[HN Gopher] Scientists recreated classic origin-of-life experime...
___________________________________________________________________
Scientists recreated classic origin-of-life experiment and made a
new discovery
Author : sohkamyung
Score : 383 points
Date : 2021-10-29 06:35 UTC (16 hours ago)
(HTM) web link (arstechnica.com)
(TXT) w3m dump (arstechnica.com)
| PGenes wrote:
| Not an expert but wondering why Methane was used as a precursor
| for the experiment since its an organic compound. Was the idea
| not to produce organic compunds from purely inorganic ones?
| gibolt wrote:
| Taken from the Ars comments:
|
| Article Quote: When Miller showed his results to Urey, the latter
| suggested a paper should be published as soon as possible. (Urey
| was senior but generously declined to be listed as co-author,
| lest this lead to Miller getting little to no credit for the
| work.)
|
| As if Urey doesn't deserve enough respect, the story is better
| than described:
|
| Sub-article Quote: After Miller showed the impressive results to
| Urey, they decided to submit them to Science. Urey declined
| Miller's offer to coauthor the report because otherwise Miller
| would receive little or no credit. Knowing that a graduate
| student could have a difficult time getting a paper like this
| published, Urey contacted the Science editorial office to explain
| the importance of the work and ask that the paper be published as
| soon as possible. Urey kept mentioning the results in his
| lectures, drawing considerable attention from the news media.
|
| The manuscript was sent to Science in early February of 1953.
| Several weeks went by with no news. Growing impatient, Urey wrote
| to Howard Meyerhoff, chairman of AAAS's Editorial Board, on 27
| February to complain about the lack of progress. Then, on 8 March
| 1953, the New York Times reported in a short article entitled,
| "Looking Back Two Billion Years" that W. M. MacNevin and his
| associates at Ohio State University had performed several
| experiments simulating the primitive Earth--including a discharge
| experiment with methane wherein "resinous solids too complex for
| analysis" were produced. The next day, Miller sent Urey a copy of
| the clipping with a note saying "I am not sure what should be
| done now, since their work is, in essence, my thesis. As of
| today, I have not received the proof from Science, and in the
| letter that was sent to you, Meyerhoff said that he had sent my
| note for review."
|
| Infuriated by this news, Urey had Miller withdraw the paper and
| submit it to the Journal of the American Chemical Society.
| Ironically, at the same time (11 March), Meyerhoff, evidently
| frustrated by Urey's actions, wrote to Miller that he wanted to
| publish the manuscript as a lead article and that he wanted
| Miller--not Urey--to make the final decision about the
| manuscript. Miller immediately accepted Meyerhoff's offer, the
| paper was withdrawn from the Journal of the American Chemical
| Society and returned to Science, and was published on 15 May
| 1953.
|
| https://www.semanticscholar.org/paper/Prebiotic-Soup--Revisi...
| [deleted]
| interestica wrote:
| > Most ancient recipes call for whole small fatty fish to be
| layered between herbs and salt in concrete vats. Palacios' team
| used large glass fermenting vessels.
|
| There's a future where the art of charred oak barrel bourbon is
| lost and scientists try to recreate it in glass vessels....
| kevinmchugh wrote:
| I think you ended up on the wrong thread
| interestica wrote:
| Yeah what. How did that happen. There's no redemption here or
| some tangential way I can relate this....
| slowmovintarget wrote:
| Somewhat related to this article, though it seems you're
| commenting on something else:
| https://www.smithsonianmag.com/arts-culture/recoving-the-rec...
| gradschoolfail wrote:
| Except, great irony, in TFA, it was the glass vessels and not
| the other ones which had bits of the walls going into solution
| and helping to make the other amino acids. Eventually perhaps
| giving rise to oak trees. Doesnt look like it to a lowly
| primate, but glass has a hallowed place in the cosmos, cherry
| oak is a fucking upstart
| evancoop wrote:
| How many fascinating analogs exist for this problem? "...the
| corrosion on the glass also forms millions of tiny pits. The
| authors think those pits could serve as tiny reaction
| chambers..."
|
| In other words, the experimental conditions, as intended, were
| almost "too perfect." The simulation of reality requires some
| amount of unspecified noise with respect to CONDITIONS, in this
| case, corroded glass.
|
| How many experiments, on the terminal or the bench, are run with
| noise in the underlying test conditions?
| giardini wrote:
| My inorganic chemistry prof was fond of saying organic
| chemistry experiments "usually fail if the labware is too
| clean"!B-))
| dekhn wrote:
| I'm not aware of any bench experiment that eliminates all noise
| (I think that would be physically impossible) but we can
| certainly isolate things from the external environment very
| well, and the physical results you get from those tend to be
| very "clean" (IE, if you're measuring a physical parameter
| which is required to be an integer, and computing a mean on
| your observed values, the mean will be near the integer and the
| variance will be tiny compared to the magnitude of the integer.
|
| On the computer, many "experiments" (really simulations) are
| 100% deterministic and therefore have perfectly predictable
| noise characteristics. Most simulations are not deterministic
| for a wide range of engineering reasons (order of summation in
| a distributed environment, inability to specify random seed)
| but are nondeterministic in a statistically useful way (IE, you
| can run a few times and get a good idea of the real result).
| thereisnospork wrote:
| > How many experiments, on the terminal or the bench, are run
| with noise in the underlying test conditions?
|
| All of them, approximately. There are a few journals like
| http://www.orgsyn.org/ that consist entirely of rigorously
| vetted methods, but that is definitely an outlier. The
| significance of the noise will depend on the specifics, of
| course.
|
| I'm fairly sure there have been a few high profile retractions
| of 'metal-free catalysis' that were ultimately traced to metal
| impurities in the reagents. There was also an incident with the
| DOE where in the process of refurbishing some of the nuclear
| arsenal they found that they couldn't reproduce one of the
| necessary ingredients due to some then unknown change. I am
| blanking on the (code)name of the material they were trying to
| reproduce though.
| icegreentea2 wrote:
| You're thinking of FOGBANK. Apparently they needed some of
| the impurities present in the original manufacturing runs to
| get the properties they wanted. Restarting FOGBANK production
| was problematic because a) the manufacturing process is in
| itself tricky and nasty and then b) once they restarted it
| they discovered the previously overlooked impurities.
|
| Apparently they've resolved that.
| noduerme wrote:
| So the new experiment has three flasks. One is borosilicate, the
| other two are teflon. One of the teflon flasks has pieces of
| borosilicate floating in it. Both the teflon flasks failed to
| reproduce the results of the original experiment.
|
| Couldn't the takeaway here be that life is allergic to Teflon?
| anshumankmr wrote:
| >Couldn't the takeaway here be that life is allergic to Teflon?
|
| Shocking
| high_byte wrote:
| I might have missed something. says the teflon flasks produced
| less organic material, but I assumed it was only the teflon
| without borosilicate? my understanding was that borosilicate
| contributed to creation of organic materials.
| mrob wrote:
| "The results: far fewer organic compounds formed in the
| experiments using just the Teflon flasks."
|
| Not the clearest way to phrase it, but I agree it most likely
| means the loose borosilicate bits worked too.
| high_byte wrote:
| that's what I thought. I think they meant "flask", or
| several "plain teflon flasks" were involved.
| nobrains wrote:
| The takeaway is that the silica / silicate in the glass acted
| as the silica in the rocks and gave a more closer to real-life
| scenario, so it solidifies the original experiment even more,
| while noting that the original authors did not intend this.
| noduerme wrote:
| what I mean is, how do they know that's what helped the
| reaction? The other two flasks were of a different material,
| but the same as each other. How do they know that material A
| aided the reaction as opposed to concluding that material B
| impeded it?
