Why does observation collapse the wave function of a particle?

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    • #168927
      Anonymous
      Guest

      Why does observation collapse the wave function of a particle? Are you telling me particles are aware of humans?

    • #168928
      Anonymous
      Guest

      >observation
      This single misnomer has been the biggest source of physics pseudery in the 21st century.

      • #168940
        Anonymous
        Guest

        physics scrotes are all to blame for this, they couldn’t develop nomenclature like chemchads.
        yeah call it spin, braket, blackbody, dark matter, force, strange, bottom, energy, heat and jerk. the public is definitely not going to confuse these for the definitions they used before and use daily.

        • #168963
          Anonymous
          Guest

          Rofl chemscrotes:
          >Oxygen: meaning "sharp/acidifying"
          >It’s actually hydrogen that causes acidity in solution

          • #169034
            Anonymous
            Guest

            you are confusing acidity with oxidation/redox. to be fair oxidation is a bit of misnomer since the first oxidation reactions were rusting of iron with oxygen so all reactions where total number of electrons decreases is called oxidation. also oxidation isn’t a household word like energy and work are

    • #168929
      Anonymous
      Guest

      There is no real wavefunction collapse. You (the measuring device) just get entangled to the system you’re measuring.

      • #169018
        Anonymous
        Guest

        Basically this. Its like trying to Smell your own nose, or see your own Eyeball. You cannot do it because you require your eyeball to be able to see. You are entangled with the Eyeball

    • #168930
      Anonymous
      Guest

      quantum mechanics proves particles are aware.

    • #168931
      Anonymous
      Guest

      >Are you telling me particles are aware of humans?
      not only are particles aware, but they are omniscient. they can know weather a particle they were entangled with during the big bang is spin up or down any number of galaxies away.

    • #168932
      Anonymous
      Guest

      The universe is a product of your mind, and you suffer from social anxiety.

      • #168936
        Anonymous
        Guest

        Stop manipulating people who don’t understand quantum physics into believing obviously scrotebrained hippy bullshit.

        • #168937
          Anonymous
          Guest

          >t. quantum-truth-denying seether

          • #168939
            Anonymous
            Guest

            >Thinks calling someone else a "seether" is a valid substitute for actually understanding the science.
            ngmi

            • #168952
              Anonymous
              Guest

              Sadly, that’s like 50% of the "arguments" on LULZ.

    • #168933
      Anonymous
      Guest

      Consider the collapse of the wavefunction for a single particle in the double slit experiment.
      There is a certain amount of information encoded in the particle waveform, but by observing which slit it passes through a lot of that information is passed from the waveform itself to the measurement system, thus there is not enough information left in the waveform to do anything other than go through one of the slits like a point-like particle. On the other hand, when not measured, the information has nowhere to go, and thus it must be encoded by the angle the particle exits the slits, with certain bands being more likely

      • #168945
        Anonymous
        Guest

        *some good comments.

    • #168934
      Anonymous
      Guest

      Observation doesn’t mean “a living being looked at it,” it means anything by which information could be determined about its state.
      If you have a particle floating around in a box how are you going to determine, for example, where in the box it is? You’d have to bounce something off of it like photons (light) or other particles and infer its location from that. And it’s that interaction that causes a wavefunction collapse.
      There is no “hands off” way to observe the properties of particles.

      • #168938
        Anonymous
        Guest

        The weird thing is why that entangled particle outside of the box also has its wave function collapse

        • #168942
          Anonymous
          Guest

          That’s definitely a weird aspect of quantum mechanics. Einstein himself was never satisfied with that “spooky action at a distance.”
          The one thing that lets me tentatively accept it is that it is impossible to actually transmit any information across arbitrary distances using this property. Measuring an entangled particle before or after it has been collapsed by its partner gives indistinguishable results without corroboration from whoever has the partners.

      • #168988
        Anonymous
        Guest

        Anons, help a libarts scrote out: What does ‘information’ mean in the quantum context? I only understand it in the Shannon sense with regards to a channel carrying capacity which is dictated by the ‘maximal entropy’ possible in that channel.

