Towards a new scientific worldview, #3: Changing the past

More weird science: A quantum entity, such as a photon of light or an electron, behaves either like a particle or a wave, but not at the same time. Which way it behaves depends on how it is being observed. That’s weird enough, an example of what we have been talking about the last few days of the evidence that reality requires an observer (or Observer).

In 2007, a team of physicists found a way to change the mode of observation of beams of photons in the course of the experiment AFTER they have already entered the measuring apparatus. Somehow, the observation in the present affected how the photons behaved in the past. As one of the authors of the study put it, as quoted in a physics forum,
“In the present, one can change something that has already happened in the past.”

The experiment was published in Science, with this abstract:

Wave-particle duality is at the heart of quantum mechanics. Particles and photons can display both properties, and which property is measured depends on the type of measurement made. What if the experimental setup changes when the photon or particle is “in flight” and has already entered the experimental apparatus? Jacques et al. (p. 966) report an almost ideal realization of such a “delayed choice” experiment as formulated by Wheeler. A triggered single-photon source provides a mechanism for precise timing of the experiment within laboratory conditions. The behavior of the photon in the interferometer depends on the choice of the observable that is measured, even if that choice is made when the photon is already in the system.

Go here for the entire original article.

Go here for a simple classroom experiment–that I have witnessed doing a class observation of our college’s excellent physics class–that shows how we know that light can be either a particle or a wave and that can help you visualize this more sophisticated experiment, in which the light apparently entered the two slits (as it were), which would involve starting to act like a wave, but then when one slit was closed reverted to acting like a particle as if the wave “decision” (the experimenters’ word) never happened.

About Gene Veith

Professor of Literature at Patrick Henry College, the Director of the Cranach Institute at Concordia Theological Seminary, a columnist for World Magazine and TableTalk, and the author of 18 books on different facets of Christianity & Culture.

  • Carl Vehse

    It is interesting when quantum mechanical properties can be exploited in unusual ways in the “real (macro) world”. An example is using the QM properties of a photon to determine the existence of an object in a given location without the photon actually interacting with the object. Using classical physics one would need to have at least one photon be blocked (or reflected into a detector) by an object to sense the object’s presence.

    In simple terms, a QM method very slightly polarizes a photon, which is sent through a couple of beam-splitter paths and recycled numerous times with mirrors. The object to be detected is present (or not) in one of the paths. After so many recyclings the photon is then sent to a polarization detector. If the photon’s polarization has not changed, the object was present; if the polarization has changed, no object was in the path. In either case the photon did not interact in any way with the object. The method’s efficiency (of really not interacting with the object) can be made to arbitrarily approach 100% by increasing the number of recycles the photon is made to have… and, of course, you need really good mirrors.

    Paul Kwiat’s 1996 Scientific American article, “Quantum seeing in the dark,” describes this technique and his experimental results of using a polarization Mach-Zehnder inteferometer and the “Quantum Zeno Effect” (the quantum level case of “a watched pot never boils”).

    Another good discussion of such interaction-free measurements is in Kwiat’s old Los Alamos article, “The Tao of Interaction-Free Measurements,” available through the Wayback Machine (web.archive.org/web/19980214105746/http://www.p23.lanl.gov/Quantum/kwiat/ifm-folder/ifmtext.html), and in various articles in scientific journals.

    One possible (but probably not very practical) application of this technique is to make a photographic image of an object without exposing it to light, i.e., “seeing in the dark.”

  • Carl Vehse

    It is interesting when quantum mechanical properties can be exploited in unusual ways in the “real (macro) world”. An example is using the QM properties of a photon to determine the existence of an object in a given location without the photon actually interacting with the object. Using classical physics one would need to have at least one photon be blocked (or reflected into a detector) by an object to sense the object’s presence.

