sciencedaily.com/releases/2011/06/110602143159.htm I'm not sure whether this is questionable so i placed it here just to be safe If it turns out to be applicable, you can move it to the physics section Basically I don't quite understand how the trajectories of the photon is like in this experiment after reading the article Mind elaborate?
This is not pseudoscience. The full article is published in Science, here: Science 3 June 2011: Vol. 332 no. 6034 pp. 1170-1173 Observing the Average Trajectories of Single Photons in a Two-Slit Interferometer Abstract A consequence of the quantum mechanical uncertainty principle is that one may not discuss the path or “trajectory” that a quantum particle takes, because any measurement of position irrevocably disturbs the momentum, and vice versa. Using weak measurements, however, it is possible to operationally define a set of trajectories for an ensemble of quantum particles. We sent single photons emitted by a quantum dot through a double-slit interferometer and reconstructed these trajectories by performing a weak measurement of the photon momentum, postselected according to the result of a strong measurement of photon position in a series of planes. The results provide an observationally grounded description of the propagation of subensembles of quantum particles in a two-slit interferometer. To read the full text you need a subscription to the peer-reviewed journal Science.
James R: The Bolded (by me) part of the following implies a disturbance view of the Uncertainty Principle, which is invalid. A consequence of the quantum mechanical uncertainty principle is that one may not discuss the path or “trajectory” that a quantum particle takes, because any measurement of position irrevocably disturbs the momentum, and vice versa.I am surprised that an article in Science would make such a statement. I wonder if the abstract was written by the author of the article or a reviewer. The Uncertainty Principle relates to some fundamental property of quantum objects (Id Est: A quantum object cannot have both a precise position & a precise momentum at the same time). It does not relate to limitations of measurement technology. Consider a Bose-Einstein condensate. A group of atoms at almost zero temeperature are known to have almost zero velocity (no measurement of particle position required). At close to zero temperature, the location of each individual particle becomes very indeterminate, resulting in unexpected behavoir of the group of atoms. I think each atom seems to occupy a volume so large that it overlaps the apparent volume containing other atoms. I might not have described the above correctly. I only remember reading a article which claimed that the properties of a Bose-Einstein condensate provide experimental validation of the Uncertainty Principle. It is interesting that some extremely knowledgeable physicists have a disturbance view of the Uncertainty Principle (or once held such a view for some period of time). Nick Herbert wrote an excellent book (Quantum Reality) in which he mentions believing in a in a disturbance model for some number of years. He developed such a view while obtaining his degree & maintained a belief in it while pursuing a career as an industrial & academic physicist. He gave up the view. He makes the following comment in his book.My belief in the disturbance model was strengthened when I read that Heisenberg once held a similar view. It did not occur to me to wonder why Heisenberg quickly abandoned such an obvious explanation to take up the mystical Copenhagen interpretation.The book describes (I think) all of the various interpretations. I do not remember if Herbert endosed one interpretation or merely described each of them. BTW: I favor the Copenhagen view. I consider the Many Worlds view & the Quantum Logic view as absurd. The Quantum Logic view claims that certain laws of logic do not apply to the quantum level of reality. It is bad enough to give up locality. Giving up on logic is too much for me.
The problem is I don't have that much money for the subscription @dinosaur I'm not sure whether your explanations are right as my understanding of quantum mechanics is still at a preliminary level...
Dinosaur: Authors normally write their own abstracts. What you say is true, but what the authors of the article say is also true. Any measurement of position irrevocably disturbs the momentum, and vice versa. More precisely, the atomic wavefunctions overlap each other to a significant extent. Yes. As you cool a condensate, you know the momenta of the atoms more precisely, so your knowledge of the positions of the atoms becomes less precise. I'd venture to suggest that most physics are aware of both versions of the principle. While it is a mistake to think that the uncertainty principle is only about measurements, it is not wrong to refer to it in the context of measurements. I'm not sure what the Quantum Logic view is. I'm not a big fan of Many Worlds myself, because having billions of new universes every microsecond just feels a bit too messy for my liking. Not that I can disprove the many-worlds interpretation, of course.
