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."

Comments

Biblical?

[DigiShaman]

Halos? Hmmmm

Re:Biblical?

[Tubal-Cain]

I'm not sure halos are even part of Christian canon.

Re:Biblical?

[Magic5Ball]

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.

Re:Biblical?

[Narcocide]

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.

Re:Biblical?

[gilleain]

it's entirely possible that extremely sensitive individuals can see the light coming off the extremely bright individuals.

If there are people who have vision that is 1,000 times normal, then they must get blinded by the sun really easily...

There may be something to metabolism ... which could easily generate 10 or 100 x the intensity observed in this study, and thus be observable by many people.

Conversely, the 'brights' (don't tell Dawkins about this!) would be producing lots more free-radicals than normal. I sure hope they also have more efficient repair mechanisms in place to mop them up.

Re:Biblical?

[JAZ]

"1,000 times less intense than the levels to which our naked eyes are sensitive"

yeah apparently Japanese scientists have a different definition of visible than I do. I always had that stupid "if I can see it then it is visible, if I can't see it then it isn't visible".

I bet it is just like with cellular mitosis: audibly noisy when my cells divide, just so quiet that I can't personally hear it.

Re:Biblical?

[davester666]

You are hereby denied permission to bask in my glow.

Re:Biblical?

[parlancex]

If there are people who have vision that is 1,000 times normal, then they must get blinded by the sun really easily...

Human sensitivity and our perception of light, as is the case with most senses is not a linear response with intensity, it is closer to logarithmic. That said, the parts of the human eye responsible for perception of very low levels of light (like at night) are very noisey and cannot distinguish between colors and I highly doubt that any person would ever be capable of actually seeing this glow even in a pitch black environment.

Re:Biblical?

[rumith]

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.

Re:Biblical?

[FireFlie]

yeah apparently Japanese scientists have a different definition of visible than I do. I always had that stupid "if I can see it then it is visible, if I can't see it then it isn't visible".

"Visible" meaning within the visible portion of the EM spectrum.

Re:Biblical?

[Tubal-Cain]

...are very noisey and cannot distinguish between colors and...

What does color have to do with this?

Re:Biblical?

[Anonymous Coward]

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.

Re:Biblical?

[Glyphn]

Assuming that light sensitivity and light emission are independently normally distributed in the population, it's entirely possible that ...

Ah yes, the ole' assume the spherical cow ...

Re:Biblical?

[OctaviusIII]

Halos aren't biblical, as was explained earlier. You could've cited, though, Jesus' transfiguration and Moses' glowing face. Not halos per se, but still biblical glowing people.

Re:Biblical?

[bill_kress]

Not that I really feel the ability to see auras would prove God or psychics or anything, but your conclusion is making an assumption that has no basis.

Just because we can see a dim light, does not mean that a bright one would blind us. It tends to be true due to the way our iris works, but even in bright indirect sunlight we can see dim directed lights, and there is no saying that the iris would filter out all of a dim directed light.

90% of our filtering goes on in our brains anyway. We filter away information we don't think we need--the way you may choose to lighten an image but lose some detail--the detail is still in the image, we've just chosen to view it in a way that doesn't allow us to see it.

So it's possible that your brain could see things that others don't in the same way that a blind man can hear sounds you can't (or more accurately "won't" hear because your brain considers them background and turns them off)

Re:Biblical?

[Chris Burke]

Also a lot of people don't know this but the Super Devil doesn't appear anywhere in the Bible.

Re:Biblical?

[maroberts]

The only thing round my Lamb is Mint Sauce (open sauce of course)

Re:Biblical?

[Anonymous Coward]

If there are people who have vision that is 1,000 times normal, then they must get blinded by the sun really easily...

Poor dogs! I hear that their sense of smell is something like 5000 times more sensitive than ours. They must not be able to smell anything when there is a strong aroma!

Or thing of the cats who can see "in the dark". Well it's not really the dark it's just thousands of time less bright than daylight. Which means that in the daytime they must get blinded!

Should I continue? :)

Re:Biblical?

[JAZ]

lol, no offense taken, I'll be sure to use the sarcasm tags in the future.

Re:Biblical?

[brentonboy]

I'm not sure halos are even part of Christian canon.

Halos are more of an art thing, used to represent a saint. A halo with a cross in it represents Christ. And they always look like yellow or gold circles behind the persons head, not rings above the head. The only thing even remotely close to a halo that I can think of in the Bible is when Moses glows after coming down from mount Siani, and the Transfiguration where Christ glows.

Re:Biblical?

[prockcore]

What's logical about it? It's just reversely defined from the GP's definition (the beginning and ending of that range are determined by the GP's definition).

Re:Biblical?

[Dragonslicer]

Also a lot of people don't know this but the Super Devil doesn't appear anywhere in the Bible.

Satan does, though. The Hebrew word satan more or less translates to "accuser" or "adversary", though I don't think it's used in modern Hebrew (my dictionary translates "accuse" to he'eshim). The most well-known appearance would probably be the book of Job.

Re:Biblical?

[really_irish_man]

Halos are more of an art thing, used to represent a saint...

Not quite. Most of the time the glow around their heads in Christian art has traditionally represented the Holy Spirit. Similarly Catholic Popes as well as Catholic and Episcopalian Bishops where pointy hats to symbolize the anointing of the Holy Spirit as described in the book of Acts.

Re:Biblical?

[BikeHelmet]

You don't even have to assume some people are more sensitive to light, and can "see" it.

There was a study a while ago about conscious and subconscious sight. Apparently certain kinds of blindness leave subconscious vision semi in-tact, so although the person couldn't see, he could snap his eyes shut if a bug was about to hit them.

"Halos" might not even be literal halos, so much as a feeling you get when looking at someone.

Your subconscious doesn't have a lot of ways to communicate. It's limited to feelings and reactions, mostly? I think this could all be processed subconsciously, so that our conscious mind would never know.

Re:Biblical?

[DigiShaman]

I could have, but didn't ;)

Usually when a new topic comes up on Slashdot and I'm one of a few people to start posting, I often decide to state an observation or ask a question. If you will, I'm throwing "chum in the water". I find it makes the discussion more interesting than for me to provide my own in-depth analysis and/or opinion.

Re:Biblical?

[Magic5Ball]

While most cows aren't spherical in real life, within a species the height of cows, their mass, horn length, volume of milk production, girth, colour, etc. all vary within known ranges, with most members of the population being distributed about the middle. It's also possible that the luminescence phenomena is mostly quantized--cows have a whole number of legs and not 3.6 +/- 0.4 legs, nor 1.1 +/- 0.1 brains--but the fact that luminescence appears to vary within each day (at least within their sample) in individuals of a species with a lifespan of 10e5 days suggests that it's not a binary or quantized trait.

So, this isn't assuming a spherical cow as much as assuming (until we have better evidence) for this discussion that this instance of a previously unobserved kind of animal (new physiological trait or process) fits into the same pattern in which the vast majority of all other known traits also fit. Scientists have been wrong in the past on this kind of confirmation bias assumption (see ring species, for example) but we always have to start with what we know and can show from available evidence.

If you have evidence that we need a new sub-field of biochemistry or physiology or genetics to deal with dimly glowing human faces which offers a more robust model of the intensity of glowing faces and/or ocular light sensitivity than we have in this discussion (for which we have really big piles of circumstantial evidence from many different circumstances and models which seem to have worked for the last few decades at least) please present it so that we may discuss your new model instead. Otherwise, your attempted counterpoint amounts to a claim without evidence that much of what we know about evolutionary biology is wrong (possible, but you didn't specify why you think that).

Re:Biblical?

[DragonWriter]

And they always look like yellow or gold circles behind the persons head, not rings above the head.

For particularly loose definitions of "always"; consider the Benois Madonna, and the derivative Madonna of the Pinks, both of which use semi-transparent disks above the head.

Re:Biblical?

[Magic5Ball]

That's great. If you're right and halos are completely explained by historical pragmatic industrial design, glowing faces doesn't tell us much that's new. However, if there could be a physiological basis for some of the spiritual things for which we don't yet have a fully satisfying explanation--potentially individuals like shamans, diviners, etc.--we'll have gained some important insights into the human religions which have shaped so much of our world. We might also learn more about how we sense and perceive other people, which would be useful for such things as clinical and behavioral psychology, the treatment of mental illness, and the performance arts industries.

While your old tech explanation is cool, I'd get more new tech toys out of understanding if and why human faces glow (and also, what else glows?).

Re:Biblical?

[c_forq]

I think this is one of those economist vs engineer vs mathematician things. If what you were studying had lumens as an important factor I'm sure your definition would closer to "electromagnetic radiation with a wavelength lying in (approximately) 380-750nm range with a lumen output of (approximately) 1/10-50,000 lumens".

Re:Biblical?

[treeves]

Which, interestingly, is the oldest book in the Bible - not Genesis.

Re:Biblical?

[4D6963]

lol, even if there were such people, they would only see something different in the very darkest conditions, after getting their eyes used to the dark. And even then, at that point they'd probably see individual dots for each photons they receive.

Re:Biblical?

[FatdogHaiku]

Conversely, the 'brights' (don't tell Dawkins about this!) would be producing lots more free-radicals than normal. I sure hope they also have more efficient repair mechanisms in place to mop them up.

If this was common I'm sure we would soon have some sort of discrimination against "brights" for mucking up the gene pool... a great time to take up the old Three Mile Island chant

Hell No, We don't GLOW!

Re:Biblical?

[complete loony]

There are a few bible reverences to men being dressed in white, but that's about it.

... they saw a young man dressed in a white robe sitting on the right side ...
... when suddenly two men dressed in white stood beside them ...

Re:Biblical?

[Tubal-Cain]

There's the events noted by brentonboy.

Re:Biblical?

[reboot246]

No, what I'm saying is that the proposition, "People Emit Visible Light", is a crock. I take words seriously. When they say "visible", I take it to mean "VISIBLE". If they meant to say, "people emit light in the visible part of the spectrum", then they should have said exactly that. Words have meanings.

Re:Biblical?

[afaik_ianal]

And his hat was gnarly.

Re:Biblical?

