[HN Gopher] Can self-replicating species flourish in the interio...
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Can self-replicating species flourish in the interior of a star?
(2020) [pdf]
Author : benbreen
Score : 100 points
Date : 2023-01-03 21:04 UTC (1 days ago)
(HTM) web link (pdfs.semanticscholar.org)
(TXT) w3m dump (pdfs.semanticscholar.org)
| jerf wrote:
| While this paper acknowledges at the beginning the need to pump
| entropy out of a system faster than the local system is injecting
| it (criterion three, but that is my own summary, and a bit
| different than they phrased it), and they claim they cover it, I
| don't actually see how they cover it. The only thing they discuss
| is the gradient between the inner star and outer star, which does
| indeed involve an energy flow, but the relevant question is
| whether you can get a gradient between the "inside" and the
| "outside" of the _organism_ and pump enough entropy out of it to
| make up for what is being generated inside.
|
| I am deeply skeptical of any such claim for the inside of a star
| because of the sheer amount of entropy constantly being jammed in
| by the environment. A star entity would be made of relatively
| normal matter (compared to some other things), even mediated
| through magnetic fields, and would be working on not entirely
| dissimilar time constraints from us, so it is difficult to see
| how that could work.
|
| (Contrast Robert Forward's story about critters living on old,
| relatively quiescent neutron stars:
| https://en.wikipedia.org/wiki/Dragon%27s_Egg While if I had to
| bet, I'd bet reality still makes that impossible, at least the
| Cheela creatures built of degenerate matter would be working with
| reactions that themselves run much more quickly than our normal
| matter reactions do, so one can imagine that even though their
| environment is pumping more entropy in than our environment does
| per second, perhaps something could run more quickly and pump it
| out again at rates conventional matter could not. A star creature
| is in an environment that could run at perhaps modest, single-
| digit multiples "faster" than us, but is getting _enormous_
| multiples more entropy pumped in. I don 't see the ratio working
| out favorably.)
| united893 wrote:
| Could you help me understand what it means to "pump entropy out
| of a system"?
|
| I asked ChatGPT and it claims "It is generally not possible to
| "pump" entropy out of a system in the same way that it can be
| added to a system. This is because the second law of
| thermodynamics states that the total entropy of a closed system
| will always tend to increase over time."
| jerf wrote:
| It's a bit of a colloquialism, I think, but the idea is, all
| of your biological processes are constantly generating
| entropy.It is constantly tending toward a system in
| equilibrium, as physical systems do, but you are essentially
| _made_ out of non-equilibrium systems. You need the water to
| be here, but not there. Your nervous system is based on
| electrical gradients that, left to their own devices, will
| normalize. Every cell has an electric potential gradient it
| maintains (google "cell proton gradient"). All of these
| things and thousands more are constantly breaking down and
| require energy to maintain. Basically, imagine the difference
| between a recently dead body that just attained ambient
| temperature and a living one. Characterizing all those
| differences would be more than the work of a lifetime.
|
| A super abstract, but physically valid, way of expressing
| that is that your body is constantly "generating entropy" and
| it needs to consume energy to fight it. "Pumping out that
| entropy" is what the body is doing when it takes in energy
| and uses it to maintain all those gradients.
|
| Life in general may not use organic chemistry, or chemistry
| at all, but the advantage of this level of abstraction is
| that any life form (in this universe) will have to do
| _something_ to "pump out the entropy". It is essentially by
| definition a deviation from the equilibrium state around it,
| and it will require energy to maintain.
|
| The point I am making here is that there must be some ability
| to pump out the entropy faster than it is being generated, or
| pushed in to the system. Otherwise those gradients and
| variations from equilibrium will be erased. Inside a sun,
| there is so much heat energy being pressed in to the system
| that it is challenging to imagine how any conceivable
| structure could push it back out again.
