[HN Gopher] New study shows plants and animals emit a visible li...
       ___________________________________________________________________
        
       New study shows plants and animals emit a visible light that
       expires at death
        
       Author : ivewonyoung
       Score  : 190 points
       Date   : 2025-09-24 03:27 UTC (19 hours ago)
        
 (HTM) web link (pubs.acs.org)
 (TXT) w3m dump (pubs.acs.org)
        
       | gnabgib wrote:
       | Title: _Imaging Ultraweak Photon Emission from Living and Dead
       | Mice and from Plants under Stress_
       | 
       | Previously (19 points, April)
       | https://news.ycombinator.com/item?id=44617867
        
       | sinuhe69 wrote:
       | Light is just a form of electromagnetic radiation. All processes
       | produce electromagnetic radiation, only different in the amount.
       | So as we improve our equipments, we naturally can see more things
       | like that.
        
         | IAmBroom wrote:
         | "See" is a poor verb choice. "Detect".
        
       | JumpCrisscross wrote:
       | Guessing these are surfacing due to the recent _Radiolab_ podcast
       | "The Spark of Life": https://radiolab.org/podcast/the-spark-of-
       | life
       | 
       | > _in the spectral range of 200-1000 nm_
       | 
       | That's UV, visible and near IR. We know that 100-600 nm (infrared
       | EDIT: UV) light "can carry out photostimulation and
       | photobiomodulation effects particularly benefiting neural
       | stimulation, wound healing, and cancer treatment" [1]. I'm
       | curious what could be producing UV and visible light.
       | 
       | Does light production tend to hang out around any particular
       | organs or organelles? If stress causes it, I'd hypothesise it's
       | metabolic or signalling related.
       | 
       | [1] https://pmc.ncbi.nlm.nih.gov/articles/PMC5505738/
        
         | alfiedotwtf wrote:
         | The brain is electro-chemical, hold all sorts of minuscule
         | charges... I guess once the process for keeping that all going
         | comes to abrupt halt, electric potentials change which would
         | take into account some electromagnetic field :shrugs:
        
         | volemo wrote:
         | > 100-600 nm (infrared) light
         | 
         | Ultraviolet, you mean.
         | 
         | > I'm curious what could be producing UV and visible light.
         | 
         | There is tons of chemoluminescent stuff in a live being. As my
         | spectroscopist friend says, everything luminesces at some
         | point.
        
         | madaxe_again wrote:
         | I would assume respiratory complexes I and III in mitochondria.
         | Both used highly reduced states to create the gradient to pump
         | protons, and electron leakage is inevitable.
         | 
         | This likely then leads to redox transitions in quinones,
         | flavins, metal centres, leaving them in unstable excited
         | states. When they relax, the excess energy has to go somewhere
         | - usually thermal energy, but just occasionally, a photon.
         | 
         | This would also tally with anaesthetics and injury having an
         | effect, as both effect mitochondrial function - and of course
         | when you're dead, so are your mitochondria.
        
           | DaveZale wrote:
           | Thanks, that's the first thought I had, thanks for reporting
           | mitochondria. Which are not localized stuctures as pictured
           | in undergrad courses.
        
             | teleforce wrote:
             | Yes, I come here to mention that this phenomena has
             | something to do with mitochondria.
             | 
             | For the next decade it most probably will be one of the
             | very important topics in science of life in general.
        
       | epicureanideal wrote:
       | Finally a way we can do the Star Trek "scanning for life forms".
        
         | nntwozz wrote:
         | He's dead, Jim.
        
           | simondotau wrote:
           | I'm a doctor, not a spectrophotometer!
        
         | tantalor wrote:
         | I just love scanning for life forms.
         | 
         | https://www.youtube.com/watch?v=dWBmaKk32fE
        
       | luxpsycho wrote:
       | This is the technology Skynet will harvest to track down and
       | eliminate all life. Finally an objective and measurable metric
       | for this pesky concept!
        
         | r0ze-at-hn wrote:
         | Perhaps this is why creatures keep evolving eyes.
        
         | elzbardico wrote:
         | Frankly, IR signature + movement is more than enough to the
         | ChatGPT+Claude+Deepseek axis to completely obliterate all those
         | pesky electricity wasters that are not involved in useful
         | industries like Energy and Chipmaking.
        