        This is how I always understood it. It’s sort of like if I ask my friend "hey, we still on for Saturday night?" the mere act of asking could change their answer "Oh shit, I forgot, yeah of course! Good thing you reminded me I was about to organize a different thing."
        >inb4 someone says "sounds like a shit friend" instead of just accepting it as a naive analogy for my understanding of what’s happening

        • #168992
          Anonymous
          Guest

          "Information" in the quantum sense is not terribly different, it’s just that things are done in "quantum bits" instead of bits. This means that the storage states can be superpositions of 1 and 0 instead of just one or the other and they can be entangled with other qubits.
          One important takeaway from quantum information theory is that a communication over a quantum channel by wave function collapse (teleported, as it were) cannot be decoded without a corresponding signal over a classical channel to convey what the sender got from their measurements. Information is thus still limited by the speed of light.

          >we don’t know.
          Case closed, but it sure took a long time for us to get there, huh?
          Ctrl-F4.

          Sure, but it’s not incompatible with CI which is where I hopped in.

          • #168993
            Anonymous
            Guest

            you lost poor brainlet me at "can be entangled with other qubits", kek so please excuse me if what I ask next is infuriating either in it’s ignorance or just plain being wrong…
            Superimposition is the state of not being a 1 or a 0 right? I remember some Suskind lecture where he giving the example of if you put a single particle in a magnetic field to influence the ‘spin’ that the particle would give off a photon and the power of that photon would tell you what the spin of the particle was before you exerted a magnetic field on it to ‘observe it’. So lets say a ‘left’ spin could be 1, and a ‘right’ spin could be 0? Am I on the right track?
            Now, in that example, the photon is part of measuring it through a ‘classical channel’ right?
            Anyway, I still don’t understand how they can get ‘entangled’ with other qubits…

            • #168995
              Anonymous
              Guest

              >Anyway, I still don’t understand how they can get ‘entangled’ with other qubits…
              Ultimately, you get entanglement because of the existence of superpositions. In turn, you get superpositions because the observables in Quantum mechanics are matrices instead of numbers and hence don’t necessarily commute i.e. if the observables are the matrices A and B, then AB is not necessarily equal to BA (the Heisenberg uncertainty principle for example states that the position and momentum observables don’t commute). As a consequence of this non-commutativity, when you have a state where the value of one observable is sharp, i.e. if you have a state which is an eigenvector of one of the observables, it need not be an eigenvector of some other observable – instead, it will be a linear combination of eigenvectors, which is what a superposition is.

            • #168996
              Anonymous
              Guest

              Superposition is a state of being some combination of basis states. "0" and "1" states of spin are the simplest to deal with (and what most quantum computing is woke af around) but you can get more complex systems. You’re on the right track with your example, yeah.
              The "how" of entangling is complicated, but it usually comes down to getting two particles produced from one event/interaction (and then NOT TOUCHING THEM or they’ll collapse (decoherence)). I’m not actually sure how they even use them in quantum computing, I just know that they do.

              The classical channel thing comes into play with communication by entangled particles. Say person A and person B each take one particle of an entangled pair. A can take a qubit and combine it with their particle to influence B’s particle as well, but the "sent" qubit can only be determined by B after A tells them what they measured on their particle.

          • #168994
            Anonymous
            Guest

            >Sure, but it’s not incompatible with CI which is where I hopped in.
            Then why did Einstein use it as a critique of CI?

            • #168997
              Anonymous
              Guest

              Because he felt it was insufficient.
              While CI pretty much says "look we get results we don’t care HOW this works under the hood," Einstein wasn’t satisfied with that. Especially since the non-local character of the phenomenon flew in the face of how he believed reality should operate.

    • #168935
      Anonymous
      Guest

      At the quantum level, observation IS interaction. It is literally impossible to measure any results at that scale without "destroying" the state you were trying to measure.

    • #168941
      Anonymous
      Guest

      […]

      >It is conjectured by many that the particle is aware and this is not too unreasonable.

      not just aware, tho. the particle is omniscient. particles know other states of all other particles at all times in the universe instantly.

    • #168943
      Anonymous
      Guest

      Photons are timeless, they are instantaneous ray traces in the environment. When the photon is created it knows if you observed it because its already ray traced its path through space and imparted momentum on your observation medium

      • #168946
        Anonymous
        Guest

        thats actually an interesting result in classical physics. I think it’s called Fermats principle or law or whatever. The principle is a ray of light through a heterogeneous medium takes the pat that minimizes time. so a ray of light somehow knows the distributions of different materials everywhere around it.

