Recent content by sliorbra

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    Graduate Dipole Radiation: Practical Considerations

    Hi, I an reading an interesting chapter of Feyman where he explains the basis of light-matter interaction with wave theory: http://cua.mit.edu/8.421_S08/Reading/Feyman_refr_index.pdf I didn't understand there one thing... to explain it he says that all the dipoles on the plate ''feel''...
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    Why does the Joule-Thomson effect cool the gas despite work being done on it?

    Hello, I have a problem to understand properly this effect. I understand that during the process the change in the internal energy of the gas is equal to the net work that have been done on it. So far everything is fine. My problem is with the physical explanation of the phenomenon. Lets...
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    Undergrad Why does wavelength affect reflection angle in diffraction gratings?

    I am not sure that I understood your answer. Can you please detail more?
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    Undergrad Why does wavelength affect reflection angle in diffraction gratings?

    hi, I am bothered by some question for a long time. From basic optics, i know that the the angle of incidence equals the angle of reflection [where we define the incident angle as the angle between the beam and the normal to the surface of course]. What I can't understand is why when a...
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    Graduate Taylor expansion of 1/sqrt(1+x) with dot products

    Hello, I have a problem to understand how the author made the following expansion: 1/sqrt{1+[2(r-r')*d]/(r-r')^2}≈1-{[(r-r')*d]/(r-r')^2+...} where all the letters go for vectors and the symbol '*' is the dot product. I suppose it is a Taylor expansion, but i just don't get it in...
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    Graduate Why Does Bra-Ket Notation Assume Linearity in Quantum Mechanics?

    Thank you Fredrik! What you have explained in the third paragraph was the thing that bothered me the most, and now it is clear to me.
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    Graduate Why Does Bra-Ket Notation Assume Linearity in Quantum Mechanics?

    thank to both of you. George, if I use the axiom like it is written in my book[linearity in the second argument], the whole definition of bra-kets is clear to me and the result i get when I use the definition of inner product for two vectors [in orthonormal basis] and when I use bra-kets is the...
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    Graduate Why Does Bra-Ket Notation Assume Linearity in Quantum Mechanics?

    hello, after some struggle,i finally understand these notations, but there is a problem. i'm studying with "principles of quantum mechanics" [R. Shankar]. in the beginning of the chapter where he discusses 'bra-kets' he mentioned the axioms of inner product. one of the axioms he mentioned...