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Post by stardustpilgrim on May 4, 2018 13:50:25 GMT -5
I got the book ZD mentioned, What Is Real? by Adam Becker. Started reading this morning (browsed some last night). It's very good so far, explaining some things I've never read specifically before. I've read about the Schrodinger wave equation numerous times previously, but the author gives the meaning, everything that is has a wave function number, and it is always changing, it's a description of what's occurring at any one time with an object, everything being in a flow/flux (my words). And the number changes incrementally, slowly, like an ocean wave, thus the name, the wave function represents the quantum state of an object, probabilities. OK, no problem here. At the subatomic level, time and space are pretty-much irrelevant, you have a sort of quantum-soup-flow, nothing has a specific location or a specific momentum. But if you want to take a photo/snap shot of the present (my words), that is, take a specific moment out-of that flow, you make a measurement. You are actually altering the quantum state, making something to be, that isn't. Traditionally, this is called the collapse of the wave function. This brings us to the central problem in quantum physics, the measurement problem. Nobody understands what exactly is happening when you go from the Schrodinger wave quantum number, which, again, is a description of stuff occurring, you, your mouse, the air you breathe, a squashed bug on your windshield, to collapsing that wave. (The Schrodinger wave consists of probabilities, never exactitude). Because, at that specific moment, you no longer have a Schrodinger wave, you have a "snapshot", that was that present moment. Nobody understands what's happening going from the wave, to no-wave, how making a measurement *causes* that, how quantum probability becomes classical (our world) *realness*.
Now, basically Bohr's interpretation, the Copenhagen Interpretation of quantum mechanics, which held sway for over 75 years (which the majority of physicists are now unhappy with) has been: we don't know what's occurring, we don't care as long as we get the right numbers to explain what's taking place in the world. And QM has never been wrong, the numbers have never been wrong. We wouldn't have the world we live in today without QM. Transistors were made possible because of QM, we wouldn't have computers without QM, no cell phones.
So the book is about how certain individuals wouldn't accept the Copenhagen Interpretation, Einstein for one, and tried to see how QM relates directly to our macro world, our classical world, what exactly is the divide between the micro-world and the macro-world? John Bell wasn't happy. David Bohm wasn't happy, he came up with an alternative interpretation using hidden variables. John Bell then read Bohm's work and began thinking on how to experimentally decide if there is a [quantum] *real world* apart from what's occurring in quantum measurements. This became Bell's Theorem (Inequality theorem). Basically, how can our macro world, where your cars keys can't be in two places at once, be constructed upon the quantum world where an electron IS two places at once? (multiple places, in fact it's *natural state* is to be in multiple places, the term for this is superposition).
To add, the Schrodinger wave equation is deterministic, but quantum events occur at random, are not caused. Maybe this is where: "You can't get there from here" originated.
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Post by stardustpilgrim on May 5, 2018 18:16:45 GMT -5
"The problem, in nutshell is this: Quantum wave functions move along nicely and smoothly, always obeying one simple and deterministic law, the Schrodinger equation--except when they don't. When a measurement happens--and what constitutes a "measurement" anyway--is the measurement problem, the central puzzle of quantum physics". pg 123 What Is Real? Adam Becker, 2018
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Post by stardustpilgrim on May 9, 2018 15:20:22 GMT -5
Finished the book today. A few quotes about the Copenhagen interpretation.
"What does quantum physics tell us about the world? According to the Copenhagen interpretation, this question has a very simple answer: quantum physics tells us nothing whatsoever about the world. ...the Copenhagen interpretation states that quantum physics is merely a tool for calculating the probabilities of various outcomes of experiments. According to Bohr, there isn't a story about the quantum world because "there is no quantum world, There is only an abstract quantum physical description". That description doesn't allow us to do more than predict probabilities for quantum events, because quantum events don't exist in the same way as the everyday world around us". pg 14
"Given the damage done to his reputation by his activities during the war (Heisenberg led the Nazi atomic bomb project, discussed in the book, Becker dug very deep to get the story straight. Heisenberg had tried to revise history, note sdp), Heisenberg's invention of a single unified Copenhagen interpretation (you can't find one anywhere, it's never been written, not even by Bohr himself. It's like E's promise of writing down an explanation of fill-in-the-blank, note sdp) may have been an attempt to rework the history of quantum physics to his benefit. The Copenhagen interpretation wasn't a pure fabrication--there were certainly similarities in the positions that Bohr and his students and colleagues took--but the differences between Heisenberg's lecture and the writings of Bohr himself should have been enough to tip off anyone who was paying attention that no such beast had ever really existed". pg 84
Bohr was famously obtuse and vague in speaking and writing about QM.