       | moduspol wrote:
       | How soon after death does it expire? Are we talking seconds?
       | Hours?
        
         | fmbb wrote:
         | Exactly 21 moments.
        
           | hhjinks wrote:
           | Imperial or metric?
        
             | ycuser2 wrote:
             | Yes.
        
         | layer8 wrote:
         | When the soul leaves the body.
        
       | stuaxo wrote:
       | We use a lot of energy, its not surprising we emit it.
        
         | cout wrote:
         | It is surprising to me that it is in the visible range.
        
           | _trampeltier wrote:
           | Every body does emit radiation. Most is in IR range, but
           | since nature is very broad, a very small amount is in a wide
           | band from the spectrum.
           | 
           | https://en.m.wikipedia.org/wiki/Black-body_radiation
           | 
           | You can see it in the picture, the radiation is very wide.
        
             | jvanderbot wrote:
             | You'll probably want to compare/contrast that with Fig 1 in
             | the paper https://www.biorxiv.org/content/10.1101/2024.11.0
             | 8.622743v1....
        
           | lovich wrote:
           | If you can see something with your biological eyes, it is
           | emitting energy in the electromagnetic spectrum
        
             | codingdave wrote:
             | More likely to be reflecting, not emitting.
        
               | 1718627440 wrote:
               | Which is actually the same.
        
               | sebastiennight wrote:
               | Simple experiment: Turn off the lightbulb, close the
               | curtains and check again how many of your household items
               | are still "emitting" light.
        
               | 1718627440 wrote:
               | When I provide the necessary energy with the necessary
               | frequency they will.
        
             | cout wrote:
             | I don't know about you, but I have trouble seeing other
             | life forms in a room that is pitch black.
        
               | lovich wrote:
               | I don't know what my comment had to do about being in a
               | situation where you don't see it
        
           | adrian_b wrote:
           | The visible range corresponds to the typical energy
           | differences between different states of an outer electron in
           | a molecule, which also correspond to the typical energy
           | differences between the input and output molecules of a
           | chemical reaction.
           | 
           | (The near infrared range corresponds to the typical energy
           | differences between different vibrational states of the atoms
           | in a molecule. Such energy differences are smaller than the
           | energy differences encountered in most chemical reactions,
           | which involve extracting or adding atoms from/to the
           | molecule, which obviously needs more energy than the
           | vibration of those atoms, when they remain bound in the
           | molecule.)
           | 
           | Thus it is normal and expected that the output molecules of
           | an exothermic chemical reaction may be in an excited state
           | from which they can decay to their ground state by emitting
           | light exactly in the visible range.
           | 
           | As long as it is living, in any organism a lot of exothermic
           | chemical reactions happen. In many cases the energy produced
           | by those reactions is used for something useful for the
           | organism (i.e. the excited output molecules transfer their
           | surplus energy to other molecules), but it also may escape as
           | emitted light, reducing the efficiency in the use of the
           | energy produced by an exothermic chemical reaction to less
           | than 100% (the efficiency is also reduced when the energy of
           | the excited molecule is transferred to other molecules than
           | those intended, which eventually results in warming the
           | environment instead of doing useful work).
        
             | jvanderbot wrote:
             | Hooold up.
             | 
             | So you're saying that there is something special about the
             | visible spectrum? I've always wondered why most eyes we
             | know of work in that range (modulo some leftovers from our
             | time as aquatic creatures)
        
               | benterix wrote:
               | Yeah, I always unconsciously assumed it's just a random
               | slice, never thought deeper about this. Thanks, HN!
        
               | Y_Y wrote:
               | I invite you to consider that most of the light that
               | earth species have had available during their evolution
               | comes from a blackbody emitter at about 6000 kelvins
               | (solar photosphere).
               | 
               | https://www.sciencedirect.com/topics/physics-and-
               | astronomy/s...
        
