#8. Seeing the electron yourself seems not to require any other detector than yourself. The von Neuman interpretation is the edge case of Copenhagen interpretation where the Heisenberg cut is placed as close to the observer as possible. Is the goal of physics to get reality to fit into our templates, or to keep an open mind and just let it tell us what it is? But it's not only measuring instruments that do the trick - any sensitive physical element will do. Epub 2005 Dec 13. Similar to their micron-scale counterparts, microbubbles (1-10 m), they can act as ultrasound contrast agents as well as locally enhance therapeutic uptake. Why does observation collapse the wave function. The two are entangled. It only exists if you think a quantum state has an external existence like say an electric field. All things can be arbitrarily divided into the observed system and the measuring system by so-called "Heisenberg cut" with the only requirement the measuring system include the observer. In the orthodox Copenhagen interpretation, quantum mechanics predicts only the probabilities for different observed experimental outcomes.What constitutes an observer or an observation is not directly specified by the theory, and the behavior of a system under measurement and observation is completely different from its usual behavior: the wavefunction that describes a system spreads out into . The wave-particle debate should have been put to rest eons ago. However, each projection only reveals a portion of the underlying wave function and often destroys uniquely quantum features, like superposition and entanglement. The argument is therefore made that the wave function of any superposed photon state or states is always objectively and stochastically changed within the complex architecture of the eye in a continuous linear process initially for most of the superposed photons, followed by a discontinuous nonlinear collapse process later for any remaining . This site needs JavaScript to work properly. On this little video you see the objects one by one, changing (or not) the rectilinear trajectory by the "oscilating interaction" with the (double-slit) obstacle, not by the after-obstacle-screen as "observer". Epub 2005 Apr 11. If this entanglement is well-controlled (as in a lab), then (a) showing this "joint interference" might be practical, and (b) undoing the entanglement is also possible, thus restoring the electron's sole superposition. This reveals that an error may have been made by them in the area of biology and its interface with quantum mechanics when they called for the reduction of any superposition states in the brain through the mind or consciousness. . the public is definitely not going to confuse these for the definitions they used before and use daily. For a start, it's only an "effective" theory. There seems to be no consensus on this subject. You may notice that this still leaves open a crucial question: when do the many branches become one? It is not a wavey process in 3 dimensional space. When you choose to do some calculation of the electron's behaviour that treats it either as a particle or as a wave, you're not saying the electron is a particle or is a wave: you're just choosing the mathematical model that makes it easiest to do the calculation. I am saying they are only ever detected as particles - never as waves so the most reasonable thing to do is model them as particles. However, that would be some sort of quantum entanglement no? How does a spinor affect a wave function? On Young's double-slit experiment the wave-particle duality (one by one photon) is more a problem of "picture of the model" than a philosophic one: see Y. Couder interpretation, by your self (!). I suggest you read multiple different introductions from some of the standard books: as with so many things in physics, there are different equivalent ways of looking at wave-function collapse. How many axis of symmetry of the cube are there? Is the goal of physics to get reality to fit into our templates, or to keep an open mind and just let it tell us what it is? One candidate model to explain this reduction process is the gravitationally induced state-vector (and its decedents). HHS Vulnerability Disclosure, Help Some people like to attribute consciousness to the act of interfering. @bhobba: I'd very much like to hear how you feel about multiverse concepts. Instead what the observer perceives as the collapse is just the event of entanglement of the observer with the observed system. As time passes, more and more wave-functi Continue Reading 1 Quora User Former broadcasf engineer and computer scientist 1 y But that is not the case. The collapse of the wavefunction is a separate issue, and one that has generated much debtae over the years. PS: of course, if a observation constitutes measurement before the screen, it will be interfere on result, changing the interference pattern at the screen. Biosystems. yeah call it spin, braket, blackbody, dark matter, force, strange, bottom, energy, heat and jerk. Once the poison is released or not released, the wave function collapses regardless of whether we open the box to see if the cat has been killed or not. Weird - of course - but if you have a stochastic theory without an underlying cause of the randomness that's what's forced on you. Some attempt to define what constitutes measurement and what causes collapse. Well, thats a simple one: because it interacts with the detector! 