        • #168947
          Anonymous
          Guest

          I think another way to look at it is length contraction.
          As any observer approaches the speed of light relative to another object, the length of that object as seen by the observer approaches 0.
          So for light, which can travel at c, all distances are 0 for it. It arrives at its destination the moment it leaves.

          • #169020
            Anonymous
            Guest

            The why does it still take time for light to travel. Like it still takes years for us to see the light from a nearby star. Why wouldn’t we see it instantly?

            • #169021
              Anonymous
              Guest

              The time to travel as "observed" by the light itself, and as seen by observers in other reference frames, are two very different things.
              From our point of view, it is the light itself that is contracted to a length of zero. A point. Kinda like a photon.

              • #169023
                Anonymous
                Guest

                >zero
                +- the quantum uncertainty (position spectrum)

    • #168944
      Anonymous
      Guest

      I am surprised that there are actually good comments on anything bio/chem related ppl are usually scrotebrained.

    • #168948
      Anonymous
      Guest

      people always choose simple sentimentalist anthropocentric supernatural explanations instead of rigorous materialistic ones. look at what people used to think about the sun, gravity, earth, etc.
      same thing with QM, there is probably an underlying mechanisms behind the weird observations that we don’t know yet but people like quantum mysticism scrotes and the like will always tell you it’s magic and justify irrational beliefs by god of the gaps (e.g. soul exists because of QM)

      • #168953
        Anonymous
        Guest

        >there is probably an underlying mechanisms behind the weird observations that we don’t know yet
        I mean, no shit?
        A significant motivating force behind QM (and similarly nuclear science, on a more macro level) is that we don’t know how the “true” underpinnings of these things work, so we instead build our understanding around statistical observations of what we CAN see.
        We can’t peer deep enough into an unstable atom to see when it will decay, but by observing large populations of them we can still get ranges/averages that we can actually use.

    • #168949
      Anonymous
      Guest

      >people always choose simple sentimentalist anthropocentric supernatural explanations instead of rigorous materialistic ones. look at what people used to think about the sun, gravity, earth, etc.
      same thing with QM, there is probably an underlying mechanisms behind the weird observations that we don’t know yet but people like quantum mysticism scrotes and the like will always tell you it’s magic and justify irrational beliefs by god of the gaps (e.g. soul exists because of QM)

      • #168951
        Anonymous
        Guest

        >same thing with QM, there is probably an underlying mechanisms behind the weird observations that we don’t know yet but people like quantum mysticism scrotes and the like will always tell you it’s magic and justify irrational beliefs by god of the gaps (e.g. soul exists because of QM)
        Bell

        • #168955
          Anonymous
          Guest

          Does not do anything to disprove non-local hidden variables.

        • #168958
          Anonymous
          Guest

          what about this?

          • #168970
            Anonymous
            Guest

            pseud

    • #168950
      Anonymous
      Guest

      >Are you telling me particles are aware of humans?
      Haven’t read the thread yet, but I hope somebody else has already said this:

      "Observation" in QM has nothing to do with a person looking at something. It’s about a wave or particle interacting with something else.

      Muh double-slit experiment:
      Huh, that’s weird, if I pass photons through a double slit WITHOUT interacting with anything first, I get one result, but if they DO interact with something else first, I get a different result!
      Woooowwww, totes spooky!

      • #168954
        Anonymous
        Guest

        >"Observation" in QM has nothing to do with a person looking at something. It’s about a wave or particle interacting with something else.
        While true the fact that particle B can know that particle A was interacted with at a speed faster then light and possibly instantaneous is quite spoopy.

        • #168957
          Anonymous
          Guest

          I might be totally off-base with this but I imagine it as one “stretched” quantum system describing two particles rather than two distinct particles.
          So when it’s observed, the whole system assumes a fixed state.

        • #168959
          Anonymous
          Guest

          >quite spoopy.
          You DO understand that quantum entanglement’s "spoopy action at a distance" is a straw-man argument intended to critique the Copenhagen Interpretation, right?
          Just like Schrodinger’s cat?

          • #168960
            Anonymous
            Guest

            Quantum entanglement has been tested and confirmed. Actual brainlet.

