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  3. Observing Schrodinger's cat [modified]

Observing Schrodinger's cat [modified]

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  • S S Houghtelin

    So if it wasn't observed, it never happed? That is so "tree falls..." if I never heard it.

    It was broke, so I fixed it.

    R Offline
    R Offline
    realJSOP
    wrote on last edited by
    #6

    Based on what we know of trees, a tree does not grow wihtout a root system and pretty much any tree we see laying on its side has - of course - fallen. We don't have to see it fall to know that it fell. The question is whether or not the tree has fallen until we have observed that it has. If the tree falls and crushes you, even with your back to it, the tree has interacted with you in a number of ways before your untimely demise, via sound, the rush of forest animals trying to run past you to get out of the way of the falling tree, and finally the tree contacting your person. You have, in the end, interacted with the tree without observing it in the classical sense of "observation".

    ".45 ACP - because shooting twice is just silly" - JSOP, 2010
    -----
    You can never have too much ammo - unless you're swimming, or on fire. - JSOP, 2010
    -----
    "Why don't you tie a kerosene-soaked rag around your ankles so the ants won't climb up and eat your candy ass." - Dale Earnhardt, 1997

    modified on Friday, July 22, 2011 8:43 AM

    N S D G W 5 Replies Last reply
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    • R realJSOP

      Based on what we know of trees, a tree does not grow wihtout a root system and pretty much any tree we see laying on its side has - of course - fallen. We don't have to see it fall to know that it fell. The question is whether or not the tree has fallen until we have observed that it has. If the tree falls and crushes you, even with your back to it, the tree has interacted with you in a number of ways before your untimely demise, via sound, the rush of forest animals trying to run past you to get out of the way of the falling tree, and finally the tree contacting your person. You have, in the end, interacted with the tree without observing it in the classical sense of "observation".

      ".45 ACP - because shooting twice is just silly" - JSOP, 2010
      -----
      You can never have too much ammo - unless you're swimming, or on fire. - JSOP, 2010
      -----
      "Why don't you tie a kerosene-soaked rag around your ankles so the ants won't climb up and eat your candy ass." - Dale Earnhardt, 1997

      modified on Friday, July 22, 2011 8:43 AM

      N Offline
      N Offline
      Nagy Vilmos
      wrote on last edited by
      #7

      Hang on. You hear the tree [observation], see the fleeing animals [observation] and finally feel it on your head [observation]. Three classic observations - hearing, seeing and touching. All you needed was the smell of leaf mold and the taste of dirt to get the set.


      Panic, Chaos, Destruction. My work here is done. Drink. Get drunk. Fall over - P O'H OK, I will win to day or my name isn't Ethel Crudacre! - DD Ethel Crudacre I cannot live by bread alone. Bacon and ketchup are needed as well. - Trollslayer Have a bit more patience with newbies. Of course some of them act dumb - they're often *students*, for heaven's sake - Terry Pratchett

      1 Reply Last reply
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      • R realJSOP

        Based on what we know of trees, a tree does not grow wihtout a root system and pretty much any tree we see laying on its side has - of course - fallen. We don't have to see it fall to know that it fell. The question is whether or not the tree has fallen until we have observed that it has. If the tree falls and crushes you, even with your back to it, the tree has interacted with you in a number of ways before your untimely demise, via sound, the rush of forest animals trying to run past you to get out of the way of the falling tree, and finally the tree contacting your person. You have, in the end, interacted with the tree without observing it in the classical sense of "observation".

        ".45 ACP - because shooting twice is just silly" - JSOP, 2010
        -----
        You can never have too much ammo - unless you're swimming, or on fire. - JSOP, 2010
        -----
        "Why don't you tie a kerosene-soaked rag around your ankles so the ants won't climb up and eat your candy ass." - Dale Earnhardt, 1997

        modified on Friday, July 22, 2011 8:43 AM

        S Offline
        S Offline
        S Houghtelin
        wrote on last edited by
        #8

        Your explaination is well put. :) My point exaclty! :thumbsup: Just because it wasn't observed, doesn't mean it didn't happen. Things happen all the time without being observed. Observation proves that stuff does happen and that observed reactions can be reasonably expected to occur again.

        It was broke, so I fixed it.

