Rainbow Curvature: Why is it Curved?

[simon willetts]

Jus a brief musing. I understand that light refracts showing the different colours when a rainbow is formed but have never known why they are curved rather than straight. Probably a simple explanation but not known to me. Can anyone explain please

 

[Orodruin]

The rainbow occurs at a particular angle from the light source (usually the sun). This makes it a circle.

 

[rumborak]

Yeah, it's just a huge circle, you just can't see the bottom half. If you see a rainbow from a plane, you can actually see the whole circle.

 

[fresh_42]

Pretty elaborated here:
https://plus.maths.org/content/rainbows

 

[Borek]

I believe it is much better to think in terms of a cone than in terms of a circle. Final effect is the same though.

 

[Andy SV]

If you want see a really beautiful effect look at the shadow of your head in mist

 

[fresh_42]

If you want see a really beautiful effect look at the shadow of your head in mist

Yep.

 

[Andy SV]

I think that is dust but it's still cool
Ice has a different way of diffraction than water drops
https://www.pinterest.com/pin/7951736812208952/

 

[fresh_42]

I think that is dust but it's still cool
Ice has a different way of diffraction than water drops
https://www.pinterest.com/pin/7951736812208952/

No it's fog. The effect has even a special name and Wikipedia entry here.
(Same phenomenon as in your link.)