8600 Rockville Pike Therefore, the collapse of the wavefunction is a phenomenon that can only be inferred, and not directly observed. Can we really believe that the weather on these planets remain in complex-number superpositions of innumerable distinct possibilities - just some total hazy mess quite different from actual weather - until some conscious being becomes aware of it and then at that point, and only that point the superposed weather becomes actual weather? Bookshelf That said, the joint state can itself show a kind of "interference effect" (though not the kind you normally think of in the two-slit experiment). Or does the experiment only work in the dark? When a die is rolled and the number 6 shows up, the possibilites of 1 through 5 disappear instantly. In quantum mechanics, wave function collapse occurs when a wave functioninitially in a superposition of several eigenstatesreduces to a single eigenstate due to interaction with the external world. I am going to refer to the state vector reduction (collapse of the wave function) as $\mathbf{R}$. . There are an article online about the experiment. What is the probability of genetic reincarnation? Secondly the issue of wave function collapse is interpretation dependent. Answer (1 of 3): Let's get one thing clear from the outset, collapse of the wave function has absolutely nothing to do with observation, humans, knowing nor consciousness. In quantum physics, the term "observation" sometimes causes confusion. Yet another aspect of the Measurement Problem is that wave function collapse appears to violate the speed limit of the universe, the speed of light. But I also disagree that this, I hope that you understand that "Observation" in this context means "interaction". Lipid-shelled nanobubbles (NBs) are emerging as potential dual diagnostic and therapeutic agents. New comments cannot be posted and votes cannot be cast. sharing sensitive information, make sure youre on a federal Very good, this should be the accepted answer. This interaction is called an observation, and is the essence of a measurement in quantum mechanics, which connects the wave function with classical observables such as position and momentum. iceaura, May 17, 2009. an observation is any . The https:// ensures that you are connecting to the Lets rephrase your question: how does the electron understand that it is being detected. The difference between the measurement and any other interaction is in that the perturbation introduced by measurement is unknown beforehand. This is what the collapse of the wavefunction is. Biosystems. The general idea was that unconscious matter or inanimate matter, would evolve according to $\mathbf{U}$, but as soon as a conscious entity becomes physically entangled with the state, then something new comes in and actually reduces the state (some $\mathbf{R}$ process). Consider the weather, the detailed weather patterns that occur on any planet, being dependent of chaotic processes, which much be sensitive to numerous individual quantum events. Score: 4.9/5 (62 votes) . The posit that it is consciousness that causes this collapse is very hard to debunk, due to the very nature of this type of argument. $\mathbf{U}$ is understood well and can be modelled accurately with the equations of QM, $\mathbf{R}$ is not well understood and it is some physicist's thoughts that QM will need to be modified to incorporate this state vector reduction process. PMC Rubik's Cube Stage 6 -- show bottom two layers are preserved by $ R^{-1}FR^{-1}BBRF^{-1}R^{-1}BBRRU^{-1} $. But if the entanglement is caused by stray photons, air molecules, etc., then any hope of controlling them becomes almost immediately dashed, and we can no longer exhibit interference in practice. In Many-worlds interpretation the wavefunction collapse never happens. From here on out, the system will appear to behave classically, with the different branches evolving independently. The electron doesn't have to "know" anything. Many years later Wigner changed his mind to reflect a simpler and more realistic objective position which appears to offer a way to resolve this issue. In the buckyballs experiment, Zeilinger and co. mention no cooling of the fullerene molecule. The other answer, suggesting that their is a dual wave-matter aspect is completely incorrect. Wave Function Collapse and the Speed of Light. government site. FOIA Why does an observer collapse a wave function? (as is seen as soon as you consider the wavefunction of two or more particles in the many body problem). The actual. The philosophers believe that this unpredictability of the system containing the observer for himself, defines the free will. What are the best sites or free software for rephrasing sentences? Observable