Quantum Physics and the Abuse of Reason

http://steve-patterson.com/quantum-physics-abuse-reason/

by dsego • 11 years ago

38 40 11 years ago

steve-patterson.com

kordless• 11 years ago

Category: philosophy

Undoubtedly.

placebo• 11 years ago

I think most attempts to support mysticism using quantum mechanics are made by people who know very little about either, but know quite a bit about what people want and how to make money from it.

skybrian• 11 years ago

You can skip most of this but the bit about the Afshar experiment looks important. According to Wikipedia it's still controversial. Does anyone know more about it?

lisper• 11 years ago

Yes, but it's hard to explain succinctly. TL;DR: the Afshar experiment does not actually show what it purports to show. It's a bit of rhetorical sleight-of-hand. The reason is the presence of the lens, which supposedly creates an image of the two slits, but in fact does not. What it really does (which can be demonstrated mathematically) is create an interference pattern that looks like an image of the two slits but really isn't. So it is not the case that because it looks like a photon went through one slit or the other at the end of the experiment that it did in fact go through one slit or the other.

If you're interested in the details, Feynman has a good explanation in "QED: The strange theory of light and matter" using a mirror rather than a lens but amounting to the same thing.

VLM2• 11 years ago

Its a redefinition game. Notice how vital it is for proponents to describe the path of an (admittedly very fast) bit of light as "at the same time" when it obviously is not.

By analogy, my coworker and I superficially drove home "at the same time" starting and stopping in about the same place, but it would be highly misguided to say we actually were coincident at any given instant, the commute was instantaneous, in some metaphysical sense we are the same we just look different sometimes, or there are not two coworkers but an infinity of coworkers in a multiverse commute. (edited to add, I'm not implying a hidden variable analogy which is obviously not how the real world works, more of a GIGO data analysis leads to weird conclusions analogy)

Light can behave like a wave or a particle. Nothing can directly detect both ways at the same time. Its perfectly acceptable to pipe the output of a gadget that sees "waves" to the input of a tester that sees "particles". Unsurprisingly, light, not having any hidden variables, doesn't know its own history very well and will happily be detected however you'd like to test it.

I think the author aims at the wrong target. The biggest problem with "quantum mystics" is TV grade technobabble and scam artists. Merely taking a fairy tale and saying its not fake anymore because "quantum" was sprinkled on it doesn't make it any less ridiculous. As we all here know, its like saying "security" is merely a checkbox, perhaps an include file setting, not something that has to be baked into the cake from the beginning.

analog31• 11 years ago

For me, a simple litmus test for a quantum phenomenon is: Can it be turned into a proposal for an experimental determination of Planck's constant? It doesn't have to be a great experiment -- determining h to within an order of magnitude would satisfy.

chrischen• 11 years ago

Seems like the author is falling into his own trap by having a bias for determinacy. For the same reason he states that observing a blurry photograph does not make the thing blurry, observing classical mechanics as deterministic does not make the world deterministic. Yet he has a bias for determinism simply because it is what he sees, comprehends, and is familiar with.

First, he brushes away the many world's interpretation, which I believe has superceeded the CI in popularity now. It addresses pretty much all of the issues he has with CI including collapse, obersvation mysticism. It even addresses Einstein's issues with CI in that God no longer plays dice.

Second, they've experimentally disproven local hidden variable theory in a quantum interaction like entanglement via disproving bells inequality. In other words scientists have already considered there might be hidden particles and properties at play affecting quantum interactions and they have disproven their existence.

jmatthews• 11 years ago

Any links to a source to this claim? I was unaware it had became possible to disprove a negative.

gbelote• 11 years ago

If quantum-entangled particles exist (they do) you can use them to coordinate in a way that's impossible within a "hidden variable" model of the universe. You can dig into this by searching for "bell's inequality" or "bell test experiments", there are a few different experiments that have been done many, many times. There's a pretty good Veritasium video that explains one such experiment in non-physicist terms: https://www.youtube.com/watch?v=ZuvK-od647c

eurleif• 11 years ago

http://lesswrong.com/lw/ph/can_you_prove_two_particles_are_i...

wyager• 11 years ago

I was unaware it had became possible to disprove a negative.

Can one not prove the positive?

lmm• 11 years ago

The popularized/simplified version is http://en.wikipedia.org/wiki/Free_will_theorem . It's logically impossible for local hidden variables to produce results consistent with this experiment; either the hidden variable must be nonlocal (able to affect two spatially separated experimenters at exactly the same time), or the experimenters' actions must be determined ahead of time (and it's not a hidden variable so much as a hidden constant).

x1798DE• 11 years ago

You can definitely disprove negative statements - any positive statement can be expressed as its negation (and vice versa), so to the extent that you can prove positive statements, you can disprove their negations.

jostylr• 11 years ago

The keyword is "local". Non-local hidden variables is trivial (Bohm's theory) in that we just posit the particles have positions and are guided by the wave function. Hence, particle and wave properties. Simple, clean, clear, mathematically proven to agree with all results, no problem with spin and it leads to insightful derivation of identical particle behavior and even Dirac's equation.

