[HN Gopher] Amino acids found in asteroid samples collected by J...
___________________________________________________________________
Amino acids found in asteroid samples collected by Japan's
Hayabusa2 probe
Author : jiocrag
Score : 287 points
Date : 2022-06-06 06:12 UTC (16 hours ago)
(HTM) web link (english.kyodonews.net)
(TXT) w3m dump (english.kyodonews.net)
| [deleted]
| andrewflnr wrote:
| > "Proving amino acids exist in the subsurface of asteroids
| increases the likelihood that the compounds arrived on Earth from
| space," he said.
|
| Are we sure it doesn't just mean the compounds were already
| sitting on Earth for the same reason they're sitting on the
| asteroid? I guess maybe if literally all of them were cooked to
| death in the Hadean and had to be refreshed from space, but then
| how do they avoid being cooked to death in asteroid impacts?
| hetspookjee wrote:
| I belief the latest theories state thet life started already
| before the end of the Hadean. From that I conclude that cooking
| to death occurs less than one might think. 4.1B years ago while
| the hadean ended 4B years.
|
| https://www.science.org/content/article/scientists-may-have-...
| ChoGGi wrote:
| Poor Stanley Tweedle
| CosmicShadow wrote:
| I guess I'm not the only person who still thinks about him
| hetspookjee wrote:
| Not the first time they found amino acids on a asteroid, but
| great news nonetheless. For example the Murchison Meteorite had
| over 70 different aminoacids found on it while parts of the
| meteorite being dated as old as 7b years.
|
| https://en.wikipedia.org/wiki/Murchison_meteorite#Nucleobase...
| jasonlotito wrote:
| The article mentions this already (that meteorites on earth
| have been found with amino acids). The important difference
| here is the in the Murchison case, it was already exposed to
| Earth's atmosphere and environment, so you couldn't be sure
| where the amino acids came from.
| TedDoesntTalk wrote:
| Can amino acids survive the intense heat on entry into the
| atmosphere?
| Knufferlbert wrote:
| Apparently it's thought that meteorites hitting the ground
| freeze water around them after a bit. They get heated up,
| but it's pretty short, so the bulk of it is "space
| temperature" only the surface is heating. And a lot of the
| stuff that heats up is ablated. (depending on size)
|
| Unless the stuff is on the surface of the meteorite it's
| probably fine.
| arbitrage wrote:
| Sometimes!
| vixen99 wrote:
| Yes, but the fact that thirty three of these Murchison amino
| acids are 'unknown in natural materials other than
| carbonaceous chondrites' gives pause for thought.
|
| https://pubmed.ncbi.nlm.nih.gov/11542462/
| mushbino wrote:
| What does this mean exactly? Or what could it mean?
| turndown wrote:
| That meteor is either proof of pre-Earth life, since
| those amino acids aren't known to exist in rock otherwise
| or proof that the relevant amino acids can be created by
| an abiotic process. If you don't want to believe the
| meteor has been contaminated since it hit the Earth.
| mattlondon wrote:
| Hypothetical question:
|
| Let's assume for a while that amino acids are everywhere in the
| solar system or galaxy (if not universe). Let's also assume that
| there are many earth-like planets.
|
| If we found alien life on another earth-like planet, could it be
| possible that it too would have independently-evolved DNA? Not
| just DNA-like substances, but chemically identical DNA?
|
| I guess I am wondering was DNA such an incredible fluke here on
| earth that we'll never see it again, or is it "the logical
| conclusion" for a bunch of similar amino acids in very similar
| environments? IIRC DNA is a chemically stable structure etc
| yababa_y wrote:
| In https://chemrxiv.org/engage/chemrxiv/article-
| details/60c7588..., they find the common nucleobases are found
| earlier in enumeration, so you might expect most life use it
| rococode wrote:
| Convergent evolution has been observed many times on Earth. I
| think it's plausible that a similar process of evolution may be
| possible for DNA.
|
| https://en.wikipedia.org/wiki/Convergent_evolution
| cdumler wrote:
| It's a good question. It seems there are meany sources,
| including production on earth[1] and in space. It seems a lot
| of commonly available chemicals in space if hit with light or
| electricity will generate them. The open question has been what
| does it take to generate RNA/DNA. There has been suggestion
| that RNA would be unlikely to form in open, active water like
| found on early Earth. However, Mars would have had shallow
| oceans with large amount of shore area for chemicals to combine
| in quiet.
