optics - rainbows

[hexa]

I was wondering how a rainbow would look like when sitting in a lowflying plane. I was thinking that it sould still be a bow as standing on a mountain doesn't change the shape of the rainbow either. But is that really true?

hexa

[marlon]

You see a rainbow depending on the position you look at it because the phenomenon responsible for it, ie dispersion, is an "angle dependent" physical process. more specifically, EM-radiation splits up into the different constituent frequencies (colours) when passing through a medium of variable refractive index. each frequency is "emitted" along a certain angle with the incident EM-radiation.

marlon

[hexa]

ah very interesting. So the higher i get relative to the ground, the more I can see of that rainbow until I see the complete circle, right?

Hexa

[marlon]

ah very interesting. So the higher i get relative to the ground, the more I can see of that rainbow until I see the complete circle, right?
Hexa

I am sorry but i do not see how you come to such a conclusion ? Am I missing something here ?

marlon

[russ_watters]

What hexa concluded doesn't necessarily follow from your post, but it is more or less correct: But if the sun is very low in the sky, either just before sunset or just after sunrise, we can see a half circle. The higher the sun is in the sky, the less we see of the rainbow.

The only way to see the full circle of a rainbow in the sky is to be above the raindrops and have the sun behind you. You would have to look down on the drops from an airplane. http://www.wxdude.com/Rainbows.html

and: However, a mountain won't work for a full circle. "On a mountain peak-no matter how high," says Greenler, "droplets on the part of the circle below the antisolar point will be shaded by the mountain." http://www.wonderquest.com/rainbow-circle.htm

[marlon]

ok, thanks for clarifying,

my mistake

marlon

[lurksalot]

I realise that this thread has been dormant for a while , and I have no scientific knowledge as such but by observation .....

If a rainbow were to be projected into a full circle the circle seems to complete itself at my feet . I noticed this particularily when driving in spray that the rainbow in the distance could be seen through the spray and seemed to come through 360 deg back to the ground beneath me .

Is this true of all rainbows to the observer ?

[NoTime]

I realise that this thread has been dormant for a while , and I have no scientific knowledge as such but by observation .....

If a rainbow were to be projected into a full circle the circle seems to complete itself at my feet . I noticed this particularily when driving in spray that the rainbow in the distance could be seen through the spray and seemed to come through 360 deg back to the ground beneath me .

Is this true of all rainbows to the observer ?
What you see depends on your vantage point in relation to the dispersing medium and the Sun.
From personal experience, flying planes, I've seen them make full circles (quite impressive), but they are somewhat below you.