properties, such as the position of an atom or the momentum of an electron, arise from projecting the wave function onto an eigenstate. Why quantum wave function collapse is not consider a signal? How does observation affect a . ELECTRO MAGNETIC QUANTUM GRAVITY. In Bohm interpretation the collapse of the wave function happens when the observer introduces into the measured system some perturbation, which is inevitable when performing the measurement. I am going to refer to the state vector reduction (collapse of the wave function) as $\mathbf{R}$. Among those who take this explanation seriously as a description of the physical world, there are those who would argue that - as some alternative to trusting $\mathbf{U}$ at all scale and believing in a many-world type view point - that something of the nature of this $\mathbf{R}$ process occurs whenever the consciousness of an observer becomes involved. In contrast to our everyday terminology, observation always requires some form of interaction. Since configurations are over the combined state of all the elements in a system, adding a sensor that detects whether a particle went one way or the other, becomes a new element of the system that can make configurations "distinct" instead of "identical". Consciousness, the brain, and spacetime geometry. In quantum mechanics, wave function collapse occurs when a wave functioninitially in a superposition of several eigenstatesreduces to a single eigenstate due to interaction with the external world. Collapse is a black box for a thermodynamically irreversible interaction with a classical . Covalent and Ionic bonds with Semi-metals, Is an athlete's heart rate after exercise greater than a non-athlete. Instead they heat them up to 900K and separate them with rotating discs and send them at the slits: Hi, I'm reviewing how they did the interference experiment and knew how but one thing puzzled me. Reddit and its partners use cookies and similar technologies to provide you with a better experience. arXiv:physics/9809042v2 [physics.gen-ph] 1 Oct 1998. In reality you are not the detector; you are only part of a detector. MeSH How do measurements collapse quantum wave functions . Personally I think we can expect some amendment to QM if this process $\mathbf{R}$ is ever going to be sufficiently explained. At the moment our best description is that the electron is an excitation of a quantum field. In other words, the observer always contains information which is unknown and cannot be determined by any means due to self-reference problem. if the $\mathbf{R}$ process does not actually take place in the absence of consciousness, then no particular weather pattern could ever establish itself out of the morass of quantum-superposed alternatives. Because I do not know how electrons could me measured in those locations they are at in that experiment without the electrons themselves following discrete wave mechanics. Among those who take this explanation seriously as a description of the physical world, there are those who would argue that - as some alternative to trusting $\mathbf{U}$ at all scale and believing in a many-world type view point - that something of the nature of this $\mathbf{R}$ process occurs whenever the consciousness of an observer becomes involved. Some of these reasons have to do with the fact that the very framework of standard QT fit uncomfortably with the curved-space-time that GR demands. As John Rennie said, field theory is how modern physics is done. Wave function collapse does not mean no outcome at all. In the following answer I am going to refer to the unitary evolution of a quantum state vector (basically Schrodinger's Equation which provide the rate of change with respect to time of the quantum state or wave function) as $\mathbf{U}$. 2022 Physics Forums, All Rights Reserved, http://arxiv.org/pdf/quant-ph/0101012v4.pdf, http://arxiv.org/pdf/quant-ph/0111068v1.pdf, http://www.scottaaronson.com/democritus/lec9.html, http://physicsandphysicists.blogspot.com/2011/04/schrodingers-cat-becomes-430-atoms-fat.html, http://www.google.com/url?sa=t&rct=7pStCA&usg=AFQjCNH5quntpOPVJgVTo6Tkw--isU1BUA, http://www.nature.com/news/2011/110405/full/news.2011.210.html. Albert Einstein and two colleagues pointed this out in a famous paper, nicknamed "The EPR Paper" for the last names of the three authors. 