I'm less familar with the copenhagen interpretation. I've breifly skimed through the copenhagen interpretation article in wikipedia. It mentioned how a measurement caused a wavefunction collapse, but then i don't understand the rest
James R. My reason for objecting to Many Worlds is the same as yours (and perhaps the same as almost all who do not accept it). I think those who believe in it would rather accept a silly notion that is understandable (they think) to a more correct notion which they (& nobody else) really understands. The Quantum Logic view claims that certain laws of logic do not apply at the quantum level. Most (all?) of the counter intuitive behavior at the quantum level is no longer counter intuitive because it conforms to the restricted rules of logic & ceases to be counter intuitive. I forget what laws of logic they eliminate.
Measuring a particle's average position isn't at all the same as measuring its instantaneous position, hence the Uncertainty Principle doesn't apply in the same way as it does with individual measurements. The experiments described here involve using multiple particles with a consistent initial state, and then reconstructing the range of trajectories these particles take. Eh? I don't know of a single rule of logic they eliminate. Determinism and causality are not rules of logic.
CptBorl: The Quantum Logic interpretation claims that logical terms like and & or do no have the same meaning at the quantum level.Eh? I don't know of a single rule of logic they eliminate. Determinism and causality are not rules of logic.This interpretation does not involve changing concepts like determinism & causality. Remeber that axiomatic logic is built on some unproven axioms & some undefined primitive terms/phrases. If you reject some of the axioms/terms, you have a different axiomatic system, which cannot prove as many theorems. If you use such a system of proof, the quantum world does not seem so paradoxical. In some book on quantum interpretations, it is imagined that a human brain is rewired to use Quantum Logic. When presented with the weird results of certain quatnum experiments, the rewired people sayWhat is the problem? That is not weird.From my point of view, it is bad enough to give up on local causality. Giving up the familiar laws of logic is too much for me to accept. I think the Quantum Logic view has very few advocates. I am surprised that it has any. I am similarly surprised that the many Worlds view has any advocates & am even more surprised at the credentials & intelligence of those who accept it. To me these views are due to being willing to accept a silly interpretation that seems understandable rather than a more accurate view which is weird & is an incomplete description. I accept limitiations of the human brain. No one can visualize the corner of a 4D or 5D hypercube, although many understand the the mathematics of spaces beyond the 3D space of our senses. For example: I and others can prove a formula for the volume of a 4D/5D hyperspher. The human brain was evolved to survive in reality which is essentially classical. It is not capable of having an intuitive understanding of the quantum reality. Be satisfied with the mathematics which works. Be happy to have lasers & other products of quantum cooks using a recipe book which is counter intuitive.
Secret: you should read other reports of this paper. The ScienceDaily piece is arguably confusing. It says "With this new experiment, the researchers have succeeded for the first time in experimentally reconstructing full trajectories which provide a description of how light particles move through the two slits..." That rather gives the impression that the photon is some kind of little bullet that follows a straight line through one slit or the other. This bit is better: "By combining information about the photon's direction at many different points, one could construct its entire flow pattern ie. the trajectories it takes to a screen". So is this quote from Steinberg ""But mostly, we are all just thrilled to be able to see, in some sense, what a photon does as it goes through an interferometer, something all of our textbooks and professors had always told us was impossible". Sadly this ScienceDaily article doesn't show you an image derived from the paper. Search google for better images like this one at physicsworld: Please Register or Log in to view the hidden image! What you're seeing is a depiction of the photon wave going through both slits at once. It's allegedly impossible, because quantum physics supposedly surpasseth all human understanding. That's what some would have you believe. Like the guys who make money out of those textbooks.
See, those aren't really rules of logic, those are just rules of human intuition. Logic itself only consists of rules such as "if \(A\to B\) and \(B\to C\), then \(A\to C\)", and nothing changes about these rules when you introduce QM. On the subject of intuition, I don't see what's any more strange about the QM picture vs. the classical picture. The classical picture has all these magic invisible forces that just do what they do because that's what they do, it doesn't even explain why a string should hold together when you tug it, and of course as you know, it doesn't provide an accurate description of the subatomic reality. As physicists like to say, "shut up and calculate". We can speculate until the cows come home about what reality actually is and why it behaves the way it does, but at least we know that careful experimentation produces consistent results which can be accurately modeled and predicted by mathematics.