            • #168961
              Anonymous
              Guest

              >Quantum entanglement has been tested and confirmed.
              "spoopy action at a distance" remains a mystery.
              And I’m not wrong about the straw-man aspect.
              https://en.wikipedia.org/wiki/Quantum_entanglement
              >Einstein and others considered such behavior impossible, as it violated
              >the local realism view of causality (Einstein referring to it as "spooky action
              >at a distance")[4] and argued that the accepted formulation of quantum
              >mechanics must therefore be incomplete.

              Let me know when the "accepted formulation of quantum mechanics" is complete.

              • #168962
                Anonymous
                Guest

                >"spoopy action at a distance" remains a mystery.
                No shit halfwit, that doesn’t mean it isn’t a thing.
                >And I’m not wrong about the straw-man aspect
                Yes you are actually, do you know what a strawman is? Einstein didn’t make up spooky action at a distance. Other scientists did, and he argued that the action is impossible. Which he later got BTFO’d on.
                >i’m going to sit around online calling scientifically tested events bulshit until we know everything there is to know about everything.
                Truly a waste of oxygen. Please feel free to have a nice day as soon as possible.

                • #168964
                  Anonymous
                  Guest

                  >halfwit, that doesn’t mean it isn’t a thing.
                  I never said it wasn’t, try to keep up, especially before insulting others.

                  >Please feel free to have a nice day as soon as possible.
                  Wow. What a guy. I’m sure your mother doesn’t lie awake at night, recriminating herself because she _didn’t_ strangle you to death in your crib when she had the chance.
                  Say "hi" to her for me.

                  • #168965
                    Anonymous
                    Guest

                    >You DO understand that quantum entanglement’s "spoopy action at a distance" is a straw-man argument intended to critique the Copenhagen Interpretation
                    Stupid scrotebrain

                    • #168968
                      Anonymous
                      Guest

                      I can’t work the 4chins well enough to quote the post I’m replying to, but surely *YOU’RE* the dum-dum.

                      • #168971
                        Anonymous
                        Guest

                        Nope, I am the one agreeing with the evidence gathered from repeated scientific experiments. You guys denying them because it doesn’t fit your world view are the "dum-dums".

                • #168966
                  Anonymous
                  Guest

                  >Which he later got BTFO’d on.
                  Quantum interpretations are (by definition) untestable.
                  The Copenhagen Interpretation alleges particles don’t have spin until that property is called into existence by measurement.
                  That might be true, but how can you tell?
                  If you don’t measure a particle’s spin, how can you be sure it doesn’t have one?
                  We definitely know two "matched" photons have complementary spin.
                  But if Heisenberg and Bohr were right, how do you explain this phenomenon?
                  This remains a mystery to this day, but instead of pretending physics has uncovered some kind of "evidence" for the supernatural, let’s assume the Copenhagen Interpretation is imperfect.

                  • #168969
                    Anonymous
                    Guest

                    Again, we have scientific experiments validating that both spoopy action at a distance is a thing, and that it happens faster then light. You morons should leave this board, this is for science discussion not denial.

                    • #168972
                      Anonymous
                      Guest

                      >we have scientific experiments validating that both spoopy action at a distance is a thing
                      No, you freaking don’t.
                      You have evidence that two "matched" photons have complementary spin, an observation wholly incompatible with the Copenhagen Interpretation. Unless you believe in essentially supernatural forces, "spooky" is bullshit, and demonstrates a flaw in the Copenhagen Interpretation.

                      • #168973
                        Anonymous
                        Guest

                        >an observation wholly incompatible with the Copenhagen Interpretation.
                        Not that guy, but how is it incompatible? As far as I know CI doesn’t say anything about it.

                      • #168974
                        Anonymous
                        Guest

                        >Not that guy, but how is it incompatible?
                        The CI says properties, such as spin, don’t actually exist until the property is called into existence by being measured.
                        A pair of entangled photons are created, and yet (supposedly) neither has spin until one of them encounters (let’s say) a magnetic field, thus revealing/causing(?) its spin to exist.
                        Since we know they have complementary (opposite) spins, we now have advance knowledge of what they other particle’s spin must be, even if that spin won’t actually manifest until it also runs into a magnetic field, thus revealing/manifesting a spin we can predict by having observed the other particle.
                        This is actually weirder than "spooky action at a distance" because it’s also "spooky action" over time.
                        What if one photon travels ten meters before reaching a spin detector, while the other is headed for deep space, and won’t have it’s spin revealed/manifested for years, maybe?

