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Can A White Photon Exist?not so easy to Answer 
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#91
Jul111, 11:04 AM

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#92
Jul511, 09:32 PM

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In between bunching and antibunching is neither. So if we start with bunched statistics, or neither, you are suggesting that reducing the intensity must alter the shape of the distribution?



#93
Jul511, 11:00 PM

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It's a basic fact of Fourier decomposition that a finite (in time) entity does not have a single frequency, it has a spectrum.
If the line width of a single quantum is sharp, it has a definite energy. And it must therefore persist for an indefinite time. The math is not forgiving on this topic. A photon that has N cycles in it's wavetrain can only have a definite energy (zero linewidth) as N approaches infinity. 


#94
Jul511, 11:09 PM

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It was amusing to me to see this pop up as a necrothread, and also to see how many posts and how much sophisticated argumentation had gone into it. I'm the person who wrote the discussion question: http://www.lightandmatter.com/html_b...ch34/ch34.html The book is targeted at biology majors who haven't had calculus. Although I included the discussion question in my book, I think I have never actually used it with any of my classes over the years. My intention was simply that the answer would be "yes, of course, because photons are waves, and waves can superpose, so you can superpose a bunch of different wavelengths."



#95
Jul611, 01:15 AM

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But surely photons are not waves, they are photons., particles, they can collide with other particles e.g. xrays with electrons and impart momentum to the electron. The properties of the photons themselves are subject to the uncertainty principle so you have to be a bit guarded when imagining you can have two of then localised in a radiation field, so that you can create a superposition in the way that you might be able to do by bringing two relatively massive bodies like electrons together into a chemical bond. Photons can all share the same state anyway so is that really a valid way to create a new superposition state?
As far as the fourier analysis of the wave goes, are we not talking about two different kinds of wave here? The electromagnetic wave (Maxwell) is not exactly the same thing as the quantum wave (Schrodinger) is it? I mean the electric field can be uncertain but these quantum waves have a kind of platonic form? I think you can use the maxwell wave to compute the quantum wave, (that's handy!) but one is a field equation and the other is a probability wave. The fourier breakdown of quantum wave packet gives probability amplitudes, not energies? 


#96
Jul611, 04:11 AM

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