A summary is here: http://scienceblogs.com/principles/2011/06/watching_photons_interfere_obs.php My summary of the summary: The concept of the trajectory of a photon is crackpot. The concept of the average trajectory of a photon is not crackpot. Clever people have measured an actual average trajectory in the iconic experimental setup of quantum mechanics: Young's two slit experiment. Nothing unexpected observed.
I am really tired of hearing these terms being used by people on the internet who think that they have understanding: Crank, Crackpot, & Troll! My personal feelings, are that people that use these terms are themselves: Cranks, Crackpots, & Trolls! These terms are only used by people who have no original ideas! Physics is not a static nor fixed field of study. As long as man is allowed to walk upon the earth, new physics and the understanding of concepts will always continue to evolve. The only thing that tries to prevent this evolution are individuals that use the terms: Cranks, Crackpots, & Trolls!, to describe what does not fit into their limited understanding for which they think is filled!! Here is a particle wave theory that matches what is being measured according to the Original Post (OP). Paper: THE PRINCIPLE OF PHOTON-INERTIA Abstract: The principle of photon inertia is a fundamental new way of describing the particle/wave duality of leptons (e.g. electrons, positrons, moun, tau, etc.) and electromagnetic waves. Photon inertia describes the inertial effects of an electromagnetic wave in terms of electromagnetic change. The principle of photon inertia uses the concepts employed in Newtonian Mechanics, the Brown Photon Theory, and concepts in modern physics, to explain the particle-wave duality as a single consistent theory. A new hypothesis that states that photons bent into stable resonating orbits are indeed leptons. Photon-photon interference causes the paths of photons to bend. Introduced as a new concept is the conservation of photon inertia, which is used to explain the natural paths of photon propagation. The principle of photon inertia describes a new equivalence in nature between mass and frequency; and a generalized electromagnetic wave, wavelength is also denoted. Paper: THE QUANTIZATION OF ELECTROMAGNETIC CHANGE Abstract: Maxwell’s equations must be modified so that they incorporate the quantum concept. Such that Maxwell's equations allow points in space to reach electromagnetic saturation as well as have a finite electromagnetic amplitude. Maxwell did not apply the quantum concept to his theory because the quantum phenomenon was not discovered until after his death. Maxwell’s equations are quantized by revealing that the electromagnetic change of a photon saturates to a quantized value within the wavelength of a photon. Hypothesized is an electromagnetic saturation constant that is a constant that couples both the changing electric and magnetic fields together and allows the fields to reach maximum electromagnetic amplitude in space. The electromagnetic saturation constant is completely necessary to link the quantum energy concept to Maxwell’s changing electric and magnetic fields. Electromagnetic saturation is shown to be the cause of Planck’s constant and the electronic charge constant.
I don't think it's standard practice for a "revolutionary" new physics argument to reference multiple books written for laymen. Whatever "facts" one might be able to derive from "A Brief History of Time" could surely derived in a more convincing fashion by referring directly to the original sources.
Magneto_1: I believe the correct response is "Fuck" and "no." Self-published tripe does not a theory make. If it was a theory, it would a communicable useful and precise description of a large subdomain of empirical phenomena and other people would be able to calculate in detail the measured observations in the Science paper. You have failed the communicable test. You have also failed the useful test because you do not present the calculations from your so-called "theory" to match what was observed. At the heart of it, you have failed the precise test because you don't consider "useful" or "communicable" to be goals in the running and never learned enough math to express your ideas precisely. You have vague intuitions about the phenomena you have never studied in detail and can't be bothered to be responsible enough to test your vague notions in the crucible of empirical confrontation. That you feel the need to cite your bad poetry as if it were science renders you firmly as crackpot -- a practitioner of cargo-cult science who intends to usurp its authority and form without adopting its methodology or actual benefits.