2006 Jan;83(1):1-9. doi: 10.1016/j.biosystems.2005.06.011. You are using an out of date browser. @bhobba: I'd very much like to hear how you feel about multiverse concepts. But I think it would be enough if I give just five of which you can choose yourself. The site is secure. "The quantum measurement problem is caused by a failure to understand that each species has its own sensory world and that when we say the wave function collapses and brings a particle into existence we mean the particle is brought into existence in the human sensory world by the combined operation of the human sensory apparatus, particle detectors and the experimental set up. Indian J Exp Biol. it does not begin with Trump 2024, but with the Congress in whatever year they choose. Personally I think we can expect some amendment to QM if this process $\mathbf{R}$ is ever going to be sufficiently explained. For example, of this one: Not sure how a question posted 1.5 years ago can be considered a duplicate of a question asked 3 weeks ago. The wavefunction is not a material object. But that description is not sufficient per reductionism because the macro, classsical world is taken to be made up of quantum interactions fundamentally. In quantum mechanics, wave function collapse occurs when a wave functioninitially in a superposition of several eigenstatesreduces to a single eigenstate due to interaction with the external world.This interaction is called an "observation". This interaction causes the electron to behave differently compared to the situation when it is not detected. If you make a measurement you effectively add a condition that the system obeys so reducing the the possibilities and so you are now considering a subset of the original list. When the wave function collapses to unity in one place and zero . In Copenhagen interpretation the collapse can be triggered by any system which is connected to the observer, including the measurement apparatus and external medium (if the observer is not isolated from it). However, if you consider the following example, it should be clear that this picture is far from complete; and that this argument for consciousness causing the $\mathbf{R}$ process is not sufficient. Why does observation collapse the wave function? In one of the first lectures on QM we are always taught about Young's experiment and how particles behave either as waves or as particles depending on whether or not they are being observed. Quantum mechanics suggests that particles can be in a state of superposition - in two states at the same time - until a measurement take place. There are many interpretations of QM. There are strong reasons for suspecting that the modification of quantum theory (QT) that will be needed, if some form of $\mathbf{R}$ is to be made into a real physical process, must involve the effect of gravity in a serious way. It is unfortunately, in classes students are still being taught the Bohr Model etc under "Modern Physics". Ann N Y Acad Sci. If particles actually existed as particles and did not oscillate like waves, shouldn't they lose all their energy by traveling real distance over time and accelerating? Just because it is QM, does not mean we stop doing science and make up random fantastical theories to suite observation. This is actually an unresolved question in QM. By rejecting non-essential cookies, Reddit may still use certain cookies to ensure the proper functionality of our platform. 2001 Apr;929:74-104. doi: 10.1111/j.1749-6632.2001.tb05709.x. 2005 Jun;80(3):263-72. doi: 10.1016/j.biosystems.2004.12.001. What causes them to occur? It essentially contains all the statistical information about a system that it is possible to have- kind of like a giant list. Tom Ostom From the perspective of one wave-function, this gives the appearance that the other wave-function has collapsed, but what has really happened is the two wave-functions' states have become locked-in with respect to each other. This is why a measurement can collapse the wavefunction everywhere instantaneously rather than propagating out from the measurement location at the speed of light as it would if the wavefunction were some sort of material thing. However whether a state has a real existence is open to question - I view it purely as a device for calculating probabilities. I've asked. The collapse of the wave function for a quantum physicist can be similar to the relativistic idea of. I'd also like to see if I have a grip on your view by restating it: Pretty sure there are only 60 atoms, but your question still stands, since that's still 720 protons and neutrons and I have no idea how many electrons. If there is to be some kind of restoration (absent major events like a civil war, total fiscal collapse, breakup, etc.) Careers. So I suppose it can't be agreed upon what particles actually are, even though if particles were actually just particles they should radiate their energy away by constantly accelerating around the nucleus whereas with a wave they would simply oscillate which is not the same as accelerating? How does one mathematically model a wave function after a collapse to a finite region? Still, a pattern will become apparent as observation continues, and year after year of observation makes it compelling to imagine that the Sun must always rise in the east. This is because initial conditions of a system containing the observer are unknown. An obvious answer is an interaction between the classical, macro world with a wavefunction. In von Neuman interpretation the collapse of the wave function happens when the observer feels any qualia(feeling) depended on the measured value. It states that wave functions collapse randomly and provides a mathematical description, but doesn't explain why. In the following answer I am going to refer to the unitary evolution of a quantum state vector (basically Schrodinger's Equation which provide the rate of change with respect to time of the quantum state or wave function) as $\mathbf{U}$. 