               | adrian_b wrote:
               | The sensitivity of the eyes is indeed matched to the
               | available light.
               | 
               | However the causal dependencies are more complex than
               | this. If the available light would have been from another
               | range of the possible frequencies, the eyes could not
               | have used the same kinds of photoreceptors that are used
               | now in the eyes of all animals.
               | 
               | For instance, if the available light would have been only
               | infrared, then photo-chemical reactions could not have
               | been used for detecting it, but such light could have
               | been detected by its warming effect, like some snakes do
               | for detecting infrared.
               | 
               | If our star would have been much colder, with negligible
               | visible light, then such light might have been not usable
               | for splitting water and generating free oxygen in the
               | atmosphere. In such a case, the planet would have
               | remained populated only by anaerobic bacteria and
               | viruses, like in the first few billion years of Earth's
               | history.
        
               | sidewndr46 wrote:
               | As other's commented it is "special" because a good
               | portion of the radiation from the Sun is in the same
               | range.
               | 
               | It's also special for a few other reasons. The most
               | obvious one being that UV light is destructive to many
               | forms of animal life, there isn't much utility in being
               | able to see for example something like X-Rays. They don't
               | occur naturally in any quantity and the mechanisms that
               | create them (lightning) also give off visible light.
               | 
               | On the other end of things, lower energy photons are what
               | we would call heat. Some animals can see it, but not
               | humans. We can sense it just fine through other
               | mechanisms however.
        
               | IAmBroom wrote:
               | You're missing a big one: organic chemistry* changes
               | often occur in the 4-7 eV range of energy, which is the
               | visible spectrum.
               | 
               | * Meaning "molecules containing carbon", not "hippy
               | chemistry done without pesticides".
        
             | cout wrote:
             | This is a lot to chew on. Thank you.
        
         | create-username wrote:
         | transforming food into energy and poop seems to be the meaning
         | of life from an individual point of view
        
           | Aerroon wrote:
           | The second law of thermodynamics! Life is the ultimate
           | expression of that. We create order, but to do that we always
           | create more chaos than order.
        
       | amelius wrote:
       | This must be the light my supermarket uses to make meat look
       | fresh.
        
       | ochronus wrote:
       | Oh no, this will feed the "aura" BSers
        
         | aa-jv wrote:
         | Corollary: it'll give the materialism jerks something to think
         | about.
        
           | ochronus wrote:
           | such as?
        
             | aa-jv wrote:
             | Such as, maybe there's more to life than just chemical
             | reactions.
        
               | Antibabelic wrote:
               | Are you implying the light discussed in the paper is
               | supernatural?
        
               | maleldil wrote:
               | Where is the indication that this light (which is barely
               | visible to instruments, let alone humans) does not come
               | from "just chemical reactions"?
               | 
               | This finding is certainly interesting, but it does not at
               | all contribute to "spiritual thinking".
        
               | ochronus wrote:
               | More, how? Come on, be more exact.
        
               | jodrellblank wrote:
               | You be more exact; I've spent plenty of time in internet
               | woo-woo ideas and I don't think I've heard of auras since
               | the nineties, reading about Kirlian photographs from a
               | hundred years before that.
               | 
               | Here you are saying that some unspecified group is
               | deriving some unspecified ideas which are, you claim,
               | life riskingly serious.
               | 
               | Just for the sake of making HN interesting to read, can
               | you stop with the one sentence comments that vaguely
               | imply you know something we don't, and be more exact,
               | explanatory and specific?
        
               | ochronus wrote:
               | no ;)
        
               | I_Lorem wrote:
               | Bioluminescence IS a natural chemical reaction, though.
        
             | richrichardsson wrote:
             | That perhaps the people who claim to see auras were in fact
             | telling the truth due to having the right genetics to be
             | able to observe this light.
        
               | viraptor wrote:
               | They don't. It's normal visible light spectrum, just
               | extremely weak. Nobody can see it with their eyes.
        
               | Aerroon wrote:
               | Supposedly the human eye can detect a single photon under
               | the right conditions though.
        
               | viraptor wrote:
               | Not really...
               | https://www.technologyreview.com/2017/08/08/105518/the-
               | thorn...
               | 
               | Or, yes, under ideal conditions, maybe sometimes. 51.6%
               | chance of being right in a yes/no question will not help
               | in this case.
        
               | codr7 wrote:
               | Nobody is a pretty strong claim.
               | 
               | Human bodies are different in many ways.
        