| scoopertrooper wrote:
| The Teflon flask with some borosilicate did have a lower
| ending PH than the flask with only Teflon. Assuming the
| authors ruled out other potential sources for that
| reduction, then one must conclude that borosilicate had an
| effect.
|
| Yes, the pure borosilicate flask had a much greater effect,
| but there was also much greater surface area for the
| solution to work on.
|
| An interesting experiment might be to see if the reduction
| in PH levels scaled with the amount of borosilicate added
| to the solution. They may have done that in the paper, but
| that'd settle the question you posed.
| snowwrestler wrote:
| If Teflon impeded the reaction but borosilicate did not
| help it, then the two Teflon flasks would have had
| identical results. They didn't have identical results,
| therefore logically one can conclude that borosilicate has
| a beneficial effect.
|
| Yes, it would take more experiments to further explore the
| role of the vessel material.
|
| This is how science works in general; someone gets an idea
| and runs a limited experiment and gets results. Then other
| people, seeing the results and understanding the
| limitations, get their own ideas and test those.
|
| What I'm trying to say is that you're not wrong to say
| there is more to test here. But, it's not a fatal flaw to
| this experiment. All experiments have limits to what they
| can prove.
| DanielVZ wrote:
| > This finding supports the authors' original hypothesis.
| Corrosion on the surface of the glass (due to the hot and
| caustic water circulating through it) plays a key role,
| since this releases silicon-dioxide molecules into the
| solution. This in turn acts as a catalyst to speed up the
| chemical reactions between the nitrogen, carbon, and
| hydrogen atoms that ultimately create organic molecules. In
| addition, they found that the corrosion on the glass also
| forms millions of tiny pits. The authors think those pits
| could serve as tiny reaction chambers, also speeding up the
| rate at which organic molecules form in the experiment.
|
| 1. It's known to be a catalyst in the chemical reaction
|
| 2. They believe that the tiny pits in the corroded glass
| also speed up the reaction. This could explain why the
| material of the flask matters.
| wongarsu wrote:
| That sounds like they had a hypothesis, did an
| experiment, the experiment matches their hypothesis, so
| they came up with a reasonable explanation why. But if
| noduerme had done the same experiment with the hypothesis
| "life can't form in the presence of Teflon" the
| experiment would have also confirmed his hypothesis, and
| he would have given you a reasonable explanation why that
| is.
|
| It would have been more convincing/thorough if they had
| also tried e.g. a steel and a silicon carbide reaction
| flask.
| burnished wrote:
| No, I don't think so. Organic compounds still formed just
| fewer.
|
| They might reasonably expect that the teflon, being far
| less reactive, did not appreciably influence the
| experiment.
| mannykannot wrote:
| If it is not the case that the Teflon + glass pieces run
| gave a result between the other two, perhaps the next
| step would be to run the experiment again in the glass
| vessels, but with pieces of Teflon in them. If Teflon is
| neutral, the results should match the glass-only run.
| beerandt wrote:
| Especially since there was borosilicate in the teflon
| tubes, but no teflon in the borosilicate ones.
| alisonkisk wrote:
| One of the teflon flasks had glass in it.
| bborud wrote:
| In my mind STEM topics exist on a scale that has math at one end,
| then there's a slight pause/discontinuity (as in point 2 in the
| underpants gnome business plan) before it continues with physics,
| chemistry, biology and onwards to god knows what. As you move
| along this axis stuff feels more and more complex, messy and hard
| to nail down definitively. More practical. More prone to get
| tripped up by silly mistakes and things you never imagined you
| had to think about.
|
| The new compounds they discovered in the old samples kind of
| illustrates how much hard work is required to get good answers.
| You can't just suck on your pipe, scratch your quill on some
| parchment and exert yourself mentally, you have to scrape gunk
| out of test-tubes and be really careful and thorough in a highly
| practical sense. The world is imprecise and gnarly and you kind
| of have to hope for the best.
|
| I really admire people who are capable of wringing results out of
| goo and specks of dust using gadgets that require calibration
| that has to be able to distinguish actual good signal from
| residues of the danish you had for breakfast.
|
| (Example not entirely random since one of our engineers eating a
| danish for lunch in his office made the electrochemical sensors
| he was working on go absolutely apeshit. Kind of good to know
| before you evacuate a whole industrial site and send in the
| people in yellow hazmat suits)
| wodenokoto wrote:
| > In my mind STEM topics exist on a scale that has math at one
| end, then there's a slight pause/discontinuity (as in point 2
| in the underpants gnome business plan) before it continues with
| physics, chemistry, biology and onwards to god knows what.
|
| Man there really is an XKCD for everything:
| https://xkcd.com/435/
| ARandomerDude wrote:
| "Now one speculative [i.e., theoretical] science is said to
| be nobler than another, either by reason of its greater
| certitude, or by reason of the higher worth of its subject-
| matter...Of the practical sciences, that one is nobler which
| is ordained to a further purpose, as political science is
| nobler than military science; for the good of the army is
| directed to the good of the State."
|
| Thomas Aquinas, ST I, q. 5., a. 1
| 8note wrote:
| I think philosophy sits on either end, making it a circle
| shmageggy wrote:
| > In my mind STEM topics exist on a scale that has math at one
| end, then there's a slight pause/discontinuity (as in point 2
| in the underpants gnome business plan) before it continues with
| physics, chemistry, biology and onwards to god knows what.
|
| https://xkcd.com/435/
| bborud wrote:
| Holy crap! :)
| LanceH wrote:
| And the joke is way, way older than that.
| bborud wrote:
| Whether or not it is a joke probably depends on how you
| label the axis along which you distribute these topics.
| :)
|
| Observe that as you move from one side to the other (math
| to biology and onwards), you are essentially dragging
| along a good portion of the stuff as prerequisites you
| have to know a bit about.
|
| By the time you reach something like immunobiology you
| can pretty much build a house out of the textbooks and go
| live in it. :)
| LanceH wrote:
| The joke as I heard it in the 80's -- and I have no
| reason to think it was new then -- went something like:
| Physics is just applied math, chemistry is applied
| physics, etc...
|
| I've always liked the view that Physics is just
| experimental discovery of the axioms "chosen" for our
| universe. Physics without experimentation just being a
| specific subset of math.
| HPsquared wrote:
| And mathematics is just applied philosophy, philosophy is
| just applied language, and language is again one of those
| "social studies"...
| snowwrestler wrote:
| I try to keep this in mind when reviewing predictions,
| speculation, and fiction about artificial intelligences that
| get super intelligent. There's more to knowledge than just
| calculating faster. Hypotheses need to be tested by
| experimentation; theories must be supported by evidence. (This
| is not my original idea, I read it in an essay from an AI
| researcher.)
|
| This is also why there is more to science than statistical
| analysis. Stats help us understand evidence we have collected.
| But at some point a new idea needs a new test in order to know
| if it is useful or correct.
| azalemeth wrote:
| I've been lucky enough to work with a few highly skilled
| organic chemists, and I know enough chemistry to know that I
| could never, _ever_ join them as such. It 's such a niche,
| specialised, and important and yet under-recognised set of
| skills.
|
| A few examples. The order in which you add nominally
| unimportant reagents to a reaction can significantly matter -
| the enthalpy of mixing is non-zero, and so if you dissolve A
| and then B in solvent C before letting it reflux for five hours
| (say), it will be a different initial condition to adding B,
| then A. Many (most?) chemists weigh vials before adding a mass
| of _x_ g /mg of a compound, in the process of adding that, and
| then again when they have removed " _x_ " grams. Lids are pared
| with volumetric flasks. Tiny variations matter. Room humidity,
| temperature, and the history of the use of the equipment
| involved may change the answers. I had one graduate student
| (who came top in her year in chemistry) make an isotopically
| labelled molecule for me, with a ~70% yield and a ~100%
| labelling purity. A few years later, a biochemist following the
| "recipe" she developed (and beautifully illustrated!) was
| unable to get above 10% yield and about 80% purity. I never
| really was able to work out why. Any "debugging" conversation
| starts with "tell me _exactly_ -- what did you do? ". Things
| occasionally don't go "as well" when certain contaminants are
| (not) present. The debugger for reality sucks.