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The idea that consciousness has something to do with the collapse of the wave function, or the measurement problem, came from John von Neumann, and Eugene Wigner. This does not come from the Copenhagen interpretation. (discussed on pg 199). Although Becker does not state so in the book, I read recently that later in life Wigner recanted on this consciousness question, decided consciousness has nothing to do with the measurement problem.
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Becker makes the point that many different physicists over the years have claimed to support the Copenhagen interpretation, yet at the same time make claims the CI does not address. IOW, it seems all physicists have their own version of what the CI is.
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Post by zendancer on May 9, 2018 17:31:33 GMT -5
Finished the book today. A few quotes about the Copenhagen interpretation. "What does quantum physics tell us about the world? According to the Copenhagen interpretation, this question has a very simple answer: quantum physics tells us nothing whatsoever about the world. ...the Copenhagen interpretation states that quantum physics is merely a tool for calculating the probabilities of various outcomes of experiments. According to Bohr, there isn't a story about the quantum world because "there is no quantum world, There is only an abstract quantum physical description". That description doesn't allow us to do more than predict probabilities for quantum events, because quantum events don't exist in the same way as the everyday world around us". pg 14 "Given the damage done to his reputation by his activities during the war (Heisenberg led the Nazi atomic bomb project, discussed in the book, Becker dug very deep to get the story straight. Heisenberg had tried to revise history, note sdp), Heisenberg's invention of a single unified Copenhagen interpretation (you can't find one anywhere, it's never been written, not even by Bohr himself. It's like E's promise of writing down an explanation of fill-in-the-blank, note sdp) may have been an attempt to rework the history of quantum physics to his benefit. The Copenhagen interpretation wasn't a pure fabrication--there were certainly similarities in the positions that Bohr and his students and colleagues took--but the differences between Heisenberg's lecture and the writings of Bohr himself should have been enough to tip off anyone who was paying attention that no such beast had ever really existed". pg 84 Bohr was famously obtuse and vague in speaking and writing about QM. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ The idea that consciousness has something to do with the collapse of the wave function, or the measurement problem, came from John von Neumann, and Eugene Wigner. This does not come from the Copenhagen interpretation. (discussed on pg 199). Although Becker does not state so in the book, I read recently that later in life Wigner recanted on this consciousness question, decided consciousness has nothing to do with the measurement problem. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Becker makes the point that many different physicists over the years have claimed to support the Copenhagen interpretation, yet at the same time make claims the CI does not address. IOW, it seems all physicists have their own version of what the CI is. Yes, and I thought Becker's description of the various physicists and their understandings of CI, or lack thereof, was interesting. The story was far more complex than I remembered, and there was far less agreement about related issues than I remembered. Definitely a fascinating book. I had assumed that Becker would bring all of the different strands of thought together at the end, and offer some sort of cohesive conclusion, but no such luck! haha. FWIW, there were things that I thought I understood about what physicists think about "the quantum world", but at the end of the book I realized that no one has a clear idea of what QM is pointing to. As I noted earlier, if I had to choose between the CI, the many-worlds theory, and the spontaneous collapse theory, I'd go with the SCT just because it seems more intuitively satisfying. I assumed that all physicists assume that the universe is non-local at both the quantum level and the macrocosmic level, but that's clearly not the case. From a ND standpoint, it's clear that no real boundaries exist (except in imagination), so why physicists would think that there could be some distinct boundary between our everyday world and the atomic world is beyond me. I can only ask them, "Where can one find any such boundary?"
