If I use proper optical equipment, (filters, etc…) could I see rainbow bands in the infrared or ultraviolet range? It seems to make sense that I would, but I’ve never heard anything about it.
Anybody got the straight dope on this?
My WAG is YES, there are additional bands on either side not visible to normal eyesight.
It should work into those bands just fine until the wavelength gets far enough from the optical band that water becomes opaque to it.
You can probably do some searches on the transmission spectra of water to find exactly how wide a rainbow is (frequency wise).
Without being able to prove it in the form of pictures, I would say yes, of course, but remember that between the atmosphere and the water droplets causing the rainbow to begin with, you’d filter out a fairly sizeable portion of the UV and IR spectra, and I’m not sure exactly how this would affect the rainbow.
scotth has it exactly right - the entire portion of the spectrum which is refracted by water is represented in the rainbow. Obviously, much of the spectrum is either blocked (very infra-red) or unaffected (x-rays, gamma rays) by water.
The Sun does not put out nearly as much UV as blue (even purple is emitted much less than blue), and what there is is heavily absorbed by air, so there is not much UV in the rainbow. IR gets through pretty well, so there is most likely IR in the rainbow. A typical prism will transmit it, and, in fact, this is how IR was discovered by Herschel. He put a thermometer on the red end of a spectrum thrown by a prism, and noted the temperature rose. You can try this yourself, but you should cover the thermometer with black magic marker so it absorbs IR better. See here for more.
You can find discussion and a picture of near-infrared rainbows in the September 24, 1971 issue of Science (“Infrared Rainbow,” by Robert Greenler). If your job/school has a subscription to the appropriate service, you can see the article here.
Here’s a plot of the Absorption Spectra of Water. With a good enough eye, you could see a rainbow colors from ~150 to 1100 nanometers or more.
You can find discussion and a picture of near-infrared rainbows in the September 24, 1971 issue of Science (“Infrared Rainbow,” by Robert Greenler). If your job/school has a subscription to the appropriate service, you can see the article here.
When we used to have an ozone layer, the UV parts tweren’t quite as bright.
Or maybe a bad eye will do, too:
The book goes on to say what has been mentioned in this thread already, so I won’t repeat it.
Resurrecting a zombie thread here, but a few years after this thread was started, someone took the photographs the image below. It’s pretty compelling (and also freely available, unlike the 1971 photographs), and I figured I would add it to the thread for future reference.
Wow. Infrared and ultraviolet are the same color.Who knew?
This has already been covered (and it’s a zombie, to boot), but pictures of IR rainbows were taken as soon as IR film was available. Besides the straight IR and UV rainbows, there should be infrared and ultraviolet secondary rainbows, infrared and ultraviolet reflected rainbows, IR and UV supernumerary rainbows, etc. Not to mention IR and UV analogues of ice crystal phenomena, like Sundogs.
And, just to make things weird, there are analogs to rainbows (complete with supernumeraries) in electron scattering. These were first brought up circa 1976, and in the early 1990s there were a lot of papers on them.
Infrared light was first discovered when William Herschel tried to measure the temperature of different colours in a light spectrum made by sunlight through a prism. He found that the highest temperature was just off the spectrum on the red side.
Aside: In an astronomy class I taught once, we covered Herschel’s discovery of infrared via thermometer, and ultraviolet’s discovery via photographic film. On the test, one question was “Describe one way that non-visible light can be detected”, for which I expected either of those answers. But one student answered that ultraviolet could be detected by exposing skin to it and getting a tan.
Ritter discovered UV by looking at the opposite end of the spectrum, inspired by Herschel’s work at the Infrared end. At first I wondered why he didn’t simply place a thermometer bulb in the ultraviolet zone, as Herschel had. Then I realized that the UV light probably wouldn’t penetrate the glass of the thermometer bulb glass block UV, but not IR).
That might explain why Herschel didn’t report a discovery of ultraviolet light – he probably tried, but found nothing. Not only would his thermometer bulb block it, but so would his glass prism. Which implies that Ritter used a salt prism or something other that wasn’t glass. (I don’t know – I didn’t read his paper).
For the record, Ritter didn’t use “photographic film” – photography hadn’t been invented yet. He used paper that had been treated with a solution of a silver salt (probably silver chloride). These had been shown to be sensitive to visible light, and so it was probably assumed it would be sensitive to invisible light as well.
Does glass opacity start at the same wavelength as the eye’s opacity? I’d expect there to be at least some margin between the two.
Did you mark him correct?
Of course. It was a valid answer.