Naked Science Forum

Life Sciences => The Environment => Topic started by: neilep on 21/11/2007 16:43:37

Title: Two Rainbows....but the second one's colours are reversed....why ?
Post by: neilep on 21/11/2007 16:43:37

I was looking at some piccys of rainbows (cos I luff them )...and then this one stood out !!

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Why is the second rainbow reversed in the order of it's colours ?

look...here's another !!

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Why's that then ?

Title: Two Rainbows....but the second one's colours are reversed....why ?
Post by: neilep on 21/11/2007 22:31:20

Come on !!....I know things are slow around here but doesn't anybody else at least wonder why ?

(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fbestsmileys.com%2Frainbow%2F1.gif&hash=fdc210b61427ef8a544c6eba4b18769c)
   
(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fbestsmileys.com%2Frainbow%2F2.gif&hash=e6bba18886e6d12bf8fc6e5a3cd61fd0)
   
(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fbestsmileys.com%2Frainbow%2F3.gif&hash=82ad588a55dd75b18db111beb4c85581)
   
(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fbestsmileys.com%2Frainbow%2F4.gif&hash=e7f62fb428ce71897a12c63328a790d2)

Title: Two Rainbows....but the second one's colours are reversed....why ?
Post by: techmind on 21/11/2007 23:19:35

I refer the Honourable Gentleman to the reply I offered eleven days ago concerning rainbow-like phenomena.

Here it is:
http://www.thenakedscientists.com/forum/index.php?topic=11300.msg138302#msg138302

Trot along to http://www.atoptics.co.uk/ which has loads of nice pictures and really good explantions of all-things atmospheric-optics.

Random bonus fact: the light in rainbows is polarized; you can increase the colour-saturation (or make it disappear completely) by looking through a polarizing filter... but the angle changes with the arc of the rainbow.

Title: Two Rainbows....but the second one's colours are reversed....why ?
Post by: Karen W. on 22/11/2007 02:39:19

I did... Those are beautiful Heres one for your collection! Seems it is the same!

(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fi17.photobucket.com%2Falbums%2Fb73%2Fkarenw44%2Falbum%2520two%2F1137668089_fd1ed43ac5.jpg&hash=50a5c2f1b3906073cdd70f5edc6f3239)

Title: Two Rainbows....but the second one's colours are reversed....why ?
Post by: paul.fr on 22/11/2007 08:23:07

I think i saw a nice drawing and explanation by Dave somewhere...can't seem to find it though.
The Simple answer is that the standard rainbow we all see is the primary rainbow and is produced by one internal reflection, we see the secondary (double) rainbow  because there are two internal reflections.

Andrews (techmind) link is quite good, if only it worked! anyway, here is a better explanation from the site Andrew mentioned.

http://www.atoptics.co.uk/rainbows/ord2form.htm

Title: Two Rainbows....but the second one's colours are reversed....why ?
Post by: Karen W. on 22/11/2007 13:04:20

It sounds like it acts like a mirror reversing its reflection in the secondary bow.So is that what the two drops of rain do is act like a mirror reflecting back the image in reverse?

Title: Two Rainbows....but the second one's colours are reversed....why ?
Post by: techmind on 22/11/2007 16:40:46

Quote from: paul.fr on 22/11/2007 08:23:07

Andrews (techmind) link is quite good, if only it worked!

Grrrrr... stupid forum (or cut'n'paste) gremlins. There was an invisible control-character at the end of the URL. The link should be fixed now.