The quantum state of a microscopic system is defined to correspond to an ensemble of subsystems of the universe with identical constituents and similar preparations and environments. A new kind of interaction is posited amongst such similar subsystems which acts to increase their distinctiveness, by extremizing the variety.
In the limit of large numbers of similar subsystems this interaction is shown to give rise to Bohm's quantum potential. As a result the probability distribution for the ensemble is governed by the Schroedinger equation. The measurement problem is naturally and simply solved. Microscopic systems appear statistical because they are members of large ensembles of similar systems which interact non-locally.
Macroscopic systems are unique, and are not members of any ensembles of similar systems. Consequently their collective coordinates may evolve deterministically. This proposal could be tested by constructing quantum devices from entangled states of a modest number of quits which, by its combinatorial complexity, can be expected to have no natural copies. Jump to Navigation.
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Then why would you expect a second measurement to show the same?? Report Block. Would it be possible then to disturb a system without to some degree measuring it?
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According to quantum theory it is possible that the cat is both dead and alive It would have been more accurate to say "According to one interpretation of quantum theory The cat is alive in one world and dead in another, and you are merely finding out which world you are observing from when you open the box. I feel that all the quantum weirdness is attributed to things popping in and out of existance our dimension. It could certainly explain the concept of "Quantum Superposition" , because much like the blades of a fan, if you stick a pencil in the area where the blades are spinning and remove it in a very small amount of time, you may or may not hit the fan blade.
I think these small particles are the same way, changing state or pulsing constantly, and if you measure it you are changing it much like the pencil hitting the fan blade and affecting its motion. Im just a layman, but it makes sense that things are so strange in the quantum world because its not made up of real matter, but merely the pulsing of matter into and out of our dimension.
The whole article shows woolly thinking. Any interaction between a one system and another system represents information exchange. That second system may well be a measuring photon or other 'particle'. The disturbance to both systems then depends on the properties of BOTH the system being measured and the type of measurement you chose to make. This much was already known. This article doesn't seem to add to the sum of human knowledge.
Except that it IMO correctly disregards the anthropic view that observers create the universe, or multiple universes exist for each interaction. Though they do fall into the standard pitfall that that cat is both alive and dead just because someone put it in a box with a contraption with a quantum trigger. Where in fact the cat is just as valid an observer of the device going off as the person opening the box.
This is more like the wave particle duality which is found experimentally. Both fans are like waves while sweeping through space and time, unmeasured and undisturbed, until they collide and their interaction is described like particles. You could say the second fan is making a measurement. The whole article shows woolly thinking You're right. Maybe the reading of the original article will make the discussion less woolly.
An information-theoretic principle implies that any discrete physical theory is classical This is indeed a nice sentence - but what does it mean? Is such sentence testable? Do we have some discrete physical theory? Are quantum mechanics or general relativity discrete theories? Which theory such a sentence is supposed to apply? However they would be very hard pressed to explain the information exchanges of QED as a classical phenomenon.
The quark transformations of weak-force interactions would have puzzled Isaac Newton greatly. Regardless though, I agree in principal- I think : If a photon has only one quanta of energy, and to measure this photon requires the exchange of at least one quanta between the photon and the observer, isn't the quanta associated with the photon "used up" for this exchange of information, thus removing the photon from 'existence' its quanta becoming associated with a different quantum system?
Destroying the photon sounds like a pretty serious disturbance from a photon's perspective. Assuming the foregoing then, if you don't have this exchange, then no information is exchanged and thus the photon is not disturbed.
The Principles of Quantum Mechanics - Paul Adrien Maurice Dirac - Google книги
Quantum gravitational theory-it correlates with Einstein's theory of relativity both general and special which would enable us to relate with the article published here. Schrodinger's cat is a probabilistic phenomena i. So are every air molecule in the box besides the cat.
You're confusing observing with concious observing, when it really means just propagation of effects from causes. Outside of the box, the scientist has not yet felt the effects of the cat being dead, regardless of whether the cat feels himself dead or alive, so what the cat observes is in a superposition to the scientist as well, and the scientist is in superposition to his supervisor who hasn't yet heard of the results of the experiment, etc.
At least the discrete ones has no energy gap, no lower energy, and so can't make harmonic oscillators so has no dynamics. And supernova photon timing shows that spacetime is perfectly smooth beneath Planck scales. On the other hand it is not really telling us why we see quantum physics in the first place. But analogous to above, a simple probabilistic model shows that classical physics is discrete, have a discrete mapping of in to out state, while quantum physics is continuous in that sense. Also seen in how we can take systems partly in and out of decoherence. And QM happens to be the smallest dimensional such physics 2D probability map instead of 1D classical - it minimizes hidden variables and visible parameters both.