                      • #168975
                        Anonymous
                        Guest

                        There is no action for there to be a spooky action. It is just a preservation of CORRELATION. This is completely consistent with the copenhagen interpretation.

                      • #168976
                        Anonymous
                        Guest

                        >There is no action for there to be a spooky action

                        yes there is. the electron sees what happened to it’s entangled pair, then made a conscious decision to become the opposite spin. it did all this faster than the speed of light too.

                      • #168978
                        Anonymous
                        Guest

                        >he electron sees what happened to it’s entangled pair
                        Completely freaking wrong lmao. The copenhagen interpretation says nothing about what the electron does or whatever bullshit. It says that the person who makes the measurement on one electron can ‘know the state of the electron’, by which they mean that IF this person also measures the other electron, he would get a result consistent with the first measurement. This is just a preservation of correlation as a I said earlier. The spooky part about copenhagen is not spooky action or some other nonsense, it’s the fact that reality itself is not that well-defined.

                      • #168981
                        Anonymous
                        Guest

                        *’know the state of the other electron’

                      • #168998
                        Anonymous
                        Guest

                        >This is just a preservation of correlation as a I said earlier.
                        pseud.

                      • #168999
                        Anonymous
                        Guest

                        ??? That is the prevalent explanation of the ‘non-locality’ of entanglement. That it is just the preservation of correlations. If you think I’m wrong, explain why.

                      • #169000
                        Anonymous
                        Guest

                        >??? That is the prevalent explanation of the ‘non-locality’ of entanglement.
                        no. its not. i read Nature. One electron sees what happened to the other and changes its state accordingly over any distance at infinite speed.

                      • #169002
                        Anonymous
                        Guest

                        Ok, I think you’re trolling but anyway, there is no real ‘state’ in the copenhagen interpretation it is just a way of quantifying an observer’s information of the system. So there is no superluminal collapse either because the ‘collapse’ is just what happens when the observer updates their information.

                      • #169003
                        Anonymous
                        Guest

                        >there is no superluminal collapse
                        read Nature.

                      • #169004
                        Anonymous
                        Guest

                        Read a textbook on quantum mechanics first.

                      • #169007
                        Anonymous
                        Guest

                        >Read a textbook on quantum mechanics first.
                        listen, your interpretation is contrary to Copenhagen, Einstein, and Nature. You can insist all you want, but your interpretation is pseud bullshit.

                      • #169005
                        Anonymous
                        Guest

                        i think you know very well that he’s trolling but some deep insecurity is preventing you from committing to a position that you know is perfectly safe, because the mere logical possibility of being wrong about anon poses enough threat to give you reservation. this is a sickness

                      • #169006
                        Anonymous
                        Guest

                        Take your meds lmao

                      • #169008
                        Anonymous
                        Guest

                        please respond

                      • #169010
                        Anonymous
                        Guest

                        please respond

                      • #169011
                        Anonymous
                        Guest

                        >there is no real ‘state’ in the copenhagen interpretation it is just a way of quantifying an observer’s information of the system
                        Alright.
                        >So there is no superluminal collapse either because the ‘collapse’ is just what happens when the observer updates their information.
                        Not quite. Getting the information necessitates interaction with the system, and that interaction does affect the other end. Call it collapse, update, or donut, it happens all the same.
                        See Bell’s Inequality for proof that the information cannot simply be embedded in the particle.

                      • #169012
                        Anonymous
                        Guest

                        "Getting the information necessitates interaction with the system, and that interaction does affect the other end."
                        ok i’m not him but it sounds like you’re saying it’s impossible to read the output of a light sensor without interacting with a laser beam? aren’t you supposed to design the experiment so that doesn’t happen? like the laser should be in a dark room with no humans breathing on it

                      • #169013
                        Anonymous
                        Guest

                        The light sensor itself has interacted with the laser beam, or it couldn’t determine anything about the beam.

