[HN Gopher] How I learned to stop worrying and love uncertainty
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How I learned to stop worrying and love uncertainty
Author : nsoonhui
Score : 81 points
Date : 2022-11-10 12:56 UTC (10 hours ago)
(HTM) web link (nautil.us)
(TXT) w3m dump (nautil.us)
| xchip wrote:
| TL;DR: I have anxiety but let me pretend I overcame it using
| quantum mechanics. I also need your validation, which is the main
| purpose of this article.
| tetris11 wrote:
| Related: https://xkcd.com/1240/
| bheadmaster wrote:
| Well put. I had the exact same conclusion reading this article,
| but couldn't put it into words.
| [deleted]
| Comevius wrote:
| Quantum physics is a low-level approach to understanding the
| Universe, not you life. This is like saying that you studied the
| microprocessor executing a chess program in order to understand
| how chess is played. We don't live in the quantum world, we live
| under the reign of the classical laws of physics, which happens
| to be powered by quantum physics and not an alien supercomputer.
| Not that it matters what powers it until you need to understand
| the underlying platform, like you do for photosynthesis or
| microelectronics, both of which exposes quantum physics.
| blueprint wrote:
| "The statements that quantum mechanics makes about the subatomic
| world fly in the face of our natural intuition about the
| macroscopic world"
|
| plenty of atomic and higher scale systems behave like "quantum"
| systems. in fact if you incorporate decoherence, _every_ "system"
| is "quantum".
|
| "The wavelike nature of matter doesn't manifest itself at
| macroscopic scales"
|
| yes it does. that's how it was discovered and where qm came from.
| google the debroglie hypothesis.
|
| this article is ridiculous
| fedeb95 wrote:
| Disclaimer: I'm not a physicist or even a good mathematician.
| I've read some things about quantum theory, and other interesting
| reads is Fritjof Capra's "The Tao of Physics" and Lazslo Mero's
| "Moral Calculations" which touches quantum theory very
| interestingly.
| howmayiannoyyou wrote:
| Paywalled after you've read 2 articles, so guess I'll have to
| keep worrying.
| wordyskeleton wrote:
| https://archive.ph/ipQ0P
| yeswecatan wrote:
| Beat me to it :)
| [deleted]
| theonemind wrote:
| incognito mode/private browsing works on this one.
| hartator wrote:
| I don't get why people overcomplexify quantum physics.
|
| Can't everything be explained by the future holding more data
| than the present and past? Like if you view time as another
| physical dimension, you are not surprised by the world when you
| start exploring what is on let say on your left. The rest of the
| bed, floor, wall, outside of the house. And if you lose your cat,
| the universe didn't magically split in multiple dimensions but
| the cat state is somewhere on your left. If you consider time
| just as a 4th dimension already written, you don't need to make
| complex theories.
| mjburgess wrote:
| If the future "holds more data" than the past then it's random
| with respect to the past, by definition. This is one of the
| major interpretations of QM.
|
| So if we have a function from past states to future states, we
| can't, eg., which of two past states occured (dead, alive).
|
| However, those who hold a many-worlds view (or chaos-theory
| view) do not believe you can just "insert data", since to do so
| is essentially equivalent to a blind miracle.
|
| To believe the future "holds more data" is to believe that at
| each instance things are happening without any prior cause, all
| of the time, and this is fundamentally inexplicable.
|
| "the future holds more data" view therefore basically gives up
| on the possibility of science in this case, indeed as a view,
| it can always be offered in place of a scientific explanation,
| and amounts to saying "its inexplicable"
| [deleted]
| mftb wrote:
| I also think your comment is pretty insightful. Most
| scientists seem stuck here:
|
| > We can't make confident predictions about the outcomes of
| experiments, but instead have to rely only on fuzzy
| probabilities. There are fundamental limits to what we can
| know.
|
| ...on the fact that we live in a probabilistic universe, not
| a deterministic one. One of the many things I don't
| understand is why it causes so much more trouble with QM than
| Relativity, doesn't it say largely the same thing? That
| eventually you reach a singularity where we have not the
| unknown, but the unknowable, because all of physics stops
| working?
| bheadmaster wrote:
| Philosophically, there is no difference between a
| deterministic universe that we can't fundamentally predict
| and a random universe, since the way we define the word
| _random_ is through unpredictability.
|
| Who would've known that the bottom line of science would be
| "you can't know nuffin".
| blueprint wrote:
| Such a good comment. But I have a question for you. You said
| this is 'one of the major interpretations' of QM. But if the
| hypothetically greater future data is not observable by
| anything outside of the universal wavefunction, then is it
| not the case that the entire system is evolving without
| external observation, i.e., the system itself does not have
| to be able to verify that it "knows" what outcome will occur
| for it to be able to generate new data by a causal mechanism.
| So it sounds like randomness is not proven by what you said
| is definition, alone. Is this what you meant by it being "one
| of the" interpretations of QM?