    In simple terms, a QM method very slightly polarizes a photon, which is sent through a couple of beam-splitter paths and recycled numerous times with mirrors. The object to be detected is present (or not) in one of the paths. After so many recyclings the photon is then sent to a polarization detector. If the photon’s polarization has not changed, the object was present; if the polarization has changed, no object was in the path. In either case the photon did not interact in any way with the object. The method’s efficiency (of really not interacting with the object) can be made to arbitrarily approach 100% by increasing the number of recycles the photon is made to have… and, of course, you need really good mirrors.

    Paul Kwiat’s 1996 Scientific American article, “Quantum seeing in the dark,” describes this technique and his experimental results of using a polarization Mach-Zehnder inteferometer and the “Quantum Zeno Effect” (the quantum level case of “a watched pot never boils”).

    Another good discussion of such interaction-free measurements is in Kwiat’s old Los Alamos article, “The Tao of Interaction-Free Measurements,” available through the Wayback Machine (web.archive.org/web/19980214105746/http://www.p23.lanl.gov/Quantum/kwiat/ifm-folder/ifmtext.html), and in various articles in scientific journals.

    One possible (but probably not very practical) application of this technique is to make a photographic image of an object without exposing it to light, i.e., “seeing in the dark.”

  • http://mesamike.org Mike Westfall

    The results of the experiment show that there is something about the experiment we don’t understand.

    At least that’s the conclusion I find more reasonable than the suggested alternative conclusion that we can change the past by observing in the present.

  • http://mesamike.org Mike Westfall

    The results of the experiment show that there is something about the experiment we don’t understand.

    At least that’s the conclusion I find more reasonable than the suggested alternative conclusion that we can change the past by observing in the present.

  • Carl Vehse

    I’ve looked at the Science paper, “Experimental Realization of Wheeler’s Delayed-Choic Gadanken Experiment,” and I would say that the physics forum comment, “In the present, one can change something that has already happened in the past,” might apply to quantum properties, like the wave-particle duality of a photon, but not to properties or behaviors of macro objects, which would run into the “grandfather paradox.”

  • Carl Vehse

    I’ve looked at the Science paper, “Experimental Realization of Wheeler’s Delayed-Choic Gadanken Experiment,” and I would say that the physics forum comment, “In the present, one can change something that has already happened in the past,” might apply to quantum properties, like the wave-particle duality of a photon, but not to properties or behaviors of macro objects, which would run into the “grandfather paradox.”

  • http://www.geneveith.com Veith

    Carl, you are one of the professional scientists here, so continue to help us out by explaining the “grandfather paradox.”

  • http://www.geneveith.com Veith

    Carl, you are one of the professional scientists here, so continue to help us out by explaining the “grandfather paradox.”

  • Carl Vehse

    The “grandfather paradox” deals with a person time-traveling to the past, but, in the case suggested in your thread, would also apply to someone in the present changing something that has already happened in the past.

    In this paradox, the person changes the event of his grandfather meeting his grandmother to prevent their producing one of his parents. But if that change occurs, that person would not be born to change that event. But this would allow his grandparents to meet, thus allowing him to be born so that he could change the event of his grandfather meeting his grandmother, and so on and so on…

    Even if a time traveler (or historical event changer) tries to avoid the grandfather paradox, it would be harder to avoid the “butterfly effect“, which could bring up the same or other problems.

    Both paradoxes are featured in many science fiction stories, movies, and TV shows.

  • Carl Vehse

    The “grandfather paradox” deals with a person time-traveling to the past, but, in the case suggested in your thread, would also apply to someone in the present changing something that has already happened in the past.

    In this paradox, the person changes the event of his grandfather meeting his grandmother to prevent their producing one of his parents. But if that change occurs, that person would not be born to change that event. But this would allow his grandparents to meet, thus allowing him to be born so that he could change the event of his grandfather meeting his grandmother, and so on and so on…

    Even if a time traveler (or historical event changer) tries to avoid the grandfather paradox, it would be harder to avoid the “butterfly effect“, which could bring up the same or other problems.

    Both paradoxes are featured in many science fiction stories, movies, and TV shows.