Also of note is that they disregard weak measurements they don't need them , which observes over ensembles in a statistical sense.
You are thinking of resuming the experiment. Claudius: And actually Shroedinger was showing how the classical Copenhagen and instrumentalist theories becomes absurd, see EyeNSteins comments. It is, in this sense too, a terrible example. The likelihood for a quantum fluctuation popping some substantial "thing" in and out is very small, on the order of the lifetime of the universe after heat death or so.
Virtual particles on the other hand are just impermanent illdefined unnatural disturbances in a quantum field allowed by the energy principle under quantum physics eg Heisenberg's uncertainty relations , while particles are more or less permanent in comparison welldefined natural ripples. Yes of course Problem solved. The 'why' of quantum physics is beginning to sound spiritual. Or vice versa. As weak measurements are probabilistic: The more certain you are of your measurement, the more probably disturbed the system is.
In the famed twin slit experiment: The wave interference pattern on the screen fades in proportion to how certain you are of a weak measurement made of the particles approaching the slits. I feel that all the quantum weirdness is attributed to things popping in and out of existance No, that is due to the Heissemberg principle, which is the easier part of Quantum mechanics.
To me the quantum weirdness is more about other examples like the particle entanglement spooky action at a distance or the double slit experiment with measurement delayed in time where a future decision seems to affect a past event. Regarding the article I don't agree, in such a system we could force the appearance or impede it of new particles from the outside that will interact with the old ones even if we do not make any measurement we will disturb the system.
I mean, if we open the box and we throw a dog into the box without looking at the cat and we close the box then we have not measured anything and we haven't got any information, but we may have disturbed the system a little bit isn't it? Moebius The big debates of physics have always had a spiritual dimension. From Einstein's "God does not play dice" to the huge row between Gamov and Hoyle over the big bang creation event. As ultimate physics becomes more uncertain and probabilistic; and every concrete classical concept like space and time becomes less invariant: Many will invoke or revoke God depending on their personal leanings.
Myself I have no problem accepting that conscious life could be an emergent property of the 'bulk space' our 'brane' universe and its time and space came from: Just as conscious life is an emergent property in our Universe. We just cant prove it either way with our current knowledge.
Making sense of quantum mechanics
Its the folk who get all definitive and shouty, without any humility, nor thinking stuff through, who cause all the loudest arguments. What I don't understand is the following; Consider an un-measured entity has not collapsed its wavefunction and can therefore be in many states at once. You now measure the entity and cause it to collapse, taking on a definitive state. How does this collapsed wavefunction entity, return back to an un-collapsed wavefunction??
It must do this, because if it didn't then every particle in the universe would surely have collapsed all wavefunctions into definitive states due to interactions, therefore quantum wierdness would have long dissapeared in the Universe. If the answer is that after measuring, it returns to non-collapsed state, then surely measurement is just a snapshot, a still frame taken from a movie we dont understand. Or is it that taking the measurement, still frame changes the movie. Anyway it seems to me that a measurement must be a snapshot of randomness.
The idea that the wavefunction collapses thus defined , seems silly as it must return back to an undefined state. Taking this idea further; Consider an electron moving in straight line from a classical point of view. Any two snapshots of this electron would yield definitive predictive solutions to its locaion in the future. Now we know this is not the case for an electron in a quantum state. So what if we now assume that an electron in quantum state, does not exist in time. So perhaps a quantum state is an entity outside of time which is changing state at an infinte rate.
Measurement gives you a snapshot still frame of an infintely changing state entity. The wavefuntion simply gives you all the states it COULD change to, and thus at infinte rate of change it appears to have all states until measured. Thus classical behaviour falls out, if an entity is repeatedly measured at a rate approaching infinity. The more frequent you measure the more classical it becomes and the more the entity appears in time.
But as researchers compile lists of principles that each rule out some theories to reach a set that singles out quantum physics, the principle of information gain versus disturbance seems like a good one to include. Actually the 'why' question of 'physics' is the question about its working mechanism, such as in quantum physics which was born from the basic concept that electron particle can manifest as wave. So if we could understand why and how electron able to do something likes that, then that is the answer for the question….
Wandering even further through my crazy thoughts we get the following; A black holes singularity is interpreted as mass with zero volume. Something we don't really understand. The singularity must have infinite density, and thus infinite gravity at that "point". Now consider trying to combine quantum mechanics with relativity, and again divide by zero's or inifities appear everywhere, and stop the convergence of these theories.
I suspect that infinity is the key to the understanding here and that a result of inifinity does not suggest a failure of the combination of the two theories, but is actually correct, and showing us the true nature of the universe. So from this, it appears our concept of time needs re-evaluating.