|
| The Panspermia theory is that RNA/DNA formed there and was
| ejected by asteroid hits to Earth. Support for that theory is
| that life appears to have formed within a few hundred million
| years of it being possible on Earth, which seems far too short
| of a time for RNA/DNA to form spontaneously in an ocean Earth.
|
| If this is all true, life may be a fluke and requiring a rather
| stable set of environments to work. All of this is hard to know
| with a sample size of one, though.
|
| [1]
| https://en.wikipedia.org/wiki/Miller%E2%80%93Urey_experiment
| mywittyname wrote:
| I'm by no means an expert on this subject.
|
| There are many different forms that RNA takes, and some of
| those forms are double-stranded, but differ from DNA in certain
| key ways. There are even "non-canonical" forms of DNA which
| exist whose nucleobases differ from the traditional four bases
| found in most DNA.
|
| Thus, you're premise that all DNA on Earth is "chemically
| identical" is flawed. But, if you expand the scope of your a
| bit, then the answer is a little more satisfying.
| sebosp wrote:
| If this was the case, then here on earth would we see more and
| more DNA appearing that doesn't follow an expected evolution
| tree? but then also our current DNA creatures would/could
| absorb/eat them before they are allowed to adapt to pressure in
| the surrounding environment?
| lend000 wrote:
| There are so many examples of convergent evolution [0] here on
| Earth that it seems reasonable to speculate that many of the
| most useful compounds for life would evolve similarly many
| times over a large number of trials/planets.
|
| Since we don't have access to such data, some metrics that seem
| useful for speculation about a property are: - How often it has
| evolved independently on Earth - How fast it evolved and
| remained dominant
|
| That being said, there is a potential positive feedback loop
| going on, where most life depends on or benefits from compounds
| it gets from other life. Because there is an abundance of
| certain types of amino acids, we could hypothetically be stuck
| in a less optimal overall biosphere state, whereas a more fit
| biosphere might exist with a different composition of amino
| acids or other building blocks that played the same role. I'm
| defining fitness of the biosphere as the amount of energy from
| the sun that life harnesses for work.
|
| [0] https://en.wikipedia.org/wiki/Convergent_evolution
| arrosenberg wrote:
| Probably not chemically identical, but similar. Different
| nucleotides and protein sequences, but you'd certainly see alot
| of the same structures (alpha helix, beta pleated sheet, etc.)
| and things like methylation. I would expect this based on the
| fact that DNA is incredibly information dense, so it would be
| surprising if the universe had completely novel ways to
| optimize for that problem.
| gilleain wrote:
| Difficult question, but there's an analogous question for
| 'carbon-based' life - are there non-carbon based life? The
| answer is likely "no", simply because the number of molecules
| based on carbon is many orders of magnitude larger than for the
| next largest (sulfur).
|
| Similarly for DNA: there are other polymers that have some of
| the same properties, but not to the same extent. Specifically,
| the ability to store information is so great in DNA. Most
| polymers are either regular like (-CH2-)n or random (eg lignin)
| while DNA (and RNA) are 'structured random', for lack of a
| better term.
|
| Add to this the ability to 'unzip' double-stranded DNA into two
| copyable halves, its great stability, and ability to be coiled
| up. Like water - which is another example of something with an
| abundance of useful features - it's very hard to see any rival
| molecule that could do as many things.
|
| Of course, you could just argue that we have not discovered or
| invented such a molecule yet. People have tried to make
| alternate compounds, and there are - as one of the other
| repliers pointed out - many variations in biology such as
| alternate nucleobases, or things like double-stranded RNA
| viruses, etc.
|
| More generally, you could of course imagine distributing the
| properties of DNA across multiple molecules or molecular
| systems. That suffers from Occam's razor a little, but cannot
| be ruled out, I suppose.
| echelon wrote:
| "DNA" itself is so complicated that there are different
| conformations [1] of the winding, sense, rise, pucker, etc.
|
| There are an unlimited number of different bases that could be
| used to encode information, too!
|
| [1] https://en.wikipedia.org/wiki/A-DNA
| gus_massa wrote:
| Nobody is sure, but if you allow me to guess ...