|
| This boils down to the observation that "Holy cow, the sun
| is, like, _REALLY HOT_! ", but, you know, wrapped up in a
| different formalism that allows us to get past "But what if,
| like, there's something that could deal with that?". You see
| this online, the challenge that someone needs to _prove_ that
| there 's no way to build something that could live in the
| sun. If you don't have thermodynamics as a tool, this isn't
| even necessarily unreasonable. But thermodynamics gives us a
| principled way to turn around and say "Any such system would
| have to have this and that and the other property, and it's
| really hard to see how plasma and magnetic fields in such a
| violent environment could have that." It's so not-close that
| it's not really plausible.
|
| ChatGPT may be referring to the general conceptual space/idea
| that you can't just build a machine to "reverse entropy"
| trivially. The most common example of this is that you can't
| just build an anti-microwave, that remotely cools things by
| shooting radiation at it in some easy manner. It is _sooooo_
| much easier to add entropy than remove it; that is definitely
| true. In fact, it 's kinda a key element of my point here.
| But you _can_ pump entropy out of a system, in some ways,
| with some machines, in some manners; since you are literally
| such a machine yourself, you are an existence proof of that.
| nextaccountic wrote:
| ChatGPT is wrong here because in order to "pump" entropy out
| of a system this system must not be closed! So to ask it, you
| must insist the system isn't closed.
|
| And, specifically, living organisms can't be closed systems,
| because their existence depend on spending energy to decrease
| their internal entropy, increasing the entropy of the
| external environment in the process, in order to keep their
| own entropy low enough to still function without random
| breakage we would expect from an aging system.
|
| And we all know that entropy _always_ wins in the end, and we
| always break if we are old enough, so this is a sisyphean
| task; but we still do it all day every day, because we are
| afraid to die.
|
| Anyway, https://en.wikipedia.org/wiki/Entropy_and_life
| mtlmtlmtlmtl wrote:
| As usual ChatGPT is only half right. The sun is not a closed
| system.
| eternityforest wrote:
| Why is asking ChatGPT becoming so common? Are people
| experimenting with AI or actually expecting google-like
| quality of information?
| mtlmtlmtlmtl wrote:
| Beats me. It was pretty obvious to me early on when
| asking about any field I know well that it had no
| understanding and would happily blurt out a wrong, but
| plausible sounding answer. So I haven't even tried to ask
| it abkut stuff I don't understand. Because how would I
| even tell if the answer made sense? Seems like an easy
| way to get the completely wrong idea.
| Arnavion wrote:
| People love DeepL translations for the same reason, that
| they sound convincing, even though they are often
| completely wrong. Even before that people were (and still
| are) trusting the infocards that Google puts in search
| results based on arbitrary snippets it extracted from the
| webpage, because those snippets are presented as
| authoritative even though they're often out of context or
| completely wrong.
|
| People are used to AI being clunky, unfocused,
| ungrammatical text, ala markov chain bots from the 2000s.
| So conversely this kind of verbose, coherent, well-
| written text appears to be knowledgeable and correct.
|
| I can only hope that deepfakes and such become popular
| enough that people learn to be less trusting of what they
| find on the internet.
| [deleted]
| idiotsecant wrote:
| I disagree, I think it's a case of the question being asked
| imprecisely. When you ask the right question chatGPT gives
| you a very insightful and accurate answer.
|
| Human :
|
| By what means might entropy be pumped out of one part of a
| system and into another part?
|
| ChatGPT:
|
| There are several ways that entropy can be transferred from
| one part of a system to another: Heat
| transfer: Entropy can be transferred from a hotter body to
| a cooler body through heat conduction, convection, or
| radiation. Work: Entropy can be transferred
| from a system to its surroundings when work is done on the
| system. Mass transfer: Entropy can be
| transferred from a system to its surroundings through the
| transfer of matter. Information transfer:
| Entropy can be transferred from a system to its
| surroundings through the transfer of information.
| Chemical reactions: Entropy can be transferred from a
| system to its surroundings through chemical reactions,
| either through the production of heat or through the
| transfer of matter. Electrical currents:
| Entropy can be transferred from a system to its
| surroundings through electrical currents.
