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RAD4921
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Does the collapse of the wave function really happen when someone observes it or is collpase a fluke of measurement? Thanks for your input and time.
RAD4921
RAD4921
RAD4921 said:Does the collapse of the wave function really happen when someone observes it or is collpase a fluke of measurement? Thanks for your input and time.
Yes. It really collapses. But this "collapse" is something totally mathmatical, not something physical.RAD4921 said:Does the collapse of the wave function really happen when someone observes it or is collpase a fluke of measurement? Thanks for your input and time.
RAD4921
pmb_phy said:Yes. It really collapses. But this "collapse" is something totally mathmatical, not something physical.
You think that that's less wacky than MWI!reilly said:To me it is very obvious that there is a wave function collapse; it's the collapse or change from uncertainty to certainty in the neurons in our brains. I like this idea because: it is simple; and it is based on empirical evidence -- in fact, it could even be tested, and perhaps already has been in some of the many, many brain scan experiments and tests. My view is that the QM founders would, today, embrace the knowledge interpretation, a fancy name for what I just described. Why invoke mysticism, or faster than light, or the non-separable Hilbert Spaces that surely must be required by MWI, or whatever just to get around the idea of probability. KISS.
reilly said:What I know has no influence on Nature unless I do something based on that knowledge. (Of course there's the radiation that comes from neural activity, not to mention heat. But these are tiny effects, which we presume have virtually no impact on anything, except for brain scans.) If a meter reads 10 volts, when it could also have read 5 or 7.8, then until I look, I don't know, so I have that superimposed representation in my brain But common sense says that the meter reads 10 quite independently of my attention or lack thereof. Why? Centuries of human experience confirm in such a case that there is continuity of effect, Newton and all that.
leandros_p said:So, do you mean that the QM is a clever mathematical trick in order to overcome the lack of knowledge ?
mathematical model of probability?
Leandros
leandros_p said:Is the missing information from our brain processed by QM's clever mathematical model of probability?
Leandros
What is this "MRI" view? Its always useful to not assume that whom you're directing a comment to will understand that acronym that you're using.vanesch said:In the MWI view, it doesn't collapse, for instance.
pmb_phy said:What is this "MRI" view? Its always useful to not assume that whom you're directing a comment to will understand that acronym that you're using.
While I certainly agree that one must distinguish our mental concept "cat" from the real, physical cat, I certainly believe that the physical cat exists independent of whether or not I think of it. Only in the most trivial sense can one say that "everything is in your head". Of course it is! But to think the world is only "in our heads" is arrant solipsism.reilly said:No brains. No physics, nor Physics Forums. We differ in how we interpret "...cat state vector" In my view, the cat's wave function is strictly a human artifact (that's a no-brainer, but an important one) just as is the name 'cat" is and the Visual perception of the cat, ...) "Cat" and cat are not the same. Thus, the knowledge interpretation makes very good sense -- it is directly connected to reality, as we know it, because it is working in the same part of our brain that stores our knowledge of reality.
This does sound like a common sense view of the external world, not of the inner world inside your brain. No problem here.Cats are alive or dead, not both -- why mess with common sense in a case in which it is perfectly applicable. And yes, my assertion about cats is an inference, but based on overwhelming evidence from centuries of human experience, (No falsification as yet, with cats.)
Of course we are subject to the limitations of our brain function. (Hey, no one is more aware of that than I! :uhh:) And, yes, any assumption of an outside world--or even of a physical brain--is an assumption, albeit a necessary, trivial one. To me, not making that assumption of an outside world is a rampant violation of Occam's razor! It is by far the simplest explanation of what we see.Probability, wave functions, real numbers, groups, differential equations are part of what might be called an extedend language, English (or Russian, or...) along with mathematics and associated conceptual notions. Always, in normal life, and in the arcane world of physics, we are bound by the limitations of language, brains, and so forth. We talk about language( and sometimes we have the conceit that we are talking about Nature rather than a description of Nature), which, we hope, gives a good account of Nature. All you know; all you experience is in your head -- that's the universe. That's the empirical Occam botom line. The rest is inference, subject to all manner of opinions.
