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Quantum Physics and the Abuse of Reason

38 points by dsego 12y ago

kordless 12y ago
> Category: philosophy Undoubtedly.
placebo 12y 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 12y 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 12y 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.
- VLM 12y 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 12y 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.
deleted 12y ago
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- deleted 12y ago
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chrischen 12y 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 12y ago
  Any links to a source to this claim? I was unaware it had became possible to disprove a negative.
  - gbelote 12y 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 https://www.youtube.com/watch?v=ZuvK-od647c
  - eurleif 12y ago
    http://lesswrong.com/lw/ph/can_you_prove_two_particles_are_identical/ http://lesswrong.com/lw/ph/can_you_prove_two_particles_are_i...
  - wyager 12y ago
    >I was unaware it had became possible to disprove a negative. Can one not prove the positive?
foldr 12y 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 12y ago
  When have physicists commented on philosophical ideas?
  - foldr 12y 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.
- VLM 12y 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?"
  - foldr 12y ago
jwklemm 12y 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 12y 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.
deleted 12y ago
[deleted]

38 points by dsego 12y ago

> Category: philosophy Undoubtedly.

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 12y 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 12y 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.
VLM 12y 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 12y 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.

deleted 12y ago

[deleted]

deleted 12y ago
[deleted]

chrischen 12y 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 12y ago
Any links to a source to this claim? I was unaware it had became possible to disprove a negative.
- gbelote 12y 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 https://www.youtube.com/watch?v=ZuvK-od647c
- eurleif 12y ago
  http://lesswrong.com/lw/ph/can_you_prove_two_particles_are_identical/ http://lesswrong.com/lw/ph/can_you_prove_two_particles_are_i...
- wyager 12y ago
  >I was unaware it had became possible to disprove a negative. Can one not prove the positive?

foldr 12y 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 12y ago
When have physicists commented on philosophical ideas?
- foldr 12y 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.
VLM 12y 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?"
- foldr 12y ago

jwklemm 12y 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 12y 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.

deleted 12y ago

[deleted]