| Magnetic fields: Entropy can be transferred from a system
| to its surroundings through the generation of magnetic
| fields. Gravitational fields: Entropy can be
| transferred from a system to its surroundings through the
| generation of gravitational fields.
| mtlmtlmtlmtl wrote:
| If the person knew how to ask the question "correctly",
| they wouldn't need to ask.
|
| They asked about systems, not closed systems. ChatGPT
| just regurgitated the 2nd law, which is just plain wrong
| no matter how you slice it. Any physicist asked this
| question would explain the distinction.
| idiotsecant wrote:
| In the context of this question, system has a specific
| technical meaning though. This is a very technical
| question so chatGPT might be forgiven for assuming the
| technical meaning.
| mtlmtlmtlmtl wrote:
| So what is ChatGPT supposed to be useful for if people
| need to understand what the answer is in order to ask the
| "correct" question? Clearly the person didn't pick up on
| this closed/non-closed distinction which is why they
| ended up asking on a forum instead of reformulating.
|
| I think GPT just saw "entropy" and "system" and predicted
| 2nd law. Which is the sort of low effort response you
| might get if you ask random non-experts on the internet.
| samus wrote:
| "Pumping entropy out of a system" to me means keeping the
| system more orderly. To drive such processes, you have to
| increase entropy elsewhere, which is also known as using
| energy.
| monkeydreams wrote:
| Wouldn't the star itself be the closed system? Any lifeforms
| within it are free to reduce their own entropy so long as
| they increase entropy within the system.
| Sharlin wrote:
| A star, of course, is itself almost as far from a closed
| system as it is possible to be in our universe.
|
| A bomb calorimeter in a chemistry class might be
| approximated as a closed system for the purposes of
| thermodynamics. Very few things in nature can.
| nextaccountic wrote:
| The star is constantly sending stuff outside (solar wind
| and light / photons)
| leejoramo wrote:
| Dragon's Egg is my favorite hard SF novel. I remember attending
| a session with Robert Forward at an early 1980s World Science
| Fiction Convention and was amazed at how much detail science
| and math Forward put into his books.
| idiotsecant wrote:
| Agreed, great book. Anyone who enjoys thinking about the
| extremes of possible life might also enjoy Blindsight by
| Peter Watts. It blew my mind about the nature of thought and
| consciousness in the same way dragon's egg blew my mind about
| the nature of time and consciousness.
| milesward wrote:
| Next try "there is no anti-memetics division"
| idiotsecant wrote:
| I could have sworn there was a popular SCP by the same
| name! I will check this out, thanks!
| akiselev wrote:
| _> I am deeply skeptical of any such claim for the inside of a
| star because of the sheer amount of entropy constantly being
| jammed in by the environment. A star entity would be made of
| relatively normal matter (compared to some other things), even
| mediated through magnetic fields, and would be working on not
| entirely dissimilar time constraints from us, so it is
| difficult to see how that could work._
|
| I am not a physicist but I think this is a moot point when the
| entire basis of the paper is string theory and requires the
| existence of hypothetical monopole particles to encode
| information like DNA. This is all sounds like wild speculation
| built on top of the most speculative _theoretical_ physics
| still active in academia.
| jerf wrote:
| I decided to cut them a bit of slack on that point, since you
| can build a magnetic monopole quasiparticle, apparently:
| https://gizmodo.com/elusive-magnetic-monopole-phenomenon-
| fou... which would probably do what they want.
|
| Though, again, how to keep _any_ "quasiparticle"
| coherent/retaining the necessary properites in the middle of
| a _star_ is, to put it charitably, an open question.
| aortega wrote:
| I read somewhere (if someone remember it, please tell) a short
| history about life in neutron stars. It would be incredible fast
| due to the abundance of energy, with the evolution from 'stone
| age' to computer age happening in milliseconds.
|
| Due to being in a deep gravitational well, such life and life
| inside a star are forever isolated from us. Unless they discover
| a way to use solar flares, in fact, perhaps solar flares are
| their way to escape the surface of the sun.