| mjburgess wrote:
| Well I define random to mean whenever P(X|Y) is neither
| always 1 nor 0, or to put that in causal modal terms:
|
| given an exhaustive description of all possible causes of
| Y, say X, then if X causes Y, *NECESSARILY* Y given X
|
| causation is a form of necessity, necessarily Y occurs or
| it doesnt
|
| In this case P(Future|Past) and P(Past|Future) are
| somewhere between 0 and 1. This isnt consistent with
| causation.
|
| ie., All possible information about all possible causes of
| Y (the future), say X (the past) are insufficient to
| gaurentee any given Y (any particular future).
|
| The "interpretation" element of QM is to say that we are
| really in this case, ie., that we have X = all possible
| information.
|
| There are several ways of denying that P(Y|X) in the case
| of QM should be read this way. You can say X is incomplete,
| either by saying there is non-local information we don't
| have, or global information we don't have. Of the "global"
| kind, which of many worlds we are in is a kind of global
| ignorance.
|
| So that if we had, P(Y|X, which-world) then we'd observe
| P(Y|X, whichworld) = either 1 or 0 --- as with classical
| mechanics
|
| P(CatDead|PoisonBox, worldA) = 1
|
| P(CatDead|PoisonBox, worldB) = 0
|
| etc.
|
| and, eg., P(F|G,M,m,r) = 1 if F=GMm/r^2
| blueprint wrote:
| what do you mean by the term information? My question is,
| rather, whether a system needs to be able to know it
| knows that information for it not to still be causal.
| Because it doesnt observe its whole wavefunction
| mjburgess wrote:
| I dont understand your use of "knows", knowing isnt part
| of the problem.
|
| Imagine, for simplicty sake, a world is a series of four
| switches which we can describe by 0 (off),1 (on).
|
| Eg., world A at time 0 is 0000, at time 1, 0001, ...
|
| Now a change from 0000 to 0001 is _causal_ if in every
| physically possible world 0001 follows 0000, ie.,
| P(0001|0000) = 1
|
| Now suppose that we enumerate every possible world, ie.,
| all the worlds containing only this kind of switch, and
| only four of them.
|
| Now if 40% of the worlds had 0000->0001 and 60% had
| 0000->1000, then P(0001|0000) = 0.4
|
| The question is how can it be that the fourth switch
| behaves randomly? Ie., without any _necessary_ flip from
| 0 to 1. Nothing at all can cause that switch to flip, by
| definition, the world contains nothing else in it.
|
| What property does the switch have such that it turns on
| 40% of the time? _NONE_.
|
| Consider two resolutions to this problem: bite the bullet
| and say the switch is "miraculous in some sense" in that
| it "just turns on" sometimes; OR, say that this thought
| experiment is physically impossible and we're missing
| information.
|
| Eg., that there's a hidden switch: 10000->10001 always,
| and 00000->11000 always, we just can't see the first
| switch, so it looks random.
| blueprint wrote:
| "Imagine, for simplicty sake, a world is a series of four
| switches which we can describe by 0 (off),1 (on)."
|
| If that's what the world is then there's no "we"
| mjburgess wrote:
| Indeed, by definition, that world consists of four
| objects with four distinct properties, ie., being on or
| off.
| blueprint wrote:
| Then where is the time bit?
| kgwgk wrote:
| > if the hypothetically greater future data is not
| observable by anything outside of the universal
| wavefunction
|
| If there is a universal wavefunction evolving
| deterministically what would it mean to talk about the
| future holding more data than the past? There would be a
| direct one-to-one correspondence between the future states
| and the past states.
| blueprint wrote:
| No, I don't think that's correct. I'm not a professional
| but.. despite unitarity and maybe CPT symmetry, I think
| that a given "past" (by which I think we mean the
| universal wavefunction at some t?) has no way of
| recording what its own state is. If measurements were to
| be done of subsets or the whole of the wavefunction, then
| it would, I imagine, contribute to the state of the
| wavefunction so as to evolve it. But keep in mind as well
| when we say "data" we're talking about state which can be
| measured, aren't we? Maybe some state can't be observed;
| and, the "universe" also definitely limits its own
| certainty anyway.
| kgwgk wrote:
| > when we say "data" we're talking about state which can
| be measured, aren't we?
|
| I don't know! If the "data" is about the state of the
| universe (i.e. the wavefunction) the "data" doesn't
| really change because of unitarity.
|
| You may be talking about something else - but it's not
| clear what.
| blueprint wrote:
| what time it is here changes from one moment to the next.
| and there are also horizons. you dont have all the data
| about things yet you operate. just trying to help
| kgwgk wrote:
| but we already knew yesterday what time would be tomorrow
| - there is no new data in that sense
| blueprint wrote:
| obviously not true - in so many ways. what exactly in a
| wavefunction knows whether it will encounter other
| wavefunctions? i think what you're claiming leads to many
| contradictions.
| blueprint wrote:
| i think it's because they're in denial about parts of
| themselves which they don't want to see properly. quantum makes
| plenty of sense. for someone to claim it doesn't is a self
| contradiction.
| canjobear wrote:
| This has nothing to do with quantum mechanics.
| Enginerrrd wrote:
| I mean it does, but it's a total violation of unitarity and
| OP doesn't appear to realize that nor understand its
| implications.
| [deleted]
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