Of course I don't understand what outside of time really means, but my thought experiments seems to suggest this is a possibility. Classical behaviour is simply something existing in time. If it is changing state, it is change per unit time, which means it is not outside of time. Or perhaps language is inadequate to describe this? Yes I realise the downfall of my language there Claudius. Perhaps a better term would be in a different time completely, one not related to our time as we know it.
Also what is the unit of time, if it is changing at an infinite rate?? You see the definition of time breaks down, when infinity is introduced, and thats my point. Quantum behaviour could be from infinte internal change state, and classical behaviour is more evident in state change below infinity. Though some will argue that infinity - 1 is still infinity!!!! So perhaps the rate of change is either infinite in rate, or NOT. If NOT it is more and more classical, if it is then it is Quantum. I must say your reply was very polite Claudius, so I don't know who gave you a ranking of 1. I will give you a 5 for being polite, and actually thinking about a difficult subject I never did buy into it, and to my mind it does not explain the theory of quantum mechanics, but merely presents an explanation by example by way of a poor analogy.
Better to just analogize using the discrete bands of frequency domains in the optical spectrum, or the discrete thermal energies required to effect separation of gases during the process of fractional distillation. I wish that everybody would just shut up about it. If the universe is a giant computer and what we are involved in is akin to a giant simulation then retaining causality to any scale whatsoever in a region would require infinite computing resources.
To dodge that, quantum mechanics is then the "resolution" of the simulation where everything beneath a certain scale becomes part of the big monte carlo simulation which can remain finite on a region. Just blathering, of course, but why not? Here is something to perplex the mind; Where does Quantum Time fit into the nature of the quantum system? Does it dictate what is finely divided or probabilisticly fuzzy? I've always read many of the equations of QM as time dependent and with time being perfectly defined.
I've always wondered if that was true. Consider a black hole. This would disturb the system without chance of observation. A black hole is the ultimate particle accelerator, but rather than smash atoms into each other, it literally breaks them into their smallest constituents. What a paradox that the natures deepest secrets are unobservable. Clever God. We see, but the beginning of the iceberg in quantum physics.
May 15, Like so many articles online these days there are a lot of words but nearly ZERO actual information. This article is garbage. Measurement is interaction that imparts a change on the thing doing the measuring. Measurement is a process of exchange. Be it charge, energy, momentum etc. If you measure something you have acquired something from or given something to the thing being measured. This has been the standard working principle in QM for as long as I can remember.
Perhaps the best place to start would be the precise definition of what it is you mean when you use the word "time". I await your definition. There is always a spatial probability distribution in detecting a quantum object. In many instances, the vocabulary used to describe quantum processes confused discreteness with stability A particle like an electron exists only in environments where it's self interference produces an electron. Electrons entering such a volume stop being electrons and become something else. Think harder. It never stops being a wave function. The "collapse" refers to the selection of a single fourier component of the wave function that is one of the mathematically allowed solutions to the interaction.
The original wave function can always be represented by a fourier series of wave components. As the following video shows. Cat's have no souls.
The Uncertainty Principle
You simply didn't notice it because of the fact that the things being measured were macroscopic. The smaller you get, the more those pesky photons matter. Eventually when you are measuring one photon with one electron or one electron with one photon, then the tools you are using to measure will dramatically alter the things you are observing.
Thought isn't a form of energy. So how on Earth can it change material processes? That question has still not been answered. If you don't get any information from the system, how can you tell that you haven't disturbed it? I'd be interested to see the schematics for your Heisenberg compensators sic. The big debates of physics have always had a spiritual dimension.
Einstein was only being poetic. He never believed in any book god. As ultimate physics becomes more uncertain and probabilistic; and every concrete classical concept like space and time becomes less invariant: Many will invoke or revoke God depending on their personal leanings People do this because they want to live forever and they want their wishes granted and they will seize upon any unknown as direct evidence that the Creature who can give them these things does indeed exist. Im sorry but this compulsion is pathological. Myself I have no problem accepting that conscious life Consciousness is not a 'thing'.
Scientifically it is a worthless notion. People use it because it is a stand-in for the 'soul', as something which might possibly live forever. You wont. I just know he is! I wonder which side of the public God debate you stand on. You couldn't be a bigoted atheist, without any humility could you by any chance? If consciousness doesn't exist there is a lot of brain research being wasted on this emergent phenomena.
You are confusing observation with thought. When a photon interacts with an electron, it has "observed" the electron. If there is no exchange then there has been no exchange with the particle that could have been observed, and it's state remains unchanged. Bad example. The cat is not "quantum" object and does not comply with the superposition entropic principle. To look at it you need to bounce light off it.
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The more accurately you want to resolve it next to your ruler, the shorter the wavelength of light you need. The shorter the wavelength, the higher the energy of the photons and the more you disturb the subject. So it applies to rulers too.