               | viraptor wrote:
               | This is like saying: "Nobody can jump over this 200m
               | wall. - Nobody is a pretty strong claim." It's really
               | beyond the scope of human vision overall, rather than
               | "really hard".
        
               | moralestapia wrote:
               | Those are ... two different things?
               | 
               | People can pick up single photons, this is definitely
               | within the realm of possibility.
               | 
               | Btw, your level zero snark can be defeated by the "on
               | which planet?" argument.
        
               | markovs_gun wrote:
               | Or perhaps there just happened to be an overlap between
               | the nonsense they believe in and some shred of truth that
               | you have to squint really hard to make work.
        
               | ochronus wrote:
               | That's not even the "BS" part (for me), but what they
               | "derive" from all of that.
        
         | Dilettante_ wrote:
         | God forbid we take something "magical" and extract the real
         | Truth from it? Like, if this is a piece of evidence, aren't you
         | happy to update your assumptions?
        
           | slightwinder wrote:
           | Sadly, that's not how it works. Those nutheads are twisting
           | everything to their convenience, and sell it to idiots, even
           | at the cost of someone's live. And any "proof" of their BS is
           | just solidifying all the other BS.
        
             | Dilettante_ wrote:
             | You have a one-dimensional view of your "opponents". Not
             | everybody who is into spiritual BS is preying on suckers,
             | or a sucker being preyed upon.
             | 
             | The thinking that preceded our current understanding of
             | physical elements was very loose and woo-woo(Water, Earth,
             | Wind, Fire), but we refined.
        
               | slightwinder wrote:
               | I never claimed that everyone is doing this. Are you
               | reflecting?
        
               | h33t-l4x0r wrote:
               | You did though. You said "those nutheads". Not "some of
               | those nutheads"
        
               | slightwinder wrote:
               | Yes, those nutheads who are twisting it, not all nutheads
               | who are in spiritual stuff. There are many old and
               | ancient creeds which are barely changing for decades and
               | centuries. Those can be also problematic, but usually
               | their believers are more pragmatic and won't tell you how
               | you can cure cancer by just praying hard enough while
               | sipping the 200 dollar tea they sell you.
        
               | Dilettante_ wrote:
               | Sorry, I muddled together your reply and the one I
               | originally replied to in my head and seem to have arrived
               | at the strawman "Auras are bs and people who take this
               | article as a hint to them are grifters/victims".
               | 
               | I guess it's a charged topic for me ( _badumm-tss_ ).
        
               | Aerroon wrote:
               | Solid, liquid, gas, and plasma fit the woo-woo
               | explanation of earth, water, air, and fire quite well
               | though. It's actually eerie how well it fits.
        
               | binary132 wrote:
               | Hey, never thought of it like that!
        
               | samus wrote:
               | We have discovered way more exotic states of matter
               | though. And for a preindustrial society there are only
               | three phenomena that involve plasma: the sun, the aurora
               | borealis, and lightning.
        
               | I_Lorem wrote:
               | Fire is not a state of matter, it's a process. Sadly, my
               | prog rock band "Solid Gas and a Process that Creates Heat
               | and Light" never really took off.
        
               | 1718627440 wrote:
               | Liquid is not literally only water either, so I don't
               | think it contradicts the comparison.
        
         | throwaway4302 wrote:
         | I don't believe in auras, but perhaps some of these photons are
         | picked up by human brains unconsciously, even though it can not
         | be seen "directly". Those that sense it feel special because it
         | is not common, and may use supernatural explanations, when it
         | is really just a natural phenomenon.
        
           | ochronus wrote:
           | Yup, could be! My problem is not with that, but rather the
           | things they seem to "derive" from this.
        
           | stocksinsmocks wrote:
           | That one has to use a throwaway to avoid losing HN good boy
           | points from the bitter fedora-posters is a shame.
        
           | codr7 wrote:
           | No one ever claimed that auras weren't natural, just
           | frequencies that most people can't see. Everything vibrates,
           | even physical matter, we've just agreed to experience some
           | frequencies differently.
        
           | Thiez wrote:
           | If humans could detect this light then we could see living
           | things in otherwise complete darkness. But we cannot. So it
           | stands to reason that these photons do not explain "auras",
           | and "It's just your imagination" remains the best explanation
           | for auras. Perhaps they are based on simple after-images: if
           | you stare at something long enough the color detecting cells
           | in your eyes get tired and you start seeing weird visual
           | effects that seem to match how people describe "auras".
        
