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3

There are a lot of good answers already here, but I think I'll add a few pictures that show the ways I have to force myself to think to keep track of the differences between light waves and light rays when thinking about diffraction patterns. Above we have some light coming through the center of the slit. If we draw it like this it seems to make sense with ...


28

Why will a blue ray bend lesser than a red ray through a slit of the size a little bigger than the wavelength of the blue ray? Don't think of bending. Think of diffraction like this: if you have a plane wave incident on a slit, then you can think about the space in the slit as being a line of infinitely many point sources that radiate in phase. If you ...


0

Take a plastic ruler and attach it to a table. Press the ruler with your finger down, after move your finger slowly back. The ruler is elastic and moves back in the outgoing position. this is because the ruler is an elastic body. Press again and take the finger away as fast as you can. Now the ruler vibrates. This happens because you put energy into the ...


1

The interference between all the rays emitted from the aperture to a fixed point on the screen can be constructive or destructive, depending on the various path lengths involved (measured in wavelengths). If you change wavelengths, the path lengths (measured in wavelengths) change. What is constructive interference between paths at one wavelength can be ...


1

A wave is a perturbation in a system that propagates. The wavelength is the typical length along which a wave is coherent, which means that what happens at some position affects the wave behaviour in the vicinity if this point at distances of a few wavelengths. The reason for that is that the medium in which the wave propagates has some rigidity and the ...


6

My answer will be quite close to that of PhotonicBoom although a bit more graphical. When it comes to light phenomena, there are different ways to comprehend them: we can use a wave picture (Hyugens-Fresnel), we can use the most modern picture we have (QED) or we can use something a bit more intermediate which is the picture of light rays travelling from ...


4

The answer lies in QED and is quite complicated mathematically. As a simple explanation this is what happens: Photons follow all possible paths from the source to the screen and each path has its own probability amplitude associated with it. Summing up all these paths cancels out most terms in the summation and you end up with your desired final "classical" ...


4

Huygen's principle alone will not answer your question, however the Huygen-Fresnel principle modifies this to include wavelength. It states that every point in an unobstructed beam acts as a secondary source of wavelets with the same wavelength as the primary wave. The amplitude of the optical field at any point is then the superposition of all the wavelets. ...


0

This same question confused me a lot "when I was just a lad". Your eye responds to the frequency of light, not the wavelength. Whatever happens to the wavelength between source and retina is immaterial to the color. The frequency does not change, as you point out in (4).


1

The focal length is a concept in geometric optics which is well-defined only to the extent that the light (or a different radiation) may be approximated by light rays. That usually requires the wavelength to be much shorter than the typical geometric dimensions of the experiment. Moreover, for the focal length to be well-defined, the light rays going along ...


1

Almost nothing. Hawking was probably just building up to the fact that quarks are "colored" under the strong interaction force (a whimsical name, nothing more), but not actually colored in terms of visible electromagnetic radiation. Collections of atoms/molecules that really are about the same size as visible light wavelengths tend to scatter all frequencies ...



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