[fractoid]

If I had mod points you would get them. Visible light is... well... visible. It is, by definition, light detectable by human eyes. What they mean is "humans emit very small quantities of light in the visible spectrum".

Re:Biblical?

[pbhj]

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.

There are no certain dates for haloes given in the Wikipedia article prior to the 1st Century AD. Only a sun disk is shown, which is clearly different to a halo in appearance and purpose.

Your comment appears to say that haloes were widely used in pre-Christian religious depictions. That is not established in your quoted source. Indeed after several hours I can't find a single image of haloes that is BCE.

Re:Biblical?

[NewbieProgrammerMan]

No. Halos are a feature of some people's imagination, not a emission of visible light.

Fixed that for you.

Re:Biblical?

[fractoid]

yeah apparently Japanese scientists have a different definition of visible than I do. I always had that stupid "if I can see it then it is visible, if I can't see it then it isn't visible".

God, I hate you sceptics. You claim that just because it's not possible to see something, it's not visible?

<.<
>.>
O.o

Re:Biblical?

[fractoid]

Actually it means he leaves it up to his guests to stick the mint and stuff in the blender, and if they complain about it he'll say "you want coriander? add the damn feature yourself, slacker!"

Re:Biblical?

[rohan972]

I'm not sure halos are even part of Christian canon.

Exodus 34:29 It happened, when Moses came down from Mount Sinai with the two tablets of the testimony in Moses' hand, when he came down from the mountain, that Moses didn't know that the skin of his face shone by reason of his speaking with him.

Ecclesiastes 8:1 Who is like the wise man? And who knows the interpretation of a thing? A man's wisdom makes his face shine, and the hardness of his face is changed.

Daniel 12:3 Those who are wise shall shine as the brightness of the expanse; and those who turn many to righteousness as the stars forever and ever.

Matthew 13:43 Then the righteous will shine forth like the sun in the Kingdom of their Father. He who has ears to hear, let him hear.

Matthew 17:2 He was transfigured before them. His face shone like the sun, and his garments became as white as the light.

Acts 6:15. All who sat in the council, fastening their eyes on him, saw his face like it was the face of an angel.

Perhaps not exactly halos, but the concept of righteous people shining visible light is certainly there.

Re:Biblical?

[muridae]

To back you up, let's run some numbers.

Magnitude 0 star, Vega, has a visible flux density of around 2*10^6 photons / second cm^2 in certain visible ranges. Google turned that up, so did an old BadAstronomy forum post; here.
Magnitude 6 stars are visible, flux difference between a 0 and 6 star is defined as 1/(2.512^6). Working downward, of course; as a 0 is 2.512^6 more bright that a 6.
So, a human looking up at a magnitude 6 star is seeing a flux density of (2*10^6)/(2.512^6) or around 7,960 photons / second cm^2.

I know, not good astronomy to say the star is putting all that out, the magnitude 6 object might be reflecting, emiting, what ever. Point is, 3*10^3 is only slightly dimmer than an object that the human eye can already detect, and in fact a magnitude 7 object would be the source of (2*10^6)/(2.512^7) or just 3,168.78337 photons /second cm^2. Just barely brighter than the light they say they have detected from a human.

Granted, the article says a 'red glow' which could just be the writer looking at the picture, which is using color to represent density and not color. All they mention about the spectrum of the light is that it is not infrared. Could be visible spectrum, could not be. Either way, it looks to be bright enough to detect should it be in visible spectrum. It would be the very bottom of the visible range, and possibly discarded by the brain as noise in normal photon saturation we call daylight. The brain does filter a lot of noise, but I am not going to count it out just yet.

Re:Biblical?

[rumith]

especially when referring to a qualitative attribute such as visibility; what's visible to one person may not be visible to another

Right. That's why the definition of "visible light" should rely more on some species-wide feature than on some feature that varies wildly from one person to another.

It would be accurate to say people emit some light within the wavelength range that is normally visible. It would be inaccurate to say people emit visible light.

This statement is exactly what I wanted to hear when I posted my first reply. :-)

Re:Biblical?

[clarkcox3]

Visible light, just means light within the visible spectrum. Even if everyone closes their eyes, and nobody actually sees it, visible light is still visible light (as distinct form Infra-red, Xrays, radio, etc.)

Re:Biblical?

[thrawn_aj]

if there could be a physiological basis for some of the spiritual things for which we don't yet have a fully satisfying explanation

Spiritual things ARE precisely those things for which we don't have a fully satisfying explanation :). The unknown breeds dragons in map margins*. Spirituality is the tracer dye that pinpoints PhD theses of future students ;). I could keep going but I sense (my 7th sense actually) that you already know all this ;).

_________
*Lois McMaster Bujold

Re:Biblical?

[thrawn_aj]

especially when referring to a qualitative attribute such as visibility; what's visible to one person may not be visible to another

Right. That's why the definition of "visible light" should rely more on some species-wide feature than on some feature that varies wildly from one person to another.

It would be accurate to say people emit some light within the wavelength range that is normally visible. It would be inaccurate to say people emit visible light.

This statement is exactly what I wanted to hear when I posted my first reply. :-)

No, that's why scientists should stop listening to the idiots who suggest making technical terms sound less jargonistic [sic]. Technical terms should be just that - TECHNICAL, with a precise meaning unrelated (or at least independent of any colloquial meaning). A physicist knows what the terms "visible light" or "auditory range (for sound)" mean (at this time, they are convenient placeholders for numerical ranges) and also know that the precise ranges are historical accidents. There is no particular significance to the boundaries between frequency ranges (in fact, there are no hard boundaries at all) - the crude divisions are based simply on the kind of interactions those frequencies have with matter.

IMO, we should have just made up new words for scientific terms instead of reusing old ones just because they seemed to fit loosely - they come with a LOT of baggage and cause great confusion among non-scientists. Radiation, microwaves, theory, energy, force, ... need I go on? The best butchery of scientific terminology can be found in the immortal words of Obi Wan Kenobi:

The Force is what gives a Jedi his power. It's an energy field created by all living things.

I used this example to teach my students the importance of units :)

Re:Biblical?

[cripkd]

Obama emits black light.

Re:Biblical?

[cripkd]

haha, exactly. And if I HAD mod points, I would mod you up too :)

Re:Biblical?

[codeButcher]

Never read anything about haloes in the Bible. And I'm a big fan of that literature.

Re:Biblical?

[shadanan]

The retina of the eye contains two types of light sensitive cells: cones and rods. The cones are responsible for the eye's ability to distinguish colour and function well in good lighting conditions. The cones are further broken down into three types of cones, each sensitive to one of the three primary colours. The rods are responsible for providing vision when the ambient lighting is low. There is only one type of rod. As a result, when observing in very low light conditions, the eye can only see in black and white.

The rods are located near the outer edges of the retina. This is why very distant stars that are barely visible appear brighter if you use your peripheral vision to view them by looking off to the side.

Re:Biblical?

[CmdrGravy]

Smell works in an entirely different way to vision and is not at all comparable whilst the way cats see is different to the way humans do and works by amplifying what light there is in low light conditions to more normal levels so they can see in it.

Re:Biblical?

[smoker2]

Your comment appears to say that haloes were widely used in pre-Christian religious depictions. That is not established in your quoted source. Indeed after several hours I can't find a single image of haloes that is BCE.

Christians stole almost every aspect of their religion from other established religions and folk tales. The halo was depicted in BCE images, there already was an existing trifecta of god(s), people were said to have been raised from the dead, turned water into wine, last suppers - the list goes on. Just because you looked in the wrong place doesn't mean they don't exist. Try this for an image of a BCE halo. You may say it's a sun disk, it looks like a halo to me. I've seen several images of christ with similar "haloes" If you dig deep enough, you'll probably find that the sun disk is a necessary part of being a god in many many religions. But you define halo in the way that suits your argument. And you suck at reading too, if you didn't even follow the link in the "quoted source" you complain about.
(hint: Helios, Apollo, Neptune, Vishnu, Krishna, Shiva, Aditya, Shakyamuni Buddha, The Heavenly Emperors, The Great Emperors of the Three Offices)

Re:Biblical?

[Kratisto]

If light in the visible part of the spectrum is emitted by a falling tree in the forest undergoing biochemical free radical reactions, but no one is around to see it, does it emit visible light?

Re:Biblical?

[Lumpy]

How about the fact that most freshly pregnant women "glow"

They really need to take their equipment and check that. I'm wondering if it's a scientific fact and they really are glowing at a near visible rate compared to others and we notice this as our eyes really do see more than they think we do, we just dont process it.

Re:Biblical?

[Lumpy]

I know 3 guys that I spent time with at a research project at Michigan State that taught themselves to process information differently. They were able to pinpoint sound locations far better than others due to training. Same as how I learned lucid dreaming.

If the information is coming in from your sensors, you CAN teach yourself to process that information.

The problem is it really easy to get stuck trying to process patterns in a noise floor.

Re:Biblical?

[Lumpy]

Cat's irises contract 1000 times more than ours does. as well as open up more than ours does.

So unless you found a freak person with cat eyes, I'd say you are way off.

Also a dog,s nose is tuned differently and designed very different than ours, please do some research on the subject.

Re:Biblical?

[phatslaab]

Well-spoken. The word Satan is a title or description, not a name originally given to the angel now known as Satan. We may never know his original name. Perhaps it is because biblical names have special meaning and the angel now known as Satan does not live up to his former name. Reminds me though of people who use the word "God" as if it is a name. Most people either don't know or don't care what God's real name is.

Re:Biblical?

[phatslaab]

Sorry, Job is actually the 4th, 5th, or 6th oldest book. Genesis, Exodus, & Leviticus were all written prior but Numbers, Deuteronomy, & Job were all completed in the same year - circa 1473 BCE.

Re:Biblical?

[Thiez]

> 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

In the same way that it is possible for genetically isolated populations to have gained extreme (1000x normal human) strength, extreme (1000x normal human) hearing, or extreme (1000x normal human) speed? I think you suffer from extreme (1000x normal human) unfounded belief in genetic diversity.