I think much of the confusion comes from not accepting that standard QM can only provide probabalistic statements about ensembles of systems, not individual systems. (Perhaps other theories that go beyond standard QM, such as Bohmian mechanics, can get us deeper. Beats me!)I was fortunate to hear Wigner talk about his "friend" and QM interpretation (1964, Washington U in St. Louis), and, much to my surprise I still have my notes. He talked at length on the consciousness issue, delayed examination of experiments. chains of communicating observers. At the end of the day, he remained puzzled -- consciousness counts, doesn't count. I've also heard Prof. Weiner and Prof V. Fock(yes, that one) debate the finer points of QM(1959, Cambridge, Mass.); but their accents were so thick that I got very little from the debate itself. But from these experiences, I came away with the strong feeling that the masters themselves were highly perplexed about many aspects of QM.
While a study of how the brain works is fascinating and important, I think it has nothing whatsoever to do with understanding quantum mechanics (or classical mechanics). Pondering how our vision system works will no more clarify electron diffraction through a double slit than it will improve one's appreciation of Shakespeare. (Unless you need glasses, of course.)I also have the feeling that the masters did not have a clear picture of the role of the brain in all of this. Modern neuroscience, to some degree, tries to finesse the consciousness issue by concentrating on measuring what the brain does. Ask yourself how things might look if say, Professor John Dowling's masterpeice, The Retina, had been available in the 20s, or the Hodgkin-Huxley explanation of neural dynamics, or ... (The Retina provides a brilliant account of the vision system in extraordinary detail.) It seems to me that given more hard-nosed info on minds and brains, the mysticism and confusion of the founders would have been substantially lessened.
Not sure what you are saying here. A quantum superposition is a description of the properties of an ensemble of indentically prepared systems. The consequent interference is an objective fact, verifiable by anyone trained to do so. Nothing, beyond the trivial, to do with the brain and its workings.I claim that the only superposition here is in the brain's representation of alternatives; my brain, conscious and unconscious, knows, sorry about that, what I'm doing, and what I'm about to do. Why would I go to the trouble of inventing a 'superposition of ra persons, each living for one alternative -- do the ra persons who guessed wrong die? Where do they go?
It seems that you are agreeing (with common sense) that there is an outside world in which the meter reads something definite regardless of your personal knowledge or lack thereof. No argument from me on this point. But the idea that you don't personally know what the meter reads until you look has nothing whatsoever to do with the quantum measurement problem or the supposed "collapse" of the wave function.What I know has no influence on Nature unless I do something based on that knowledge. (Of course there's the radiation that comes from neural activity, not to mention heat. But these are tiny effects, which we presume have virtually no impact on anything, except for brain scans.) If a meter reads 10 volts, when it could also have read 5 or 7.8, then until I look, I don't know, so I have that superimposed representation in my brain But common sense says that the meter reads 10 quite independently of my attention or lack thereof. Why? Centuries of human experience confirm in such a case that there is continuity of effect, Newton and all that.
Very soon the philosophical waters will be too deep for me to keep afloat--I can only tread water for so long before swimming to shore!Sorry, this got a bit out of hand.
pmb_phy said:What is lacking in this conversation is a clear and precise definition of "wave function collapse."
Question to Reilly - A measurement is automatically taken on a quantum system on Feb 25, 2006 at 7:15pm. The results are stored on a computer's hard drive. At 10:00pm Feb 25, 2006 Reilly prints out the stored data and reads it. At what time does the wave function of the quantum system collapse?
Pete
Wave collapse is a concept in quantum mechanics where a wave function, which describes the behavior of a particle, collapses into a single point when it is observed or measured.
This is a highly debated question in the scientific community. Some scientists argue that wave collapse is a real phenomenon that is supported by experimental evidence, while others believe it is just a mathematical concept with no physical meaning.
Understanding wave collapse is important because it is a fundamental concept in quantum mechanics and plays a crucial role in many experiments and technologies, such as quantum computing.
Wave collapse itself cannot be directly observed, but its effects can be seen through experiments and measurements. It is a theoretical concept that helps explain the behavior of particles in the quantum world.
There are several alternative theories to explain the behavior of particles in quantum mechanics, such as the many-worlds interpretation and the pilot-wave theory. However, wave collapse is still the most widely accepted explanation by scientists.