| ars wrote:
| There's also enormous time dilation, they would appear to be
| moving very very slowly from our POV.
|
| It would be magical if both those phenomenon exactly counter
| each other (I have not run any numbers, but my instinct tells
| me time dilation will win out).
| idiotsecant wrote:
| I think a neutron star would have time dilation below 2x.
| Would be interesting at our time scale, but on the order of
| magnitude we're discussing of the increased chemical speed i
| think it would just be noise.
| ars wrote:
| A neutron star is right on the edge of being a black hole,
| which has infinite time dilation. A neutron star should
| have very very high time dilation.
| jessriedel wrote:
| https://en.wikipedia.org/wiki/Dragon%27s_Egg
| lajy wrote:
| Dragon's Egg [1] and Starquake [2] by Robert L. Forward are
| both hard sci-fi novels about fast-moving life on a neutron
| star. I enjoyed both of them, especially the xenobiology and
| xenoarcheology.
|
| [1] https://en.wikipedia.org/wiki/Dragon%27s_Egg
|
| [2] https://en.wikipedia.org/wiki/Starquake_(novel)
| at_a_remove wrote:
| Buried in the first assumption is the question of _structure_.
|
| Instead of chemistry, which I will refer to only by analogy,
| let's imagine Tinkertoys, the old wooden ones.
|
| 0) A tinkertoy ball with zero holes can connect to nothing. It is
| a monad. It is boring. You can build nothing with it. This is
| rather like a noble gas. (Hahah yes you can build a cage around
| Xenon very clever thank you move along)
|
| 1) A tinkertoy ball with one hole can connect to another
| tinkertoy ball. If you have only these, well, you can form pairs
| with them, but nothing beyond the pairs. This looks like diatomic
| molecules. You can jumble them about but you cannot build a
| larger structure with them. Another dead end.
|
| 2) A tinkertoy ball with two holes can connect with two other
| tinkertoy balls with the same number of holes. If this is all you
| have you can build a long chain, as long as you like. Were it not
| so ruthlessly hungry for other electrons, ozone, which is to say
| three oxygen atoms, is a very flawed example. Sulfur, the next
| Group VI element, is better ... you can make chains of six to
| thirty sulfurs rather easily.
|
| Let me pause here. This is really a fundamental question: can you
| do anything _interesting_ with this chain of sulfur atoms? Are
| there fascinating Van der Waals self-interactions? Can you
| effectively "knot" these chains, forming a higher level
| structure? This is the absolute bleeding edge.
|
| I propose that you need to hit ...
|
| 3) Tinkertoy balls with three or more holes. At that point you
| can form branching structures or a flat plane, and so on. This
| would be your nitrogens and phosphorus-analogues.
|
| My general thought is that, whether you have whole atoms with
| valence electrons, or wads of nuclei in a neutron star, whatever
| "chemistry" or equivalent is going on, you need three holes, or
| the ability to form three connections to other components, to
| create structure more than a humble chain, and that these
| connections must be relatively stable. If there is a chemistry
| analogue occurring on or in a neutron star, or some kind of
| strange plasma, or really _anything_ , you must have a minimum
| number of connections to form a large enough structure to be more
| than just isolated bits of matter.
|
| I will allow that the "chain" model of just two connections might
| lead to something, but I wouldn't lay money on it.
|
| Granted, I'm a fan of Forward (and his son's work as well), but
| my guess is that the nucleonic matter alone wouldn't support
| those kind or number of connections, or "bonds," as fun as it is
| o think about.
| JoBrad wrote:
| Reminds me of a less-snarky version of Ryland Grace's paper (from
| Project Hail Mary).
|
| The absolute extremes a living organism would need to be able to
| survive are insane.
| steppi wrote:
| There's a 1964 story, _The Truth_ , by Stanislaw Lem on this
| matter which is worth a read [0]
|
| [0] https://thereader.mitpress.mit.edu/the-truth-by-stanislaw-
| le...
