In quantum mechanics, wave function collapse occurs when a wave function -initially in a superposition of several eigenstates -reduces to a single eigenstate due to interaction with the external world. 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. Using quantum field theory allows us to calculate the behaviour of electrons whether they happen to be involved in particle-like or wave-like interactions. That is the point, "anything" should not just go. In Relational interpretation the collapse happens when the interaction affects the ultimate measurement performed by ultimate observer on the universal wave function at infinite future. What causes them to occur? However, that would be some sort of quantum entanglement no? 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 $\mathbf{U}$. 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 person has the special property which no other object in universe is capable of. official website and that any information you provide is encrypted 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 superposed photons, thereby guaranteeing that only final, measured information is presented to the brain, mind or consciousness. JavaScript is disabled. 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. The wave-particle debate should have been put to rest eons ago. It's QM, anything goes now. Put simply, the act of observation involves obtaining information about a system - i.e making some measurement of it. @bhobba: I'd very much like to hear how you feel about multiverse concepts. 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 $\mathbf{U}$. What are the best sites or free software for rephrasing sentences? I am going to refer to the state vector reduction (collapse of the wave function) as $\mathbf{R}$. it does not begin with Trump 2024, but with the Congress in whatever year they choose. An analysis has been performed of the theories and postulates advanced by von Neumann, London and Bauer, and Wigner, concerning the role that consciousness might play in the collapse of the wave function, which has become known as the measurement problem. Careers. 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. The idea of probability - or possibilities - "collapsing" is much easier to understand. Why quantum wave function collapse is not consider a signal? 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. This is how we know that it hasn't "collapsed.". It essentially contains all the statistical information about a system that it is possible to have- kind of like a giant list. 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. Number of unique permutations of a 3x3x3 cube. There are traces of the view in earlier work by von Neumann (1955) and London and Bauer (1939).1 In recent years the approach has been pursued by Henry Stapp (1993) and others. Consciousness enigma: the "hard problem"--binding problem entanglement, "extra ingredient" and field principle. I strongly feel this to be a duplicate. The actual. 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. 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. Observable properties, such as the position of an atom or the momentum of an electron, arise from projecting the wave function onto an eigenstate. yeah call it spin, braket, blackbody, dark matter, force, strange, bottom, energy, heat and jerk. 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. Biosystems. It is most certainly agreed what atomic sized particles are - they are quantum objects. $\mathbf{U}$ 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. Similar to their micron-scale counterparts, microbubbles (1-10 m), they can act as ultrasound contrast agents as well as locally enhance therapeutic uptake. The ball part comes from its similarity to the association football ball. 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? 2006 Jan;83(1):1-9. doi: 10.1016/j.biosystems.2005.06.011. In quantum mechanics, wave function collapse is said to occur when a wave functioninitially in a superposition of several eigenstatesappears to reduce to a single eigenstate (by "observation"). However, I had assumed that the act of observation was passive, not actively interfering in any way. But I also disagree that this, I hope that you understand that "Observation" in this context means "interaction". Just because it is QM, does not mean we stop doing science and make up random fantastical theories to suite observation. Epub 2005 Dec 13. and transmitted securely. 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. How many ways are there to solve a Rubiks cube? The other part is the light source and the photons interacting with the electrons. In quantum physics, the term "observation" sometimes causes confusion. I want to know what about observation causes this change? In some interpretation, wavefunctions never collapse. 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. It must have a finite value or it must be normalized. 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). Occams razor has us accepting, for now, the simplest models we can get away with. Only then does the wavefunction describing the particle collapses into one of the two states. . How do measurements collapse quantum wave functions . HHS Vulnerability Disclosure, Help I am going to refer to the state vector reduction (collapse of the wave function) as $\mathbf{R}$. "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. As John Rennie said, field theory is how modern physics is done. The wave function must be single valued. 8600 Rockville Pike However, "measurement" is more accurate that "observation" because measurement apparatus itself rather than consciousness . 