       | AngryData wrote:
       | Pretty much everything that is either capturing or releasing
       | energy is giving off a spectrum of EM radiation. Usually it is
       | mostly in the IR range, but you really just need sensitive enough
       | equipment to get all sorts of EM noise.
        
         | indoordin0saur wrote:
         | Not "pretty much everything" but actually everything. The only
         | way an object wouldn't emit radiation is if it was at absolute
         | zero, which is something that exists literally no where in the
         | universe.
         | 
         | That said, this light is not the result of just radiating heat
         | and must have a different source.
        
       | dayvster wrote:
       | Woah that's wild, so this gives credence to some more spiritual
       | stuff out there.
        
       | amelius wrote:
       | Can we detect it on exoplanets?
        
         | viraptor wrote:
         | No. If it's barely detectable right next to the organism, it's
         | extremely below the noise level on a planetary scale.
        
           | ourmandave wrote:
           | What if we got 8 billion people to all jump, er, bio-luminate
           | at once?
        
             | viraptor wrote:
             | You'd still get less than 1 cd of luminance in total,
             | unless my napkin math is way off.
        
       | drcongo wrote:
       | Does this mean we can finally answer the question "at what point
       | is a strawberry no longer alive"?
        
       | slightwinder wrote:
       | I prefer to call it heat. Just to clarify the picture.
        
         | alterom wrote:
         | > _visible_ light
        
           | cenamus wrote:
           | > 10-10^3 photons cm^-2 s^-1
           | 
           | So probably invisible but under the very darkest of
           | conditions?
        
             | ricardobeat wrote:
             | Visible refers to being _in the visible spectrum_.
        
           | SkiFire13 wrote:
           | I thought black bodies emitted light the whole spectrum,
           | albeit with differences in the distribution depending on
           | their temperature?
        
             | Sharlin wrote:
             | Yep, but the exponential decay at the short-wavelength end
             | means you're going to hit a single-digit number of
             | photons/m^2/s fairly quickly.
        
         | griffzhowl wrote:
         | This is specifically not thermal (blackbody) radiation, which
         | is negligible at the visible frequency range for mice at these
         | temperatures. The researchers find a difference in visible
         | wavelength emission between living and dead mice _at the same
         | temperature_
         | 
         | This point is addressed on page 2 of the paper.
         | 
         | Paper is accessible on bioarxiv:
         | https://www.biorxiv.org/content/10.1101/2024.11.08.622743v1
        
           | somenameforme wrote:
           | You should post this as a top-level comment because it's
           | extremely informative and most of everybody is just assuming
           | this is just talking about thermal radiation.
        
             | griffzhowl wrote:
             | Done ^^
        
       | zx8080 wrote:
       | Is that just heat?
        
         | neuronic wrote:
         | The source specifically tells you the answer.
        
       | ginko wrote:
       | ..so black-body radiation?
        
         | estearum wrote:
         | no
        
         | neuronic wrote:
         | Is there a reason why you feel compelled to compose a comment
         | before reading or even just skimming the source? Why ask
         | questions that are specifically answered by the provided link?
        
           | ginko wrote:
           | You can only access the abstract without logging in and I see
           | no argument that this isn't black-body radiation in that.
        
       | griffzhowl wrote:
       | A lot of comments are assuming this is just heat.
       | 
       | This is specifically not thermal (blackbody) radiation, which is
       | negligible at the visible frequency range for mice at these
       | temperatures. The researchers find a difference in visible
       | wavelength emission between living and dead mice _at the same
       | temperature_
       | 
       | This point is addressed on page 2 of the paper, accessible on
       | bioarxiv:
       | 
       | https://www.biorxiv.org/content/10.1101/2024.11.08.622743v1
        
         | jvanderbot wrote:
         | Specifically from paper: The live/dead mice (and container)
         | were all held at 37C, which google tells me is a normal mouse
         | body temp. And, the observed light does not match the spectrum
         | of black body radiation expected for the temps at which images
         | were taken or subjects were held.
         | 
         | Also strange: The effect changed w/ injury or anesthetic
         | treatment according to the abstract.
        