        G 1 Reply Last reply
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        • H hairy_hats

          As the cat is an active observer inside the box, isn't the whole premise of the thought experiment flawed? On a related topic, in a QM collapsing-the-waveform sense, what does an "observation" mean? Does it mean an observation by an intelligence or just an interaction with another system? If the latter, then wouldn't "interaction" be a better description than "observation"? If the former, then how does the QM system being measured know that the interaction it is experiencing is an observation by an intelligence and not just a random interaction with a passing particle/wave? And finally, how much Scotch does it take to make yourself believe you understand this stuff? Edit: An interesting blog entry on this topic is here[^].

          modified on Friday, July 22, 2011 10:52 AM

          W Offline
          W Offline
          Wjousts
          wrote on last edited by
          #9

          viaducting wrote:

          As the cat is an active observer inside the box, isn't the whole premise of the thought experiment flawed?

          You're over thinking it. It's a thought experiment and, like an analogy, it only goes so far.

          P 1 Reply Last reply
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          • H hairy_hats

            As the cat is an active observer inside the box, isn't the whole premise of the thought experiment flawed? On a related topic, in a QM collapsing-the-waveform sense, what does an "observation" mean? Does it mean an observation by an intelligence or just an interaction with another system? If the latter, then wouldn't "interaction" be a better description than "observation"? If the former, then how does the QM system being measured know that the interaction it is experiencing is an observation by an intelligence and not just a random interaction with a passing particle/wave? And finally, how much Scotch does it take to make yourself believe you understand this stuff? Edit: An interesting blog entry on this topic is here[^].

            modified on Friday, July 22, 2011 10:52 AM

            D Offline
            D Offline
            Dalek Dave
            wrote on last edited by
            #10

            It was only recently when I found out that cats do not, in fact, have nine lives.

            ------------------------------------ I will never again mention that I was the poster of the One Millionth Lounge Post, nor that it was complete drivel. Dalek Dave CCC Link[^] Trolls[^]

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            • R realJSOP

              Based on what we know of trees, a tree does not grow wihtout a root system and pretty much any tree we see laying on its side has - of course - fallen. We don't have to see it fall to know that it fell. The question is whether or not the tree has fallen until we have observed that it has. If the tree falls and crushes you, even with your back to it, the tree has interacted with you in a number of ways before your untimely demise, via sound, the rush of forest animals trying to run past you to get out of the way of the falling tree, and finally the tree contacting your person. You have, in the end, interacted with the tree without observing it in the classical sense of "observation".

              ".45 ACP - because shooting twice is just silly" - JSOP, 2010
              -----
              You can never have too much ammo - unless you're swimming, or on fire. - JSOP, 2010
              -----
              "Why don't you tie a kerosene-soaked rag around your ankles so the ants won't climb up and eat your candy ass." - Dale Earnhardt, 1997

              modified on Friday, July 22, 2011 8:43 AM

              D Offline
              D Offline
              Dalek Dave
              wrote on last edited by
              #11

              If an old woman falls over in a house and there is no-one there, does she make a noise?

              ------------------------------------ I will never again mention that I was the poster of the One Millionth Lounge Post, nor that it was complete drivel. Dalek Dave CCC Link[^] Trolls[^]

              S 1 Reply Last reply
              0
              • D Dalek Dave

                If an old woman falls over in a house and there is no-one there, does she make a noise?

                ------------------------------------ I will never again mention that I was the poster of the One Millionth Lounge Post, nor that it was complete drivel. Dalek Dave CCC Link[^] Trolls[^]

                S Offline
                S Offline
                S Houghtelin
                wrote on last edited by
                #12

                "Help I've fallen and I can't get up!" http://en.wikipedia.org/wiki/I've_fallen_and_I_can't_get_up![^]

                It was broke, so I fixed it.

                1 Reply Last reply
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                • H hairy_hats

                  As the cat is an active observer inside the box, isn't the whole premise of the thought experiment flawed? On a related topic, in a QM collapsing-the-waveform sense, what does an "observation" mean? Does it mean an observation by an intelligence or just an interaction with another system? If the latter, then wouldn't "interaction" be a better description than "observation"? If the former, then how does the QM system being measured know that the interaction it is experiencing is an observation by an intelligence and not just a random interaction with a passing particle/wave? And finally, how much Scotch does it take to make yourself believe you understand this stuff? Edit: An interesting blog entry on this topic is here[^].

                  modified on Friday, July 22, 2011 10:52 AM

                  B Offline
                  B Offline
                  Ben Breeg
                  wrote on last edited by
                  #13

                  viaducting wrote:

                  As the cat is an active observer inside the box, isn't the whole premise of the thought experiment flawed?