You have such a way with words; I am sure that you make women swoon! Maybe you should consider the career profession of a Philosopher or Politician!! Please Register or Log in to view the hidden image!
From the sciencedaily article, and from that picture included there, I thought the photon somehow split into two and pass through the slits, and I thought it has lost its wave properties But your source and the accompany diagram help me to clarify. So the photon is still acting as a wave (as in the Young's double slit experiment) when passing through the slits. I don't understand how the photon wave is theoretically not allowed to pass through both slits at the same time, as it simply behave like a wave. A classical wave approaching a double slit can arrive at both slits at the same time and then undergone diffraction at both slits, the wave produced then interfere with each other to produce the interference pattern. (but then I may be wrong as my understanding of quantum mechanics is still preliminary,(and my high school physics is already a year ago,thus I'm not sure whether i still remember the details correctly)) Btw I noticed sciencedaily love to use some words to exagerrate the breakthroughs featured in the science journals (Nature, Science etc.), for example, some few years ago, where some scientist had use spin ice to create a system which collectively behave like a monopole. In sciencedaily, its title gives you an impression that the elusive monopole is discovered. I still remember that excitement I had when I read that article and showed it to my physics teacher, but then he immediately noticed the details and told me it's just a system. Also they sometimes had an habit of putting old articles near the top, some are more than a month old It seemed that although sciencedaily is a convenient source to read science news,caution should be exercised and further searches are needed to look for other sources with a more neutral and objective writing
Although I see the traditional vile trashing of a person, I do not see any thought about why the advocated idea may be wrong. If you are so convinced, why don't you claim the prize. After all, it is the Ten Million Dollar Wagman Trust. It is awarded by committee, so maybe it would work. The double slit experiment is easily explained by the Magneto_1 idea. It is this: Photons react at their points of maxima, the place where the rate of change is greatest. However, a photon's trajectory through space is determined by its fields, which extend spatially out from the points. The slits affect the fields which drive the points, which react with the target.
CptBork: Compare your post with the views of some others.On the subject of intuition, I don't see what's any more strange about the QM picture vs. the classical picture. Feynman: I think it is safe to say that nobody understands quantum theory. Do not keep saying to yourself: “how can it be like that?” You will go down a blind drain from which nobody has yet escaped. Nobody knows how it can be like that. Bohr: If you are not confused by Quantum Theory, you do not understand it. If someone says that he can think about quantum physics without becoming dizzy, that shows only that he has not understood anything whatever about it.Perhaps you are more intelligent/insightful than both Feynman & Bohr. Perhaps you do not understand quantum theory as well as you think you do. Classical physics at least seems to match our intuitive notions relating to reality. Quantum physics seems counter intuitive to those who have a good understanding of it. Relating to the Quantum Logic view.Formal logic is based on Boole’s original ideas formalized in Principia Mathematica (Russell & Whitehead). It is based on a set of axioms & undefined terms. Von Neumann pointed out that discarding some of the axioms reduced the scope of formal logic in such a way that quantum theory does not result in paradoxical results. I do not think that Von Neumann advocated this view. However, he considered it at least an interesting interpretation.While I consider the view silly (as do most others), it is involved in certain interpretations of quantum theory. You dismiss it as follows.Logic itself only consists of rules such as "if A ---> B and B —> C, then A —> C", and nothing changes about these rules when you introduce QM.You are claiming that standard axiomatic logic applies at the quantum level (as do I). The difference in our views it that I accept that standard axiomatic logic results in viewing various quantum theory results as paradoxical, while a more restricted set of axioms would view those results as not being paradoxical. You do not seem to appreciate the effect of reducing the number of axioms in an axiomatic system. Most axioms of any system seem to be so obviously valid that it is difficult to recognize that they are unproven assumptions. Perhaps you might see it a bit differently if you read a more complete description of it. John Gribbin’s book (Schrodingers’s Kittens) mentions in briefly in his chapter titled Desperate Remedies. Nick Herbert’s book (Quantum Reality) gives a more complete description in his chapter titled Quantum Realities: Four More.