|
| And still, despite all the fiddly nature of the work, it's
| downright _dangerous_. Organic chemists, as a species, live
| less long. They get blown up and gassed. I 've been in a
| building when a "small scale" reaction has exploded and you
| feel the vibrations of it - nobody was seriously injured
| because the fume hood's shock sensors detected the azide
| derivatives decomposing rapidly and, within microseconds,
| dumped a load of cold CO2 down the front of the hood, stopping
| combustion and redirecting/reducing the blast. Another
| acquaintance of mine managed to have the building evacuated
| after ordering a 10 ml bottle of a compound he distilled from a
| hops extract and identified via GC-MSMS and MS^n spectrometry
| as part of a project trying to understand beer foam (and make
| better non-alcoholic beers; this is in about 2000 or 1999,
| before "good" alcoholfrei bier was available) - he naively
| opened the lid to see what it smelt like outside of the fume
| hood, and immediately uncontrollably vomited. So did his
| neighbours. Then the rest of the room. Then the floor. They
| closed it over a weekend, opened all the doors and windows, put
| in industrial fans, and it still stank for months.
|
| Chemists do important, undervalued work. They make drugs,
| materials, batteries. They do everything from quantum mechanics
| to what I still consider to be not far removed from alchemy.
| Some of them are slightly odd people, but they are usually very
| fun to share a drink with...
| localhost wrote:
| We didn't have fancy fume hoods like that back in the day. Do
| you have a link to the device used in that fume hood? I only
| found this [1] but it doesn't sound like the device you're
| talking about.
|
| [1] https://www.labmanager.com/how-it-works/fume-hood-fire-
| prote...
| bborud wrote:
| speaking of dicey chemistry, I'm sure you have already read
| the book, but to anyone else who hasn't: "Ignition!: An
| informal history of liquid rocket propellants" by John Drury
| Clark (https://www.goodreads.com/book/show/677285.Ignition_)
| made me realize two things: 1) I'm glad I didn't pursue a
| career in chemistry as I would doubtless have been drawn to
| things that are "interesting", 2) people who do "interesting"
| things in chemistry have the best stories.
| taeric wrote:
| I mean. I am not trying to underscore the work. But I feel
| you are making it sound magical. This is not much different
| than cooking, is it? Try making bread or beer by adding
| things out of order.
|
| I feel so much of this mysticism is driven by over reliance
| on associative and distributive laws for elementary math. And
| it is super annoying because I know I do the same thing.
| [deleted]
| maroonblazer wrote:
| He's not making it sound magical. He's pointing out how
| hard it is.
| taeric wrote:
| I think I was just sticking on the gp's "In my mind STEM
| topics exist on a scale that has math at one end..."
|
| Especially with the first supporting evidence being that
| order matters on how you mix things. Only in very
| elementary math, it seems, is that not the case. Yet, we
| stick on that heavily.
|
| That is, I wasn't trying to counter the point. I intend
| my point to be a further exploration on why that makes
| things feel more complicated. Near mystical, in that we
| can't always explain why an order is important. Sometimes
| we can, of course.
| DiggyJohnson wrote:
| I track your point, though I might add that in advanced
| mathematics, things can often be reasoned in multiple
| directions, or sometimes proved via multiple methods.
| Often things are demonstrated irrespective of changing
| parameters, or otherwise the parameters are well
| understood to define the problem.
|
| This isn't true for many orgo chemicals, based on the OP.
| The scale of sensitivity to initial and intermediate (!)
| conditions is un-intuitively high.
| taeric wrote:
| Makes sense. I think it is from a definition perspective,
| though. Statically, it is easy to define things
| independent of the process that governs them. Such that
| it is a middle college class that really covers dynamic
| systems for structural analysis. With most earlier
| classes being static analysis.
|
| Even electrical classes started on analog circuits and
| power transmission later in courses. Early circuits are
| centered around ready dc connections. Or steady state ac
| ones.
| DiggyJohnson wrote:
| I see it as a sensitivity to initial conditions. If
| anything, beginner cooks are more likely to _overestimate_
| this sensitivity (afraid to sub ingredients,
|
| Your examples of bread or beer avoid this, but then
| consider whether brewing beer is a good, differentiating
| counter-example to organic chemistry. ;)
| taeric wrote:
| Yeah, I confess I picked baking and brewing specifically.
| Was also thinking cheeses making.
|
| And agreed that for many processes, it is initial
| conditions. I also consider scaffolding for things like
| keystone arches. The final result being something that is
| only doable with items that are no longer there.
| smitty1110 wrote:
| > azide derivatives decomposing rapidly
|
| I got some major "Things I Won't Work With" vibes reading
| that. Checked the archives and yep, that's a repeat offender
| right there.
| AnimalMuppet wrote:
| "Decomposing rapidly" has an innocuous sound, until you
| stop to think: _how_ rapidly?
| Osiris wrote:
| Stories like this are what make me so frustrated with the
| "anti-science" rhetoric you hear in politics coming from the
| same people that carry a miniature computer in their pocket
| that's the result of (wild guess) millions of man hours of
| research in physics, chemistry, and many forms of
| engineering.
|
| The people that do this work are ACTUALLY making the world a
| better place.
| JoeAltmaier wrote:
| Another anecdote (because it's Friday): We hired a chemist
| from a big rocket company into our computer company. He
| designed organic flammable compounds (rocket fuel) that got
| made in a clean room in vats and packed into tubes by
| technicians. They scraped the rapidly-hardening stuff with
| paddles and smeared it into the tubes. If they left any, the
| vat was toast and had to be replaced.
|
| So they would try really hard to get it all, scraping the
| sides and sometimes jamming the paddle down on recalcitrant
| bits to get them unstuck.
|
| My friend was very nervous about this, and so looked for
| another job, which was how I met him.
|
| Not long after he was working with us, he got a call and
| turned white. He explained: the fellow hired in after him was
| standing behind a technician when the batch went up, turning
| them both into crackly bits of toast. That could have been
| him.
|
| Anyway, no I'm not cut out to be an organic chemist.
| DiggyJohnson wrote:
| Thank you for sharing this story. It's easy to think the
| well-educated/professional/R&D/STEM-academia fields are
| devoid of danger - they are for the most part - but
| survival and safety is not a solved problem in many niches
| of these domains.
|
| I walk through a high-tech, massive industrial factory most
| days I go into the office. I find it harder to remember to
| look for wires and forklifts than I did when I was in roles
| closer to the danger. It's clearly a "natural" risk-
| analysis response, but risk doesn't go to zero, nor should
| the individual ever _completely_ export their risk
| management to confidence in systems, processes, and
| organizations.
|
| The key-cards and clean rooms and smart people can lead us
| to forget these things.
| dekhn wrote:
| tertiary amines, man. That's the reason I couldn't be an
| organic chemist. If you don't like the smell of decaying
| fish, it's tough.
|
| Also pretty much everything in OC ends up being a yucky resin
| at the bottom of a flask you can't remove.
|
| When I visited my grad school for the first time, there were
| ambulances and firetrucks outside the building. I went to the
| main office and there were EMTs everywhere and firemen. Turns
| out, they were doing spring cleaning of a fume hook and
| accidentally touched a bottle of ether. The ether had formed
| free radicals over time, and just touching the bottle caused
| it to expose, popping all the windows out 20 feet away. The
| chemist's face was permanently scarred (although his life was
| safed by the safety glass). That was later my office,
| although I did mostly computational work.