                  Your premise of Schroedinger's Cat experiment being flawed is in itself flawed. Schroedinger came up with the cat in the box idea to illustrate the incompleteness of - at the time - quantum mechanics theory. It was only through the act of observation upon the cat that would cause its state to be revealed; until the box was opened, the cat could either be: dead, alive or any state in between. The fact that the cat could observe itself wouldn't make any difference to its state or the outcome. In fact, if you read up on QM, it is the act of measurement that changes the state of what is being observed. This from wikipedia: "The best known is the "paradox" of the Schrödinger's cat: a cat is apparently evolving into a linear superposition of basis vectors that can be characterized as an "alive cat" and states that can be described as a "dead cat". Each of these possibilities is associated with a specific nonzero probability amplitude; the cat seems to be in a "mixed" state. However, a single, particular observation of the cat does not measure the probabilities: it always finds either a living cat, or a dead cat. After the measurement the cat is definitively alive or dead. The question is: How are the probabilities converted into an actual, sharply well-defined outcome?"

                  You do trust me, don't you? IF EVERY nation gets the leaders it deserves, what in God's name have we done to deserve Francis Urquhart?

                  1 Reply Last reply
                  0
                  • H hairy_hats

                    As the cat is an active observer inside the box, isn't the whole premise of the thought experiment flawed? On a related topic, in a QM collapsing-the-waveform sense, what does an "observation" mean? Does it mean an observation by an intelligence or just an interaction with another system? If the latter, then wouldn't "interaction" be a better description than "observation"? If the former, then how does the QM system being measured know that the interaction it is experiencing is an observation by an intelligence and not just a random interaction with a passing particle/wave? And finally, how much Scotch does it take to make yourself believe you understand this stuff? Edit: An interesting blog entry on this topic is here[^].

                    modified on Friday, July 22, 2011 10:52 AM

                    D Offline
                    D Offline
                    David1987
                    wrote on last edited by
                    #14

                    "Intelligence" is not a special magic property that makes a system behave fundamentally differently. "Observation" does not have to be done by an intelligent being - even photons can be observers and collapse waveforms.

                    H 1 Reply Last reply
                    0
                    • H hairy_hats

                      As the cat is an active observer inside the box, isn't the whole premise of the thought experiment flawed? On a related topic, in a QM collapsing-the-waveform sense, what does an "observation" mean? Does it mean an observation by an intelligence or just an interaction with another system? If the latter, then wouldn't "interaction" be a better description than "observation"? If the former, then how does the QM system being measured know that the interaction it is experiencing is an observation by an intelligence and not just a random interaction with a passing particle/wave? And finally, how much Scotch does it take to make yourself believe you understand this stuff? Edit: An interesting blog entry on this topic is here[^].

                      modified on Friday, July 22, 2011 10:52 AM

                      L Offline
                      L Offline
                      Lost User
                      wrote on last edited by
                      #15

                      As it is impossible for information to move from within the box, the fact that the cat knows whether it is dead or not is immaterial (to all but the cat). I think an observation can be classed as the exchange of information. So it doesn't matter if it is an intelligence or not - because if something is measurable it is measurable - whether is measured or not. The cat's state of health CANNOT (by definition) be determined by any observation from outside the box - because there is no transfer of information between the two systems. Anything inside the box "doesn't count" in this case, because we are talking about transfer of information specifically from within to outside of the box. Within the box, the state of health of the feline is known - whether the box contains only the cat, some decaying radioactivity and some poison, or contains the cat, a marching band and a pile of bell-bottom trousers.

                      viaducting wrote:

                      how much Scotch does it take to make yourself believe you understand this stuff?

                      Looking at the bottle (most of which is within my system, and therefore measurable by me), I'd say about a third of a 750ml bottle, plus a couple of pints of Guinness.

                      MVVM# - See how I did MVVM my way ___________________________________________ Man, you're a god. - walterhevedeich 26/05/2011 .\\axxx (That's an 'M')

                      L H B 3 Replies Last reply
                      0
                      • R realJSOP

                        Based on what we know of trees, a tree does not grow wihtout a root system and pretty much any tree we see laying on its side has - of course - fallen. We don't have to see it fall to know that it fell. The question is whether or not the tree has fallen until we have observed that it has. If the tree falls and crushes you, even with your back to it, the tree has interacted with you in a number of ways before your untimely demise, via sound, the rush of forest animals trying to run past you to get out of the way of the falling tree, and finally the tree contacting your person. You have, in the end, interacted with the tree without observing it in the classical sense of "observation".

