicist's way and the computer scienctist's way. You were probably taught it the physicist's way, which is not wrong, but obscures the parts you need to know to understand the MWI. That part really is pretty simple. You should try again.

According to Einstein nature is parsimonious:many worlds is proliferate.

Sure, but parsimony only applies when all else is equal, and here all else is not equal. Newtonian mechanics is a lot more parsimonious than GR.

That’s human theories which is way downstream of the classical interpretation/paradigm of nature being defined as physical processes.

My understanding is that the best current interpretation of quantum mechanics is that there is no interpretation and that you just have to do the math.

Yes, that's right. But if you want to assign any meaning to the math, and in particular if you want to adopt an ontology where you exist, then the math leaves you no alternative than to conclude that parallel universes also exist (unless you resort to special pleading like the Copenhagen interpretation).

I mean, just doing the math and being agnostic about the strengths of different interpretations seems to be an interpretation. Maybe it's more of an epistemic position than a metaphysical one, but it still kinda counts.

When you look at the actual history of science, this path of “tangible progress” you rely on is shown mostly to be a constructed narrative.

And yet somehow your computer seems to work.

> It's not mystical nonsense, it's a logical consequence of the mathematics of quantum mechanics.

Aren't the various interpretations of QM all empirically indistinguishable from within the universe, which is why they are interpretations and not, say, hypotheses?

It turns out that all of the various interpretations are more or less equivalent, with the exception of the various collapse theories, which are empirically testable and have so far all been falsified.

>> mystical nonsense such as the many-worlds interpretation of quantum mechanics

> It's not mystical nonsense, it's a logical consequence of the mathematics of quantum mechanics

you're both wrong. What the many-worlds interpretation is, is philosophy. It's thinking about what could be that would be explanatory, in the absence of being able to test it; just as atomic theory was philosophy before it was experimentally shown... and it's still philosophy to think about what has actually been shown, since it was not long after it was "shown" that indivisible atoms became divisible into fundamental particles, that they in turn turned out not to be fundamental either.

To be clear, I never suggested the many-worlds interpretation isn't philosophy, but I still think it's mystical nonsense (as most indulgent metaphysical speculation is).

No one, even the most ardent of postmodernists, is going to disagree that science is a very successful human enterprise and produces progress that philosophy cannot. But that doesn't mean science approaches an account of reality on its own terms. To suggest otherwise is to postulate additional metaphysical baggage that even I, the lowly philosopher, find intolerable.

> that doesn't mean science approaches an account of reality on its own terms.

That's true. But just because this is not a valid justification of the assertion that science does not approach an account of reality on its own terms, it does not follow that science does not in fact approach an account of reality on its own terms.

> To suggest otherwise is to postulate additional metaphysical baggage that even I, the lowly philosopher, find intolerable.

Really? Why? What aspect of reality do you believe is inherently beyond the scope of scientific inquiry?

The new riddle of induction, perhaps? You can dodge that by choosing suitable priors, or using heuristics like Occam's Razor, but then what justifies those?

The best answer to that question that I know of can be found in chapter 7 of David Deutsch's book, "The Fabric of Reality." But he's just channeling Karl Popper if you want to go straight to the source. The TL;DR is that science does not rely on induction at all.

That's a cop-out. Sure, the methodical process of science doesn't, strictly-speaking, require induction, but we still have to decide whether to expect the result of scientific inquiry to be useful.

> That's a cop-out.

A reference to the published literature is a cop-out??? Sorry, no.

> Sure, the methodical process of science doesn't, strictly-speaking, require induction, but we still have to decide whether to expect the result of scientific inquiry to be useful.

What??? No! We just have to observe empirically that the results of scientific inquiry are useful.

Karl Popper's position on this issue is a cop-out. See the last paragraph of the relevant SEP entry: https://plato.stanford.edu/entries/induction-problem/

> Popper’s account appears to be incomplete in an important way. There are always many hypotheses which have not yet been refuted by the evidence, and these may contradict one another. According to the strictly deductive framework, since none are yet falsified, they are all on an equal footing. Yet, scientists will typically want to say that one is better supported by the evidence than the others. We seem to need more than just deductive reasoning to support practical decision-making (Salmon 1981). Popper did indeed appeal to a notion of one hypothesis being better or worse “corroborated” by the evidence. But arguably, this took him away from a strictly deductive view of science. It appears doubtful then that pure deductivism can give an adequate account of scientific method.

> Karl Popper's position on this issue is a cop-out.

where "this issue" is:

> The new riddle of induction, perhaps?

The reference I gave you was not directly to Popper, but rather to chapter 7 of David Deutsch's book, "The Fabric of Reality", which you quite obviously did not read because it directly answers the problem described in https://en.wikipedia.org/wiki/New_riddle_of_induction

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