  • Carl Vehse

    I should add that the grandfather paradox is resolved in the “many worlds interpretation” of quantum mechanics proposed by Hugh Everett and John Wheeler in the late 1950s. In the many worlds interpretation each possible quantum event provides its own universe, including a world in which a person’s grandfather never met his grandmother, and a world in which he does.

    Thus the universe we live in today is the one produced when you decided to put on brown socks last Thursday, while another separate universe was created by the decision to wear black socks… and another universe exists where you put on socks of a different color, along with separate universes created by every possible alternative that has ever existed right on down to the quantum level over all past time.

    This interpretation saves trying to explain what (or who!) makes quantum wave functions collapse by their observation.

    However, as physicist Paul Davies (The Ghost in the Atom, 1986, p.84) explained, the many worlds interpretation is “cheap on assumptions, but expensive on universes.”

  • Carl Vehse

    I should add that the grandfather paradox is resolved in the “many worlds interpretation” of quantum mechanics proposed by Hugh Everett and John Wheeler in the late 1950s. In the many worlds interpretation each possible quantum event provides its own universe, including a world in which a person’s grandfather never met his grandmother, and a world in which he does.

    Thus the universe we live in today is the one produced when you decided to put on brown socks last Thursday, while another separate universe was created by the decision to wear black socks… and another universe exists where you put on socks of a different color, along with separate universes created by every possible alternative that has ever existed right on down to the quantum level over all past time.

    This interpretation saves trying to explain what (or who!) makes quantum wave functions collapse by their observation.

    However, as physicist Paul Davies (The Ghost in the Atom, 1986, p.84) explained, the many worlds interpretation is “cheap on assumptions, but expensive on universes.”

  • http://www.toddstadler.com/ tODD

    “Cheap on assumptions, but expensive on universes”. Indeed. :)

  • http://www.toddstadler.com/ tODD

    “Cheap on assumptions, but expensive on universes”. Indeed. :)

  • http://www.toddstadler.com/ tODD

    This stuff is at the fringe of my understanding (or beyond), but I’ve always enjoyed it, especially because the experiments are relatively simple so far, at least in concept.

    “That’s weird enough, an example of what we have been talking about the last few days of the evidence that reality requires an observer (or Observer).” I think this is the wrong way to say that. All it really shows is that how you observe (or, more dully, what you observe) determines what you observe. But to say that it “requires” an observer goes too far. Even if you believe in an Observer.

    And while, again, my grasp of this area is shaky at best, I think the main problem with quantum physics is that we — at least we laypeople — lack the proper vocabulary to discuss the things it talks about. Well, that and it’s still a relatively new field, so there’s not a solid consensus all the time.

    One problem is ascribing will to inanimate objects, such as a proton “deciding” how to behave. That’s how it seems to us, but then, humans are simply uncomfortable with the probabilistic, indeterminate world of quantum mechanics. We don’t have very good metaphors to cope with wave-particle duality. We live in the Newtonian world, and our words and ideas reflect this. Reality, to us, is “either/or”, and when we ask a scientific question, we don’t know what to do with “maybe”.

    This can also be seen in the sentence “In the present, one can change something that has already happened in the past.” What “happened” in the past, exactly? Well, in the experiment, the particle “chose” how to behave, right? Except that I’ll maintain that it didn’t actually “choose” — that’s the wrong way to think about it. And if you can say it didn’t really choose, then you can say that something didn’t really happen at that point in the past.

    To be sure, quantum mechanics is weird and wild stuff. But I don’t think it’s as weird as it often gets spun by the time it makes its way into the common vernacular. That, unfortunately, is the realm of your Wired, Discover, or Omni magazine articles (is Omni still around?). The actual science is counterintuitive, to be sure, but ultimately not as sexy as, say, time travel or instant communication across vast distances.

    Any practical application of this stuff necessarily involves scaling it up beyond the quantum level. And at that large scale (where “large” is defined as something the size of a small molecule, on up), quantum effects, while perhaps technically possible, are insanely improbable.