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Post by stardustpilgrim on May 9, 2018 18:14:15 GMT -5
Finished the book today. A few quotes about the Copenhagen interpretation. "What does quantum physics tell us about the world? According to the Copenhagen interpretation, this question has a very simple answer: quantum physics tells us nothing whatsoever about the world. ...the Copenhagen interpretation states that quantum physics is merely a tool for calculating the probabilities of various outcomes of experiments. According to Bohr, there isn't a story about the quantum world because "there is no quantum world, There is only an abstract quantum physical description". That description doesn't allow us to do more than predict probabilities for quantum events, because quantum events don't exist in the same way as the everyday world around us". pg 14 "Given the damage done to his reputation by his activities during the war (Heisenberg led the Nazi atomic bomb project, discussed in the book, Becker dug very deep to get the story straight. Heisenberg had tried to revise history, note sdp), Heisenberg's invention of a single unified Copenhagen interpretation (you can't find one anywhere, it's never been written, not even by Bohr himself. It's like E's promise of writing down an explanation of fill-in-the-blank, note sdp) may have been an attempt to rework the history of quantum physics to his benefit. The Copenhagen interpretation wasn't a pure fabrication--there were certainly similarities in the positions that Bohr and his students and colleagues took--but the differences between Heisenberg's lecture and the writings of Bohr himself should have been enough to tip off anyone who was paying attention that no such beast had ever really existed". pg 84 Bohr was famously obtuse and vague in speaking and writing about QM. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ The idea that consciousness has something to do with the collapse of the wave function, or the measurement problem, came from John von Neumann, and Eugene Wigner. This does not come from the Copenhagen interpretation. (discussed on pg 199). Although Becker does not state so in the book, I read recently that later in life Wigner recanted on this consciousness question, decided consciousness has nothing to do with the measurement problem. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Becker makes the point that many different physicists over the years have claimed to support the Copenhagen interpretation, yet at the same time make claims the CI does not address. IOW, it seems all physicists have their own version of what the CI is. Yes, and I thought Becker's description of the various physicists and their understandings of CI, or lack thereof, was interesting. The story was far more complex than I remembered, and there was far less agreement about related issues than I remembered. Definitely a fascinating book. I had assumed that Becker would bring all of the different strands of thought together at the end, and offer some sort of cohesive conclusion, but no such luck! haha. FWIW, there were things that I thought I understood about what physicists think about "the quantum world", but at the end of the book I realized that no one has a clear idea of what QM is pointing to. As I noted earlier, if I had to choose between the CI, the many-worlds theory, and the spontaneous collapse theory, I'd go with the SCT just because it seems more intuitively satisfying. I assumed that all physicists assume that the universe is non-local at both the quantum level and the macrocosmic level, but that's clearly not the case. From a ND standpoint, it's clear that no real boundaries exist (except in imagination), so why physicists would think that there could be some distinct boundary between our everyday world and the atomic world is beyond me. I can only ask them, "Where can one find any such boundary?" Yes, I thought Becker did some very fine historical study. I've read over 20 popular books for the layperson on quantum physics, and Becker brought out many things I've never heard before, a lot of subtle distinctions. ...I've been trying to think of an analogy for the particle-wave duality problem, what the quantum world Is pointing to, thought of one today, will post it on the QM thread, shortly. Current experiments show without doubt we live in a nonlocal universe, so all physicists necessarily must accept this. Bell's Theorem shows this even apart from quantum physics.
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Post by laughter on May 9, 2018 19:11:10 GMT -5
Haven't read the book yet, but a baseball doesn't refract with the previous arcs of itself into the catcher's mit because. Well. It's a baseball. It's not an electron. Or even a buckyball. It's a baseball. By the physicists models, the baseball is comprised of elections, protons and neutrons, but why would they expect the aggregate to behave like it's parts? Asking why a baseball doesn't refract is kind of like asking why noone builds windows on a dinner fork or why car breaks use direct friction on the wheel instead of a parachute strung out behind it. The fact is, the effects of the quantum world are all around us, and always have been. Eventually, someone's going to build a space elevator. The main reason noone's even considered attempting it yet is that any material currently known that can be used to build a 22,000 mile long cable down from geostationary orbit would snap under it's own weight at even a small fraction of that length. But when they do eventually build it, the current vision is for the elevator car to be powered by a laser from the ground. Laser light is different from natural light in that the phases of the photons are all aligned, and this leads to the property of the beam as focused in a line rather than dispersing out in a hemisphere from the source. So that's one example of a quantum effect (syncrhonizing photon wavelets) that we experience by our senses: a laser beam, as distinct from a flashlight beam. One material that would-be space elevator designers are interested in is carbon nanotube, because it's at least theoretically possible to build a 22,000 mile cable from carbon nanotubes that won't snap under it's own weight. That's still only a dream because the longest carbon nanotubes grown to date are just a few feet. What gives this material it's unusual properties is the structure of this material is entirely uniform and well-ordered, similar to the way that all the phases of the photons in a laser beam conform with each other. The carbon atoms are aligned in a lattice reminiscent of a crystal. The bonds between them are atomic: each carbon atom shares an electron with every other adjacent atom. This is called a "covalent bond", and is orders of magnitude stronger than the molecular-level "metallic bond" that holds steel or titanium together in a relatively disordered aggregate form. So while there's no elevator cable from carbon nanotubes yet, the material is to the point where it's unique properties - quantum properties - can be directly experienced by the human senses. And the double-slit experiment has been performed using a cousin of carbon-nanotubes, the buckyballs. The scientists who ran these experiments are also interested in this boundary between where quantum effects end and the "classical world" begins. But I say, just look at the math, and then go step outside in a short sleeved-shirt on a warm sunny day. Maybe go take in a baseball game. Because oh yeah. Nuclear fusion. That's a quantum effect too.
