2006-08-16 21:08:34 · 10 answers · asked by yogen p 2 in Science & Mathematics ➔ Physics
A semi-circle IS just part of a circle.
Rainbows are not cirular (or semi circles, or arcs) because the earth is round!
They are the shape they are because of the way they are formed, by sun shining on rain, the sun light being refracted and reflected, by the rain, and you seeing it. You will only see a primary rainbow on an arc 42 degrees around the anti-solar point (the shadow of your head).
2006-08-17 09:25:13 · answer #1 · answered by Anonymous · 0⤊ 0⤋
The rainbow is a circle (42 degrees diameter, if I remember well) centered at the point of the sky directly opposite of the sun. In order to see the rainbow full circle, the sun should be 42 degrees below the horizon, which only happens at night, when there is not enough light to see a rainbow.
2006-08-16 21:18:01 · answer #2 · answered by dutch_prof 4 · 1⤊ 0⤋
Actually, they aren't. Under proper conditions (sun low in the sky), in an airplane you can see a rainbow form a full circle. However, since a rainbow's arc is always centered at a point directly opposite the sun, if you are on the ground, some of the rainbow's arc would be underground.
2006-08-16 21:17:01 · answer #3 · answered by Anonymous · 0⤊ 0⤋
It's not ALWAYS, just usually. I've seen a rainbow completely encircle the sun.
2006-08-16 21:17:18 · answer #4 · answered by beast 6 · 0⤊ 0⤋
Each raindrop is not parallel. They are all slanted to point to the center of the earth. What you see is the light following the curvature as each ray passes through the raindrops.
2006-08-16 21:13:54 · answer #5 · answered by Tim 2 · 0⤊ 0⤋
Actually it is a complete circle but half of it is seen in the other hemisphere of Earth
2006-08-16 21:24:52 · answer #6 · answered by Anonymous · 0⤊ 0⤋
Why, have you got something against semi circles?
2006-08-16 21:13:42 · answer #7 · answered by Anonymous · 0⤊ 1⤋
it is cicular but the earth is too large for us to see it as a full circle
2006-08-16 21:16:15 · answer #8 · answered by anjith g 1 · 0⤊ 0⤋
I dunno, but I've seen circular rainbows so I don't think they're all semi-circular.
2006-08-16 21:15:50 · answer #9 · answered by Anonymous · 0⤊ 0⤋
It's all about the angles.
2006-08-16 21:13:55 · answer #10 · answered by Holly 2 · 0⤊ 1⤋