    By the way, the full-text Science magazine article is unavailable at the link you provide (at least to those of us without subscriptions), but there is a summary of the experiment elsewhere at their Web site. If you follow that link, there’s also a link at the bottom of the page to read “More on the delayed-choice experiment”. I’d recommend reading both those pages if you want a better explanation of what this is all about. I thought the explanation at BottomLayer.com (the aforementioned “More” link), while actually only about the thought experiment, was very clear.

  • http://www.toddstadler.com/ tODD

    This stuff is at the fringe of my understanding (or beyond), but I’ve always enjoyed it, especially because the experiments are relatively simple so far, at least in concept.

    “That’s weird enough, an example of what we have been talking about the last few days of the evidence that reality requires an observer (or Observer).” I think this is the wrong way to say that. All it really shows is that how you observe (or, more dully, what you observe) determines what you observe. But to say that it “requires” an observer goes too far. Even if you believe in an Observer.

    And while, again, my grasp of this area is shaky at best, I think the main problem with quantum physics is that we — at least we laypeople — lack the proper vocabulary to discuss the things it talks about. Well, that and it’s still a relatively new field, so there’s not a solid consensus all the time.

    One problem is ascribing will to inanimate objects, such as a proton “deciding” how to behave. That’s how it seems to us, but then, humans are simply uncomfortable with the probabilistic, indeterminate world of quantum mechanics. We don’t have very good metaphors to cope with wave-particle duality. We live in the Newtonian world, and our words and ideas reflect this. Reality, to us, is “either/or”, and when we ask a scientific question, we don’t know what to do with “maybe”.

    This can also be seen in the sentence “In the present, one can change something that has already happened in the past.” What “happened” in the past, exactly? Well, in the experiment, the particle “chose” how to behave, right? Except that I’ll maintain that it didn’t actually “choose” — that’s the wrong way to think about it. And if you can say it didn’t really choose, then you can say that something didn’t really happen at that point in the past.

    To be sure, quantum mechanics is weird and wild stuff. But I don’t think it’s as weird as it often gets spun by the time it makes its way into the common vernacular. That, unfortunately, is the realm of your Wired, Discover, or Omni magazine articles (is Omni still around?). The actual science is counterintuitive, to be sure, but ultimately not as sexy as, say, time travel or instant communication across vast distances.

    Any practical application of this stuff necessarily involves scaling it up beyond the quantum level. And at that large scale (where “large” is defined as something the size of a small molecule, on up), quantum effects, while perhaps technically possible, are insanely improbable.

    By the way, the full-text Science magazine article is unavailable at the link you provide (at least to those of us without subscriptions), but there is a summary of the experiment elsewhere at their Web site. If you follow that link, there’s also a link at the bottom of the page to read “More on the delayed-choice experiment”. I’d recommend reading both those pages if you want a better explanation of what this is all about. I thought the explanation at BottomLayer.com (the aforementioned “More” link), while actually only about the thought experiment, was very clear.

  • Carl Vehse

    Typically for articles in scientific journals, you have to have a subscription or access to an online library service to see the entire article. (Abstracts are usually open to the public.)

    Occasionally the journal’s website will make an important (or an example) article available to the public, or the journal will make an article’s “supplemental documentation” openly accessible. Sometimes one of the authors will put a .pdf copy of the article or his manuscript on his own website. Some preprints of scientific articles are available on the arxiv.org website.

    And to find some scientific articles, you really have to surf the web, such as using Google’s Scholar.

  • Carl Vehse

    Typically for articles in scientific journals, you have to have a subscription or access to an online library service to see the entire article. (Abstracts are usually open to the public.)

    Occasionally the journal’s website will make an important (or an example) article available to the public, or the journal will make an article’s “supplemental documentation” openly accessible. Sometimes one of the authors will put a .pdf copy of the article or his manuscript on his own website. Some preprints of scientific articles are available on the arxiv.org website.