           | api wrote:
           | If we had good enough sensors could we use this for screening
           | or diagnostics?
           | 
           | "Aura scanners" has an appropriately cyberpunk feel.
        
             | XorNot wrote:
             | From the abstract the answer basically seems to be yes, and
             | that's how they're pitching it.
             | 
             | They note increased emissions due to injury, which would be
             | consistent with repair activities increasing the general
             | intensity of chemistry happening to facilitate repair at
             | wound sites.
        
           | Fanofilm wrote:
           | Research is finding MicroTubules in the brain likely are the
           | LINK (quantum entanglement) to where Consciousness "lives"
           | (is located). Note that the Microtubules link STOPs while
           | under Anesthesia.
           | 
           | https://www.youtube.com/results?search_query=microtubules+co.
           | ..
        
             | Y_Y wrote:
             | Your idiosyncratic use of capital letters only adds to my
             | skepticism.
        
               | noir_lord wrote:
               | First video when I hit that YouTube link was Joe Rogan.
               | 
               | Skeptic meter caught fire before I could get a reading.
        
               | codr7 wrote:
               | This is such a weird way to navigate life.
               | 
               | Joe Rogan has interviewed plenty of people, different
               | people that have very little in common, just because some
               | of them have controversial views that make you nervous
               | that doesn't mean all the information is useless.
        
               | afthonos wrote:
               | We are constantly bombarded by links to information. It
               | is reasonable to make snap judgments about the quality of
               | the information based on who is providing it. If I'm
               | looking for accurate, factual information on a topic that
               | is clearly prone to magical thinking, a provider whose
               | reputation is to listen to anyone, including people who
               | very much engage in magical thinking, is actually a very
               | bad source. Because they will not filter on anything
               | beyond "is this neat to listen to."
        
               | Starman_Jones wrote:
               | You are correct. However, Joe Rogan should not be the
               | first stop for assessing the scientific plausibility of a
               | new idea. If that is where someone is sending you, that
               | can- and should- be a red flag.
        
               | freejazz wrote:
               | I don't think it's the controversy of his guests so much
               | as many of their unqualified ramblings that get treated
               | as expertise. It's really obnoxious that it all gets put
               | into political controversy when it's just often facially
               | stupid BS.
        
               | codr7 wrote:
               | And you're enough of an expert on all subjects to judge?
               | 
               | Or are you rather shielding from whatever makes you
               | think?
        
               | freejazz wrote:
               | The odd defensiveness of it wherever any criticism is
               | labeled as some sort of philosophy _against_ thinking.
               | 
               | >And you're enough of an expert on all subjects to judge?
               | 
               | Never claimed to be
        
               | indoordin0saur wrote:
               | And to add to that he's interviewed just as many
               | absolutely mainstream scientists whose ideas are not
               | considered controversial
        
               | Terr_ wrote:
               | Nothing weird or new about it: Suppose the foremost
               | source for Dr. Example's claims happens to be the one
               | time they interviewed on Coast To Coast AM [0]. That
               | tells you something about the media-landscape they seek--
               | or have been stuck inside.
               | 
               | [0] https://en.wikipedia.org/wiki/Coast_to_Coast_AM
        
               | runlaszlorun wrote:
               | I havent even RTFA to be fair but I like how often
               | Bayesian heuristics like this turn out to be... Useful...
               | If even not provably "true".
        
               | jamal-kumar wrote:
               | Yeah he types weird and linked some generic YouTube
               | search result that pops Joe Rogan up for some people, but
               | there's some pretty interesting research along these
               | lines that's becoming harder to dismiss as just Roger
               | Penrose stepping way outta his field (I don't see people
               | personally attacking Hameroff or Tuszynski for their
               | roles in this research which always struck me as
               | telling). I think it's more trying to zero in on how
               | consciousness works from the perspective of trying to
               | figure out how xenon administration in anesthesiology
               | works to induce its effects.
               | 
               | https://www.youtube.com/watch?v=QXElfzVgg6M
               | 
               | https://pubs.acs.org/doi/10.1021/acs.jpcb.3c07936
               | 
               | https://www.sciencedirect.com/science/article/pii/S157106
               | 452...
        
