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The wavelength of sound is of the order of 1 meter. So any objet visible to the eye can deflect it. In the case of light , we need sofisticated equipment to observe the effect of diffraction. Diffraction of light an be best observed when a small slit is used. THe slit should be the order of few microns. Then the light is diffracted which is observed in the ...

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As a general guide, if we consider diffraction of a wave with wavelength $\lambda$ from an object of size $d$ then the characteristic angle of the diffraction is given by: $$\sin\theta = O\left(\frac{\lambda}{d}\right)$$ where the $O()$ symbol means of order i.e. roughly the same as. So for example in a Young's slits experiment, where $d$ is the slit ...

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Because Light Wavelength is actually less than a sound wave. And Diffraction is more in longer wavelength waves, as is less in wider slits.

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In microscopy you can get super-resolved images, either as mentioned before going in the near field (atomic force microscope, NSOM..), or all-optically in the far field. All the super resolution techniques in the far field involve fluorescence. In PALM-STORM you tag your sample with fluorophores which are photo-switchable and you let them blink on-off so to ...

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We usually assume that the screen, $L$, is much further away than the distance $d$ between the lattice planes. Then the lines which converge on a point are NEARLY parallel, although they are not quite parallel. Then we make the approximation that they ARE parallel. If you work through the math carefully, you'll see this approximation only changes the length ...

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Actually, this is a nice question $-$ why do the dimensions of the slit or a hole (which are transverse to the direction of your incident plane waves) limit possible range of wavelengths (which are longitudinal, between two EM planes) of the transmitted wave. Without deriving the behavior from wave equations which would do the job, one may say that it's due ...

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Some brief answers, and references for further reading below. 1) You are right to be concerned about your sample having crystals with a preferred orientation. A single crystal would produce points instead of circles. The points would fall somewhere on the circles. But the image you provided shows that it is possible for the point to be off the film. ...

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It's a pinhole camera image of the sun - as DJohnM's comment said. My question is: Aren't 'lenses' required to converge the rays to make an image? How can a hole in the centre of a cardboard form 'images'. No - all that is required is an aperture (hole) to restrict the range of rays that reach the screen to form an image. All a lens does is allow a ...

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The calculation is identical, except that the waves start with a phase difference at the entrance to the slits. If you have perfectly narrow slits, the only difference in the pattern will be a shift of the maximum (the maximum occurs when the waves from the two slits are in phase, so there should be a maximum in the forward direction of the incident beam). ...

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Some of the light is blocked by the wire. But the light passing immediately off the upper and lower edges of the wire's silhouette act as two point sources, which interfere with each other when they reach the screen behind the wire. Babinet's principle says that the diffraction pattern from the edges of an opaque body is the same as that from the edges of ...

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Unfortunately, I think you are speaking about what people commonly say is "Huygen's Principle", "In order to explain waves diffraction, it says that every point in a wave front behaves as a source, so the next wave front is the sum of all secondary waves produced by these points.", but this is not actually what Huygen's principle says. Huygen's principle ...

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First off I think I should sort out a misconception about Huygens Principle. You can apply this principle efficiently if you have a slit, which is equal or smaller than the wavelength you are considering. If on the other hand the slit is substantially larger than the wave length, you should consider multiple Huygens sources. Take a look at this animation ...

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