    And to find some scientific articles, you really have to surf the web, such as using Google’s Scholar.

  • http://www.toddstadler.com/ tODD

    Thanks, Carl (@9). I’d heard of, but never used, Google Scholar before. I found a PDF of the article on Arxiv.org. I’ll have to read it another day.

  • http://www.toddstadler.com/ tODD

    Thanks, Carl (@9). I’d heard of, but never used, Google Scholar before. I found a PDF of the article on Arxiv.org. I’ll have to read it another day.

  • http://www.geneveith.com Veith

    tODD and Carl, I’m glad to see how well you are getting along. Carl, as a nuclear engineer, you seem to be the only one who can really understand this stuff. It is certainly true that these odd effects occur only on the quantum level. But quantum entities include light, which is everywhere around us, and electrons, which are part of every atom. Also, I read that at the moment of the big bang the whole universe existed at a quantum level. So quantum mechanics do relate to the world we experience.

    What does it mean, Carl, that quantum mechanics require an observer, something that I’ve read from a non-Lanza source? Is the role of the observer just that the apparatus affects the behavior of the photons, or isn’t it something more? (I am haunted by the thought of the Observer at the Big Bang.)

  • http://www.geneveith.com Veith

    tODD and Carl, I’m glad to see how well you are getting along. Carl, as a nuclear engineer, you seem to be the only one who can really understand this stuff. It is certainly true that these odd effects occur only on the quantum level. But quantum entities include light, which is everywhere around us, and electrons, which are part of every atom. Also, I read that at the moment of the big bang the whole universe existed at a quantum level. So quantum mechanics do relate to the world we experience.

    What does it mean, Carl, that quantum mechanics require an observer, something that I’ve read from a non-Lanza source? Is the role of the observer just that the apparatus affects the behavior of the photons, or isn’t it something more? (I am haunted by the thought of the Observer at the Big Bang.)

  • NQB

    I know Veith asked Carl directly, but I thought I’d offer my take on the “necessary observer” idea.

    In quantum jargon, physicists say quantum entities exist as “probability waves,” which have no intuitive, physical interpretation outside the math and formalism that describe them. But if someone “observes” the particle, the wave function (or probability wave) collapses to something that is much more intuitively available. Seemingly, the ethereal state of the particle becomes physical upon observation. I think some take this to mean that a physical reality composed of quantum entities (i.e., our reality) must therefore have an observer, or Observer. Unfortunately, things become even more confused when one asks what constitutes an observation.

    For example, in the two-slit experiment cited at the end of the post, initially both slits are open and an electron seems to pass through both slits at once because of its probability wave behavior (sort of like how a single water wave can pass through two slits at once). If one slit is closed, well now we are observing which slit the electron physically is passing through (because only one is possible) and any wave behavior disappears because of the “observation.”

    But another way to collapse the wave behavior is to put a magnetic field across the path. Because electrons have a quantum “spin” (which, once again, only loosely relates to our macroscopic idea of physical spinning), each electron will either be pushed or pulled by the field. Thus, the field can direct an individual electron toward one slit or the other. Notice that I never mentioned anyone physically observing or knowing which slit a particular particle goes through, yet this magnetic field constitutes an observation such that the wave behavior disappears.

    So in the end, I think the idea of a necessary observer is humanity’s demand to understand quantum physics in our own, physical terms. But I’d let sleeping dogs lie and just admit that God’s universe is so fearfully and wonderfully made that we can’t fully grasp the workings of quantum mechanics.

  • NQB

    I know Veith asked Carl directly, but I thought I’d offer my take on the “necessary observer” idea.

    In quantum jargon, physicists say quantum entities exist as “probability waves,” which have no intuitive, physical interpretation outside the math and formalism that describe them. But if someone “observes” the particle, the wave function (or probability wave) collapses to something that is much more intuitively available. Seemingly, the ethereal state of the particle becomes physical upon observation. I think some take this to mean that a physical reality composed of quantum entities (i.e., our reality) must therefore have an observer, or Observer. Unfortunately, things become even more confused when one asks what constitutes an observation.

