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ltd5241
Jun10-09, 06:33 AM
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?

maverick_starstrider
Jun10-09, 07:06 AM
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
Jun10-09, 08:46 AM
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

What about the sunlight?

Andy Resnick
Jun10-09, 11:55 AM
What about it?

haloshade
Jun10-09, 12:03 PM
I think he means that sunlight appears to come from more than one source spots, so how can it just oscillate in one direction?

berkeman
Jun10-09, 12:03 PM
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?

This should help you:

http://en.wikipedia.org/wiki/Electromagnetic_wave

.

Andy Resnick
Jun11-09, 07:27 AM
I think he means that sunlight appears to come from more than one source spots, so how can it just oscillate in one direction?

I'm not sure what the OP means... as for your interpretation, who claimed sunlight was polarized?

ltd5241
Jun11-09, 08:18 AM
water vibrate up-down right? what about the one colour normal light?

Bob S
Jun11-09, 10:57 AM
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.

ltd5241
Jun12-09, 08:39 AM
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.

Do you mean the direction is random and vibrate in all direction which is orthogonal to the light travel direction?

Bob S
Jun12-09, 10:25 AM
Do you mean the direction is random and vibrate in all direction which is orthogonal to the light travel direction?
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
Jun13-09, 07:49 AM
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.

That's what i want.And thank you all who answer my question!