Ok my trolling aside, super-nightvision would be a great advantage and very likely to spread. Cats (according to wikipedia...) apparantly have a minimum light detection threshhold seven times lower than that of humans, that is, to observe the light we emit you'd have to have a threshold over 140 times lower than that of a cat. Cats and many other animals have special adaptations in their eyes to improve nightvision. For a few mutations in a small isolated human population to so completely and utterly *OWN* many animals nightvision by 2 orders of magnitude would be pretty damn unlikely. With that in mind I think I can safely conclude that you are almost certainly wrong to suggest some humans might be able to see the light from the article.

Re:Biblical?

[skarphace]

The rods are located near the outer edges of the retina. This is why very distant stars that are barely visible appear brighter if you use your peripheral vision to view them by looking off to the side.

Neat. I always thought that was because I stared at the sun too much as a child.

Re:Biblical?

[Chris Burke]

Words have meanings.

Indeed they do, and I direct your eyeballs to definition 1b.

Or, heck, this.

Re:Biblical?

[Deanalator]

optics::"visible light", not
english::"visible" english::"light"

Re:Biblical?

[pbhj]

Your comment appears to say that haloes were widely used in pre-Christian religious depictions. That is not established in your quoted source. [...]

Just because you looked in the wrong place doesn't mean they don't exist.

I looked at the source you mentioned first, it didn't support your statement, I asked for expansion. Nor did I say they didn't exist, nor even that I'd looked in the right places. I've been trawling around lots of sites looking for pre-Christian images of haloes as everyone says they were widely used by everybody in depictions all over before CE. Yours is the first hint of actually imagery.

The pictures from Taq-e Bostan (eg http://en.wikipedia.org/wiki/Taq-e_Bostan, http://en.wikipedia.org/wiki/Mithra, http://static.newworldencyclopedia.org/1/10/ArdashirII_.jpg) are either Ardashir I or II. I again can't find a better image but if you notice each of the old-king, new-king and priest wear crowns/helms with what appears to be a fabric band (ribbon) extending down, on the right 2 images this comes down in drapes from the central crown on the left images it appears to hang from the ray-like crown (reminiscent of Aztec headdresses, http://images.travelpod.com/users/mebiner/2.1230803220.elaborate-aztec-headdress.jpg). In the other images Ardashir's crown appears to have an ostrich feather or similar. It seems a leap to suppose that only one of the crowns depicted is an artistic device.

The fabric pieces can be seen best in images like http://flickr.com/photos/37514330@N00/3202629664 [or http://static.panoramio.com/photos/original/16084455.jpg%5D which unfortunately doesn't include the priest (Izad Mithra, or in the Taq-e Bostan page it's said to be Izad Bahram; Izad being the Zoroastrian form of Yazata which means "worshipful" and some render as "god").

It's the best I've seen however, a good find, dating from 300BCE around Persia. I'd want to see other instances of "haloes" in the Persian culture of the time to be convinced on this, as like I said I think it's just a picture of a headpiece.

And you suck at reading too, if you didn't even follow the link [http://home.comcast.net/~taoistresource/art_halo.html] in the "quoted source" you complain about.

You did say "according to this page" and not "according to links on this page". Obviously being an illiterate makes it hard for me to check your post to be sure, perhaps you could do that?

Buddhist art and writings don't appear to exist from before about 100-200AD the canon of Buddhist lore being passed down orally since 400BCE. Whilst that link shows images it doesn't date the images, so establishing a date from them is impossible. They appear mainly to be Thangka which date from a Nepalese influence in 600AD.

The greek image of apollo is one I know, it's about 200AD IIRC (certainly post-Christian). The others look like standard depictions of Helios, being the sun after all, they're more than likely CE. The naive image at the bottom is similar in showing gods of the Sun, Dawn and Morning Star, that they should be shining is not necessarily a depiction of deity/holiness but a simple reflection of their purpose - but they'd be relevant if dated early.

Hindu art is full of haloes, eg http://www.hindu.com/fline/fl2503/stories/20080215250306500.htm the end of that page shows a Jaina shrine from 900AD. "Hindu art" by T. Richard Blurton states that imagery of Vishnu appeared in the "early centuries AD

Re:Biblical?

[lannocc]

The word Satan is a title or description, not a name originally given to the angel now known as Satan. We may never know his original name.

Lucifer?

Re:Biblical?

[maop]

I say visible light is a definition based on the frequency of the light. Intensity of the light doesn't factor in. Taking words literally, using the simplest definition, obscures the meaning.

Re:Biblical?

[nivek1385]

So do phrases

Re:Biblical?

[barncha]

The rods are located near the outer edges of the retina. This is why very distant stars that are barely visible appear brighter if you use your peripheral vision to view them by looking off to the side.

Neat. I always thought that was because I was weird. Oh wait...

Re:Biblical?

[badkarmadayaccount]

Lucifer is/was a god of light and darkness, IIRC. Mod parent up, BTW.

Re:Biblical?

[badkarmadayaccount]

I've always wanted something like cat eyes, preferably with dragon coloration - emerald green and ruby red. I'll have all the chicks into Twilight at my feet... :P

Re:Biblical?

[Rosy At Random]

Todd?

Re:Biblical?

[Dunavant]

Wow, mod this up if nothing else for the research.

Re:Biblical?

[Magic5Ball]

I'm still having an internal debate about whether the spiritual journey is more complete beginning with nothing to let go, or beginning with everything to let go.

Whatever the answer to that is, I'm in favour of any research or basis for dialogue that could engage individuals to take on more complete views of their lives, whether that's through organized or personal religion or more careful observation and action in other domains of practice. Some of my Eastern religious explorations point to an expansion of physics which could alleviate much unwarranted suffering (and thereby also to some new intellectual and other tools/toys). I'll give up the mystery of dragons at the edge of our physical world to have a chance to seek the dragons of our humane world.

Re:Biblical?

[Magic5Ball]

This doesn't need 1000x in variation, just the 10x which is fairly common, but on all sides.

With hearing, we know that humans can be trained to use echolocation without external instrumentation. With sight, we've spent more Homo spp.-hours successfully hunting in pitch black than not. With smell and taste, there are countless food and wine experts who seem to be able to do basic analytical chemistry without kit. So sensitivity is trainable within the hardware limits.

It's unclear if the article refers to 1000x less than average light sensitivity (random human) or maximum recorded conscious light sensitivity (exceptional human), or the maximum theoretical sensitivity based on the hardware. Since it's a fairly mainstream science article, average is as good a guess as any.

Just for kicks, let's say that a trained human could be usefully "10x more sensitive" to light than the average. Further, let's assume that being 3 s.d. out in one direction yields 10x more natural sensitivity (this is not unusual, given the not tiny number of super tasters, etc. who work professionally, and the logarithmic responses of the sense hardware). Let's also toss some inhibition-lowering herbs in there for some uber-sensitive good times. On the other side, let's assume that the scientists detected light at the basal rate, and not at some stressed rate. We know that stressed or determined humans can manifest unusually high strength, loud vocalizations, concentrated emissions of various gases, etc. which span more than four orders of magnitude (e.g. speaking at 30 db versus yelling at 110 db). We know that the ability to generate these signals at various intensities is subject to the usual genetic variation, and also that physical illness and mental state may enhance the generation of (sometimes warm, sometimes smelly) signals. Light emissions may, or may not follow that pattern, but in the absence of information to the contrary, I'll assume we don't need to create a new biology for this case.

If you leave out genetic variations on both sides, training, drugs, and dynamic range of human signals at 10x each easily produce an overlap of the two points of interest which are nominally at 1000x apart.

If you're a religious trainee but have sharpened your senses through meditation for years and are slightly medicated from incense in a room with no light, a random confused stressed out person with a common illness might not seem so dark.

muridae's information from astronomy a few posts up suggests that all these things don't even need to line up to achieve sensitivity.

I'm not saying that any of this is actually the case, but that it's plausible from what we know and that supporting or refuting data would be fairly easily accessible through experimentation.

Re:Biblical?

[pbhj]

Thanks for the comment - I think it's now more thorough then the wikipedia article but I enjoyed researching it. Hoping they have some more images for me to look at ...

nothing special...

[Draque]

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.

Re:nothing special...

[Anonymous Coward]

Er. Your argument is that because something emits enough photons, then some are bound to be inside the visible spectrum?

That is not how light works. If you want a different wavelength, you need photons with different energy, and you need a different process.

Re:nothing special...

[dgatwood]

Just to be pedantic, you'd have to move it into a colder room or it won't be distinguishable from the background emissions of everything else. The only things that could possibly be distinguishable would be things that produce their own heat, whether electrically or chemically.

Re:nothing special...

[Bemopolis]

No. His argument, correct but incompletely stated, is that any macroscopic object with a temperature emits a blackbody(-ish) spectrum which, since it spans the entire range of EM radiation, emits some light in the visible portion of the spectrum.

Re:nothing special...

[Draque]

You're right that they need different energies. If you graph the energies of photons emitted due to heat radiation, they'll form your typical bell curve, with the peak of the bell curve representing and energy level corresponding with infra-red radiation. That having been said... a few standard deviations from the center, you'll see the (very rare) photons emitted that have energy levels corrosponding with visible light. This happens when enough energy concentrates (by random, highly unlikely chance) to create a photon with much higher energy than is typical for a radiating body. It's very, very unlikely for ay given photon, but photons are created very, very often, so it happens frequently, though not enough to create intense enough light to see.

Re:nothing special...

[ckthorp]

Photons only come in quantum energy levels when they are generated from a quantum process. Conversely, blackbody radiation is a probability distribution of energy levels.

Re:nothing special...

[Eukariote]

This isn't any kind of new or unpredicted phenomenon.

It is definitely unpredicted by conventional theory. The visible part of the black-body radiation spectrum (which you seem to be referring to) for an object at human-body temperature is far less than 1/1000th of what is still visible. These emissions are therefore not thermal. And the is no other conventional theory that mandates such emissions.

Re:nothing special...

[Quaoar]

These results are specifically about the deviation of the spectrum produced by a human from a black body, and how that varies throughout the day. For a blackbody, the number of photons coming out as visible radiation is 1/10^3000 the total number (assuming a body temperature of ~280K, the number is so tiny because visible photons fall into the exponential Wein tail of the BB distribution), so you would naÃvely predict that no human has ever emitted a visible photon. Ever. So yes, it is something special.