| eyear wrote:
| Facebook should put more money into this kind of research instead
| of hiring PR company to change its name.
| DonHopkins wrote:
| Julia Child had a great recipe for Primordial Soup!
|
| https://en.wikipedia.org/wiki/Julia_Child
|
| Julia Child Cooks Primordial Soup (1973):
|
| https://massasoit.instructure.com/courses/346438/pages/video...
|
| Also a great recipe for shark repellent, that she made for the
| CIA.
|
| https://web.archive.org/web/20180408020021/https://www.cia.g...
|
| >Julia Child and the OSS Recipe for Shark Repellent
|
| >"The answer to the threat of man-eating sharks, the scavengers
| which infest all tropical waters of the world, was announced here
| today..." (quote from draft OSS/ERE Press Release on the
| development of a shark repellent; April 13, 1943)
|
| And she showed how to bone a chicken on Saturday Night Live:
|
| https://www.youtube.com/watch?v=eSxv6IGBgFQ
|
| Previous HN discussion:
|
| Julia Child Cooks Primordial Soup (1973) [video]
| (instructure.com)
|
| https://news.ycombinator.com/item?id=24467695
|
| Video: The Primordial Soup with Julia Child. (Click on the small
| thumbnail in the second row with the (>) "play" icon to see the
| video.)
|
| https://massasoit.instructure.com/courses/346438/pages/video...
|
| The National Air and Space Museum used to show this delightful
| video in its "Life in The Universe" exhibit, in which Julia Child
| recreates Stanley Miller's famous experiment, cooking up a
| delicious hot batch of Primordial Soup!
|
| https://www.smithsonianmag.com/science-nature/julia-child-an...
|
| >Julia Child and the Primordial Soup
|
| >Scientists don't yet know how life began here on Earth.
| Mineralogist Bob Hazen, who is profiled in the October issue of
| Smithsonian, thinks that rocks were key to the development of
| life. Reporter Helen Fields wrote:
|
| >It's the complexity of the hydrothermal vent environment--
| gushing hot water mixing with cold water near rocks, and ore
| deposits providing hard surfaces where newly formed amino acids
| could congregate--that makes it such a good candidate as a cradle
| of life. "Organic chemists have long used test tubes," he says,
| "but the origin of life uses rocks, it uses water, it uses
| atmosphere. Once life gets a foothold, the fact that the
| environment is so variable is what drives evolution."
|
| https://en.wikipedia.org/wiki/Miller%E2%80%93Urey_experiment
|
| >The Miller-Urey experiment (or Miller experiment) was a chemical
| experiment that simulated the conditions thought at the time
| (1952) to be present on the early Earth and tested the chemical
| origin of life under those conditions. The experiment at the time
| supported Alexander Oparin's and J. B. S. Haldane's hypothesis
| that putative conditions on the primitive Earth favoured chemical
| reactions that synthesized more complex organic compounds from
| simpler inorganic precursors. Considered to be the classic
| experiment investigating abiogenesis, it was conducted in 1952 by
| Stanley Miller, with assistance from Harold Urey, at the
| University of Chicago and later the University of California, San
| Diego and published the following year.
|
| https://www.wired.com/2009/05/dayintech-0515
|
| >May 15, 1953: Cookin' Up Some Primordial Soup
|
| >1953: Stanley Miller, just 23 years old, publishes his landmark
| work on the production of amino acids, a necessary component of
| life, in a jar.
| AltruisticGapHN wrote:
| "Wherever there are rocks... watch out!" - Alan Watts
|
| (context: https://www.youtube.com/watch?v=3iEE561GhO8 )
| rdevsrex wrote:
| It's kind of ironic that both in cosmology and biology we know an
| incredible amount, but yet we still don't how the universe or
| life on earth began. Sure, we have educated guesses, but until we
| can unify QM and GR or produce a cell from simple elements, they
| remain guesses.
| SavantIdiot wrote:
| That's how _lots_ of science works. Especially science
| involving the past, or science very far away.
|
| Even if we do create a "cell" (whatever that means), it will
| only give us a possible explanation of how it happened on
| Earth. It will shrink the possible probabilities of all other
| methods, such as Aliens engineering us, but we cannot reduce
| all probabilities to zero... without a time machine.
|
| Unfortunately we live in a world where even 100% definite in-
| your-face proof will not convince a frighteningly large %age of
| humanity.
|
| IMHO claiming everything is "still a guess" shows a lack of
| understanding of science. I'm not judging, because I can't tell
| what you do and don't know from just three sentences. But it
| kinda sounds like it.
| api wrote:
| There are numerous possibilities for how life began, and
| whatever process was involved probably took a minimum of
| millions of years to lead to something self-replicating and
| stable enough to start adapting. This makes abiogenesis
| theories likely impossible to directly test over human time
| scales.
|
| Not that we shouldn't try... it's possible that certain
| conditions can give rise to self-replicating molecular systems
| that can adapt very quickly. This doesn't prove that these
| conditions were the exact ones responsible on primordial Earth,
| but it does prove that the phenomenon of abiogenesis is
| categorically possible under plausible early Earth conditions.
|
| There are lots of other phenomena in nature that may be
| impossible to directly test. Biological evolution for instance
| is _somewhat_ testable, but only on a small scale in both time
| and organismal complexity:
|
| http://myxo.css.msu.edu/ecoli/
|
| We can also run computer evolution experiments that validate
| some of the theoretical assumptions underlying biological
| evolution in a very abstract way, but these can't validate
| specific biological hypotheses about physical systems.
| thriftwy wrote:
| Then there is a mystory of how environment with high availability
| of phosphates, which are responsible for energy transfer in all
| life cells cells, came to be:
| https://shkrobius.livejournal.com/401292.html
| adrian_b wrote:
| While there is much that is unknown yet, there is much less
| mystery about phosphates than many people think.
|
| In the modern oceans, there is a very high abundance of calcium
| and magnesium ions.
|
| This keeps the phosphate concentration in the water low,
| because when there is much phosphate, it precipitates with the
| calcium ions, making apatite rocks.
|
| However the oceans at the time when life appeared had a
| composition different than today.
|
| The oceans have formed by the condensation of the volcanic
| gases, which are made of water and of acidic substances (mainly
| oxides of carbon and sulfur and hydracids of halogens and
| sulfur).
|
| So the initial oceans were very acid. After formation they
| began to dissolve the more easily soluble rocks, e.g.
| carbonates and phosphates and then also the easier soluble of
| the silicates, starting with the alkaline silicates.
|
| So the concentration of phosphate in the initial oceans was
| much higher than today, due to the very low pH of the water and
| due to the lack of calcium and magnesium ions in appreciable
| quantities.
|
| In time the pH of the oceans increased tending towards the
| neutral value (today the oceans are slightly alkaline, but that
| changes with the increase of carbon dioxide in atmosphere,
| which makes them more and more acid), while the concentration
| of sodium and potassium increased, neutralizing a part of the
| acids.
|
| Because the rocks with calcium and magnesium dissolve much
| slower than those with sodium and potassium, the concentration
| of calcium and magnesium in the sea water remained low for a
| longer time and it probably reached the current levels much
| later, after the apparition of life.
|
| Only then the concentration of phosphate diminished to the
| current values.
|
| So a much higher initial availability of phosphate in solution,
| in the sea water, is expected, it is not mysterious.
| ldehaan wrote:
| This makes me think, maybe the most important thing in the
| universe is silicon, and also, we're silicon life, computers Are
| our babies. I am yo neighbor.