                      • #169014
                        Anonymous
                        Guest

                        i see so you can never see how light behaves when there’s nothing to absorb it unless you have some ESP eye of god

                      • #169015
                        Anonymous
                        Guest

                        More or less. You can make very accurate predictions, but you can’t know every property of a system all at the same time.
                        On the macroscopic scale we see things at in day to day life the effects of observation are vanishingly small, but on the quantum level the effects are dramatic and unavoidable.

                      • #169019
                        Anonymous
                        Guest

                        this makes me worry like there’s an unresolved problem with my way of thinking because i don’t see the world around me (with sense organs that require interaction) in the same way i see things in my internal model of the world (with my imagination). this asymmetry bothers me

                      • #169022
                        Anonymous
                        Guest

                        >this makes me worry like there’s an unresolved problem with my way of thinking
                        this is precisely the intended effect, most of quantum physics is gatekeeping and copenhagen interpretation garbage like the OP is literally misinformation.

                        Yes they literally just made you go though a whole roundabout to say that no we can’t observe light without it hitting something. The best part is that its all a ruse because this has NOTHING to do with the actual uses of QM. look its pictures of electron orbitals, surely this should be impossible right!?! freaking quacks the majority of them, they dont care about science they care about the gay mysticism with muh observation causes wave-function collapse

                      • #169016
                        Anonymous
                        Guest

                        >Getting the information necessitates interaction with the system, and that interaction does affect the other end.
                        It does not ‘affect’ anything distant because that would violate relativity. Whatever you measure is just guaranteed to be correlated with what the person who measures the distant particle observes. You can see this by considering a third observer who observes the entire system consisting of the two distanct observers and the particles which they perform the experiments on.

                      • #169017
                        Anonymous
                        Guest

                        *distant observers

                      • #168977
                        Anonymous
                        Guest

                        >There is no action for there to be a spooky action.
                        Seems likely.

                        >It is just a preservation of CORRELATION.
                        Ok, I’ll buy that. But how is the correlation preserved _before_ ether’s spin is manifest and there (supposedly) aren’t any local hidden variables?

                        Not saying you’re wrong, we’re just getting beyond my understanding.

                      • #168980
                        Anonymous
                        Guest

                        How the correlation is created in the first place depends on how the entangled photons are produced if that’s what you’re asking

                      • #168979
                        Anonymous
                        Guest

                        >The CI says properties, such as spin, don’t actually exist until the property is called into existence by being measured.
                        I don’t quite get that out of the (most common) properties of the Copenhagen Interpretation.
                        It says (among other things) that the wave function gives probabilities for the outcome of measurements on a system, and measuring any property means that any complementary properties cannot be known at the same time. I don’t think that’s what you’re referring to but it’s my closest guess. Can you point to a specific statement somewhere where you’re getting this from?

                      • #168982
                        Anonymous
                        Guest

                        >Can you point to a specific statement somewhere where you’re getting this from?
                        Mostly just picking up pop-sci as I go along.
                        I’m pretty sure I’ve heard that CI prohibits "local hidden variables".
                        Also, if your explanation is common knowledge, then why the "spooky" interpretation so commonly voiced?

                      • #168983
                        Anonymous
                        Guest

                        >CI prohibits "local hidden variables".
                        QM itself prevents local hidden variables. That is a mathematical theorem, it’s not dependent on the interpretation.

                      • #168985
                        Anonymous
                        Guest

                        >QM itself prevents local hidden variables.
                        OK, then how do the entangled photons "keep track" of the (apparently predestined?) spin?

                        Again, not disagreeing, just genuinely ignorant.

                      • #168986
                        Anonymous
                        Guest

                        >the entangled photons "keep track" of the (apparently predestined?) spin?
                        It would only ‘keep track’ if the entanglement isn’t destroyed by some other process. For that to happen, these photons would have to be very isolated from the environment so as to prevent any decoherence. But really, you can’t make statements like ‘the electron keeps track’ etc. in the copenhagen interpretation. In CI, the wavefunction is just a way the observer keeps track of information, it’s not something real.

                      • #168987
                        Anonymous
                        Guest

                        >it’s not something real.
                        OK, then why do they have complementary spin?
                        I’m not hearing an answer to this basic question, and I guess I’m really not expecting one.
                        I kind of assume there’s no ready reconciliation between a lack of local hidden variables and the consistently complementary spins, which (I guess) is why people keep calling it "spooky".
                        Unless, of course, you _are_ arguing for action at a distance?