Re:nothing special...

[geekgirlandrea]

See Planck's law. The power density at a given wavelength is inversely proportional to an exponential function of the photon energy, for wavelengths short compared to the peak. For humans (37 celsius), the peak lies at about 9.3 microns. If this were thermal radiation from a blackbody spectrum, the exponent for the longest visible wavelengths would be about 66.3, corresponding to about 1.9 * 10^-20 W/m^2 of radiated power in the visible spectrum, assuming perfect emissivity. If a typical human has a surface area of 2 m^2, that's around one thermal photon every ten seconds in the visible spectrum. This is many more than 1,000 times too dim to see. The photons referred to in the article come from chemical reactions, not thermal radiation.

Re:nothing special...

[fmita]

Yes, but you're talking about a blackbody spectrum, whereas the article is implying that this is something else (photons released by chemical reactions, not by the thermal jiggle of charge). See http://en.wikipedia.org/wiki/Biophotons

Re:nothing special...

[smellsofbikes]

Read about Planck's Law. It predicts the distribution of photons by frequency dependent on temperature. The scale is from wavelength = 0 to wavelength = inf, but the distribution is an asymmetric peak that goes to shorter wavelengths as the temperature increases. The extremely large majority of photons emitted by an object at 293K will be in the infrared, but a few will be visible, ultraviolet, and x-ray.

Re:nothing special...

[hattig]

Yes, for more energy you should eat Ready Brek every morning, because it will wrap you in a warm visible glow. Clearly we now have direct proof of Ready Brek's effectiveness in providing more energy to the body, and hence the photons that the body emits.

*hopes that Americans have Ready Brek and used to get the same TV adverts*

Re:nothing special...

[AndersOSU]

not a bell curve

But it is a distribution, and the human body does radiate some visible photons. This phenomenon, however, is theorized not thermal radiation, but as something else.

Re:nothing special...

[lawpoop]

they'll form your typical bell curve, with the peak of the bell curve representing and energy level corresponding with infra-red radiation... This happens when enough energy concentrates (by random, highly unlikely chance) to create a photon with much higher energy than is typical for a radiating body.

So what process creates the other half of the bell-curve, the photons at a lower energy than infra-red radiation?

Re:nothing special...

[BSAtHome]

X-rays, hmm, so being in crowded places does increase the exposure to harmful radiation. I always knew that one should avoid crowds and now it is confirmed. That also means that, given enough people, one can demonstrate an attack using photonic means.

[tinfoilhat_hat]Makes me wonder when an overzealous politician picks it up and limits demonstrations to few people to lower exposure to radiation.[/tinfoilhat_hat]

Re:nothing special...

[momerath2003]

The chance of emission at higher energies decreases exponentially. You're getting far, far, far more exposure to ionizing radiation from the naturally radioactive potassium in others' bodies than by their black-body emission.

Re:nothing special...

[Tubal-Cain]

So what process creates the other half of the bell-curve, the photons at a lower energy than infra-red radiation?

/me checks electromagnetic spectrum

Looks like extremely low-energy photons are radio.

Assuming it actually is a bell curve.

Re:nothing special...

[floppycat]

Well, people do emit some visibe light because of their temperature, but this does now explain why face is way brighter or why the brightness varies with time. Of course, the temperature is not constant, but I believe the differences are too small to account this.

Re:nothing special...

[arthurpaliden]

I have know this for years, after all my parents always called me Sun....

Re:nothing special...

[BobGod8]

Caveat: while not persistent, the human eye can detect a very low photon count, down in the 10 photon range, so technically emitting 1 photon would only be 1/10 as dimmer than visible. Wouldn't persist, however, but the eye and brain are great at averaging.

Other than that props on the math.

Re:nothing special...

[Gilmoure]

Do photons have mass?

Can I market a quack diet scheme to people by convincing them that if they just get 'brighter' they'll lose weight?

Re:nothing special...

[geekgirlandrea]

1.) The human eye can detect a low count of *absorbed* photons; the number of photons that will enter the eye from any given vantage point is much lower than the total number of visible thermal photons a human body might *emit*. 2.) That 10 photon figure is meaningless without a time frame.

Re:nothing special...

[idontgno]

Tell 'em they'll get lighter.

Leveraging homographs for fun and PROFIT!!!

Re:nothing special...

[jonaskoelker]

See Planck's law

Or look on the backside of your t-shirt: http://store.xkcd.com/xkcd/#Science ;-)

Re:nothing special...

[Dogtanian]

Yes, for more energy you should eat Ready Brek every morning, because it will wrap you in a warm visible glow.

Yeah, Ready Brek. WTF were they putting in that stuff?

*hopes that Americans have Ready Brek and used to get the same TV adverts*

Probably not, so here are a few videos of this exciting not-so-new source of energy:-

Very Retro #1, Pretty Retro Ad #2, Not so retro but still obviously around 20 years old #3.

Re:nothing special...

[gardyloo]

Depends on how they get brighter. If it's because of being doused with gasoline and set aflame, they'll probably lose some weight.

Photons have mass in the sense that they respond to gravity. They also have mass in the sense that they can impart momentum to objects. They also have mass in the E = mc^2 sense. On the other hand, as carriers of the electromagnetic field, which has infinite range, they don't possess mass!

Re:nothing special...

[Gilmoure]

I wonder if people give off neutrons as well? Could you pack enough people around a lump of u-235 to cook it off? Or would it make more sense to be like a breeder reactor and start with u-238?

Re:nothing special...

[Shakrai]

is that any macroscopic object with a temperature emits a blackbody(-ish) spectrum which, since it spans the entire range of EM radiation, emits some light in the visible portion of the spectrum.

So the human body gives off the occasional gamma-ray?

Re:nothing special...

[Fluffeh]

Can I market a quack diet scheme to people by convincing them that if they just get 'brighter' they'll lose weight?

Of course you can! Don't let poor science get in the way of selling some new fab diet. Clearly that's NEVER been an issue in the past with the dieting industry.

Re:nothing special...

[dimeglio]

Since nothing with mass can travel at the speed of light, it unlikely to have measurable mass. However, since E=MC^2 if a photos has enough energy, it can gain weight.

Re:nothing special...

[dimeglio]

Mark me redundant.

Re:nothing special...

[Gilmoure]

Ooh, I don't think I want my future customers to think about gaining weight. I better tell them to stay as still as possible, as opposed to all the running around and stuff.

Re:nothing special...

[Phanatic1a]

That's not correct. If blackbody(-ish) radiation covered the entire range of EM radiation, then the radiated power would be infinite. That's why there's this whole "Planck's constant" thing, because people realized that it doesn't work that way.

Re:nothing special...

[NewbieProgrammerMan]

I wish I had mod points for you. I also wish I had a dollar for every blatantly stupid quack diet idea that's sold a book.

Re:nothing special...

[DavidTC]

Screw quantum physics, I'll emit in every frequency if I want to! If anyone objects, I'll emit in the zettahertz range and turn them into a cloud of pions, so ha!

But, seriously, while people, and other objects that exist, obviously don't emit black body radiation in in all frequencies (As that would require infinite energy, but, more importantly, piss off Einstein.), they can indeed emit it in the visible light spectrum, as far as I can figure out.

Re:nothing special...

[DavidTC]

What the hell other sorts of processes could create photons?

Even pretending there was a way to change energy levels in a non-quantum manner, where the hell would the energy be stored 'while' it was changing? How does that possibly work?

I know of no other way to create a photon.

Re:nothing special...

[DavidTC]

Except that has nothing to do with people at all. All objects emit black body radiation.

The only thing that's an argument for is to hurtle people into outer space.

If anything, having more people around you means there are more objects to suck up the radiation. (Not that a single x-ray photon is going to be harmful to anyone.)

Establish in 2005

[eldavojohn]

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?

Re:Establish in 2005

[Anonymous Coward]

It was discovered in 1923 by a Russian scientist, Alexander Gurvitsh. It was re-discovered in the 70s by a German physicist named Fritz-Albert Popp. This stuff is really old, they discovered nothing new. Popp proposes that this emission is very different from typical black body radiation.

Re:Establish in 2005

[schon]

It was re-discovered in the 70s by a German physicist named Fritz-Albert Popp

Soo.. you're trying to tell us that this is just some sort of Popp-physiology?

/me ducks

Re:Establish in 2005

[dave562]

On a related tangent, there are optimal times of day for practicing qi gong and tai chi. I wonder if the amount of light emitted correlates to those times of the day.

Michael Stipe was right!

[scubamage]

So, I guess we really are all "Shiny Happy People!" I suppose next we should begin holding hands.

Re:Michael Stipe was right!

[Krojack]

I'm not touching anyone.

Re:Michael Stipe was right!

[nschubach]

I'm not very shiny though...

Re:Michael Stipe was right!

[snspdaarf]

Me neither. No telling what they might have been polishing with those hands.

Re:Michael Stipe was right!

[Chris Burke]

Naw, this only proves that we're shiny. There's still other kinds. Stipe just likes the happy ones. Other potential variants on the song include:

Shiny Angry People holding knives!

Shiny Horny People holding wangs!

Shiny Stupid People reading digg!

Re:Michael Stipe was right!

[geekgirlandrea]

Physics may force me to shine, but I refuse to be happy.

Re:Michael Stipe was right!

[Genrou]

And people never believed when I told them I was brilliant!

Re:Michael Stipe was right!

[clone53421]

A flu mask is really only effective at stopping yourself from spreading germs when you're sick. It isn't really going to help keep you from getting sick from other people's germs.

Re:Michael Stipe was right!

[bertoelcon]

Just as long as we don't have to deem all of humanity 'bright', shiny is fair enough.

Re:Michael Stipe was right!

[Captain Spam]

Yeah, well, you can just bite my (apparently) shiny non-metallic ass!

Re:Michael Stipe was right!

[swillden]

I'm not touching anyone.

And we appreciate that.

Re:Michael Stipe was right!