    For example, in the two-slit experiment cited at the end of the post, initially both slits are open and an electron seems to pass through both slits at once because of its probability wave behavior (sort of like how a single water wave can pass through two slits at once). If one slit is closed, well now we are observing which slit the electron physically is passing through (because only one is possible) and any wave behavior disappears because of the “observation.”

    But another way to collapse the wave behavior is to put a magnetic field across the path. Because electrons have a quantum “spin” (which, once again, only loosely relates to our macroscopic idea of physical spinning), each electron will either be pushed or pulled by the field. Thus, the field can direct an individual electron toward one slit or the other. Notice that I never mentioned anyone physically observing or knowing which slit a particular particle goes through, yet this magnetic field constitutes an observation such that the wave behavior disappears.

    So in the end, I think the idea of a necessary observer is humanity’s demand to understand quantum physics in our own, physical terms. But I’d let sleeping dogs lie and just admit that God’s universe is so fearfully and wonderfully made that we can’t fully grasp the workings of quantum mechanics.

  • http://www.toddstadler.com/ tODD

    Veith (@11), you keep going to this, so can I ask where you read that “quantum mechanics require[s] an observer”? I just don’t think it means what you seem to think it does, if it’s even an accurate thing to say.

    “Is the role of the observer just that the apparatus affects the behavior of the photons, or isn’t it something more?” Well, sometimes there’s that. As an analog we may be more familiar with, imagine trying to measure how big someone’s pupils get when it’s completely dark. You can’t really know, because you need photons to measure (let’s say), but the presence of photons means it’s not completely dark. But that’s not really what most of the quantum mechanics experiments mentioned here have been getting it.

    Rather, they touch on the particle-wave nature of quantum-level objects, something which we just don’t have very good “real-world” words to describe. Does light “choose” to behave either like a particle or like a wave? I think that’s a bad way of thinking about it, or at least talking about it. The observer doesn’t change the nature of the particle, he only changes what he observes about it.

    My wife, who knows way more about quantum mechanics than I do (though it sadly must be filtered back through my brain in this telling), gave me this example over dinner last night, which will only be useful if you’ve read Edward Abbott’s Flatland. Otherwise, the metaphor itself will be as confusing, I’m afraid.

    Imagine that you live in Flatland (that is, a two-dimensional world), and a cube (a 3-D object) comes to visit your world one day. As the cube passes through and moves around the plane that is your world, it will at times appear to be a square, and at times a hexagon (okay, and a point). Flatlanders (who only know of fixed-shape objects) will be astounded. “This entity has a square-hexagon duality,” they might say. Assuming they can physically manipulate the cube, they will talk about the fact that how they move it causes the object to assume either a square shape or a hexagon shape. It is baffling to them.

    Of course, it is baffling because they live in a 2-D world and don’t know about the 3-D world of the cube. How a shape can not only grow and shrink in size, but also acquire a different number of sides, is beyond them. They can only talk about the fact that it sometimes appears one way, sometimes another. They don’t understand how it’s not only both, but, in a more accurate sense, neither.

    My contention here is that the particle-wave duality is the same thing. We talk of particles “behaving” one way or another, but really, all we’re talking about is what aspect of the particle we can observe. The particle is the same, either way, observer or not. Just like the cube remains a cube, no matter what aspect of it the Flatlanders see, and no matter whether there’s an observer there or not.

    Anyone who knows more about this field can feel free to correct me. Anyone who knows less can tell me if that example makes sense.

  • http://www.toddstadler.com/ tODD

    Veith (@11), you keep going to this, so can I ask where you read that “quantum mechanics require[s] an observer”? I just don’t think it means what you seem to think it does, if it’s even an accurate thing to say.