| qvrjuec wrote:
| The Miller-Urey experiment isn't relevant to me after learning
| more about the hydrothermal vent theory for abiogenesis. "The
| Vital Question" by Nick Lane is a great read for anyone
| interested in the topic
| StuntPope wrote:
| Only problem is that the Miller Urey experiment never told us
| anything about the origin of life.
|
| Inorganic to organic compounds, sure. But nobody has ever been
| able to get from there to cells and DNA.
| FabHK wrote:
| > never told us anything about the origin of life
|
| There are several steps to go from no life to life as we know
| it. This experiment illuminates one of those steps. How is that
| "nothing"?
| ballenf wrote:
| It's kind of like saying learning to jump really high is the
| first step to getting to the moon.
| csee wrote:
| This is an example of why analogies and metaphors make
| clear thinking difficult. They're easy to think up - anyone
| can find some abstract similarity between X and absurd
| thing Y - but there is no substance there since the two
| things being compared are actually very different beyond
| that abstraction.
| 1_player wrote:
| Certainly. It would help to understand gravity, which is
| absolutely crucial to flying to the Moon.
| AutumnCurtain wrote:
| Also helps with an immediate understanding of ballistics
| and escape velocity
| pfdietz wrote:
| Or like saying "look, the monkey can sometimes make small
| words appear when it bangs on the keys of this typewriter.
| This tells us something about the origins of novels."
| SavantIdiot wrote:
| A better analogy, but it still can be steered toward,
| "...without a Writer. This is why there is a Writer."
| Capital intentional.
| gliptic wrote:
| Learning how writing was invented is certainly a step
| towards understanding the origin of novels.
| FridayoLeary wrote:
| studying the behaviour of a monkey when introduced to a
| typewriter doesn't. Studying the formation of a few
| molecules in a controlled environment hardly explains how
| living forms came to exist.
| gliptic wrote:
| If you never learn where a few molecules came from, how
| could you possibly make progress on the problem?
| dekhn wrote:
| we made substantial progress in biology before we
| understood molecules. this is because it's not necessary
| to be entirely reductive to understand larger systems.
| gliptic wrote:
| Yes, but we're talking origin of life.
| dekhn wrote:
| this experiment only reduces the uncertaintly that the
| building blocks are widely available. The big problem wiht
| this experiment is that it misestimated the nature of the
| early atmosphere and os they basically simulated another
| planet. We don't know if any other planets have life, so
| simulating another planet isn't useful to illuminate anything
| about life on earth.
| ls612 wrote:
| Huh? We know whatever the early conditions of earth were
| they were clearly amenable to the formation of these
| organic compounds since life arose here. It's absolutely
| also interesting to know that in certain known conditions
| this can also arise, even if those conditions are not the
| only conditions capable of creating the phenomenon.
| phonypc wrote:
| It doesn't tell us _nothing_ , it's just not the whole story.
| And why should one expect a single experiment to tell the whole
| story?
| TheRealDunkirk wrote:
| It would seem that the next logical experiment is to take
| Miller-Urey as a given, throw a perfect blend of polymer
| chains into the "soup," and see if they can start forming RNA
| chains. I thought I had read about such an experiment, but I
| can't find a reference to it now. Anything coming up in
| Google for me is being obfuscated by this recent study, and
| mRNA COVID vaccine stuff.
| JumpCrisscross wrote:
| The term you're looking for is the RNA world hypothesis.
| mannykannot wrote:
| I think what the naysayers are missing is that if this
| experiment had failed to generate any of the sort of organic
| molecules strongly associated with life, that would have shaken
| things up - or would you have been just as eager to dismiss
| this experiment in that case?
| SavantIdiot wrote:
| I think this is the fallacy of arguing the middle usually
| deployed against science.
|
| There's a great example of Futurama, where the evolutionary
| naysayer demands an intermediate form, and Farnsworth shows
| him one... then he demands another, and Farnsworth shows THAT
| form... and this cycle repeats hundreds of times until
| Farnsworth has no intermediate form and the naysayer declares
| victory.
| pfdietz wrote:
| Indeed.
|
| There is just enormous amounts of shoddy thinking out there
| from people on the subject of Origin of Life. I'm particularly
| annoyed by the non sequitur "the universe is large, so there
| must (with high probability) be life elsewhere." (If anyone
| reading this thinks that's a valid argument, go look in a
| mirror and slap yourself.)
| whaaswijk wrote:
| Would you like to say a bit more about why that's not a valid
| argument. To be clear, I'm not saying it is (I don't know
| enough about the subject to do so) but it doesn't seem that
| far-fetched to me. Isn't similar probabilistic reasoning used
| to explain why evolution by natural selection gives rise to
| various complex life forms? If so, do you also think that
| that reasoning is shoddy?
| pfdietz wrote:
| Let N be the number of places life could arise, and p the
| probability that life arises in one of those places.
|
| That argument is basically "there is a value of N such that
| for any p > 0, N p is much greater than 1."
|
| But that's obviously wrong. For any N, there are values of
| p > 0 that make the product N p arbitrarily close to 0.
|
| The dim intution behind the argument was that p can't be
| "too small". But given our current understanding of OoL,
| that's not a justified assumption. p could be exponentially
| small, if OoL requires some extremely unlikely step.
|
| Natural selection is great once the system's reproductive
| fidelity is good enough to support it. The problem is
| bridging the gap from small molecules to that system. The
| smallest system we know of that can independently support
| Darwinian evolution has billions of atoms.
| mannykannot wrote:
| This explains why it may not be a sound argument, not a
| demonstration of its invalidity. The distinction matters,
| because while invalid hypotheses can be summarily
| rejected, valid ones might turn out to be right.
|
| Of course, if some people don't understand that this one
| is not an established fact, and that annoys you, I can't
| say you are wrong.
| pfdietz wrote:
| Yes. Of course, I was not arguing that life must be rare,
| I was arguing that the evidence we have does not compel
| one to believe life must exist elsewhere in the universe.
| The opposite of belief is not belief in the opposite.
| JZumun wrote:
| In this formulation, isn't p^N the probability that ALL
| places where life is possible, actually has life? It
| makes sense for that to approach zero.
|
| What we want is the probability for at least one other
| place other than ours to have life. This would be 1 -
| (1-p)^N, which does tend to 1 as N gets arbitrarily
| large.
|
| To get that formula: (1-p) is the probability that life
| does not exist in a place, so (1-p)^N is the probability
| that ALL places where life is possible, has no life.
| Therefore, 1-(1-p)^N is the probability of the opposite
| of that (where at least one place has life).
| pfdietz wrote:
| For a random variable X taking on non-negative integer
| values (here, the number of occurrences of life elsewhere
| in the universe), by Markov's inequality the probability
| that X = 0 is >= 1 - E[X]. Here, E[X] = Np, so if Np is
| very close to 0, the probability that X = 0 will be very
| close to 1.
|
| That the probability goes to 1 as N goes to infinity FOR
| FIXED p is just another example of assuming p can't be
| "too small". The probability also goes to zero as p goes
| to zero. Why are you fixing p and not N? Why are you
| assuming p is large enough that N is in that asymptotic
| range where the probability has approached 1?
| mannykannot wrote:
| That seems right, but from a scientific point of view (as
| opposed to, say, a certain sort of theological view), two
| occurrences is not much more than one (even though one is
| so much more than zero.)
| pfdietz wrote:
| Two occurrences would actually be much more than one! Our
| own existence is useless due to observer selection, but
| discovery of even a single other independent OoL event
| nearby would allow us to infer OoL cannot be too
| uncommon.