                        ".45 ACP - because shooting twice is just silly" - JSOP, 2010
                        -----
                        You can never have too much ammo - unless you're swimming, or on fire. - JSOP, 2010
                        -----
                        "Why don't you tie a kerosene-soaked rag around your ankles so the ants won't climb up and eat your candy ass." - Dale Earnhardt, 1997

                        modified on Friday, July 22, 2011 8:43 AM

                        G Offline
                        G Offline
                        Gary Wheeler
                        wrote on last edited by
                        #16

                        One word: chainsaw.

                        Software Zen: delete this;

                        1 Reply Last reply
                        0
                        • H hairy_hats

                          As the cat is an active observer inside the box, isn't the whole premise of the thought experiment flawed? On a related topic, in a QM collapsing-the-waveform sense, what does an "observation" mean? Does it mean an observation by an intelligence or just an interaction with another system? If the latter, then wouldn't "interaction" be a better description than "observation"? If the former, then how does the QM system being measured know that the interaction it is experiencing is an observation by an intelligence and not just a random interaction with a passing particle/wave? And finally, how much Scotch does it take to make yourself believe you understand this stuff? Edit: An interesting blog entry on this topic is here[^].

                          modified on Friday, July 22, 2011 10:52 AM

                          G Offline
                          G Offline
                          Gary Wheeler
                          wrote on last edited by
                          #17

                          Schrodinger was an idiot. No self-respecting cat would have allowed itself to be placed in a box, so his reasoning is obviously flawed.

                          Software Zen: delete this;

                          L 1 Reply Last reply
                          0
                          • L Lost User

                            As it is impossible for information to move from within the box, the fact that the cat knows whether it is dead or not is immaterial (to all but the cat). I think an observation can be classed as the exchange of information. So it doesn't matter if it is an intelligence or not - because if something is measurable it is measurable - whether is measured or not. The cat's state of health CANNOT (by definition) be determined by any observation from outside the box - because there is no transfer of information between the two systems. Anything inside the box "doesn't count" in this case, because we are talking about transfer of information specifically from within to outside of the box. Within the box, the state of health of the feline is known - whether the box contains only the cat, some decaying radioactivity and some poison, or contains the cat, a marching band and a pile of bell-bottom trousers.

                            viaducting wrote:

                            how much Scotch does it take to make yourself believe you understand this stuff?

                            Looking at the bottle (most of which is within my system, and therefore measurable by me), I'd say about a third of a 750ml bottle, plus a couple of pints of Guinness.

                            MVVM# - See how I did MVVM my way ___________________________________________ Man, you're a god. - walterhevedeich 26/05/2011 .\\axxx (That's an 'M')

                            L Offline
                            L Offline
                            Lost User
                            wrote on last edited by
                            #18

                            _Maxxx_ wrote:

                            the fact that the cat knows whether it is dead or not

                            Can something know it is dead? Surely it can only know it is not dead. Or at least suspect that it is not dead. That's my problem with death, not knowing. I'd hate to die and not be aware of the fact.

                            Every man can tell how many goats or sheep he possesses, but not how many friends.

                            G 1 Reply Last reply
                            0
                            • D Dalek Dave

                              It was only recently when I found out that cats do not, in fact, have nine lives.

                              ------------------------------------ I will never again mention that I was the poster of the One Millionth Lounge Post, nor that it was complete drivel. Dalek Dave CCC Link[^] Trolls[^]

                              P Offline
                              P Offline
                              Peter Mulholland
                              wrote on last edited by
                              #19

                              How many times did you observe that outcome, and was it statistically significant?

                              Pete

                              1 Reply Last reply
                              0
                              • L Lost User

                                As it is impossible for information to move from within the box, the fact that the cat knows whether it is dead or not is immaterial (to all but the cat). I think an observation can be classed as the exchange of information. So it doesn't matter if it is an intelligence or not - because if something is measurable it is measurable - whether is measured or not. The cat's state of health CANNOT (by definition) be determined by any observation from outside the box - because there is no transfer of information between the two systems. Anything inside the box "doesn't count" in this case, because we are talking about transfer of information specifically from within to outside of the box. Within the box, the state of health of the feline is known - whether the box contains only the cat, some decaying radioactivity and some poison, or contains the cat, a marching band and a pile of bell-bottom trousers.

