Talk:Infrared
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"If your computer monitor is warm, the following patch should be coloured infrared"
I like this joke a lot :-D. But technically, all objects above absolute zero radiate infrared, right?
I imagine if something gets cold enough its black body spectrum will have very little infrared in it, with the peak dropping down into the frequencies below infrared. There will still be infrared emission, but I'm not sure if the swatch could be termed to be colored infrared at that point. Maybe it would be colored microwave.
considering that no one can "see" infrared, it seems wierd to say that it is colored as such. if the combination of colors creates other colors, then the square can't be "colored" infrared because it would then be a combination. if you say that it just emits or reflects infrared, then the color is still meaningless, because any visible color could do that if it contains IR reflective qualities. and, black would both emit and absorb IR since it absorbs, and it gets hot.
Who wrote that about sunburn? are you sure? "Although relatively harmless, overexposure to IR can cause damage to cells and is the cause of sunburn (despite ultraviolet commonly being thought of as the culprit.)"
Scientific American seems to diagree: http://www.sciam.com/askexpert/medicine/medicine57/ --rmhermen
How does the infrared in remote controls work? How does our sensation of radiated heat work? Does our skin sense infra-red, or does it heat up because of it and we then sense the heat (are the two different?) -- Tarquin 16:47 7 Jun 2003 (UTC)
I put in a few sentences about remote controls. As for skin, it senses heat, not radiation directly. There is a difference. Direct radiation sensing, as happens in the eye, is a photochemical process caused by photons colliding with light-sensitive (and, if you're a cat, IR-sensitive) molecules. These molecules are highly selective about what wavelength of photon they respond to, which is why we can see in colour. Heat receptors in the skin are different. It seems that nobody knows how they work, but they just sense temperature in the bulk of the skin. This temperature is mediated by mechanical vibrations of atoms, not by radiation. The skin receptors don't know if the heat got there by IR radiation, or by conduction from a hot object. By the way, some snakes can see infra-red, too, but they do it in a different way from mammals with IR-sensitive eyes. Their IR sensors, called pits, are separate from their eyes. The pits detect IR by its heating effect on the skin inside the pit. They can work out which part of the pit is hottest, and therefore roughly where the hot object is. -- Heron
- thanks! The above is probably enough to make a start on Thermoception. -- Tarquin 19:45 7 Jun 2003 (UTC)
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Infrared as a color
Do you have any way to modify the human eye so that we can see infrared as a color?? This should be known by 2100.
- It should? omigosh I better get to work then! WTF?!--Deglr6328 16:31, 16 Aug 2004 (UTC)
- http://www.amasci.com/amateur/irgoggl.html Yes, and for $10.00. --Alexander
Fahrenheit and Celsius scales
The image only has a Fahrenheit scale. Does anybody know how to add a Celsius scale to it? Bobblewik (talk) 12:16, 10 Oct 2004 (UTC)
- Done. --Heron 09:37, 12 Nov 2004 (UTC)
what danger can infrared cause?
It's non-ionising, so the only danger is due to heating. In other words, if it's powerful enough, it will burn your skin. --Heron 09:08, 12 Nov 2004 (UTC)
This is only tue in a certain range of pulse lengths and intensities. There are several effects involved at higher intensities (like these found in lasers), like multiphoton processes, plasma generation and such. But in the low intensity case the heating effect is the dominant. --BoP 11:44, 2 Jan 2005 (UTC)
15 micron band saturation and the greenhouse gas effect
I am doing some research on the question of the carbon dioxide greenhouse effect. Specifically, some critics of Global Warming claim that the 15 micron band is "optically saturated" for CO2 in the atmosphere. Further increases in CO2 will not have the expected effect, they argue, since the band cannot absorb anymore. There just ain't more 15 micron IR left to absorb. We would appreciate any info you could provide on this question. Specifically, how does the IPCC model IR saturation in the 15 micron band for the climate change predictions?
IR vs Heat
The article and discussion here seems to reflect a common misconception about IR that I'd like to clear up. Basically, IR does not equal heat, "heat radiation", etc. Warm/hot objects radiate many wavelengths of electromagnetic radiation ("light"), INCLUDING infrared. Have you ever seen something extremely hot glow red? Or get hotter and glow orange, then yellow, then white? Same phenomenon.It glows IR first, you just can't see it. As for transmission of heat via IR, well yeah. Absorption of any wavelength of "light" warms things, INCLUDING infrared. Um, that's all. Thanks.
- EDIT*
After adding this comment, I went to clarify the article, and realized that this misconception /wasn't/ reflected in it after all. But in that case, what prompted me to post this and "fix" it? Twilight zone...