[Man On Pink Corner]

Not really true. Most people who get the flu give it to themselves, by touching the mucous membranes on their face with dirty hands. The real purpose of a flu mask is to keep you from doing that. It won't stop airborne viral particles, but then that's not how people get sick, for the most part.

Re:Michael Stipe was right!

[ColdWetDog]

Sounds more like a pretty dim bulb to me.

Just sayin.

An "aura"?

[Viper2026]

Whod've thunk it...

1,000 times too faint to see?

[Anonymous Coward]

Shouldn't that be invisible light?

Re:1,000 times too faint to see?

[Garridan]

Oh no, it's not invisible light. It's visible. You just can't see it.

Compare this to the light emitted by stars. It's hugely bright... but from millions of light-years away, it might be too faint to see with the naked eye. Does the star emit visible light? I'd say yes.

Re:1,000 times too faint to see?

[amicusNYCL]

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.

Re:1,000 times too faint to see?

[noundi]

You're trying to redefine the word visible. It's within the visible spectrum. Which means that while we have one ingredient to the recipe, we're still lacking enough quantity. This makes it invisible. Same goes with your star example.

Re:1,000 times too faint to see?

[Chris Burke]

And you're playing a semantic trick where you take a word with multiple definitions, and change the definition you're using from the one that was clearly implied by the original context.

In the headline "People Emit Visible Light", "Visible" means "in the visible portion of the spectrum". "Visible Light", especially in a scientific context, usually means "light which is in the visible portion of the spectrum".

Re:1,000 times too faint to see?

[clone53421]

In the headline "People Emit Visible Light", "Visible" means "in the visible portion of the spectrum".

I don't think that's obvious... well, other than the fact that they don't emit visible light by the definition I'd normally assume was meant. Since I can look around and see that they don't...

If I told you that a lightbulb emitted an "audible" sound, you'd assume I meant you could hear it. It wouldn't make sense to claim that if it was emitting sound at 120 hertz (an "audible" frequency) but at a volume far too low to be perceived by the human ear.

Re:1,000 times too faint to see?

[Gabrill]

And you're assuming that Slashdot headlines are viewed as Scientific forum (capitalization used to emphasize your bias). Slashdot is not a scientific forum, but a nerd-emphasised general forum. Thus the common or vernacular definition should always be used, and the editors should remember that headlines are summaries of the article and stand alone frequently without further explanation.

Re:1,000 times too faint to see?

[Chris Burke]

I don't think that's obvious... well, other than the fact that they don't emit visible light by the definition I'd normally assume was meant. Since I can look around and see that they don't...

It's extremely obvious if you're aware of the meaning of "visible light" in a scientific context. Anytime you see the phrase "visible light" in the same sentence as "scientists say" or "researchers have shown", then it is nearly 100% certain that this is the intended meaning. The clincher would be if you consider the layman's definition of "visible", realize that this is clearly not true, then consider the scientific definition and realize it is the only one that makes sense. Of course this still depends on knowing the scientific definition.

And I'll admit I'm rather shocked that so many /.ers apparently don't know that meaning of the phrase "visible light". I know we have a more diverse background than we used to, but I still figured the average slashdotter was likely to have gotten a science degree where basic physics was a requirement, or at least have payed more attention than normal in high school physics or even just read the many science/astronomy related articles posted here, or read xkcd, or something.

It made more sense to me when I just assumed people were being pedantic dicks. :P

Re:1,000 times too faint to see?

[HTH NE1]

Shouldn't that be invisible light?

More like subliminal light. Subluminal?

Re:1,000 times too faint to see?

[Chris Burke]

And you're assuming that Slashdot headlines are viewed as Scientific forum (capitalization used to emphasize your bias).

When the sentence containing the phrase in question also includes the phrase "scientists reveal" and the next sentence includes "researchers show", then it is probably safe to interpret it in a scientific context.

I will admit that I am biased towards thinking that most slashdotters would have attended and been interested enough to pay attention to high school or entry-level college physics. I realize that's not true. I guess I'm just really surprised that the term "visible light" is outside so many /.ers experience.

Slashdot is not a scientific forum, but a nerd-emphasised general forum.

Uh-huh. And one common attribute of nerds -- at least a virtue of anyone who I would call a nerd as a compliment -- is the desire to learn. When I read articles on /. about things not in my area of expertise, I often learn things from the article and from other readers who are familiar with the terms and phrases used in the article. It's one of the more enjoyable aspects of this forum.

And now you know what "visible light" means in a scientific context. That's the most common context for that phrase, by the way. When talking in layman's terms, using "visible" to describe "light" would generally be redundant. Nobody would say "Then I saw a visible light shining through the woods."

Slashdot may not be a scientific forum, but there are a lot of science articles on it. So you should be prepared to see scientific terms and to interpret them in a scientific context. You should probably not be upset when a scientific article uses scientific terms.

Thus the common or vernacular definition should always be used, and the editors should remember that headlines are summaries of the article and stand alone frequently without further explanation.

Okay, so next time an article mentions "infrared", it should instead specify "electromagnetic radiation with wavelengths between 750 nm and 100 m" so that readers don't say "What's infrared? I know from latin that 'infra' means 'below', but what's 'below' red? Maroon? Fuchsia?" Er, but wait, "electromagnetic" and "wavelength" don't aren't vernacular in any way... So no science terms? No technical terms? How do you even describe what this article is about using only vernacular definitions?

Look, I don't understand a lot of legal terms (for one example among many), but I'm not about to ask that every YRO article avoids using them, or kvetch about it when I fail to comprehend a term and am corrected.

Re:1,000 times too faint to see?

[Chris Burke]

Whatever researchers may use it to mean, the majority of people will probably be inclined to use the dictionary definition, and the most common one, if you don't clarify:

1 a: capable of being seen <stars visible to the naked eye> b: situated in the region of the electromagnetic spectrum perceptible to human vision < visible light>

Wait. You're telling me that the majority of people will use definition 1a, and only 1a, without even considering 1b, even though 1b specifically and directly refers to the exact phrase being used -- "visible light"?

You're telling me that the majority of English speaking people do not ever consider the multiple definitions that nearly every word in our language has, and choose based on contextual clues what the most likely intended meaning is? I don't buy that for a second. You know why? Because just now, without even thinking about it, you automatically processed the word "buy" and based on the contextual clues chose meaning number 5.

This has nothing to do with people choosing the first definition from a dictionary as opposed to the second, because nobody was looking in a dictionary. This has to do with people not knowing a scientific term so common and non-obscure it's definition 1b in said dictionary.

So basically, if you mean "light in the visible spectrum", just say that. "Visible light" will be interpreted by most people according to the 1a definition of "visible", not the 1b definition. It comes first because it's common...

Okay, once again I'm surprised, and again I admit it must just be the fault of my perception.

I would never have guessed that people who have no idea what "visible light" means would find the phrase "light in the visible spectrum", or even just "spectrum" meaningful. I wouldn't have thought those people even knew that the stuff outside the visible spectrum was light. So you're telling me that people know that the colors in a rainbow and X-rays and radio waves are all the same thing, they're all light, but at the same time have no idea what "visible light" could mean? I really never would have expected that.

I guess this illustrates one of the difficulties of writing about technical material for a layman audience -- remembering what it was like to be a layman, and thus what a layman would understand, when that could have been a long time ago. As far as I can remember, I learned about the EM radiation spectrum that includes X-rays, radio waves, infrared, and the light our eyes are sensitive to along with the phrase "visible light" to describe the latter section of the spectrum in a single class session in high school physics. So it would never have occurred to me that you could expect your audience to know one and not the other.

Re:1,000 times too faint to see?

[parlancex]

Oh no, it's not invisible light. It's visible. You just can't see it.

That's what I keep trying to tell people about these gnomes that keep stealing my underpants! With this newfound scientific evidence I will finally be able to make the nay-sayers eat their words.

Re:1,000 times too faint to see?

[DragonWriter]

Shouldn't that be invisible light?

It is both "invisible light" and "visible light".

"visible light" is a composite technical term with a meaning which is not the same as the the adjective "visible" applied to the noun "light", though it is related.

"invisible light" is not such a technical term, so its meaning would simply be what one would expect with the adjective "invisible" applied to the term "light".

Re:1,000 times too faint to see?

[Garridan]

To the contrary, Slashdot is a nerd-emphasized general forum. Therefore, the reader is expected to read, "People Emit Visible Light" and not think,

ZOMG, 'visible' means 'I can see it with my naked (har har he said naked) eye' but I've never seen a person emit visible light ZOMG slashd0t is wrongz0rz and my haed asplode!'.

Rather, the nerd is expected to think something along the lines of,

In my experience, humans do not emit visible light that I can see. What awesome tech did they use to detect visible light coming off of a human???

So today, we found out who's a nerd, and who's a nerd poser. Hint: nerd posers have trouble when language use deviates from the common or vernacular.

Re:1,000 times too faint to see?

[DavidTC]

It is not 'invisible light'.

It is visible light using the technical terms, and it is (not visible) light using the common terms for 'visible' and 'light'.

Although strictly speaking, talking about 'light' that is 'visible' in common terms verges on the silly. You cannot 'see' light by the common usage of 'see' meaning 'received light that bounced off it and hit your eyes'. Light isn't 'visible' in the common meaning, light is the carrier of 'visible'. It's like calling water 'a boat'.

Anyway, back to invisible, invisible means something that you would expect to see but cannot, or can see under certain circumstances, but not this one. It is not the same thing as 'not visible', and it is not the opposite of 'visible'.

For example, the air is not invisible. It is not visible, but it's not 'invisible' in any normal sense of that word.

Whereas someone hiding under your bed is invisible, at least figuratively. You'd expect to see people in the same room as you, when you cannot, they are 'invisible'. Likewise, a piece of paper seen edge-on, or a sliding glass door, can be invisible.

Very very dim light is not 'invisible'. Things in total darkness can be considered invisible to start with, but emitting unpercievable light does not make them moreso.

Re:1,000 times too faint to see?

[clone53421]

I agree with Anonymous Cowardon.

New definition of visible.