| bmitc wrote:
| _Dragon 's Egg_ by Robert L. Forward is a novel that has a
| species living on the surface of a neutron star.
| viksit wrote:
| this was amazing thank you! do you have a list of books you
| read or recommend (goodreads) to peek at?
| johngossman wrote:
| Thank you! Did not realize there was a Lem book I had not read.
| rollcat wrote:
| Photino Birds immediately jumped into my mind.
| https://xeelee.fandom.com/wiki/Photino_Birds
| https://en.wikipedia.org/wiki/Xeelee_Sequence
| Geee wrote:
| Could you engineer a system, with a huge computer and fusion
| reactor to look like a star? Consider that all life would be
| digital at this point. If we take energy production and
| computation to the limit with huge scale, it might start to
| resemble a star. It would also be a perfect hiding place and
| defensive structure against aggressors. Rather than trying to
| eliminate your heat signature, you max it and hide in plain
| sight.
| [deleted]
| FredPret wrote:
| That's a great idea for a scifi novel right there. I wonder if
| you could steer the star around by shining more of the
| radiation out of one end, or focus it all into a beam of death
| olex wrote:
| There's a great concept that I found out about reading
| Schlock Mercenary (a sci-fi webcomic), about using a gas
| giant as an interstellar spaceship [1]. It probably
| originates elsewhere, but it was nicely explained there. You
| build a "candle" (huge tube) that is inserted into the gas
| giant on one side, then ignite the gases inside it (iirc the
| comic uses fusion reactors on both ends, and an intake in the
| center of the candle). Both ends of the candle are open,
| "inner" end counteracts the gas giant's gravity to keep the
| candle from sinking into the core, the other end produces
| thrust. You put your payload on moons that orbit around the
| gas giant, and steer by moving the candle. The "thrust end"
| of the candle also doubles as a light and heat source for the
| moons, replacing the sun while in interstellar space. There
| are... some risks involved into the whole operation.
|
| [1]: https://www.schlockmercenary.com/2003-08-03
| Geee wrote:
| In addition to Kardashev scale, there should be a scale for
| how much power can a civilization project on an enemy at
| once. More advanced civilization should be able to project
| more power on similar scale as Kardashev. I.e. being able to
| project one star's power on an enemy would be a type 2
| civilization.
| idiotsecant wrote:
| Not only is there a scifi novel or a zillion about such a
| thing but you can read the best (i think) one right on the
| authors website.
|
| Accelerando by Charlie Stross is not only about sun-brains,
| but is also about how they change human society and culture.
| Good book.
|
| https://www.antipope.org/charlie/blog-
| static/fiction/acceler...
| Tangurena2 wrote:
| Corrected link: https://www.antipope.org/charlie/blog-
| static/fiction/acceler...
|
| Note: I have both a dead-tree and kindle edition of this
| book.
|
| I really like the idea of freeing the lobsters and I agree
| with the points he makes about "owning" minds.
| pixl97 wrote:
| I would think a black hole would be much more practical to use
| as an energy source and keep hidden.
| NegativeK wrote:
| Energy production from a black hole requires adding to its
| mass, which might not be a good long-term plan.
| jmyeet wrote:
| Let me introduce you to Matrioshka Brains [1]. It's not quite
| what you suggest. In this case it's one (or more) successive
| shells around a star to use the solar output into computing
| power. The amount of computing power you could get from this is
| simply unimaginable.
|
| This structure would have similar properties (and honestly
| isn't really that different to) a Dyson Swarm. Assuming
| thermodynamics holds the only way to get rid of heat ultimately
| is to radiate it away into space. At any temperature you're
| likely to get to this is going to be infrared light. The
| wavelength of radiated heat is solely determined by
| temperature.
|
| So could you instead radiate away visible light? Technically,
| yes. Kind of. One way is simply to use a lot less of the
| energy. Now could you get the temperature up to where this has
| a visible light signature instead? You're talking about
| thousands of degrees. What material could get that hot? It's a
| big problem.
|
| Also, such a material will still have telltale signs.
