Naked Science Forum

Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: thedoc on 28/04/2013 00:28:52

Title: Discuss: Did I see 3 Rainbows?
Post by: thedoc on 28/04/2013 00:28:52
Does holding a car remote to your head make it work better? Why does a boat float? Are triple rainbows real? What's a near-death experience? This week we also look at a new scientific study into why - and when - breast milk transmits HIV to a baby...
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Title: Re: Discuss: Did I see 3 Rainbows?
Post by: syhprum on 28/04/2013 19:52:10
Triple rainbows do exist in theory but generally they are too dim to see without image enhancement
Title: Re: Discuss: Did I see 3 Rainbows?
Post by: David Cooper on 28/04/2013 19:56:35
The weather conditions in Aberdeen frequently produce triple rainbows which are very clear to the eye, though I don't think I've ever seen three full arcs - usually it's just the lower ends of one side of a rainbow against thudding black cloud. It came as a big surprise to me to hear that science was questioning their existence. I don't think I've never seen a quadruple one though.
Title: Re: Discuss: Did I see 3 Rainbows?
Post by: RD on 28/04/2013 20:09:46
Quote from: the Doc
Does holding a car remote to your head make it work better?

The radio remote at temple increasing range has been discussed before : you are a better antenna for the transmitter if you hold the the remote control near your head  ...

Quote
When a transmitter is connected to an antenna by a feed line, the impedance of the antenna and feed line must match exactly for maximum energy transfer from the feed line to the antenna to be possible. The impedance of the antenna varies based on many factors including: the antenna's natural resonance at the frequency being transmitted, the antenna's height above the ground
http://en.wikipedia.org/wiki/Standing_wave_ratio#Practical_implications_of_SWR