[140Mandak262Jamuna]

So the allegedly emitted light is 1000 fainter than what human eyes can see. Then why call it "visible", meaning viewable, seeable, ocularly pursuable (thanks Charles Dickens, Tale of Two Cities ... it has been a long time since I had the pleasure of ocularly pursuing you ... is Dickenesque for long time no see) ?

May be I can use this definition to claim my code is fully documented when the sole documentation is a line of comment that says, "Someday I should document this insane hack."

Re:New definition of visible.

[scubamage]

Its visible to kitties and puppies, of course. I think. Maybe.

Re:New definition of visible.

[amRadioHed]

From wikipedia: "The visible spectrum is the portion of the electromagnetic spectrum that is visible to (can be detected by) the human eye. Electromagnetic radiation in this range of wavelengths is called visible light or simply light."

Re:New definition of visible.

[gt6062b]

Visible Light = Light which falls in the part of the spectrum that our eyes can see. They're talking about the wavelengths of the light.

Re:New definition of visible.

[thisnamestoolong]

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.

Re:New definition of visible.

[Demonantis]

There are two factors when considering light. The number of photons and the wavelength of each photon. In this experiment the first one makes the light they are considering faint. The wavelength of those few photons is what makes them in the visible spectrum. Or another way to look at is ultraviolet light from the sun is fairly intense outside, but we don't see it because our eyes aren't designed to detect that wavelength. The neat part, that is probably most useful, is that it detects how the metabolism is doing. A rather in evasive test to see who is sick that could be set up in air ports or health facilities.

Re:New definition of visible.

[StikyPad]

Right on.. It would help if popular culture could just call it all EM Radiation, and call "visible light" EM Radiation in the visible spectrum, but the term radiation scares people. Maybe as an acronym, EMR and EMR-V would be less frightening. Nonetheless, it would be more technically accurate, and remove the ambiguity of the term "light".

Re:New definition of visible.

[Actually, I do RTFA]

, it only refers to light with a particular wavelength, roughly 380 to 750 nm, which our retinas happen to be sensitive to.

Our eyes happen to be sensitive to. Our retinas are sensitive to UV, but the cornea filters out some UV light: as much as we normally see absent looking at the Sun, etc.

Re:New definition of visible.

[noidentity]

I thought "light" pretty much meant it was visible electromagnetic radiation, by definition, but what do I know...

Master Yoda called this...

[Casharelle]

Master Yoda called this back in The Empire Strikes Back: "Luminous beings are we...not this crude matter!"

Re:Master Yoda called this...

[powerlord]

Considering how much the concept of "The Force" borrowed from Eastern Philosophy (see http://en.wikipedia.org/wiki/Ch'i) ... at least in the first films ... that's much less surprising then it could be. :)

To quote the full quote: http://www.imdb.com/title/tt0080684/quotes

Yoda: Size matters not. Look at me. Judge me by my size, do you? Hmm? Hmm. And well you should not. For my ally is the Force, and a powerful ally it is. Life creates it, makes it grow. Its energy surrounds us and binds us. Luminous beings are we, not this crude matter. You must feel the Force around you; here, between you, me, the tree, the rock, everywhere, yes. Even between the land and the ship.

As I always suspected

[Bemopolis]

People are visible, but they aren't all that bright.

Re:As I always suspected

[snspdaarf]

I guess that's why Dad always said, "Rise and Shine!"

Re:As I always suspected

[Chris Burke]

Huh. Maybe you could come back with "I'm already shining!" and trick him into letting you sleep another ten minutes?

link to paper

[welcher]

In PLoS One: http://www.plosone.org/article/info:doi/10.1371/journal.pone.0006256

Re:link to paper

[FleaPlus]

I'm a little worried that their first reference is Fritz-Albert Popp, who's kind of a pseudoscientific quack and into biophotonics, which is often used to try to validate things like homeopathy.

Re:link to paper

[Danny Rathjens]

Even a broken clock is correct twice a day.

Midi-Chlorian

[phrostie]

It's the Midi-Chlorian

duh

Re:Midi-Chlorian

[MenThal]

Midi-Chlorian

What's that? A music standard for sanitizing swimming pools?

Biophotons

[Eukariote]

Similar "biophoton" phenomena have been studied in the past at the International Institute of Biophysics. It is most interesting as conventional theories do not predict such emissions.

Re:Biophotons

[Anonymous Coward]

It's just simple blackbody radiation. Anything with a temperature emits blackbody radiation, which is made up of photon that are mostly infrared. But the various photons have different frequencies, and some of those frequencies are in the visible spectrum.

Your missing the point

[drukawski]

The important thing here is we just discovered the solution to the energy crisis, all we need are MORE people.
Think about it; if 1 person emits light 1000 times too faint to see, that means 1000 people emit exactly enough light to see. All I need are 1000+ Chinese people willing to stand around in my hallway for a couple pennies a month and I don't need a nightlight to find my way to the pisser at 4am anymore!!!

Re:Your missing the point

[bertoelcon]

Wasn't there a film on using humans as a power source, I think it had 3 main parts and some short anime extra bits?

Re:Your missing the point

[geekboy642]

You lie. That film had ONE main part. Any evidence of some kind of 'sequel' was planted by the machines to confuse your mind.

Re:Your missing the point

[killthepoor187]

http://xkcd.com/566/

Re:Your missing the point

[xerxesVII]

And you're missing an apostrophe and a letter e.

Re:Your missing the point

[Chris Burke]

You lie. That film had ONE main part. Any evidence of some kind of 'sequel' was planted by the machines to confuse your mind.

Huh, are you sure? I could have sworn that movie had a sequel where the bad guy from the first movie put on a mask and became a poetic anti-hero. :)

Re:Your missing the point

[An anonymous Frank]

No, no! What we need, is more HOT people.

Re:Your missing the point

[Hurricane78]

It's funny, how intelligent people tell me, the second part explained it all, and the third was the logical conclusion.
And dumb people tell me, that the second part made no sense, and that there was no reason for the third part.

I admit, that when I first watched it, if was just at the border of my capabilities, to understand it. But after a bit of thinking and watching it the second time it was pretty clear.

And the third part, in a loud THX cinema, was just sheer fun of action. Also the machine world at the end was the most impressive I had seen in TV up to that day.

Obligatory

[Dunbal]

"Luminous beings are we, not this crude matter." - Yoda

1000 times too faint?

[kybur]

If studies have shown the human eye can perceive as few as 5 photons (some say even fewer is perceivable), what exactly to they mean by 1000 times fainter? Just spread out in time, I suppose.

Re:1000 times too faint?

[adonoman]

Saying that the human eye can perceive 5 photons is missing a bunch of units. The time portion is very important, as well as how spread out they are over the eye. In the pictures in the article, the light emitted from the face peaked out at around 3000 photons per second per square centimeter. If humans need 3,000,000 photons / s*cm^2 to perceive light, then you just need to focus the beam tightly over a short stretch of time - if you send those 5 photons in a single ms over .17 mm^2, you'll get approximately the requisite 3,000,000 photons/s*cm^2 to perceive them.

Re:1000 times too faint?

[kybur]

Makes sense as long as it's impossible to perceive just 1 photon, for then the time and spacial cross section would be meaningless.

I can't find any reputable references online for for this though.

Re:1000 times too faint?

[Attila Dimedici]

There is a link further up to study that found that the human eye can perceive a a 1 millisecond flash of 90 photons under ideal conditions. This suggests to me that what this study is dealing with is where the idea of physically perceivable psychic auras comes from. Someone with mystic tendencies (and perhaps exceptional sensitivity to low level light) observed this light and made some interpretations from it (some of which might have had some connection to the actual state of the person observed). Later others made further observations that built on the original. Unfortunately, since most people would not be able to observe this phenomenon, some (probably many) of these people were either frauds or hallucinating, so their observations and conclusions were contrary to the reality of what was going on.

We are made of "Star Stuff". No surprise.

[bareman]

We're made of the elements found in stars...
http://en.wikipedia.org/wiki/Delenn
http://www.youtube.com/watch?v=iE9dEAx5Sgw

Though I don't think we necessarily glow brighter if we have a good idea. :-D

Take THAT, Prissy Twilight Vampires!

[cacepi]

You plonks just sparkle. We shine.

Oh, and to E.T.: I've got your ouch right here.

Mood rings!

[scubamage]

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.

Re:Mood rings!

[Anonymous Coward]

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.

So you're saying we should judge people by the color of their skin?

Re:Mood rings!

[T Murphy]

"Hi there, how are you? Oh, wait- Let me get out my spectrometer!"

Re:Mood rings!

[Remus Shepherd]

Go one step further. If it's a metabolic process, in theory it is possible to overclock it. Next step: Recreational pharmaceuticals that send the light-generation process into overdrive, causing people to glow.

At last, we can get rid of those stupid glow sticks at raves.

Re:Mood rings!

[tnk1]

Go one step further. If it's a metabolic process, in theory it is possible to overclock it. Next step: Recreational pharmaceuticals that send the light-generation process into overdrive, causing people to glow.

At last, we can get rid of those stupid glow sticks at raves.

This is referred to as a "fever".

Or in extreme cases as "spontaneous combustion".

Re:Mood rings!

[merreborn]

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.

To actually detect this, wouldn't you need the subject to be in a completely dark room?

Otherwise, how do you differentiate their 'trickle' of emitted photons, from the flood of ambient photons reflecting off them?

And once you have them alone, in a room so dark that they can't see their hand in front of their face... Well, that's probably going alter the subject's mood a little.

Re:Mood rings!

[lennier]

That'll show those stupid jellyfish monkeys who's really top species!

Re:Mood rings!

[Sibko]

So, since this light is directly related to biological processes, that means in theory it should be tied to mood.

I'm not really following your logic on that. You may as well have said "in theory it should be tied to how often they brush their teeth." Your connection between the two seems to be the unstated assumption that 'happy people glow', and following that, since happy people glow, and this study shows that people emit light in various amounts, then the brighter ones are happy.

Here's my own theory: More light being emitted would probably be a result of more energy in the system, so an individual with more than the average number of ongoing chemical reactions would be giving off more light than other people. Variations in light intensity could be explained by something as simple as whether or not the person's digestive system is currently breaking down food.

Re:Mood rings!

