RAINBOW

[burrowsy]

rainbow normally occurs when rain drop suspended in clouds are passed by light ray of the sun which reflect 7 colors. the question here is that what phenomenon causes rainbow?

[Fuzzwood]

http://en.wikipedia.org/wiki/Prism_%28optics%29#How_prisms_work same idea basically.

[dimreepr]

rainbow normally occurs when rain drop suspended in clouds are passed by light ray of the sun which reflect 7 colors. the question here is that what phenomenon causes rainbow?

 

 

It’s caused by being in the right place at the right time i.e. having the sun at 42 degrees above and behind you.

 

 

[Ronald Hyde]

rainbow normally occurs when rain drop suspended in clouds are passed by light ray of the sun which reflect 7 colors. the question here is that what phenomenon causes rainbow?

 

There's an important difference between a prism and a rainbow, the prism represents forward scattering of the light, the rainbow back scattering.

The forward scattering equivalent of the rainbow is the 'glory', which displays very little dispersion of the colors. It's a very interesting subject,

well worth further study.

[imatfaal]

Here is Prof Walter Lewin's lecture on Rainbows. It is the closing lecture in his world famous videoed first year physics course.

 

http://video.google.com/videoplay?docid=-2978729867097229598

 

The videos and other stuff can be found at http://ocw.mit.edu/index.htm along with many other wonderful resources

[tomgwyther]

Off topic:

How does he draw those dotted lines so quickly? he does the first at about one minute in.

Edited September 12, 2012 by tomgwyther

[imatfaal]

Off topic:

How does he draw those dotted lines so quickly? he does the first at about one minute in.

 

You cannot help but be impressed can you? I think he uses slip/stick process (same as violin bow, making tune on top of wine glass etc); the chalk sticks, draws a bit of a line and he is able to judge the pressure he is exerting well enough that the dposition of chalk eases the friction enough to cause the chalk to slip/slide until it catches again and draws a bit of line, the chalk laid down causes it to slide ... He also emphasises/causes it by tapping as well. Well that's what i thought when I watched them a few years ago