    “Is the role of the observer just that the apparatus affects the behavior of the photons, or isn’t it something more?” Well, sometimes there’s that. As an analog we may be more familiar with, imagine trying to measure how big someone’s pupils get when it’s completely dark. You can’t really know, because you need photons to measure (let’s say), but the presence of photons means it’s not completely dark. But that’s not really what most of the quantum mechanics experiments mentioned here have been getting it.

    Rather, they touch on the particle-wave nature of quantum-level objects, something which we just don’t have very good “real-world” words to describe. Does light “choose” to behave either like a particle or like a wave? I think that’s a bad way of thinking about it, or at least talking about it. The observer doesn’t change the nature of the particle, he only changes what he observes about it.

    My wife, who knows way more about quantum mechanics than I do (though it sadly must be filtered back through my brain in this telling), gave me this example over dinner last night, which will only be useful if you’ve read Edward Abbott’s Flatland. Otherwise, the metaphor itself will be as confusing, I’m afraid.

    Imagine that you live in Flatland (that is, a two-dimensional world), and a cube (a 3-D object) comes to visit your world one day. As the cube passes through and moves around the plane that is your world, it will at times appear to be a square, and at times a hexagon (okay, and a point). Flatlanders (who only know of fixed-shape objects) will be astounded. “This entity has a square-hexagon duality,” they might say. Assuming they can physically manipulate the cube, they will talk about the fact that how they move it causes the object to assume either a square shape or a hexagon shape. It is baffling to them.

    Of course, it is baffling because they live in a 2-D world and don’t know about the 3-D world of the cube. How a shape can not only grow and shrink in size, but also acquire a different number of sides, is beyond them. They can only talk about the fact that it sometimes appears one way, sometimes another. They don’t understand how it’s not only both, but, in a more accurate sense, neither.

    My contention here is that the particle-wave duality is the same thing. We talk of particles “behaving” one way or another, but really, all we’re talking about is what aspect of the particle we can observe. The particle is the same, either way, observer or not. Just like the cube remains a cube, no matter what aspect of it the Flatlanders see, and no matter whether there’s an observer there or not.

    Anyone who knows more about this field can feel free to correct me. Anyone who knows less can tell me if that example makes sense.

  • http://www.geneveith.com Veith

    “Flatland” is a great tool for breaking people out of a simplistic materialism. Of course there are dimensions beyond our grasping, which is how spiritual realities are. That quantum mechanics points to realities beyond our limited minds testifies to the same point. As for where I heard of the necessity of an observer, I read it someplace, in one of those physics popularizer books and I heard it referred to in a lecture I once attended and my wife is getting it in a graduate education course she is taking (!). Here is a statement from a New Agey site: “Fundamental to contemporary Quantum Theory is the notion that there is no phenomenon until it is observed. This effect is known as the ‘Observer Effect’. The implications of the ‘Observer Effect’ are profound because, if true, it means that before anything can manifest in the physical universe it must first be observed.” Now I think you are right that this misunderstands quantum theory. I suspect, though, that since this ties in so well to what postmodernists are looking for, it may be a component of an emerging worldview that is not just for scientists.

  • http://www.geneveith.com Veith

    “Flatland” is a great tool for breaking people out of a simplistic materialism. Of course there are dimensions beyond our grasping, which is how spiritual realities are. That quantum mechanics points to realities beyond our limited minds testifies to the same point. As for where I heard of the necessity of an observer, I read it someplace, in one of those physics popularizer books and I heard it referred to in a lecture I once attended and my wife is getting it in a graduate education course she is taking (!). Here is a statement from a New Agey site: “Fundamental to contemporary Quantum Theory is the notion that there is no phenomenon until it is observed. This effect is known as the ‘Observer Effect’. The implications of the ‘Observer Effect’ are profound because, if true, it means that before anything can manifest in the physical universe it must first be observed.” Now I think you are right that this misunderstands quantum theory. I suspect, though, that since this ties in so well to what postmodernists are looking for, it may be a component of an emerging worldview that is not just for scientists.