| [deleted]
| mannykannot wrote:
| Observer selection does not eliminate us as evidence for
| the proposition that life can exist. As for whether it is
| rare, you added the qualification 'nearby', and while it
| is true that it is most likely that any extraterrestrial
| life we detect will be nearby, the post I was replying to
| was arguing about the universal probability of life
| coming into existence, not about whether it will be
| discovered by us.
|
| Furthermore, proponents of an extraterrestrial origin of
| life on Earth will doubtless argue that nearby life may
| have had a common origin.
| ls612 wrote:
| Observer selection means p > 0 (ie the inequality is
| strict) but it can't tell us any more. Bayesian reasoning
| from our own solar system can put a reasonable upper
| limit on p but that isn't very helpful.
|
| However, if we found life on Mars that same Bayesian
| reasoning would imply a meaningful lower limit on p as
| well, since life on Mars is independent of our existence
| to observe it.
| gliptic wrote:
| But selection can happen with autocatalysts as well. I
| agree that you can't say life /has/ to exist elsewhere,
| but I think the trend in research has shown that life
| seems likelier and likelier to arise the more it is
| studied.
| pfdietz wrote:
| "Trend in research"? How could that possibly work?
| Research will tend to clear the low hanging fruit early,
| which means the easy steps. This tells us nothing about
| how difficult the difficult steps (if any) might be.
|
| The analogy I like here is those "collect the letters"
| games you see at fast food outlets and grocery stores.
| Buy a Happy Meal, get a scratch off ticket. If you
| collect all the letters in some phrase you win $N
| million. When you start the game, the trend is great.
| Letters are arriving and the phrase is filling in. But
| try as you might, that last letter never shows up. The
| game ends and you've won nothing. Of course, the way the
| game was designed was that last letter controls how many
| winners there could be. All the rest were distractions.
| gliptic wrote:
| It does however tell us that the "easy" steps are easy,
| which was never a foregone conclusion. The other steps
| will remain what they are. It doesn't mean the trend will
| continue.
|
| I find it weird to use a deliberately rigged game as an
| example. If one of the previous letters was wrong, the
| last letter being right means you don't win either. It's
| like saying the difficult steps are going to be extra
| difficult because other steps were found easier than
| expected.
| pfdietz wrote:
| The point is that if you have N independent boolean
| random variables X1 ... Xn, establishing a lower bound on
| the probability that some proper subset of the Xi are
| true doesn't provide any useful lower bound on the
| probability they all are true.
| gliptic wrote:
| Sure, my point was only that if the lower bound on the
| subset is higher than anyone expected, that will increase
| the probability of them all being true compared to your
| prior belief. And it will also increase the probability
| that life is more common.
|
| You could argue that the priors were garbage I suppose.
| I'm not arguing for any particular probability.
|
| The McDonalds example does not have independent variables
| as X1..Xn-1 are deliberately increased as Xn is
| decreased. I'd also argue that origin of life doesn't
| have independent variables. If chemistry turns out to be
| more or less powerful in one setting, it should do
| _something_ for our assessment of other settings,
| especially when it 's similar processes.
| adgjlsfhk1 wrote:
| The question becomes what do you think the hard step is?
| pfdietz wrote:
| It's not up to me to show that, since I'm not claiming
| life is rare. It's up to the person making the strong
| statement that life is (not just could be) common to
| convince me that there is no sufficiently difficult step.
| All I need to do is plausibly argue there could be a
| difficult step. Pointing out the complexity of all known
| self contained systems capable of Darwinian evolution is
| sufficient for that.
| sophacles wrote:
| > p could be exponentially small, if OoL requires some
| extremely unlikely step.
|
| "exponentially" is not a measure of size, nor is it a
| measure of relative size. If you think this anything base
| on "exponentially small" is a valid argument, go look in
| a mirror and slap yourself.
| csee wrote:
| What about the argument that our existence is some
| evidence that a Bayesian estimates of p can't be so small
| that N p is less than one?
|
| You're focusing on (lack of) evidence for a mechanistic
| explanation but that's not exhaustive.
| pfdietz wrote:
| The problem there is we don't know the "world" of
| possibilities from which our existence was drawn. It
| might be the universe (which I read "observable
| universe"), or it might be out of a large number of
| causally disconnected universes, or even other branches
| of a universal wave function (in a Many Worlds
| interpretation). The "N" there is not the same as the "N"
| of "our universe".
| csee wrote:
| We know approximately the lower bound of N, which is the
| approximate number of stars in the observable universe
| multiplied by an informed estimate of the expected number
| of planets within the goldilocks zone. That's usually
| what people mean when they discuss N. N could be that, or
| it could be much much larger, but I think it's fine to
| limit the discussion to the lower bound, we still have a
| huge N to work with.
|
| Also I think you missed my point which is about Bayesian
| estimation of p, not of N.
| ibraaaaa wrote:
| https://youtube.com/c/DrJamesTour
| gliptic wrote:
| https://youtu.be/ghJGnMwRHCs
| dandotway wrote:
| TL;DR summary: The actual glass the lab flasks were made of
| mattered.
|
| Miller's lab flasks were made of borosilicate glass and this
| caused more organic compounds to form than a more truly inert
| Teflon flask. But Earth's crust is over 90% silicates which could
| have similarly contributed to the formation of organic compounds
| in ancient pre-life earth.
| mod wrote:
| I thought the more important fact was that the original
| experiment produced a bigger variety of aminos than previously
| thought, discovered by re-examining the original material with
| modern tech.
| jonplackett wrote:
| It's weird how this was the headline of the article but it's
| only mentioned very briefly right at the end of the article
| with very little explanation.
| WesolyKubeczek wrote:
| It's so that you get to read the whole thing. Granted, it's
| written well, so the time reading it has been spent well.
| gaoshan wrote:
| So does this mean that any planet with a reduced atmosphere,
| electrical storms, silicate-rich rocky surfaces, and liquid water
| would have a good chance of developing life, at some point?
| dekhn wrote:
| you can't conclude anything from these experiments like that.
| we can conclude that many planets are likely to have rich
| organic soups, but nobody has made plausible link from organic
| soups to true living information processing systems.
| freeflight wrote:
| _> nobody has made plausible link from organic soups to true
| living information processing systems_
|
| Even "true living information processing systems", whatever
| those are supposed to be, are only made up of the same basic
| parts as said organic soup.
| dekhn wrote:
| yes, but apparently through some irreducible complexity
| (arguable), and most of the original history of we got from
| "a soup" to "life" has been erased.
| xbmcuser wrote:
| So the ancient belief of 3 elements that led to existence of life
| is correct. soil, water, fire/lightning,
| mrfusion wrote:
| I think the simplest life is at least few orders of magnitude
| more complex than creating amino acids though. I feel people
| gloss over this fact.
| reubenswartz wrote:
| I don't know if people gloss over it, or it's just a good place
| to start. It's like if you were wondering how a giant Lego set
| came to be, you might start with the pieces.
| mrfusion wrote:
| I think an analogy would be we created some of the lego
| blocks in this experiment but a single cell would be akin to
| all the lego creations in the world.
| briffid wrote:
| And it is also especially helpful if intelligent beings drive the
| whole process :)
| wombatmobile wrote:
| > In addition, they found that the corrosion on the glass also
| forms millions of tiny pits. The authors think those pits could
| serve as tiny reaction chambers, also speeding up the rate at
| which organic molecules form in the experiment.
|
| Interesting. Photo please, anyone?
| xor99 wrote:
| This reminds me of the chemist who's beard was so long and dirty
| it led to his experiments crystallising with high frequency due
| to the amount of matter falling off the hairs into solution.
| dekken_ wrote:
| Organic/non-organic distinction is arbitrary. Life is just
| complexity manifest.
| sabellito wrote:
| Is this your area of expertise? I'm asking because making this
| distinction does sound useful to me, but I'm no biologist nor
| philosopher.
