Living beings emit a faint light that extinguishes upon death, study
phys.org
phys.org
The big question has been just how much useful information can be derived from that light? It is difficult to tease out signal from noise and the human body is far from transparent at those frequencies so it's not like you could use it for imaging.
Since breathing stops and various oxidation reactions thus also slow or stop it makes sense the emitted light would decrease.
I haven’t read the study but I studied remote sensing in undergrad and one thing we worked on was how to detect the stress of an agricultural crop from multispectral satellite data. You can quite clearly detect how plants are handling temperature, pest damage, drought conditions, largely based on their near- and middle-infrared responses. On the surface this sounds a lot like that, which I think is neat.
Part of that is in the infrared spectrum, and the other end in UV (including A, B, and C). Isn't this just https://en.wikipedia.org/wiki/Black-body_radiation that everything with a non-zero absolute temperature emits? Dead beings would obviously cool down and reduce the amount of radiation they emit.
I think that they explicitly controlled for that. From the article:
> The results revealed that despite both groups having the same body temperature of 37°C, the live mice showed robust emissions, whereas the UPE from the euthanized mice was nearly extinguished.
It's possible that they controlled improperly, but that's another question - from my reading of the above, they artificially heated the corpses (or measured immediately after death) to control for blackbody radiation.
Or would you rather not study this at all?
Also unclear how the light would be invisible to the human eye, given that the human eye has single-photon sensitivity smack in the middle of that range.
Or maybe they're just wrong and didn't realize that 500 nm is visible light - that's possible too.
Would someone be so kind as to clear up my long-held misconceptions?
At the point when its wavelength is outside of visible range, roughly 380 to 750 nm. (Some experts will call (parts of) IR and UV radiation “light”, but that’s neither here nor there.)
> Because it seems obvious to me that since our bodies are warm, and heat is a form of EMR, then of course we radiate "light".
Of course, everything radiates, and everything radiates light if you heat it up enough (> 500°C, > 1000°F).
> But also, things that wouldn't be described as warm still do this - all matter in the universe emits EMR, does it not?
Yep, only things at absolute zero temperature truly do not radiate, and it’s impossible to get there.
However, afaiu, the study describes chemiluminescence, i.e. specifically radiation above thermal.
It's not that wildly different from the 1980s -- even then I never heard anyone say something like:
> Of course, everything radiates, and everything radiates light if you heat it up enough (> 500°C, > 1000°F).
Like, literally, in an undergraduate class that I taught, one of the short-answer questions on the midterm was to ask what kind of light the teacher's hair emitted. The answer is, of course, infra-red light.
I still find it cool that all electromagnetic radiation is the same stuff, from LF radio to ultra violet, to microwaves and beyond.
The OP title made me think of the aura seen by Xenomorphs in the original Alien vs Predator video games.
Of note, 200-1,000 nm overlaps with the wavelengths we perceive.
Could it be that under some particularly dark environments, some particularly sensitive humans (or animals) can get a glimpse of it? I believe it's quite plausible.
Are you suggesting this light is of lower intensity than what a single photon puts out? Explain your reasoning.
It's pretty easy to see the layer closest to the body. It's kind of like a bright outline about 1cm thick.
The layer with colours is further out and I've only ever seen it once. It was rad though, 10cm apple green flames appearing to shoot off my body as I moved my eyes around.
Certain lighting conditions make it easier, eg slightly dark environment with a backlit subject.
Anyway cue the downvotes from the overly analytical people here. As with all things meditation, the more you try the less you'll experience.
> Anyway cue the downvotes from the overly analytical people here
This breaks these guidelines:
Please don't fulminate. Please don't sneer, including at the rest of the community.
Eschew flamebait. Avoid generic tangents. Omit internet tropes.
Please don't comment about the voting on comments. It never does any good, and it makes boring reading.
I know it can be upsetting to face hostility when sharing experiences and concepts that are deeply meaningful to you, but let's try and avoid taunting people like this. When it's predictable that a comment will attract downvotes, it's an indication that there might be a better way to express things.
One way to study this is to shut off the neural channels for external stimuli with NMDA-antagonists or isolating the entire body, you'll experience immersive perceptions, including visions. Falling for various degrees of decoration your brain provides spontaneously or has been trained to provide is foundational to many religious and mystical currents throughout history. Some of them consider not falling for at least some of these things to be the basic exercise of their regimes, e.g. non-reaction to mental phenomena in Goenka's vipassana or time-locked prayer as in canonical hours and islamic prayer.
Be kind. Don't be snarky. Converse curiously; don't cross-examine. Edit out swipes.
I have always been interested that we cannot see infrared, but some reptiles can, we cannot because our eyeballs are flooded with warm blood, there is no way for our bodies to distinguish signal from noise.
This made me think of the scrotums purpose to maintain the testes slightly below body temperature, which then amused me with the idea that it might therefore be able to function as a kind of infra red, body light retina.
so I was mocking some primal hunter ideas, but certainly no one posting on this page
Subunit and chlorophyll organization of the plant photosystem II supercomplex https://www.nature.com/articles/nplants201780
But talk to an electrical/computer engineer about it though. To be a signal, such light needs to be both received and aimed...
It is also brighter the further you die from home.