                                viaducting wrote:

                                how much Scotch does it take to make yourself believe you understand this stuff?

                                Looking at the bottle (most of which is within my system, and therefore measurable by me), I'd say about a third of a 750ml bottle, plus a couple of pints of Guinness.

                                MVVM# - See how I did MVVM my way ___________________________________________ Man, you're a god. - walterhevedeich 26/05/2011 .\\axxx (That's an 'M')

                                H Offline
                                H Offline
                                hairy_hats
                                wrote on last edited by
                                #20

                                _Maxxx_ wrote:

                                As it is impossible for information to move from within the box, the fact that the cat knows whether it is dead or not is immaterial

                                I disagree. The waveform collapses upon being observed, it doesn't matter whether or not the observer is outside or inside the box. The cat "observed" the radioactive decay by inhaling the poison and dying, therefore the waveform has collapsed to a definite state of dead. Whether or not the external observer knows which state the cat is in doesn't mean that the cat itself is in an indefinite state, it is the observer who is uncertain.

                                1 Reply Last reply
                                0
                                • D David1987

                                  "Intelligence" is not a special magic property that makes a system behave fundamentally differently. "Observation" does not have to be done by an intelligent being - even photons can be observers and collapse waveforms.

                                  H Offline
                                  H Offline
                                  hairy_hats
                                  wrote on last edited by
                                  #21

                                  That's what I thought. That makes the description "observation" inaccurate and "interaction" preferable.

                                  L G 2 Replies Last reply
                                  0
                                  • D Dalek Dave

                                    It was only recently when I found out that cats do not, in fact, have nine lives.

                                    ------------------------------------ I will never again mention that I was the poster of the One Millionth Lounge Post, nor that it was complete drivel. Dalek Dave CCC Link[^] Trolls[^]

                                    H Offline
                                    H Offline
                                    hairy_hats
                                    wrote on last edited by
                                    #22

                                    How many times did you have to reverse over it to find out? (Sorry Elaine. :rose: )

                                    1 Reply Last reply
                                    0
                                    • H hairy_hats

                                      As the cat is an active observer inside the box, isn't the whole premise of the thought experiment flawed? On a related topic, in a QM collapsing-the-waveform sense, what does an "observation" mean? Does it mean an observation by an intelligence or just an interaction with another system? If the latter, then wouldn't "interaction" be a better description than "observation"? If the former, then how does the QM system being measured know that the interaction it is experiencing is an observation by an intelligence and not just a random interaction with a passing particle/wave? And finally, how much Scotch does it take to make yourself believe you understand this stuff? Edit: An interesting blog entry on this topic is here[^].

                                      modified on Friday, July 22, 2011 10:52 AM

                                      A Offline
                                      A Offline
                                      Andy Brummer
                                      wrote on last edited by
                                      #23

                                      viaducting wrote:

                                      As the cat is an active observer inside the box, isn't the whole premise of the thought experiment flawed?

                                      That's the point he was trying to make. We are just starting to get to experiments that probe the boundaries of when a "collapse" happens. In the Copenhagen version, "observation" is an axiom that is put in place until something better is figured out because it works in almost all cases.

                                      viaducting wrote:

                                      And finally, how much Scotch does it take to make yourself believe you understand this stuff?

                                      I think you need something stronger than alcohol.

                                      Curvature of the Mind now with 3D

                                      1 Reply Last reply
                                      0
                                      • G Gary Wheeler

                                        Schrodinger was an idiot. No self-respecting cat would have allowed itself to be placed in a box, so his reasoning is obviously flawed.

                                        Software Zen: delete this;

                                        L Offline
                                        L Offline
                                        lewax00
                                        wrote on last edited by
                                        #24

                                        Of course not. The cat would jump in of its own accord. And then out again. Then back in...

                                        1 Reply Last reply
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                                        • L Lost User

                                          _Maxxx_ wrote:

                                          the fact that the cat knows whether it is dead or not

                                          Can something know it is dead? Surely it can only know it is not dead. Or at least suspect that it is not dead. That's my problem with death, not knowing. I'd hate to die and not be aware of the fact.

                                          Every man can tell how many goats or sheep he possesses, but not how many friends.

                                          G Offline
                                          G Offline
                                          Gary Wheeler
                                          wrote on last edited by
                                          #25

                                          I am dead people.

                                          Software Zen: delete this;

                                          L 1 Reply Last reply
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