What gives the shape of the rainbow? everytime I see a rainbow it looks like half circumference of a circle?

Question

this question may seem silly. If the shape of the sun were like a triangle (forget about volume) would the rainbow shape be the same? (in my opinion yes. but I need confirmation) This question comes about after watching a very vivid complete rainbow.It occured to me that the outer part of the rainbow (the red part) is actually the outer part of the sun (sort of its circumference) Twenty years ago I would not ,probably, asked this question or I would have answered this question myself but I have forgotten a lot of basic physics. Thanks for your help Please give details of links where I can actually visit and understand or refresh my lost knowledge Thanks

Answer 1

The curvature of the earth.

Answer 2

A rainbow forms an arc in the sky which is always 42 degrees away from direction opposite to the sun. The cause is the refraction and reflection of light within water droplets. The shape of the light source plays no part in determining the shape of the rainbow. Red light and blue light are refracted by different amounts, which is why red appears on the outside of the rainbow and blue appears on the inside. There is an explanation at http://www.photocentric.net/rainbow_angl...

Answer 3

the rain

Answer 4

Seriously , this question question is NOT silly.

you will see different shapes of rainbow.

for example, someone flying a plane will see the rainbow as a shape of a round circle ( meaning he/she can see the whole rainbow as a circumference of a circle ) .

for a farmer who is on the land in the field , he can see the rainbow as a circumference of a quarter circle ( 1 out of 4 of the circular rainbow , that is , if he is standing on a 'totally' perfect straight ground, with no slopes ) .

for us standing on slopes of ground , the light tends to retract so we see it as a semi circle shape circumference .

p.s. note that light refraction is not the same as gravitational lensing...........

a person who is