ltd5241
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If the light move from left to right, what's the vibration direction of light wave? up-down or front-back or some other ways?
The discussion revolves around the vibration direction of light waves, particularly in the context of classical electromagnetic theory and the nature of sunlight. Participants explore concepts related to polarization, the orientation of electric and magnetic fields, and the behavior of unpolarized light.
Participants express various interpretations of how light oscillates and the implications of polarization, with no clear consensus on the implications of sunlight's multiple source appearance or the nature of its vibration direction.
Some assumptions about polarization and the behavior of light may not be fully explored, and the discussion includes references to external sources for further clarification.
maverick_starstrider said:well, in a classical picture, light is an oscillating magnetic wave reinforcing an oscillating electric wave (or vice versa) which is perpendicular to it. However, the polarization of light determines its orientation. See http://en.wikipedia.org/wiki/Polarization
ltd5241 said:If the light move from left to right, what's the vibration direction of light wave? up-down or front-back or some other ways?
haloshade said:I think he means that sunlight appears to come from more than one source spots, so how can it just oscillate in one direction?
Bob S said:The direction of a photon (radio wave, microwave, IR radiation, visible light, UV radiation, x-rays, gamma rays, synchrotron radiation, etc.) is given by the Poynting vector, P = E x H.. Since it is a vector cross product. Both E and H are orthogonal to P.
Precisely. For all unpolarized light, the direction of vibrations of the electric and magnetic fields is random, as long as they are orthogonal to the direction of travel. For individual light "photons", the individual quanta of light, the electric and magnetic vibrations are orthogononal to each other, and both are orthogonal to the direction of travel. But light is composed of billions of photons, and for unpolarized light, they are all randomly oriented.ltd5241 said:Do you mean the direction is random and vibrate in all direction which is orthogonal to the light travel direction?
Bob S said:Precisely. For all unpolarized light, the direction of vibrations of the electric and magnetic fields is random, as long as they are orthogonal to the direction of travel. For individual light "photons", the individual quanta of light, the electric and magnetic vibrations are orthogononal to each other, and both are orthogonal to the direction of travel. But light is composed of billions of photons, and for unpolarized light, they are all randomly oriented.