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People Emit Visible Light
An Anonymous Reader writes "The human body literally glows, emitting a visible light in extremely small quantities at levels that rise and fall with the day, scientists now reveal. Japanese researchers have shown that the body emits visible light, 1,000 times less intense than the levels to which our naked eyes are sensitive. In fact, virtually all living creatures emit very weak light, which is thought to be a byproduct of biochemical reactions involving free radicals."
This isn't any kind of new or unpredicted phenomenon. Everything that emits heat emits some light. The chances that the wavelength of a photon emitted by a human being (while giving off normal heat) will fall within the visible spectrum is very low, but given that we emit billions and billions of photons on a regular basis, it's sure to happen every now and then. Get sensitive enough cameras, and you'll see that glow from everything that isn't at absolute zero.
I thought this was discovered and establish in 2005 by Mitsuo Hiramatsu, a scientist at the Central Research Laboratory at Hamamatsu Photonics. The only new information I recognize is that it varies by time of day, not that people emit visible light. Did this new study find anything else out additionally or just make pretty pictures that show it?
My work here is dung.
So, I guess we really are all "Shiny Happy People!" I suppose next we should begin holding hands.
Master Yoda called this back in The Empire Strikes Back: "Luminous beings are we...not this crude matter!"
People are visible, but they aren't all that bright.
"I guess the moral of the story is, don't paint your airship with rocket fuel." -- Addison Bain
The terms are a bit confusing, but the term "visible" light has nothing to do with magnitude, it only refers to light with a particular wavelength, roughly 380 to 750 nm, which our retinas happen to be sensitive to. The term visible is not meant to differentiate visible light from invisible light, but rather to differentiate these waves from radio waves, infrared, ultraviolet, X rays, microwaves, and gamma rays. So yes, even if the light cannot be seen, if it is in that particular spectrum, it is visible light.
To the haters: You can't win. If you mod me down, I shall become more powerful than you could possibly imagine
Visible in this context doesn't mean perceptible, it's describing the wavelength, not the intensity. The light is very low intensity that has a wavelength within the visible spectrum.
"Our two-party system is like a bowl of shit looking at itself in a mirror." - Lewis Black
So, since this light is directly related to biological processes, that means in theory it should be tied to mood. For instance, clinical depression is tied to a general depression of all physiological processes. So, it would stand to reason that if you're down, you would emit less light. Someone who is euphoric should look (relatively) like a lightbulb in comparison. I know in the article it says that the amount and color of light varies, I wonder if this would lead towards a mood-ring style ability to read emotions. For instance, someone who is emitting a "pensive" light spectrum, along with other biological cues like sweat, and fidgiting may be a good suspect for scrutiny.
http://xkcd.com/566/
Not really a halo...
At least not to most people. Assuming that light sensitivity and light emission are independently normally distributed in the population, it's entirely possible that extremely sensitive individuals can see the light coming off the extremely bright individuals. Further, it is possible for genetically isolated populations to have gained extreme sensitivity or extreme brightness through the usual biological mechanisms, or if such traits were selected for through cultural or religious practices. Also, consider that relatively unstressed young Japanese men may not be fully activating whatever metabolism or physiology issues the light. There may be something to metabolism around "afterglow", women glowing when they're pregnant, unusual mental capacity, etc. which could easily generate 10 or 100 x the intensity observed in this study, and thus be observable by many people. (All sorts of biological processes span several orders of magnitude in concentration, intensity, energy, etc., and plenty of other bio-luminescent organisms show that the energy levels required to emit naked eye visible light are mostly not harmful to the organism.)
Whether we are consciously aware of the brightness of others, or if we do anything with that information are topics for future study.
There are 1.1... kinds of people.
Correct. Doing a quick back of the envelope calculation a human body will emit one photon with a wavelength of 600nm every 10 seconds. If we scale that up by a factor of 1,000 that would mean the human eye would need to be capable of seeing a flux of 100 photons/second per unit solid angle. This is well below the threshold of a human eye - you'd need a photomultiplier or low temp photon counter device to pick this up. So clearly this is not the source of light.
They aren't, as such. What we know as a "halo" is more of a Hanna-Barbera cartoon knock-off of something that appears in a lot of early Christian art as a nimbus - a sort of glowing aura around Jesus and sometimes an accompanying Lamb. According to this wikipedia page the concept was used earlier in a lot of other historical religious art too before becoming bastardized by pop culture's somewhat clumsy literal interpretation.
Close. A single photon is capable of making a single cell (rod) in your retina fire. To actually perceive light, you need around 9 or 10 rods to fire at around the same time. Problem here is that only around 10% of the photons entering your eye end up striking a receptor - the rest are reflected off of the cornea, get absorbed in the vitreous humor (fluid inside the eye), or pass through the retina without striking a spot where a receptor is located.
Usually "visible light" means "electromagnetic radiation with wavelength lying in (approximately) 380-750nm range". At least that's what they taught us in the university. Somehow, I find this definition much more logical than yours, no offense meant.
What does color have to do with this?
Well if you're black, this means you're probably going to be more popular at raves.