  • http://mesamike.org Mike Westfall

    I agree. Some people (no — a lot of people) will take what little we know about the physical universe, and if something seems paradoxical, draw kooky metaphysical inferences where none are warranted.

    It’s a metaphysical eisegesis ofn our limited physical knowledge.

  • http://mesamike.org Mike Westfall

    I agree. Some people (no — a lot of people) will take what little we know about the physical universe, and if something seems paradoxical, draw kooky metaphysical inferences where none are warranted.

    It’s a metaphysical eisegesis ofn our limited physical knowledge.

  • Carl Vehse

    First, I’m not a nuclear engineer; I’m a nuclear chemist, a chemist who studies and works with radioactivity and nuclear materials… and that’s “nuclear”, not “nukular.”

    Second, I’m not a quantum mechanical engineer and I don’t really understand quantum mechanics, which puts me in the same company as Nobel Laureate Richard Feynman, who said, “I think I can safely say that nobody understands quantum mechanics.” And, if I can brag, I think I fit his description a lot better than Feynman does.

    As for the question about the role of the observer and the effect of the measurement apparatus on the photon or other subatomic particle, I think NQB explained it well. I’d add that the Heisenberg Uncertainty Principle limits the inherent precision with which pairs of properties (called canonical conjugates) of an object may be measured, important in the subatomic world, but small compared to experimental error in the macro world.

    As for the Big Bang, In his book (referenced in the Science article, Speakable and unspeakable in quantum mechanics (Cambridge, 1987), J.S. Bell has a chapter/paper on “Quantum Mechanics for cosmologists.”

    An even more curious chapter discusses “The moral aspect of quantum mechanics.”

  • Carl Vehse

    First, I’m not a nuclear engineer; I’m a nuclear chemist, a chemist who studies and works with radioactivity and nuclear materials… and that’s “nuclear”, not “nukular.”

    Second, I’m not a quantum mechanical engineer and I don’t really understand quantum mechanics, which puts me in the same company as Nobel Laureate Richard Feynman, who said, “I think I can safely say that nobody understands quantum mechanics.” And, if I can brag, I think I fit his description a lot better than Feynman does.

    As for the question about the role of the observer and the effect of the measurement apparatus on the photon or other subatomic particle, I think NQB explained it well. I’d add that the Heisenberg Uncertainty Principle limits the inherent precision with which pairs of properties (called canonical conjugates) of an object may be measured, important in the subatomic world, but small compared to experimental error in the macro world.

    As for the Big Bang, In his book (referenced in the Science article, Speakable and unspeakable in quantum mechanics (Cambridge, 1987), J.S. Bell has a chapter/paper on “Quantum Mechanics for cosmologists.”

    An even more curious chapter discusses “The moral aspect of quantum mechanics.”

  • Carl Vehse

    On a lighter note, in his book, Quantum physics: illusion or reality? (Cambridge University Press, 1986) Alastair Rae includes the first limerick below from Monsignor Ronald Knox (1888-1957) and the follow-up limerick from an unknown author:

    There once was a man who said, “God
    Must think it exceedingly odd
    If he finds that this tree
    Continues to be
    When there’s no one about in the Quad.”

    Dear sir, your astonishment’s odd;
    I am always about in the Quad.
    And that’s why the tree
    Will continue to be,
    Since observed by, yours faithfully, God.

  • Carl Vehse

    On a lighter note, in his book, Quantum physics: illusion or reality? (Cambridge University Press, 1986) Alastair Rae includes the first limerick below from Monsignor Ronald Knox (1888-1957) and the follow-up limerick from an unknown author:

    There once was a man who said, “God
    Must think it exceedingly odd
    If he finds that this tree
    Continues to be
    When there’s no one about in the Quad.”

    Dear sir, your astonishment’s odd;
    I am always about in the Quad.
    And that’s why the tree
    Will continue to be,
    Since observed by, yours faithfully, God.


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