- The black circle represents
a drop of water in the atmosphere. Red light coming from the left.
- 50%| and 50%+ means
the incoming ray is unpolarized. And we can mathematically transform
unpolarlized light into the superposition of two polirized waves
whose planes of vibration are perpendicular to each other. In this
case, 50%| in the up-down direction, and, 50%+ perpendicular to
the screen.
- You can click inside
the colored block to change the color of the incoming light.
- Part of the incoming
ray is reflected back to the atmosphere. (indicated by number 1)
- The intensity of each
polarized component is shown along the ray path.
- Parts of the red light
refracts into the drop, then refracts back to the atmosphere.( number
2)
- Some reflects from the
drop's inner surface, and refracts back to the atmosphere.(number
3) --> Rainbow.
- Some reflects again,
then refracts back to the atmosphere.(number 4)
- You can drag the incoming
ray, move it up and down, and watch how the relative intensity changes.
- R is the radius of the
water. b is the vertical distance from incoming ray to the center
of the circle.
- You can click inside
the white box, and see what will happen.
- When light refracts,
it follow the law of refraction ni sin(£ci)=nr
sin( £cr)
- where n is the index
of refraction.
- Number in the left-bottom
corner : i is the angle of incidence, r is the angle
of refraction.
- Most of the light are
refract out from ray 2.
If your eyes intercept the
separated colors from raindrops, the red you see comes from drops angled
slightly higher in the sky than dose the blue. You can see a circular
arc of color, with red on top and blue on bottom. Clicks inside the
colored box to show this effect. You can drap one of the rain drop,
Try it!
- Did you noticed that
rainbow consists of partially polarized light.
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