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2

Yes, the waves do interfere when they are not parallel. In fact, there's no such thing as parallel waves: their direction is always fuzzy. See this image of one wave going through an aperture with size comparable to wavelength: You can see that it goes not only upward, but also expands to the left and right. Now let's add another source such that ...


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Put simply, yes waves interfere even if they are not directly aligned. In fact all waves interfere of a given type. Interference is really just a re-statement of the superposition principle; that is, given 2 waves, the resulting pattern is simply the sum of the two waves at all positions in the space. The first figure you provide shows how, in 1D, 2 waves ...


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The waves in the first picture are not necessarily parallel. Their amplitudes are simply projected onto a screen, which makes them appear to propagate only in the $x$ direction, while really they could be propagating in any direction at all (still assuming they are confined to a plane, so no propagation in the '$z$' direction. Without loss of generality we ...


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I think you will observe something which will look like a dot because the interference pattern will become too small to be observable (but it will be there). This doesn't mean that the photons will behave as particles.


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I believe you will observe a dot. The reason for this is that you interfered way too much with the photon's wavefunction, and essentially forced it to behave classically. This phenomenon is known as Quantum Decoherence.


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The reason incoherent light is passed through a slit is to make it coherent . The light from a point source is forced to be coherent, the incoherent part is scattered off, or absorbed, at the opaque surface where the slits are formed. Laser light is by construction coherent so no first slit is needed. Scattering also often results in coherent waves and ...


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Yes, you will see interference pattern, provided the slit widths and their separation are appropriate. Look here. If laser beam width is greater than the separation of the slits, the beam may split and might form interference pattern. It is to be noted that particles of appreciable size (coming in the path of laser) will also scatter light according to ...


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This question is all about the signal to noise ratio you achieve in your experimental setup, so the details are highly dependent on the latter. Here are the physical principles you would use to calculate how long it takes a fringe pattern to form. Assuming the source sends unentangled photons, each photon propagates following Maxwell's equations. So the ...


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Light is a wave, it does not change its nature from particle to wave. Light, and this is true for any particle, is a an excitation is some field, and we model its propagation/time evolution using waves, but also quantise some of that wave's parameters, and in a sense, modelling it as a particle when convenient. Now answering your question, light during the ...


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The separation of the 2 slits is in the order of micrometers. A beam, taking into account its divergence usually has a radius much bigger than that. Its a key part of the experiment to have the 2 slits very close to each other, so the path difference between the beams is an integer multiple of the wavelength of the laser.


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I have another perspective on it. Interference is a wave phenomenon which nobody knows why and how it happens. I am just putting my thoughts and see if it answer yours. When a photon reaches slit it needs to decide whether to continue as a photon or convert to a wave. Conditions which are favorable for conversion is wavelength and phase correlation of nearby ...


4

You will not easily find the second one because in a sense it is trivial. Here is the single slit and double slit pattern from wikipedia . If you try to detect which slit the particle went through you get two single slits except for some experiments that are very careful not to disturb too much the wave functions of the setup. If you go to a lab that ...


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The effect you are describing in your question is known as wave-particle duality and is a form of complementarity, it has been observed in various experiments. Realisations of Wheelers delayed choice thought experiment are what I find most interesting. In a delayed choice experiment the particles are not measured before they go through the slits but ...


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It is fringe width ,the distance between centers of adjacent secondary maxima's or minima's and it is $\lambda d/D$.This is what question expects from you here to use.But instead I think you are confused because actual width of fringe looks only half of above.But note it is varying intensity of light there so you choose only lines as fringe centers and just ...


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A very simple answer to you question is that it's impossible to observe a system without interacting with it in some way. By weighing an apple, we are scraping atoms off its base which reduce its weight. Even by observing a star, our eyes are absorbing photons which may have otherwise been reflected right back into the same star. It is impossible to be ...


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I think the experiment you are proposing is not possible in the way you want it. Let us say we produce two photons in an electron-positron-annihilation with total momentum zero. (Since I don't see an easy way to produce entangled electrons I will talk about photons here, but I think it is not important for the argument). Those two photons are of course ...



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