23 comments on LinkedIn It must have a finite value or it must be normalized. [Physics] Practically, how does an observer collapse a wave function, [Physics] How does the electron understand that it being observed in the double slit experiment. The quantum particle HAVE a location, there are only a limitation in choose a good pictoric model when you is constrained by "wave or particle" picture options: Couder demonstrates that a good picture, In the following answer I am going to refer to the unitary evolution of a quantum state vector (basically Schrodinger's Equation which provide the rate of change with respect to time of the quantum state or wave function) as $\mathbf{U}$. As I understand it, the term "collapse" is a little over-exaggerated, but why is it that we measure things as points and not waves even though particles exist as waves? "Can we really believe that (your theory here)" - yes we can. The .gov means its official. There is much to say about the $\mathbf{R}$ process, but I will address your question directly; basically "is it consciousness that reduces the state vector/collaspes the wave function?". Wave Function Collapse and Thermodynamic Irreversible Processes, Objective-collapse theory, collapse for large objects. The wave function tells us the abstract probability of finding the particle somewhere. of an "intermediary wave/particle object" model, exists! There are strong reasons for suspecting that the modification of quantum theory (QT) that will be needed, if some form of $\mathbf{R}$ is to be made into a real physical process, must involve the effect of gravity in a serious way. Bingo. This doesn't mean that the electron is a quantum field, and we'll almost certainly replace quantum field theory by some even more complicated e.g. The wave collapse can also be illustrated by our thought selection. Consider the weather, the detailed weather patterns that occur on any planet, being dependent of chaotic processes, which much be sensitive to numerous individual quantum events. That is the point, "anything" should not just go. I am going to refer to the state vector reduction (collapse of the wave function) as $\mathbf{R}$. thanks, that really helped me think about this process more clearly. Bethesda, MD 20894, Web Policies That an electron say from an electron microscope is colliding and interfering with the superposition; therefore fixing a position of the particle in question. von Neumann's all-quantum description will not work unless such a collapse really occurs as a physical process in every quantum measurement (Herbert, 1985 . The collapse of the wave function in quantum mechanics is sometimes loosely described as caused by "observation," which implies consciousness can physically affect the universe by causing the collapse. But they obey the rules of QM which is described by a quantum state that has, in some circumstances, wave-like solutions. E. Wigner once sketched a theory of this kind in Nature in the 60s. For more information, please see our The wave function must be square integrable. To make the Presidency be anything other than a false prize, the agencies need to be brought to heel in a meaningful way. Minimum number of random moves needed to uniformly scramble a Rubik's cube? If the pattern remains very consistent, it can be considered reliable even if the underlying cause isn't obvious. Two independent systems interfering with each other through no medium? Your descriptions here are very straightforward, "down to earth". Come again - can't follow that one. These buckyballs obviously stay as particles in between (as it's hard to imagine the 430 atoms with their protons and neutrons just dissolving into waves in between). The ball part comes from its similarity to the association football ball. On the Quantum Principle of Equivalence, Quantum Inertia, and the Meaning of Mass. Roger Penrose describe a new model (based on other candidates) in his book The Shadows of the Mind (not an easy read!) An experiment to be conducted in the near future may enable us to simultaneously resolve the measurement problem and also determine if the linear nature of quantum mechanics is violated by the perceptual process. It is most certainly agreed what atomic sized particles are - they are quantum objects. Do 3 - 5 with your team (10 min) Group discussion of test plan (10 min) Do 6 - 9 with your team (20 min) - Perform experiment in groups - everyone should do some of the testing and combine the data Group discussion (20 min) Do part 10 individually (5 min) Group discussion and closing (10 min) Unable to load your collection due to an error, Unable to load your delegates due to an error. One way to understand it is to rephrase the loaded terminology: Wow I didn't know they called it a Bucky-Ball outside of Wisconsin. But wouldn't photons hit the electron regardless of them being observed or not? It is important to note that these two processes are separate and distinct.