             | etrautmann wrote:
             | Why does consciousness have to live somewhere? I currently
             | prefer to think of it as an emergent phenomenon that arises
             | (somehow, we have no clue) from the complex and distributed
             | computations in the brain. Many different systems
             | contribute, and saying that a single level of abstraction
             | is where it lives seems meaningless. Kind of like saying
             | that your video game "lives" in a transistor. It's not
             | wrong, but it's not useful.
        
               | codr7 wrote:
               | We don't seem to be able to find it inside the physical
               | brain, and not for a lack of trying. Just throwing
               | emergent behaviour out there changes nothing, just like
               | it doesn't for AI.
        
               | griffzhowl wrote:
               | There are observed differences in brain function between
               | conscious and unconscious patients. What's wrong with
               | that as an initial characterization of "consciousness in
               | the brain"? The investigation of these "neural correlates
               | of consciousness" is quite a rich research field in its
               | own right
        
               | codr7 wrote:
               | Obviously, but that doesn't tell us shit where
               | consciousness comes from.
        
               | etrautmann wrote:
               | What would "finding it" mean, whether inside the brain or
               | out? It's quite easy to perturb consciousness by messing
               | with the pieces of the brain, via pharmacology, injury,
               | electrical stimulation, etc. I'm not sure why we need to
               | assign responsibility to a single specific component like
               | microtubules. That seems like saying the axle is
               | responsible for a car moving. Sure, not wrong, but not
               | right or explanatory either.
        
             | Terr_ wrote:
             | It sounds like it's time for The Talk [0].
             | 
             | The whole thing is good, but the final punchline in the
             | last three panels are particularly relevant.
             | 
             | [0] https://www.smbc-comics.com/comic/the-talk-3
        
           | griffzhowl wrote:
           | Specific electrochemical processes have their own
           | characteristic photon emissions. Since there are some
           | processes that occur distinctively in living organisms (e.g.
           | to do with metabolism), it was previously thought that these
           | would have characteristic photon emissions, but as far as I
           | know these are the first observations of this kind of thing.
           | 
           | The effect changing with injury or anaesthetic I guess
           | reflects the fact that there are different electrochemical
           | processes occurring in these cases that have detectable
           | differences in the photon emissions
        
             | roughly wrote:
             | I seem to recall the mechanism for anesthetics being
             | something like temporarily depolarizing the mitochondrial
             | walls to shut down ATP synthesis, so that might point
             | towards where the effect is originating.
        
               | pfdietz wrote:
               | That would be lethal. Instead, they affect cell membranes
               | of nerve cells.
        
               | roughly wrote:
               | Ah, thank you, I was misremembering. That sounds more
               | feasible.
        
         | lucozade wrote:
         | Sure but, in fairness, the HN title is a bit misleading. The
         | paper says that the bodies are emitting light in the visible
         | part of the EM spectrum not that the light is visible. And the
         | intensity isn't really high enough to see the light without
         | instruments.
        
           | griffzhowl wrote:
           | True, there's an ambiguity in "visible light" between "EM
           | radiation within the visible frequency range" and "EM
           | radiation within the visible frequency range which is of
           | sufficient intensity that we can detect it with our eyes"
           | 
           | But this is independent of the misconception that the
           | radiation observed in this experiment is thermal. Thermal
           | radiation in the visible range at this temperature is much
           | lower in intensity than the biological radiation observed
           | here, but both kinds of radiation are well below the
           | intensity that we can see with our eyes.
        
           | freejazz wrote:
           | Sure, what isn't fair about debating the headline in the
           | comments without reading the article?
        
         | veunes wrote:
         | The fact that they're seeing visible photon differences between
         | live and dead tissue at the same temperature suggests it's tied
         | to metabolic or biochemical activity, not just thermal noise
        
           | griffzhowl wrote:
           | Yes, exactly.
           | 
           | I should have added that this result wasn't unexpected or
           | mysterious as it might sound, because it's known from physics
           | that different chemical processes have characteristic photon
           | emissions. Since it's known that different chemical processes
           | occur in living and dead organisms, it was expected that
           | there would be differing emissions in the two cases. As far
           | as I know this research is the first actual detection of
           | these differences
        
             | cogman10 wrote:
             | I believe there's an example of something similar happening
             | when fertilization of an egg occurs. There's a zinc
             | reaction which creates "flash" of visible light.
             | 
             | Animals (and plants? Bio 101 was a long time ago) use ATP
             | for a lot of their metabolism and phosphates are pretty
             | well known for emitting light as they react.
        