| robbiep wrote:
| The philosophical name for this concept is panpsychism.
|
| Personally, I'm a panentropist (my own creation) - I hold
| that the spectrum of life/consciousness varies depending on
| the level of entropy. So a flame has a higher level of
| consciousness than a piece of paper and oxygen molecules. But
| when you combine them they increase their level. It's weird
| but it might be correct - doesn't address issues of the hard
| problem of consciousness however
| The_rationalist wrote:
| A living being is a machine designed to reduce entropy, the
| opposite of your hypothesis
| angst_ridden wrote:
| A living being is a machine designed to reduce
| _localized_ entropy. In decreases internal entropy while
| creating greater external entropy.
| bufbupa wrote:
| That still doesn't rectify the conflict. The living being
| is reducing local entropy -- meaning it's less conscious
| than if it maximized local entropy per gp comment. Or put
| in real terms, lighting yourself on fire likely does not
| make you more alive/conscious even though it definitely
| increases your entropy.
|
| If anything, it seems like the reversal of entropy would
| be a better description of life. To make paper and oxygen
| from fire would have higher consciousness than a fire
| itself
| dekken_ wrote:
| We are the universes own entropy minimization function.
| And are the product of a local equilibrium.
| FredPret wrote:
| That's pretty interesting. The more possible states a
| system has, the more room for consciousness.
|
| The ultimate organism is then either civilization itself,
| or the whole universe, depending on how you want to draw
| the line.
| FabHK wrote:
| > The more possible states a system has, the more room
| for consciousness
|
| That is one of the postulates of Integrated Information
| Theory, which aims to give an account of how
| consciousness can arise from physical substrates. (The
| idea seems closely related to the concept of entropy.)
|
| https://en.wikipedia.org/wiki/Integrated_information_theo
| ry
| dekken_ wrote:
| I didn't say it wasn't useful. My comment is in terms of
| physics rather than biology or chemistry. i.e. in physics,
| there is little difference but complexity between a rock and
| a human.
| enkid wrote:
| I don't think that many physicists would agree. There's
| this whole idea if entropy in physics, which is basically a
| valuation of information in a system, and humans would be
| much more complex when looking at that than a rock. There's
| also a lot more interesting stuff going on inside a human
| body than there is for a rock.
| dekken_ wrote:
| > There's also a lot more interesting stuff going on
| inside a human body than there is for a rock.
|
| Yes, it's complexity, that's my point.
|
| > There's this whole idea if entropy in physics
|
| I am aware, you're assuming it's not related, whereas I
| would say it very much is.
| dahart wrote:
| What does complexity mean, exactly? How does it demark
| the line between living and not, is there a threshold,
| and what is the threshold?
|
| There's also a lot more interesting stuff going on inside
| a car, a computer, or the planet earth that is made of
| rocks, than there is for an individual rock. Our solar
| system is extremely complex, yet is not alive. So
| complexity doesn't seem to mark the line between living
| and non-living things at all.
|
| Saying life is "complexity" seems reductionist and almost
| information-free, it doesn't really explain or even shed
| any useful light on the difference between living things
| and non-living things, since there are plenty of examples
| of high complexity, low-entropy inorganic objects &
| systems. We can synthesize complexity all day, but we
| don't know how to synthesize life yet.
| yldedly wrote:
| One interesting aspect is that living organisms are in
| thermodynamic non-equilibrium, while most dead matter
| always evolves towards equilibrium.
| neatze wrote:
| This is also, best strategy to search of extra
| terrestrial life, the concept of entropy for living
| systems deeply fascinates me, because how simple
| everything becomes (conceptually); life is entropy
| maximization systems in universe, looking at human kind
| it most efficient too.
| dekken_ wrote:
| > One interesting aspect is that living organisms are in
| thermodynamic non-equilibrium
|
| On what scale? Can you provide some sources/references
| please?
| yldedly wrote:
| Can't find a good general intro, but these articles take
| this viewpoint:
|
| https://science.mit.edu/life-away-from-equilibrium/
|
| https://www.pnas.org/content/114/3/423
|
| Edit: Here's a good intro:
| https://www.youtube.com/watch?v=10cVVHKCRWw
| nathias wrote:
| so is bad code, the distinction is about emergent properties
| desertraven wrote:
| This is succinct and quite eye-opening for me. Would you be
| willing to elaborate in any direction you please?
| nmaleki wrote:
| The commenter is likely referring to complexity from
| simplicity, best shown in Stephen Wolfram's Rule 30. I'll be
| talking about this topic, and its implications, at length in
| an upcoming video on https://recursion.is/youtube.
| 74B5 wrote:
| Since the beginning of time, things merge. Subatomic
| "particles" into atoms into molecules into bigger molecules,
| all directed by physics. Biochemistry, is just chemistry, is
| just physics.
| zKqGcn wrote:
| And physics is just applied mathematics! It's applied
| complexity all the way down.
| bloopernova wrote:
| And physics is mathematics, correct?
| FabHK wrote:
| > physics is mathematics, correct?
|
| Just applied linear algebra (or so claimed my professor
| of linear algebra...)
| solarengineer wrote:
| I thought physics is described by mathematics.
| goatlover wrote:
| If it's all physics, where does the math to describe it
| come from?
| GoblinSlayer wrote:
| From imagination.
| goatlover wrote:
| The physics imagines math to describe itself?
| datashaman wrote:
| axioms
| goatlover wrote:
| And the axioms?
| Invictus0 wrote:
| God
| mewpmewp2 wrote:
| And the God?
| nxmnxm99 wrote:
| God
| macromagnon wrote:
| From one perspective, mathematics is the study of the
| methods of reasoning on abstract concepts. Theorems
| follow from any set of axioms that do not lead to any
| contradiction. In physics, one is usually only interested
| in results relating to the current universe we live in.
| In that sense, mathematics can be viewed as more general.
| goatlover wrote:
| For Tegmark, that's enough to argue reality is every
| possible universe of mathematics.
| goatlover wrote:
| That ignores emergent features, and that it's impossible
| for us to describe chemistry or biology only in terms of
| physics. Reproduction is one of the emergent features of
| biology.
| acceit wrote:
| That doesn't sound right to me[1]. Surely physics +
| enough detail _is_ biology? Maybe it 's not a level of
| detail we actually understand with contemporary science
| -- hence the addition of higher level abstractions like
| biology which are derived "top down" rather than "bottom
| up" (i.e., empirically) -- but "emergent systems" !=
| "magic".
|
| [1]: me: a complete layperson.
| goatlover wrote:
| We should distinguish the field of physics, which is a
| human study, from the world, which it attempts to map or
| model on a fundamental level. We can say biology and
| chemistry are made up of the fundamental stuff of the
| world which physics seeks to understand, but that's
| different from saying chemistry and biology are just the
| science of physics. We have different domains for a
| reason. How that cashes out in the world itself are
| metaphysical questions of ontology, emergence,
| reductionism, mereology and Platonism/universals. Also
| the status of causality and laws of nature.
|
| But then again, philosophy is also a domain of human
| inquiry. The world is just whatever it is, however we
| think it best to describe. Problem is that our different
| domains of descriptions and questions don't always fit
| easily with one another. So to say it's all just the
| domain of physics is to mistake one map for the
| territory.
| GoblinSlayer wrote:
| By organic here are meant aminoacids specifically and possibly
| their polymers.
| FabHK wrote:
| To be fair, it was not just "organic", but quite specific
| organic, namely proteinogenic amino acids that make up
| proteins.
| sdhfjg wrote:
| Are you ok?
| JimWestergren wrote:
| Very interesting. From a book? Please elaborate :)
| taneq wrote:
| We're all just pretentious chemical reactions.