                      • #168991
                        Anonymous
                        Guest

                        >OK, then why do they have complementary spin?
                        For you to know that they have complementary spin, you need to measure both the spins in the first place. If the observer knows that the photons are entangled in the first place, then his initial knowledge of the unmeasured system would be represented by a wave function of the form [math] frac{|1 rangle |0 rangle + |0 rangle |1 rangle}{sqrt{2}} [/math] (assume that both the spins are in the x-direction). Once the obsever measures the spins of both the electrons in the x-direction, the only results he can get are either 0,1 or 1,0 – that is just the definition of what it means to be entangled. If instead of measuring both the particles, suppose the observer only measures one particle and gets the result 0. Then even without measuring the other particle, he could conclude that IF he did measure the other particle, he would get a 1. That’s all there is to it. In the copenhagen interpretation, you simply don’t talk about what is ‘really going on’ or things like that because if you do, you be lead to make wrong conclusions (conclusions inconsistent with experimental evidence). That is what things like the double-slit experiment are meant to show.

                      • #168989
                        Anonymous
                        Guest

                        In all honesty we don’t know. CI doesn’t claim to answer that, but it isn’t falsified by its existence either. It cares about what we can measure, the results.
                        What we do know is that there is some character to quantum systems that cannot be explained by classical/"local" approaches.

                        >it’s not something real.
                        OK, then why do they have complementary spin?
                        I’m not hearing an answer to this basic question, and I guess I’m really not expecting one.
                        I kind of assume there’s no ready reconciliation between a lack of local hidden variables and the consistently complementary spins, which (I guess) is why people keep calling it "spooky".
                        Unless, of course, you _are_ arguing for action at a distance?

                        >Unless, of course, you _are_ arguing for action at a distance?
                        Not him but it’s not exactly something we can claim doesn’t exist.
                        "Action" may be pushing it though.

                      • #168990
                        Anonymous
                        Guest

                        >we don’t know.
                        Case closed, but it sure took a long time for us to get there, huh?
                        Ctrl-F4.

                      • #168984
                        Anonymous
                        Guest

                        As far as I know "spooky" was just Einstein’s wording for the phenomenon, as he was not a fan of it. And the nomenclature stuck.

    • #168956
      Anonymous
      Guest

      particles be dropping pocket spaghetti since dawn of time

    • #168967
      Anonymous
      Guest

      Measuring is taking something in, like light entering the retina. That or light just bounces of a wall, so yes measurements give light a new ride.
      Hence different info on measure or not.
      In this case measurement aperatus.

      Seems freaking obvious really.

      Just that now you so small you see the tiniest changes of the lights journey. Etc.

    • #169001
      Anonymous
      Guest

      >Why does observation collapse the wave function of a particle? Are you telling me particles are aware of humans?
      because particles dont really exist, they are just detection events. only the wave exists.

      Waves can have energy put into or taken out of them only in discrete quantities. When you ‘see’ a particle what you are seeing is that wave emit energy. Inside the wave all the energy of all the particles is homoginous. A single particle makes a wave existing in all places along that waves path, untill it is detected, the detection event then makes ‘the particle exist in the observed location’.

      This is the truth the quantum memers dont want you to know.

    • #169009
      Anonymous
      Guest

      You’re brain takes time to process stuff so things seem shorter. Like if a horse did the double slit experiment and can’t measure things the electrons would probably still be chaotic too.

    • #169024
      Anonymous
      Guest

      Honestly, the only people who complain about the copenhagen interpretation are those who have understood incorrectly due to some bad explanation of it – symptoms of this misunderstanding include thinking that wavefunctions are real things and collapse is some physical process. What the copenhagen interpretation does imply is that the idea of a classical reality where things definitely happen and have precise values is only an approximation/emergent concept. Once you accept that, it’s all completely logical and sensible.

    • #169032
      Anonymous
      Guest

      I never studied QM beyond introductory course and this thread made me very insecure. Is everything I’ve learned from Griffiths a lie?

      • #169033
        Anonymous
        Guest

        >I never studied QM beyond introductory course and this thread made me very insecure. Is everything I’ve learned from Griffiths a lie?
        no. electrons are omnipresent and omniscient. Whats so hard to understand about that?

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