       | felineflock wrote:
       | I couldn't get to the PDF.
       | 
       | Here are articles commenting some of the content:
       | 
       | https://nrc.canada.ca/en/stories/worlds-first-ultraweak-phot...
       | 
       | https://www.sciencealert.com/we-emit-a-visible-light-that-va...
       | 
       | https://phys.org/news/2025-05-emit-faint-extinguishes-death....
        
       | samirillian wrote:
       | You're all made of stars you gotta let that shit shine okay?
        
       | Dove wrote:
       | Luminous beings are we, not this crude matter.
        
       | nottorp wrote:
       | Was "AI" used in this study?
        
       | Poomba wrote:
       | As someone wise once said, "You just gotta ignite the light and
       | let it shine"
        
         | veunes wrote:
         | Turns out Katy Perry was low-key talking about ultraweak
         | biophoton emission all along
        
       | veunes wrote:
       | Kind of makes you wonder if this could eventually become a
       | diagnostic tool, though I imagine the sensitivity requirements
       | and ambient light issues are pretty brutal in real-world settings
        
         | xattt wrote:
         | "Pause CPR and turn off all the lights."
        
         | cardiffspaceman wrote:
         | When you get dental X-rays, the technician aligns the
         | instrument and leaves the room to push the button that triggers
         | the image capture.
         | 
         | Another problem to solve though, is ignoring the E-M radiation
         | from small life forms that may be in the room.
        
       | rixed wrote:
       | I find it totally inline with expectations that, given
       | sufficiently accurate measurement aparatus, one could detect a
       | difference in light (and sound, and moves, and smell...) between
       | living, stressed or dead things. After all, those are very
       | distinguishable state of matter.
        
       | beanjuiceII wrote:
       | thats because they are npc's
        
       | dgrin91 wrote:
       | I listened to the Radiolab podcast. I remained fairly unconvinced
       | by the reporting on the show, but the part that really didn't
       | make sense to me was, what is their definition of death? My
       | (limited, non-medical) understand is that death has a bit of a
       | spectrum associated with it. At what point does this light stop
       | emitting? When you flatline exactly?
        
         | PorterBHall wrote:
         | I came here with a similar thought. Given that we don't have a
         | really precise definition of that transition from living to
         | dead, I wonder if this could be it.
        
           | sieste wrote:
           | Some parts of the dead mice still emit in that spectrum.
           | There won't be a clear and distinct "the lights went out"
           | moment but a gradual fading, so you'll have to define some
           | threshold to translate from radiation distribution and
           | intensity do dead/alive. I don't think an image of photon
           | emission will help pronounce someone dead.
        
         | andersmurphy wrote:
         | I mean the definition of death is when the light fades right?
         | Everything else is just an approximation. Would be wild if
         | true.
        
       | tantalor wrote:
       | TIL local anesthetics works on plants
       | 
       | https://medium.com/@lukehollomon/anesthesia-works-on-plants-...
        
         | stevenwoo wrote:
         | You might enjoy The Light Eaters, it covers latest studies on
         | plants for consciousness. I'm still very skeptical after
         | reading it, I.e. how to differentiate between automaton like
         | behavior derived from genetic programming and consciousness
         | (argued for in the book) is still not clear to me.
        
       | tropicalfruit wrote:
       | why does it feel like the world is full of "explainers" and
       | "rationalisers"
       | 
       | usually unintentionally pushing the accepted narrative
       | 
       | anytime something interest comes up everyone seems to try to
       | downplay or explain it
       | 
       | the fact is even your explanation is wrong on some level
        
       | buildbot wrote:
       | Isn't it well known you can tell plant health via there spectral
       | return? NVDI cameras/filters?
       | 
       | https://static.publiclab.org/#wiki/ndvi
       | 
       | The difference here being absorption vs. emission I guess?
        
       | butlike wrote:
       | "Luminous beings are we; not this crude matter"
       | 
       | - Yoda
        
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