[scubamage]

That's why I used depression as an example, not happiness. The physiological effects of depression cause all biological processes to slow down - both catabolic and metabolic. That includes your example, breaking down of food. Likewise, a person who is not suffering from depression has faster, more responsive biological processes. A simple class in biopsych will illustrate and explain that better than I could. I think it's a pretty neat line of research.

Re:Mood rings!

[Trogre]

I don't really feel like reading your whole post, sorry. Feeling a little blue today.

Comment removed

[account_deleted]

Comment removed based on user account deletion

I have a Photomultiplier Tube

[SomeoneGotMyNick]

Something in my kit of salvage electronics which I could never figure out what to use it for, to try and detect the presence of these "humans".

Now if only I can only safely generate the 1000-2000 volts to drive it.

Color?

[PagosaSam]

Gee, I wonder what color I am? I hope it's blue.

Nothing special aside from what was in TFA

[interkin3tic]

The summary, most commenters, and largely the article itself seem to be missing the big point here

The researchers found the body glow rose and fell over the day, with its lowest point at 10 a.m. and its peak at 4 p.m., dropping gradually after that. These findings suggest there is light emission linked to our body clocks, most likely due to how our metabolic rhythms fluctuate over the course of the day...

Since this faint light is linked with the body's metabolism, this finding suggests cameras that can spot the weak emissions could help spot medical conditions

So yes, people glow, and yes, this was known previously. The point of the research is that this can be used, for studying circadian rythms and maybe identifying problems with it and metabolism. The scientist quoted is billed as a "circadian rhythm biologist," you've got to think he's probably not studying this to find out if people glow or not.

The information in the summary is thirdhand at best: whoever makes the summary makes it from an article, which in this case wasn't primary literature from the actual scientists but was AOL news or whoever "imaginova corp" is interviewing several japanese scientists about their work. AOL news seems to have misunderstood the research that they were writing about.

So how many human light bulbs do I need . . .

[PolygamousRanchKid]

. . . to replace that old 25W bulb? I've been experimenting with these newfangled florescent thingies, but the labels always seem to lie like rugs: 1W = 1000GW!

Maybe I need to know how *bright* the things actually are. Like, how many humans would I need to illuminate the Library of Congress? That would seem like appropriate Slashdot units.

Re:So how many human light bulbs do I need . . .

[DriedClexler]

So you're asking, how many lightbulbs does it take to replace a scientist?

Twilight?

[osoroco]

with all the teenage girls already fantasizing about sparkling vampires, do we really need to feed their imaginations with this?

or is this a new era of teenage pickup lines: "I heard you like people who sparkle as a result of the sun hitting on their skins... baby, I emit my own light"

Single Photons???

[polyomninym]

I once heard that the human eye can detect a single photon. I wonder how true that is. When I heard that, I thought that there must be some minimum threshold to trigger the optic nerves. Any thoughts about this?

Needed research

[Walt Dismal]

Careful analysis tells me it is absolutely necessary for the survival of the human race to investigate photon emission from women. Since cloth would interfere with measurements, experiments will have to be clothing-free, and in a dark room. Volunteers are needed, apply now. Scientific requirements show a need for women between 18 and 40 with large busts. No pay, but refreshments will be served in sufficient quantities to achieve experimental results.

Re:Light, zombies, vampires, and global warming

[MightyYar]

Can I get a dead-dar that goes off if someone isn't emitting light?

An infrared thermometer ought to do the trick.

Absolutely.

[jeffb (2.718)]

How humbling, though, to realize that a four-watt nightlight harbors something like a billion times more chi than you do.

Not Just Visible Light!

[AioKits]

I'm still applying for a grant to research this, but I'm told people also emit a scented gas! Part of my research will focus on this 'silent but deadly' scenario as it appears this scent is not always accompanied by sound.

Ponder

[KingPin27]

Light travels faster than sound -- thats why most people appear bright......until they open their mouth. --unknown

Aha! So that's why...

[KC7GR]

FTA: "...In fact, virtually all living creatures emit very weak light, which is thought to be a byproduct of biochemical reactions involving free radicals."

This explains why the city of Berkeley (California) shows up so bright on satellite photos taken at night. Way too many free radicals.

(and I should know... I grew up there!)

Rate is far too low for this

[Roger W Moore]

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.

Re:Rate is far too low for this

[Steegest]

Apparently the rods of a human eye can detect that intensity level approximately once every 15 minutes... http://www.ronen.net/physics/Quantum/see_a_photon.html

Re:Rate is far too low for this

[fractoid]

TFS says that it's "thought to be a byproduct of biochemical reactions involving free radicals." So the light is produced as a part of a chemical reaction, not spontaneous emission a la black body radiation. It's like the small blue fringe at the base of a candle flame; the reaction is directly generating higher energy photons (you in the back, put your dilithium crystals down!).

Re:Rate is far too low for this

[rcw-home]

The eye can respond to single photons, but the brain filters them out below about a hundred per second.

Re:Rate is far too low for this

[Roger W Moore]

Ah - but you are forgetting the solid angle. My rate is 100 photons/second/per steradian. I have no idea how small a rod is but probably on the 1 micrometre? (it has to be bigger that the wavelengths it detects which are 100's of nm). Hence you would have to place your retina within ~5 micrometres of the source for each rod to subtend a solid angle of 0.01 steradians to get one photon a second - which the article says that you still won't be conscious of - particularly since at this point you've rammed the source into your eyeball!

Re:Rate is far too low for this

[Roger W Moore]

I know the article said that but, as a physicist, I would not trust a biologist to have checked something like black body radiation to see if it could be responsible. They might have checked and ruled it out but it is the sort of thing that could easily be missed by a non-physicist.

Re:Rate is far too low for this

[Roger W Moore]

Your calculus text book is right. Unfortunately your understanding of physics is wrong. dN/dlambda is the number of photons emitted per unit lambda i.e. you do not need to integrate it, it already is the quantity you need.

Re:Rate is far too low for this

[Roger W Moore]

See my reply above - you need to account for the solid angle of a single rod. This means that the rate seen at a single rod will be a lot lower than 1 photon/second unless you crush you eyeball!

Re:Rate is far too low for this

[fractoid]

Fair enough. Eliminating simpler explanations first is just good science, and your post did so efficiently. :)

Re:Rate is far too low for this

[powerlord]

I'm curious though if the brain can be trained to pick up this information though.

Most people believe that their entire vision is in color, despite the fact that the cones detecting color are only in the center of the eye. The edges of our vision (the "corner" of our eye) only sees black and white. The brain fills in the detail so we think we see it all in color.

Likewise, if you can get the brain to NOT suppress the very rare photon events, then its possible that it could "save and correlate them" into what some people perceive as auras.

It would explain why some people innately see them (their brain happens to have wired that way), and why others can see them after Meditation and practice (to train the brain to unfilter things).

I'll admit I'm neither a Psychologist, a Biologist or Physicist, but to me at least its an interesting hypothesis.

Re:Rate is far too low for this

[clone53421]

Most people believe that their entire vision is in color, despite the fact that the cones detecting color are only in the center of the eye. The edges of our vision (the "corner" of our eye) only sees black and white. The brain fills in the detail so we think we see it all in color.

Interesting, but now I'm wondering how this works... I guess it must be close enough to the centre of your vision that you can see the colour despite looking at a fixed point in the middle of the picture. Otherwise, if you couldn't see the colour, the optical illusion wouldn't work.

Re:Rate is far too low for this

[powerlord]

When I said center vs. edge is more "what you directly look at" vs. "peripheral vision".

Re:Rate is far too low for this

[jeffb (2.718)]

TFA (link copied from a post above) states explicitly that they did thermal imaging as well, and that there was no correlation between temperature and the photon emission they discuss. While they don't directly address black-body radiation, this would seem to rule it out as an explanation.

Embarassing

[DoofusOfDeath]

The human body literally glows, emitting a visible light in extremely small quantities at levels that rise and fall with the day,

Thank goodness. I thought it was just me who had nocturnal emissions.

Joy.

[Kaptain Kruton]

I am just glowing with excitement!

Uh, duh.

[pi_rules]

Anybody that's ever taken LSD could have told you that!

Re:Uh, duh.

[Kozz]

And you also are anticipating new scientific research stating that audible frequencies have corresponding colors?

Re:Uh, duh.

[ChefInnocent]

What, you aren't familiar with synesthesia?

Re:Uh, duh.

[Beerdood]

I think you're confusing "people" with "everything" here, when it comes to emitting light. I recall doing some once at this outdoor music festival, then staring at the stars for somewhere between 15 seconds and 45 minutes and thinking how bright and beautiful they were. Then I realized I was in my tent.

Re:Uh, duh.

[Anonymous Coward]

I'm not sure if your statement is insightful or anything, the only scientific proof I would think we have right now that acid would affect any real light perception is the simple fact that it causes major pupil dilation which makes you much more sensitive to light because youâ(TM)re obviously absorbing a bit more of it but I'm a skeptic if the effect you notice on LSD is anything short of just a hallucination. It is a hallucinogen after all.

I've taken way more than my share of acid and talked to many people who have also and it's pretty well known experience to see major and minor "halo" affects around living things in particular but inanimate objects also. That said discounting all the other major affects you experience on acid it's remarkable enough to stand out and does make you think or at least explains where the mystical aura idea may have started from and crazy religions. Shrooms!!!

Re:You're not afraid of the dark, are you ?

[HTH NE1]

With the right prosthetic eyes, not any more :)

Nah, you just need some eyeshine like Riddick. Though it's not shaving down the lens, it's an injection of a reflective substance behind the retina so you sense the photons twice.

Can't the eye detect single photons?

[pongo000]

I read that somewhere once...fact or fiction? If fact, then how can any light in visible wavelengths be "1000x" under the detection threshold of the human eye?

Re:Can't the eye detect single photons?

[Anonymous Coward]

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.

Re:Can't the eye detect single photons?

[pongo000]

Learned something new from an AC today...thanks!

Re:Wait...what?

[clone53421]

The visible spectrum. I agree that the headline is misleading, but I get what they meant.