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Post by laughter on May 10, 2018 1:37:36 GMT -5
Finished the book today. A few quotes about the Copenhagen interpretation. "What does quantum physics tell us about the world? According to the Copenhagen interpretation, this question has a very simple answer: quantum physics tells us nothing whatsoever about the world. ...the Copenhagen interpretation states that quantum physics is merely a tool for calculating the probabilities of various outcomes of experiments. According to Bohr, there isn't a story about the quantum world because "there is no quantum world, There is only an abstract quantum physical description". That description doesn't allow us to do more than predict probabilities for quantum events, because quantum events don't exist in the same way as the everyday world around us". pg 14 "Given the damage done to his reputation by his activities during the war (Heisenberg led the Nazi atomic bomb project, discussed in the book, Becker dug very deep to get the story straight. Heisenberg had tried to revise history, note sdp), Heisenberg's invention of a single unified Copenhagen interpretation (you can't find one anywhere, it's never been written, not even by Bohr himself. It's like E's promise of writing down an explanation of fill-in-the-blank, note sdp) may have been an attempt to rework the history of quantum physics to his benefit. The Copenhagen interpretation wasn't a pure fabrication--there were certainly similarities in the positions that Bohr and his students and colleagues took--but the differences between Heisenberg's lecture and the writings of Bohr himself should have been enough to tip off anyone who was paying attention that no such beast had ever really existed". pg 84 Bohr was famously obtuse and vague in speaking and writing about QM. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ The idea that consciousness has something to do with the collapse of the wave function, or the measurement problem, came from John von Neumann, and Eugene Wigner. This does not come from the Copenhag en interpretation. (discussed on pg 199). Although Becker does not state so in the book, I read recently that later in life Wigner recanted on this consciousness question, decided consciousness has nothing to do with the measurement problem. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Becker makes the point that many different physicists over the years have claimed to support the Copenhagen interpretation, yet at the same time make claims the CI does not address. IOW, it seems all physicists have their own version of what the CI is. Heisenberg is very clear on what he means by it and is quite consistent with Bohr in what he wrote about it. The term is based on the presentation Bohr and Heisenberg made at the 1927 Solvay conference in Copenhagen. You know, the one where Einstein said (pre-fake internet quote) "god doesn't play dice". Last I looked the CI still appears on college syllabi, and when I was in school in the early '80's it was taught in a uniform way across professors from a textbook. And noone liked it. There was a play running in New York when I lived there and we almost went and now I really wish I had: "Copenhagen". Heisenberg visited Bohr (his former Phd thesis adviser) in 1941. It's widely speculated that Heisenberg deliberately didn't succeed in building the bomb for Germany. By Heisenberg's recollection, which is corroborated by Bohr, Heisenberg said to Bohr: "I know that this is in principle possible, but it would require a terrific technical effort, which, one can only hope, cannot be realized in this war." If you read what Heisenberg wrote about how rationality had become a sort of collective madness in the latter part of the 19th century, essentially supplanting Christianity, it tells a tale of more than just regret in hindsight. He likely recognized the madness from the inside as it was happening. It would make no more sense to get attached to the CI than it would to get attached to Newtonian physics. It's a foregone conclusion that something will eventually supplant it. But the math has been so successful, that when that happens, the fate of the CI will likely be similar to that of classical mechanics. Subsumed as a special case of a wider and deeper understanding.
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Post by Deleted on May 13, 2018 15:38:11 GMT -5
Schrodinger's cat experiment is a jab at CI. These mind twisting paradoxical QM dilemmas remind me of Zen koans.
