# Tag Info

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Terminology doesn't matter much as long as people understand the ideas involved. You should call and idea whatever you want to call it as long as you are clear about the substance of your ideas. Some commentators have stated that the Standard Model or other scientific results are well-grounded. So far, these ideas have not been refuted. If somebody invented ...

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From http://en.wikipedia.org/wiki/Scientific_theory: "Scientific theories are testable and make falsifiable predictions. They describe the causal elements responsible for a particular natural phenomenon, and are used to explain and predict aspects of the physical universe or specific areas of inquiry[...]. Scientists use theories as a foundation to gain ...

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This mass–energy relation states that the universal proportionality factor between equivalent amounts of energy and mass is equal to the speed of light squared. This also serves to convert units of mass to units of energy, no matter what system of measurement units is used. To find out how much energy an object has, multiply the mass of the object by the ...

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In his comment, Emilio Pisantry points to the Aharonov-Bohm effect. Aharonov is also one of the authors of the book. The resemblance is quite nice, and I think that when the author(s) come across Addams' cartoon, there must have been a strong sense of recognition. I believe that you might even interpret the change in the direction of the path of the skier as ...

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The skier passing through the tree is classically "impossible". Thus, the picture suggests quantum tunneling.

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The operator, as you say, seems to evoke periodicity, but this is in general illusory, aside from when the quantum system has energy eigenstates whose energies are rational number multiples of one another. The quantum harmonic oscillator is a simple example of this, indeed one of the very few possible examples when we talk about countably infinite ...

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Although unitarity is necessary for conservation of the norm, indeed there is some periodicity ingraved in its form. For time-invariant bounded systems (the Hamiltonian does not depend on time and has a discrete, or at least non-dense number of eigenstates) there is always a recurrence time $\tau_r$ after which the state of the system is again the initial ...

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A nice example is the harmonic oscillator, where we see that the periodicity of the operator just corresponds to the periodicity of the motion. For a harmonic oscillator the hamiltonian is $$\hat H = \frac{\hat{\mathbf p}^2}{2m} + \frac{1}{2} m \omega^2 \hat{\mathbf x}^2.$$ and the stationary solutions can for example be ...

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The first thing that comes to mind is the fact that energy eigenstates have a periodic phase factor, $e^{iEt/\hbar}$. In general we usually say that states are defined up to a phase factor, so for a single particle in an energy eigenstate we can ignore it, but this phase factor can manifest physically when you have a state which is a superposition of energy ...

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You will probably find it is connected to photons that could excite it, similar to the photo-electric effect. But in the main, the solution to a particular problem is a wave equation as well as a particle. In the case of electron microscopes, electrons behave as waves, based on a term $\exp(imc^2/hf)$, which allows us to see very small detail. In ...

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Very few physicists in my school's department seem to care about these questions. The "history and philosophy of physics" tag on arXiv lists only a single page of papers. I believe John Bell worked on these questions as an avocation. That said, there are a lot of different ways to approach "philosophy of physics" type questions, and you can pose such ...

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539.7 is the code for Atomic and nuclear physics books in the Dewey Decimal Classification system. For more informations about it, check the wikipedia article http://en.wikipedia.org/wiki/Dewey_Decimal_Classification

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I'm only a grad student myself, but this is my take on the subject: Any advice on the best path of education to get to QIT/QIS or QM? Difficult, as depending on what you want to learn. Generally speaking, there are many different routes - you can go via maths or via physics. You probably whant to start out with quantum computation, since this is ...

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I have found that for older books, you want to check out Alibris.com, rather than Amazon. So a quick search there turned up a few copies of the 1972 edition.

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A great tool to quickly derive a formula for a quantity is dimensional analysis. Essentially, you identify the dimensions, or units, of all relevant quantites, and derive the formula for another quantity, e.g. energy by combining them in such a way that the dimensions are correct. A famous example of the power of this formalism is given by physicist G.I. ...

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The best people way to learn formulas is to know the units for all the different quantities. You can then figure out almost any formula you want by reasoning it out. As a simple example consider the kinetic energy formula. The units of energy are $$Joules = kg \cdot \frac{m^2}{s^2}$$ If you remember that kinetic energy depends on ...

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I would read abstract and conclusions, formulate some questions to the conclusions and than look it over to see where my questions could be answered. Than read those parts first. Include the figures in your first lookover.

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Comment: A Prof once said to me you should read the abstract, look at the pictures, then read the conclusion at the end, and then start reading the paper. It's only an overhead of minutes and you're slightly less lost and get an idea what the author thinks the value of the paper is. What I also like to do when taking notes is keeping in mind the search ...

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There is a recent textbook which gives a fairly complete and concise presentation of group theory, covering both structure and representations of both finite and continuous (Lie) groups, with a brief discussion on applications to music (finite groups) and elementary particles (Lie groups). The target level is advanced undergraduate and beginning graduate. It ...

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Physics holds no prejudices. Aside from knowledge an important trait to be a great scientist is having insight, that can come at anytime to anyone in any place. Keep questioning things, you never know the next thing you question could be worth a Nobel prize.

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I only wanted to comment, but I don't have enough reputation, so excuse me for taking up a whole answer for this. The statement "The mole is the SI unit for amount of substance" doesn't mean anything to me. I think of a mole as the ratio of the SI standard unit of mass, the gram, to another fundamental mass, that of the proton. That doesn't match the true ...

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The first major step would be calculus. Really just becoming familiar with integration and differentiation on all types of functions. From there a little knowledge on differential equations can go a long way. Knowing just this can get you solving some basic problems. "Early Transcendentals" by Thomas is a good calculus book. Then there are some nice ...

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As for the symplectic reduction, a good place to look at is Chapter 6 of Olver's Applications of Lie Groups to Differential Equations. This chapter is almost independent from the rest of the book.

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Assuming you mean a BS degree in Physics, she can get any job which only requires a BS degree. Since only the 4th year (of a typical 4 year study) is used to specialize (EE, CH, Phy, Math, etc.), these degrees are 75% the "same." Most hiring managers know this, that is why the specialty is not very important in the hiring process. What is most important is ...

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These scams typically operate in a very formulaic manner: first they make large press releases for the concept, ask for funding, find funding, make press releases claiming they are a year away from releasing a gigantic version of it, cite technical difficulties when the release date passes and ask for more funding, and so on. They never ask for funding to ...

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Now my question: Does this make sense? No. Or is it just esoteric hocuspocus? Yes. I didn't watch the video but read the text. Before mentioning the mechanism they tell you about their patents to make themselves seem legitimate. (first "red flag".) They claim that their product work by harnessing Earth Energy. "Earth Energy is electromagnetic ...

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First of all, there are journals publishing a lot of review papers : Physics Reports, Reviews of Modern Physics, Living Reviews in Relativity, etc., so you may search on their web sites. As for a database, the only one that comes to mind so far is the Net Advance of Physics.

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Quantization usually means the association of a Hilbert space to the classical phase space (in our case a Poisson manifold). However, in deformation quantization, this task is achieved indirectly, first through the construction of an associative $C^*$ algebra, in this case the deformed algebra of functions equipped with a star product which serves as the ...

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