Infrared, for instance, is invisible no matter how intense it is. For example, the infrared light from the LED on your TV remote is perfectly invisible to your eye, but a digital camera (which certainly isn't intended to be "incredibly sensitive") will pick it up just fine. Try it!

Aliens!!!

[IamNotAgeek]

Great, this just means the aliens will have an even easier time hunting us down. I wonder if covering yourself in mud can block the photons?

Already knew this.

[NoPantsJim]

I made the mistake of venturing outside and wandering to a beach about a month ago. After returning home at the end of the day, I was clearly visible in a dark room with the lights turned off.

Re:Already knew this.

[OrangeTide]

The room was not dark, or you have infravision(+1) on your character sheet.

Out of curiousity

[shock1970]

If you eat less foods with anti-oxidants, eat more junk foods, and stress yourself out to the max... all in turn creating more free-radicals... will you glow brighter?

-- Everything is, nothing is as it seems.

Re: Do Women emit more light than men?

[HTH NE1]

Another topic-inspired quote recall:

Jake Scully: Are you married?
Sam Bouchard: Separated.
Jake Scully: Me too, as of yesterday. We weren't married, but it was almost the same thing.
Sam Bouchard: What happened? I'm sorry. That's none of my business.
Jake Scully: That's okay. It's just... sounds so stupid.
Sam Bouchard: These things usually do.
Jake Scully: Caught her in bed with another guy. Can you believe that?
Sam Bouchard: Man. You had no idea?
Jake Scully: None. Christ, I keep seeing it. Carol lying there. Her face was glowing.
Sam Bouchard: Her face was glowing?
Jake Scully: Yeah.
Sam Bouchard: [feigning incredulousness] How do you get a girl's face to glow? I got 16 years of good humping, not once did I get a glimmer, let alone a fucking glow!
[Jake sputters a laugh into his drink]
Sam Bouchard: Glowing? I'm sorry. That's tough.
Jake Scully: No, you're right. It's not that big a deal, really.
Sam Bouchard: You kicked the bitch out I hope.
Jake Scully: [shakes head] I didn't.
Sam Bouchard: Why not?
Jake Scully: It was her place.
[a beat, then they both laugh]
Sam Bouchard: Oh, you've been through the shitter.

People do Not emit light!

[Well-Fed Troll]

They suck dark.

Citation here.

Midiclorians?

[argent]

What, what, they're detecting midiclorians?

Poor science

[Dire Wo1f]

The article claims that a biological process is producing this light, but it has no evidence to back this up. The light is at it's lowest at 10 AM and it's peak at 4 PM and is most visible on areas that are exposed to the sun. Doesn't it seem more likely that this is photoluminescence rather than bioluminescence?

Of course we're all glowing

[PunditGuy]

It's an energy field created by all living things. It surrounds us and penetrates us. It binds the galaxy together.

We glow a little brighter here since 1943

[Pontiac]

It's nice to know that people can shine no mater where they are and not just the ones at radioactive dump sites.
http://en.wikipedia.org/wiki/Hanford_Site

Photons are divisible?

[izomiac]

1,000 times less intense than the levels to which our naked eyes are sensitive

Hmm... what I was always told was that rod cells in the retina are sensitive to single photons. IIRC, that's also why spinthariscopes work. Now, sure, I understand that the probability of a random photon entering the eye hitting a rhodopsin pigment is fairly low, and the response could be inhibited by nearby neural cells, but it's still my understanding that you can see individual photons in very dark surroundings. So, is this threshold more of a "what people notice under normal lighting", or are these researching splitting photons somehow?

We probably just evolved from flueorescent monkeys

[Subm]

We probably just evolved from fluorescent monkeys

free radicals?

[frinky525]

007: free radicals?

m: yes, toxins that destroy the body and brain. caused by eating too much red meat and white bread, and too many dry martinis.

007: (ponders) then i shall cut out the white bread sir.

Re: Do Women emit more light than men?

[Dogtanian]

Interesting quote, but where's it from? It doesn't Google.

I've always known

[kent_eh]

I've always known that my eyes had a dull red glow some Saturday mornings.
It certainly felt like they were burning, anyway

Re: Duh?

[Anonymous Coward]

John? The disciples?

Then Jesus spoke to them again, saying, "I am the light of the world. He who follows me will not walk in darkness, but will have the light of life."

John 8:12

I assume "no shit, join the club" would be in there somewhere if they had.

Mr. and Mrs. Kirlian

[treeves]

were photographing human (and other living things) "auras" a long time ago. I'm surprised no one else mentioned it. Really they were just taking photos of high voltage coronas around things, but hey, it was fun!

Vampires?

[grantek]

This is why I like hanging out in a place less likely to be filled with Twilight fangirls :)

Re: Do Women emit more light than men?

[BitZtream]

Soviet Russia ...

In Soviet Russia, quotes Google you!

I hate that meme due to overuse, but I just couldn't pass it up :(

Re:When computer geeks and engineering collide...

[treeves]

As other posters have said, these are not photons from blackbody radiation, but from biochemical reactions, of an undisclosed type. I'd be interesting in seeing the spectral sensitivity of the detectors used to make the images in TFA. Do we glow green, blue, or what?

Two Theories

[DynaSoar]

1. The rods of the human retina can react to a single photon. However, to be consciously perceived between 5 and 10 photons must be detected within 100 milliseconds. To pick up light that's 'visible', but "1,000 times less intense than the levels to which our naked eyes are sensitive" ('Which is, of course, impossible. -- Hitchhiker's Guide) the researchers in TFA are claiming to detect small fractions of a photon (repeat HHG assertion here).

As stated, the above applies to conscious perception. A normally non-conscious perception via an alternate visual channel has been proven to exist. This 'blindsight' has been discussed here previously http://science.slashdot.org/article.pl?sid=08/12/24/2330245 . It has been shown to not only exist in the sighted, but can be trained in them so to become functional. There was a school for this in New Mexico that was written up in Co-Evolution Quarterly almost 20 years ago. In the discussion thread here, more than one person admitted to having developed or noticed having this ability.

2. The spirit of we two legged can become attuned to the spirit of the four legged, and so the hunter can find prey in darkness, and one can also avoid becoming hunted. Likewise, we can feel the spirit of the standing people (trees) and so find our way between them with surprising speed. Although it works as though it were sight, because it is a working of the spirit, the impressions received are not detected as visual images to the mind, but only to the spirit.

I've got a lot of academic training in #1. I've got some training, and have ancestors with a lot more in #2. They may be incompatible, but since no viewpoint perfectly and completely describes reality, none can be said to be the only truth. In any case, learning to use dark sight doesn't require believing either.

Still, there ain't no such as pieces of photons.

Re:Two Theories

[clone53421]

to be consciously perceived between 5 and 10 photons must be detected within 100 milliseconds ... the researchers in TFA are claiming to detect small fractions of a photon

Not at all. A ratio can also be reduced by increasing the denominator, you know. The ratio 5 photons per 100 ms reduced by a factor of 1000 would be 36 photons per hour, or a photon every 1:40 on the average.

Pregnancy

[corigo]

What I want to know is whether it is true that pregnant women "glow." Who wants to test whether pregnant women emit more light than usual?

Healthy Green Glow

[edbob]

A lifetime of being in a nuclear power plant has left me with a healthy green glow.

Dragonball

[nicodoggie]

Now all we have to figure out is how to collect that light into a ball of energy in between our palms and we're set!

To find out if free radicals are involved

[petterb]

Given that antioxidants neutralize free radicals, here's a test one could do to see if free radicals really are involved.

Take two groups of people. Group #1 are people who's on the paleolithic diet (stone age diet), with very high intakes of antioxidants and thus a low level of free radicals. And group #2 are on the fast food diet or something that's really low in antioxidants and thus have a high consentration of free radicals in their bodies.

I would expect to see more light from group #2.

Re: Duh?

[dalesc]

Well, I would have modded it funny.

And, while I'm at it, can we stop trying to make things smaller by multiplying them by large numbers? "1000 times less intense" is a nonsense. "A one thousandth as intense" or "a thousandth of the intensity" is what they mean. If you can't handle fractions, then "it would need to be a thousand times brighter to be visible to the naked eye".

new-age hippie karma pipe dream.

[PMBjornerud]

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.)

Excuse me for not sharing your excitement, but this is way too close to some happy new-age hippie karma pipe dream. Sorry about that, but please apply a little bit of critical thought here.

The light in question is 1000 times less intense than our sensitivity. Even if you increase it hundredfold it does not become observable by many people. It is STILL invisible - in absolute darkness, nonetheless.

Your ideas further assume this invisible light could be noticeable in broad daylight. Which, I am afraid to say, almost certainly brings this idea well into crackpot land.

Others can probably expand further on why we need a certain amount of photons for the receptors in our eyes to trigger and how it would be impossible for that mechanism to work when we're 3 orders of magnitude off the threshold.

Infrared?

[furby076]

Isn't that infrared light, or heat signature that everything with a temperature emits? The naked eye can't see it but special tools (infrared lenses) can.

Quantum Physics

[Roger W Moore]

You need to learn some quantum physics - which is actually where the Planck spectrum comes from. The universe does not define photon energies (i.e. wavelengths) to such an arbitrary precision. In addition the spectrum comes from the allowed standing waves which the object can emit. While the spacing of these is tiny it is not a continuus spectrum - although given the limitations on measuring the wavelengths precisely it appears so.

Re:Quantum Physics

[Roger W Moore]

Integrate the black body spectrum (dN/dlambda) between those two points and figure it out yourself.

Re:Quantum Physics

[Roger W Moore]

When quoting the emission at a particular wavelength the convention is to use the differential spectrum (dN/dlambda). Technically this is the number of photons per unit time per wavelength but physical meaning is that it gives the measure of the number of photons per unit time at a particular wavelength which is why it is stated as such. See your A level physics course at school (UK) or 2nd year university physics course (US/Canada) for details.

Re: Do Women emit more light than men?

[HTH NE1]

It should. I had to Google it to make sure I got it right, though I added the stage directions from memory.

I've left it as a mystery long enough. It's from the 1984 movie Body Double.

Location, Location, Location...

[supernova_hq]

Was this test conducted near Hiroshima?