| Spectroscopic signature would reveal it wasn't the expected
| hydrogen-helium mix.
|
| Another possibility is a truly giant star. Stars can get
| incredibly large. IIRC the largest known star (UY Scuti) if it
| were placed at the Sun's position would be large enough to
| swallow Jupiter.
|
| The thing is. These supergiants/hypergiants don't have a
| hostile boundary or surface in the same way a cloud from a
| distance looks solid. It would be hot but really diffuse.
| Technically it would be possible to build within the star's
| atmosphere and dump the heat.
|
| [1]: https://www.youtube.com/watch?v=Ef-mxjYkllw
| RajT88 wrote:
| The paper hedges its bets on a rather lower bar for the
| definition of life.
|
| By which definition, prions would likely be considered to be
| alive. But I think the consensus is that prions _aren 't_ alive,
| and are just self-replicating proteins.
| itronitron wrote:
| Reminds me of a thought I had after learning that it takes about
| 100,000 years for a photon to escape from the interior of a star.
| That is a long time, and the photons might be useful in conveying
| information throughout the structure of a star, in the same way
| that an electron propagates information through a brain.
| Extrapolate from there...
| neatze wrote:
| Relevant short sci-fi story how such alien lifeform would view
| us;
|
| https://www.mit.edu/people/dpolicar/writing/prose/text/think...
| raydiatian wrote:
| > Life can be thought out as a dynamical hy- percycle (DNA
| encodes proteins, proteins help DNA to self- replicate, DNA
| encodes proteins, etc.) that can survive indefi- nitely as long
| as free energy is available for it, and as long as self-
| replication goes faster than the destruction of information
| carriers.
|
| Somebody posted something on here awhile back, definitely last 2
| years, that suggested a really novel & fun to think about view on
| "life", stating that life is a manifold for information through
| spacetime. DNA must replicate in order to prevent its dissolution
| into entropy, and life therefore exists because nature threw
| together the right random shape for the building blocks of self-
| preserving space-time informational manifolds. I'm doubtlessly
| paraphrasing and summarizing poorly, but my inner hippie was
| going "whooaaaa mannnnn far out!!"
| drjasonharrison wrote:
| AFAIK, this isn't an "April's Fools" paper.
| https://www.sciencealert.com/physicists-argue-that-life-base...
| optimalsolver wrote:
| This was the idea behind Frederik Pohl's novel The World At The
| End Of Time:
|
| https://en.wikipedia.org/wiki/The_World_at_the_End_of_Time
| irrational wrote:
| And Dragon's Egg
|
| https://en.wikipedia.org/wiki/Dragon%27s_Egg
| ndsipa_pomu wrote:
| On seeing the title, I was wondering if this was connected to The
| Algebraist by Iain M Banks.
|
| Edit: I've misremembered the story and confused stars with gas
| giants
| yababa_y wrote:
| but it may be connected to sundivers, by david brin :)
| vesrah wrote:
| or Flux by David Baxter, maybe :)
| henearkr wrote:
| _Stephen_ Baxter, not David.
| vodou wrote:
| Betteridge says no.
|
| https://en.wikipedia.org/wiki/Betteridge%27s_law_of_headline...
| bobkazamakis wrote:
| How about you let us know when it says yes.
| helf wrote:
| No one has mentioned Andy Weir's "Hail Mary" yet?? :) fun book
| with "astrophages".
| mcdonje wrote:
| IIRC, they didn't live inside stars.
| helf wrote:
| True. I think it's on the surface.
|
| BUT THATS JUST WHAT WE KNOW ABOUT in that universe XD
|
| _jazz hands_
| raydiatian wrote:
| ...sssssssspoiler alert
| skykooler wrote:
| For the first chapter, sure.
| raydiatian wrote:
| Reflexive contrarianism detected
| helf wrote:
| I actually thought about that after I had typed it and left
| it for awhile. WOOPS
| marcusverus wrote:
| Fun is the perfect word for it. Hail Mary was the first time I
| ever read a newly released book and immediately thought "that's
| a classic".
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