| dekken_ wrote:
| trying to minimize our own action
| taneq wrote:
| That pesky free energy, it's gotta go.
| mypastself wrote:
| We have such a limited understanding of life that calling it
| "just" anything, at least with any degree of confidence, seems
| unfounded.
|
| Our definitions are somewhat inadequate and full of edge cases
| and blurred lines. It doesn't mean we should dismiss them out
| of hand, especially since the circumstances of life's origin
| are so mistifying.
| secondaryacct wrote:
| It s not mistifying that much if you look at the chemical
| timescale. Give me 2 bn years and see where I go. Try to
| imagine what that amount of time for random permutation can
| give in the entire space of the universe and you're bound to
| have a self reproducing machine popping up once.
| pfdietz wrote:
| This is a total non sequitur. The smallest organism we know
| of capable of independent self replication and Darwinian
| evolution has billions of atoms. The complexity gap from
| Miller-Urey style experiments to that is enormous, vastly
| overwhelming mere billions of years. Maybe there's some
| trick that evades this gap, but if so we don't know what it
| is, or how likely Origin of Life would be even with the
| trick.
| XorNot wrote:
| Well this seems extremely specious. To presume the entire
| history of life must remain in existence on a heavily
| life-colonized world is bizarre reasoning. Any "simple
| self-replicator" would have long since been exterminated
| by it's more sophisticated next generation species, not
| to mention the multiple ages of radically different
| environmental pressures (i.e. the oxygen apocalypse) in
| the Earth's history.
|
| You're essentially arguing that the absence today of
| simple replicating amino-acid organisms somehow implies
| that they must spontaneously form far far more complex
| systems to do so: yet the evidence says otherwise - we
| know for a fact and can observe the existence of purely
| RNA-based enzymatic systems
| (https://en.wikipedia.org/wiki/RNA_world) which are
| curiously involved in things like protein synthesis in
| our cells today.
| pfdietz wrote:
| You are now committing the other Origin of Life non
| sequitur that annoys the hell out of me: confusing the
| statement "the evidence does not require one to believe
| X" with the statement "the evidence requires on to
| believe not-X".
|
| I'm not arguing that life must be rare. I'm not arguing
| that the smallest Darwinian replicator must have billions
| of atoms. I'm arguing against the PRESUMPTION that there
| must be a small replicator, and the inference (from that
| presumption) that life must be common. There is no
| evidence for such a small replicator (the RNA world work
| does not provide it). And understand that even if the
| smallest replicator were much smaller than this billions-
| of-atoms thing, it could still present a super-
| astronomical complexity gap.
| tlb wrote:
| The evidence for small replicators is that we now have
| large replicators. Whatever the absolute probabilities
| are, the relative probability of spontaneous emergence of
| small replicators is much, much larger than large
| replicators. Therefore, large replicators most likely
| evolved from small replicators.
|
| Put another way: the most likely ancestor of all
| replicators was probably close to the smallest molecule
| that works.
| pfdietz wrote:
| Ah, this is the inference "we are here, therefore life
| must be common".
|
| This is bogus, because it ignores Observer Selection. We
| are not at a randomly chosen planet in the universe (or
| in a larger multiverse), we are at a planet where there
| exists observers who could observe life exists. The more
| uncommon observers are, the more biased our position
| would be.
|
| Ask yourself: if OoL were exponentially unlikely,
| requiring super-astronomical numbers of tries to get it
| to occur, far beyond the number of stars (or even atoms)
| in our visible universe, what exactly would we see that's
| different from what we do see? If there is no such thing,
| how could current evidence rule out that possibility?
|
| I will totally agree that the mechanism by which life
| arose should be among the easiest routes to life. But
| this doesn't mean that process was likely in any absolute
| sense, just that it was among the least unlikely.
| freeflight wrote:
| With people as insistently contrarian as you seem to be,
| I really wonder what alternatives, of how life came
| about, you are proposing?
|
| Is it really just pure agnostic nihilism along the lines
| of _" We know nothing!"_? Or do you know of more
| reasonable alternative explanations, not investigated in
| experiments like this?
| pfdietz wrote:
| I have a strong objection to claims that are based on
| specious logic. Why are you so tolerant of such claims?
|
| You seem to be suggesting that a bogus conclusion is
| better than admitting we don't yet know. This is
| dishonest and I reject it.
| tlb wrote:
| I'm not claiming life must be common. The strong
| anthropic theory explains why we can be having this
| conversation despite the probability of life emerging
| being arbitrarily low, so there's no reason to assume the
| probability of life must be high.
|
| But no matter what that probability is, when there are 2
| alternative pathways for a step, we should assume the
| more likely one. I merely claim that
| inorganics -> small replicators -> large replicators
|
| is more likely than inorganics -> large
| replicators
| neatze wrote:
| This is false (to some degree), if my memory is correct,
| life on earth emerged as soon as condition where favorable
| ~400m years after earth was formed, I am not saying it's
| aliens, aliens?
| pfdietz wrote:
| Another explanation for that would be that the conditions
| under which life could arise were only temporary: it had
| to arise then, or it wouldn't arise at all. For example,
| possibly life arose in one of a very large number of wet
| planetesimals that were still warm enough (due to decay
| of short lived isotopes like 26Al) for the water to be
| liquid. Or perhaps phosphides in infalling meteorites
| were necessary to provide some necessary form of chemical
| energy.
| neatze wrote:
| Such a fascinating point that I did not think about, it
| seems this is related to competing theories what world
| was first; RNA world vs Protein World (may be even both).
| pfdietz wrote:
| Another possibility would be that panspermia could be
| possible in densely packed newly forming star clusters,
| like the one our solar system was born in.
|
| These clusters can be very dense (10,000 stars per cubic
| parsec, perhaps). With such closely spaced stars, and
| with residual gas around the stars, it might be much
| easier for material ejected from one system to be
| captured in another.
|
| So, IF life arose very early in one such system, it might
| spread to all the others. The statistical weight of
| "early OoL" events would be amplified, vs. OoL events
| that occurred later after the cluster had spread out and
| dissipated. Observers would tend to derive from these
| prolific spreading events, just because they'd seed so
| many systems.
|
| This is a nice scenario for science fiction, since it
| would allow thousands of life bearing systems in our
| galaxy (with compatible biosystems!), while evading much
| of the bite of the Fermi argument. In this scenario, SETI
| should look for stars with compositions very similar to
| the Sun, spread on an arc ahead/behind our system on its
| orbit around the center of the galaxy (the stars would
| have spread to about 180 degrees along this orbit since
| their formation).
| alisonkisk wrote:
| That's an assumption not a conclusion.
| XorNot wrote:
| Self-replicating machines already happened once, in many
| varieties. It's far from an assumption unless you want to
| appeal to the idea that they were intentionally created,
| but that really only pushes the problem further down the
| stack.
| gameswithgo wrote:
| carbon is probably the only atom with enough chemistry for that
| complexity to manifest. half of chemistry is organic chemistry
| zackmorris wrote:
| Carl Sagan made amino acids with a similar experiment, I remember
| my dad telling me about it back in the 80s. It looks like he
| joined the scene a little later though, and that Urey (who only
| won a Nobel prize for discovering deuterium) was his mentor:
|
| http://abyss.uoregon.edu/~js/glossary/miller_urey_experiment...
|
| https://www.loc.gov/collections/finding-our-place-in-the-cos...
|
| https://www.discovermagazine.com/planet-earth/scientists-fin...
| dekhn wrote:
| the original article was used in my graduate program as a list of
| all the things biologists shouldn't do when working on origin of
| life. Like, "they got the basic details of the atmosphere wrong".
| https://en.wikipedia.org/wiki/Atmosphere_of_Earth#Evolution_...
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