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. Answer (1 of 19): The problem is that the "wavefunction" is itself an inference. It means for any given values of x and t , there should be a unique value of (x, t) so there is only a single value for the probability of the system being in a given state. But they obey the rules of QM which is described by a quantum state that has, in some circumstances, wave-like solutions. I don't think so - do you? In Many-worlds interpretation the wavefunction collapse never happens. At the moment our best description is that the electron is an excitation of a quantum field. Disclaimer, National Library of Medicine There seems to be no consensus on this subject. Wave Function Collapse and the Speed of Light. Quantum mechanics suggests that particles can be in a state of superposition - in two states at the same time - until a measurement take place. Privacy Policy. One candidate model to explain this reduction process is the gravitationally induced state-vector (and its decedents). "how does the electron understand that it is being observed?. that uses a quantum gravity model to explain the elusive quantum process $\mathbf{R}$ - this is well worth a read if you want a better understanding of this mysterious process and it implication on human consciousness. And yet, it would seem in order to learn more we do need a template, one that might give us an idea where else to look for additional information. In reality you are not the detector; you are only part of a detector. 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 $\mathbf{U}$. And I assume you already know about the double-slit experiment (just to be sure)? Prior to the instant in which we select and attach to a thought, we are like the wave, in a state of potential. 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 for most of the superposed photons, followed by a discontinuous nonlinear collapse process for any remaining superposed photons, 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. some future development of string theory. Recently, it has been shown that the reduced size of NBs (<1 m) promotes increased uptake and accumulation in tumor interstitial space . The von Neuman interpretation is the edge case of Copenhagen interpretation where the Heisenberg cut is placed as close to the observer as possible. When does the quantum wave function collapse? Reddit and its partners use cookies and similar technologies to provide you with a better experience. 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). sharing sensitive information, make sure youre on a federal of an "intermediary wave/particle object" model, exists! physics fags are all to blame for this, they couldn't develop nomenclature like chemchads. Why doesn't the electron "wave" collapse at the double-slit. Roger Penrose describe a new model (based on other candidates) in his book The Shadows of the Mind (not an easy read!) Wave function won't collapse under a microscope? Lipid-shelled nanobubbles (NBs) are emerging as potential dual diagnostic and therapeutic agents. I want to know what about observation causes this change? Describing the electron as a particle is a mathematical model that works well in some circumstances while describing it as a wave is a different mathematical model that works well in other circumstances. I've asked. 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) No doubt there's a Nobel prize or two in whoever figures this out. 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 $\mathbf{U}$. Accessibility Therefore, the collapse of the wavefunction is a phenomenon that can only be inferred, and not directly observed. When the wave function collapses to unity in one place and zero . You may notice that this still leaves open a crucial question: when do the many branches become one? Roger Penrose describe a new model (based on other candidates) in his book The Shadows of the Mind (not an easy read!) An official website of the United States government. However whether a state has a real existence is open to question - I view it purely as a device for calculating probabilities. The https:// ensures that you are connecting to the The locus classicus of this consciousness-collapse thesis is Eugene Wigner's 1961 article "Remarks on the mind-body question". This leads us to consider a wavefunction in a quantum rather than classical world where it interacts . I'd also like to see if I have a grip on your view by restating it: Remember a molecule composing of 430 atoms called buckyball can still interfere with itself in the double slit. And as mentioned by Ulf, interaction with gravity is weak and its contribution is very small in the total effect. But that description is not sufficient per reductionism because the macro, classsical world is taken to be made up of quantum interactions fundamentally. So far one theory is the act of observation interferes. E. Wigner once sketched a theory of this kind in Nature in the 60s. You are using an out of date browser. How does one mathematically model a wave function after a collapse to a finite region? bringing about wave function collapse. physics.stackexchange.com/questions/93703/, physics.stackexchange.com/a/622476/226779. A thing is a wave function in its native state, when observed, it is removed from its native state and within our frame . Come again - can't follow that one. @bhobba: I'd very much like to hear how you feel about multiverse concepts. Bingo. 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. The wave collapse can also be illustrated by our thought selection. This site needs JavaScript to work properly. Consciousness, the brain, and spacetime geometry. 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. Well, thats a simple one: because it interacts with the detector! Score: 4.9/5 (62 votes) . Clipboard, Search History, and several other advanced features are temporarily unavailable. Answer (1 of 3): Dr Ojo's answer is a bit brief, albeit for the most part correct. Why does an observer collapse a wave function? I think that the "students debate" is about use of ". 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. The canonical interpretation, Copenhagen interpretation, simply dodges this question. As time passes, more and more wave-functi Continue Reading 1 Quora User Former broadcasf engineer and computer scientist 1 y Covalent and Ionic bonds with Semi-metals, Is an athlete's heart rate after exercise greater than a non-athlete.