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Post by zendancer on May 13, 2018 16:00:37 GMT -5
Schrodinger's cat experiment is a jab at CI. These mind twisting paradoxical QM dilemmas remind me of Zen koans. Me, too. Quick tell me, is the cat dead or alive?
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Post by Deleted on May 13, 2018 16:08:10 GMT -5
Schrodinger's cat experiment is a jab at CI. These mind twisting paradoxical QM dilemmas remind me of Zen koans. Me, too. Quick tell me, is the cat dead or alive? There is no life or death, therefore no cat. Did I pass?
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Post by laughter on May 13, 2018 16:14:55 GMT -5
Schrodinger's cat experiment is a jab at CI. These mind twisting paradoxical QM dilemmas remind me of Zen koans. Me, too. Quick tell me, is the cat dead or alive? Don't matter what we think. The cat knows.
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Post by laughter on May 13, 2018 16:35:55 GMT -5
Schrodinger's cat experiment is a jab at CI. These mind twisting paradoxical QM dilemmas remind me of Zen koans. "There is no quantum object independent of the observation of it". See now, that's the end of the line of a particular position for the science of Physics. As long as everyone assumed that the objects we experience could be defined in terms of their own, independent reality, reality could be said to be physical. This meant that the sciences of chemistry and biology each rested on a solid foundation, and could trace back their statements about the nature of reality to the truth of the reality of the fundamental building blocks: chemistry is the science of how atoms form molecules and how those molecules interact, and biology is the science of how chemicals form cells, organs and organisms. The lay-secular assumption in the West was -- and still is -- that consciousness is an emergent phenomenon of the brain. Not all the scientists at Copenhagen in 1927 were secular. Einstein wasn't. But relating the CI to the question of consciousness as time went on afterward was a natural progression of thought given the obvious implications. Neurology is, after all, that branch of biology dedicated to a particular organ and a particular class of cells that comprise it. "What observes?" is obvious self-inquiry. Sometimes it gets done collectively. My apologies for the repetition, but the one single most striking quote by Heisenberg on the issue to me is: "It may be said that classical physics is just that idealization in which we can speak about parts of the world without any reference to ourselves". The CI was a clue to the collective cultural movement of self-inquiry about the limits of objectivity. "Humpty-dumpty sat on a wall ..."
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Post by Deleted on May 13, 2018 17:10:54 GMT -5
Schrodinger's cat experiment is a jab at CI. These mind twisting paradoxical QM dilemmas remind me of Zen koans. "There is no quantum object independent of the observation of it". See now, that's the end of the line of a particular position for the science of Physics. As long as everyone assumed that the objects we experience could be defined in terms of their own, independent reality, reality could be said to be physical. This meant that the sciences of chemistry and biology each rested on a solid foundation, and could trace back their statements about the nature of reality to the truth of the reality of the fundamental building blocks: chemistry is the science of how atoms form molecules and how those molecules interact, and biology is the science of how chemicals form cells, organs and organisms. The lay-secular assumption in the West was -- and still is -- that consciousness is an emergent phenomenon of the brain. Not all the scientists at Copenhagen in 1927 were secular. Einstein wasn't. But relating the CI to the question of consciousness as time went on afterward was a natural progression of thought given the obvious implications. Neurology is, after all, that branch of biology dedicated to a particular organ and a particular class of cells that comprise it. "What observes?" is obvious self-inquiry. Sometimes it gets done collectively. My apologies for the repetition, but the one single most striking quote by Heisenberg on the issue to me is: "It may be said that classical physics is just that idealization in which we can speak about parts of the world without any reference to ourselves". The CI was a clue to the collective cultural movement of self-inquiry about the limits of objectivity. "Humpty-dumpty sat on a wall ..." I believe Schrodinger studied Indian philosophy. The prevalent notion is that objects exist apart from consciousness, but in observing events the photons needed for the observation, impact the results. Most are reluctant to take the step you outline. So in observing the photons going through the one slit, we affect the outcome of the double slit experiment. Einstein proposed that paired particles contained the quantum data of their partners which Bell disproved. I think he was reluctant to discard objects.
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Post by Deleted on May 13, 2018 17:36:49 GMT -5
Has anyone looked into Susskind's lectures -- The Theoretical Minimum? I once was a Physics student. I've had a bunch of math, thinking it might be fun or is there something better?
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Post by zendancer on May 13, 2018 18:45:40 GMT -5
Me, too. Quick tell me, is the cat dead or alive? There is no life or death, therefore no cat. Did I pass? Nope. No thinking allowed.
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