Why do rainbows appear as an arc?

Answer 1

Actually they are a full circle but you only see part of the circle due to your position on the Earth--hence the bow .

Answer 2

A major flaw in Randy's answer he said " if you imagine the rainbow coming from a single plane of water spheres in the air, as you look at the light source you are seeing light hitting perpendicularly on the spheres and refracting with little bend, coming straight at you." With a rainbow you are always looking 180 degrees away from a light source and not at it. So then how do you see it? Because the light is refracted as it penetrates the raindrop and some light is reflected by the back of the raindrop to the observer. That is why a rainbow is not very bright as not all the light is reflected. If all light were reflected the rainbow would be near as bright as the sun.

Answer 3

Rainbows are usually only partial - part of - the cirlce around the anti solar point (shadow of your head) on which rainbows are seen. They can not be square or straight, because of the way rainbows are formed. Read about how a rainbow is formed to understand this better.

Answer 4

Naturally occuring rainbows, which I assume you're referring to (i.e. not from a prism) occur because of the refraction of light through water droplets suspended in the air. You have a light source, millions of spheres of water, and your eye. The light source emits white light, which collides with all the spheres of water and reflects and refracts. The water that reflects, you don't see, and we won't worry about. The water that refracts bends following snell's law n1Sin(angle of incidence)=n2Sin(angle of refraction) soooo if you imagine the rainbow coming from a single plane of water spheres in the air, as you look at the light source you are seeing light hitting perpendicularly on the spheres and refracting with little bend, coming straight at you. Farther to the side, and above and below the light source the angle of incidence on the spheres is ghreater, and therefore the angle of refraction is greater, the bend is more significant. Since the objects refracting are tons of spheres, in all directions around the light source, for a given angle, you will get a given refraction, a given color.

The bend of light is equal in a circle around the light source because spheres are symmetrical, so you get equal changes in the light at equal angular distances from the light source.

I hope this helped... I tried to explain it..

Answer 5

They appear as circles, except you normally can't see the bottom of the circle unless you're riding in a plane.

Seeing a rainbow depends upon the angle between the water droplets and your eye. The angle is the only thing it depends on. The angle can be above, to the side, or below (if you're in a position to see the portion below you).

That probably isn't as intuitive as I make it sound. Water droplets are basically round, so you can get the same angle regardless of whether the drop's below or above, etc.

Answer 6

wen u see a rain bow it usually is in an arc because it is a distant away from u the closer u get the straiter it apears to be, gravity might also take in part, for istance if u water ur lawn with the hose the water is also shot from an arc. in other cases such like after a rain the suns rays go throgh the waters 3d figure making the colors visible

Answer 7

It's because the prisms that make the rainbow are round themselves as they are raindrops in the air.

Answer 8

Because too many skittles are slidding down the sides from the center.

Answer 9

because the sun is round

Answer 10

because if they didnt u would have nothing to ask