It is a bit embarrassing that the "hidden" part of the theory is particle position seeing that is what we see, after all. The wave is the more hidden part of things, gleaned only via many particle observations of similar states.

Bell's inequality is theory agnostic except for demanding that experiments have results when performed. Thus, the experiments show that either reality is nonlocal or reality is not definite. Many worlds opts for the latter and it can be perfectly well-formulated (think of fuzzy videos overlaid on each other; any particular instance is not discernible, but through evolution you can distinguish which is which). Most presentations of many worlds I have seen is not understandable, but there are versions that are perfectly well-defined and fits the data.

Finally, the issue why people objected to CI is not determinism, but wanting a well-defined theory. Bohm's theory and other interpretations give us that.

StevePatterson• 11 years ago

Hey there - author here. Somebody emailed me this thread. I'll just make a couple points:

1. Yes, I am biased toward determinism in this case. But that's largely because of the methodology used by proponents of indeterminism (I don't believe their conclusion necessarily follows from their data. In fact, I think it's an entirely unnecessary conclusion). Determinism is my default, unless a more convincing argument prevents itself.

That being said, if indeterminism is true, I'm fine with that - so long as "superposition" doesn't include mutually exclusive states. If the theory can avoid logical contradiction, then it's possible.

2. I'm fine with the MWI. However, I think it's unnecessary and have difficulty getting around Occam's razor in this situation. If the choice is between a) believing a practically-infinite set of real-universes exist (all requiring explanations) or b) remain skeptical for a more compelling theory preserving the simplicity of one universe, I'll take the latter. (Given enough time, the highest levels of abstraction about reality seem to be universally simple, so I'll hold out a bit longer)

3. I also have a difficult time accepting that there's logical proof that hidden variables don't exist. Mathematical proof (satisfying a particular, non-necessary set of mathematical theories) does not sufficiently qualify as logical proof. And, indeed, Bell's theorem has likely already been proven invalid.

foldr12• 11 years ago

Many of the people arguing that quantum physics undermines logic are physicists who understand QM as well as anyone. For example, Lawrence Krauss often suggests that theistic arguments based on classical logic are undermined by QM (which shows that reality isn't "logical").

The idea that QM is deeply weird, counterintuitive, challenging, profound, etc., is one that's relentlessly pumped out by the physics PR machine. In other words, physicists are fine with physicists making wild philosophical speculations about QM; they just don't want anyone else to join the party. Well, it doesn't work like that. Either this stuff has philosophical implications or it doesn't. And if it does, those are fair game for philosophers to comment on. (And sure, some of these philosophers don't always know as much about the physics as they should, but their ignorance in this respect is usually nothing in comparison to modern physicists' ignorance of philosophy.)

sumitviii• 11 years ago

When have physicists commented on philosophical ideas?

foldr12• 11 years ago

Many of the great physicists of the first half of the 20th century did. There was a lot of interchange between logical positivism (the Vienna Circle etc.) and physics.

VLM2• 11 years ago

When a physicist speculates, and someone points out that implies a sign reversal in ohms law, "oh well, I'll try again later". There's an immense collection of constraints based on experimental results that they try to respect.

When a philosopher speculates, and someone points out a problem with the theory, welcome to the wonderful world of sophistry and logical fallacy, would you like your ad hominem attack flame merely well done or extra crispy? Usually with a trendy side dish of political correctness and authoritarianism. Not to mention the typical attitude of "experimental results, who needs em?"

foldr12• 11 years ago

When a physicist speculates..there's an immense collection of constraints based on experimental results that they try to respect.

No, not really. See e.g. Krauss's speculations that I mentioned above.

What you say about philosophy is just a caricature. At least point to specific philosophers or specific articles.

nevinera2• 11 years ago

Of course it has philosophical implications. The problem is that philosophers largely don't understand QM well enough to talk about them. To be fair, many physicists don't either.

foldr12• 11 years ago

Could you give a specific example of such a philosopher? Or some kind of justification of the "largely"? How carefully have you examined that body of work?

stolio6• 11 years ago

(And sure, some of these philosophers don't always know as much about the physics as they should, but their ignorance in this respect is usually nothing in comparison to modern physicists' ignorance of philosophy.)

I realize you're just debate-baiting, but this isn't anywhere near a symmetric situation. For the philosopher physics is a bridge to reality, it's a source of invaluable information. I've seen no evidence philosophy has anything to offer the physicist that's of equal importance.

foldr12• 11 years ago

For the philosopher physics is a bridge to reality,

The claim that physics plays that special role within philosophy is itself a philosophical claim. If you want to justify it you'll have to study some philosophy!

More generally, your attitude is one that's typical of physicists these days, who tend to approach the philosophical literature with a huge superiority complex. That's not an attitude that was shared by the 20th century's greatest physicists.

jwklemm• 11 years ago

The author initially sets up this piece to be a criticism of quantum mysticism. However, as the post goes on, it seems to become a dismissal of quantum mechanics all together -- based on an obvious bias for determinacy.

api• 11 years ago

You don't need QM for paradoxes... they come up in all kinds of classical systems with feedback loops. You also don't need QM to do a number on determinism. Look up the work of Ilya Prigogine.

Quantum Physics and the Abuse of Reason

Related Stories