|
| Perhaps DNA and RNA are inevitable, or at least they are the
| easiest solution for they problem they solve. I guess even the
| same sugars and some nucleotides. The only variation on Earth
| is that some parts of the DNA are methylated, but it can be
| added and removed. There are some weird bases in the RNA for
| very special task, but my guess is that they will use the same
| main bases. I'd not be surprised if alien has DNA and RNA that
| is chemically identical to us (but in other order).
|
| Even proteins are probably inevitable. Here there is more
| wiggling room. We use 20 amino acids, but there are like 5 more
| weird amino acids that are mostly modifications of usual amino
| acids and are made after the protein is formed. For example
| collagen uses a lot of proline that is a normal amino acid, and
| also hidroxyproline that is a modification of proline made
| during the creation of collagen
| https://en.wikipedia.org/wiki/Collagen#Synthesis I guess that
| the list of amino acids used by aliens will be slightly
| different. Perhaps between 15 and 25 instead of the 20 we use.
| Perhaps also some replacements. But perhaps the list has some
| special property we have not discovered yet. I don't expect a
| smoking gun here to determine if aliens are unrelated to us.
|
| The most interesting part is the translation from DNA/mRNA to
| proteins https://en.wikipedia.org/wiki/Genetic_code It's a
| translation from the 64 combinations of 3 bases of DNA/RNA to
| amino acids. It's almost blocked, so there are 16 blocks with 4
| options in each one. But some blocks have small changes. We
| know like 20 versions of the small changes. The 20 versions are
| very similar, they are not very different. So it's possible to
| make changes in this translation table. The most interesting
| part are the 16 blocks. As far as we know the elections it
| arbitrary, like a frozen random initial election that was
| inherited by all of living things on Earth.
|
| So the first thing to check in an alien life is if they
| translate in the 16 blocks the same amino acid that we
| translate. I'd be very surprised if this is the case. My guess
| is that it's almost random, and any election is fine, and each
| independent alien life will have a very different initial
| random election.
| unixhero wrote:
| So life beyond Mars confirmed then?
| MattPalmer1086 wrote:
| No, but some building blocks of life are found on an asteroid.
| So we know now that those molecules are present there. We have
| found amino acids in gas clouds in space before.
| JasserInicide wrote:
| Wait _what?_ How was that not bigger news?? How is not
| finding them on an asteroid not bigger news??? This brings up
| _many_ more questions than answers, but how is it not
| possible at least to say that we 're not the only place in
| the universe where life exists?
| ivanbakel wrote:
| Because naturally-occurring amino acids are nothing new.
| You can make them yourself by sticking some chemicals
| together and applying energy to the mixture [0].
|
| "Building blocks of life" is a phrase with no strong
| definition. Science journalists like to apply it to
| anything from water to DNA chains, though those are very
| different molecules in terms of complexity.
|
| 0: https://en.wikipedia.org/wiki/Miller%E2%80%93Urey_experi
| ment
| pfdietz wrote:
| Especially when the life-relevant amino acids are mixed
| with all sorts of irrelevant amino acids, with the
| concentration of any particular species of molecule
| declining exponentially with the number of atoms it
| contains. This is supposed to be exciting?
| MattPalmer1086 wrote:
| It is uncertain where the amino acids on earth came from.
| A leading theory is that asteroids and comets seeded the
| early earth with a good mix of them.
|
| So it is a data point supporting the idea that they could
| have been a source of these molecules. You may or may not
| find that exciting.
| pfdietz wrote:
| I just find it an indication that formation of amino
| acids is not that important as a bottleneck for the
| origin of life. It's also not that surprising, as you'd
| expect life to use monomers that are fairly stable (and
| therefore could be formed by random processes, because of
| that stability.)
| jerf wrote:
| It's important to understand what amino acids _are_ , if
| you want to know why this is more "interesting, but only
| somewhat so, science" than "groundbreaking news that
| changes our view of life in the universe": https://en.wik
| ipedia.org/wiki/Amino_acid#General_structure
|
| Those may seem complicated, but you have to also remember
| an "amino acid" is the entire family, and carbon tends
| towards "a bit complicated" naturally because it has so
| many bonds it needs to fill in. Fill an environment with
| carbon and the right other elements and it isn't
| "surprising" that amino acids form, it's _inevitable_.
| Like, literally unavoidable, you couldn 't stop it if you
| tried. "The right environment for amino acids" would also
| be full of many other larger structures. It's a thing
| carbon does no matter where it is, not an exception. They
| would just be, if you'll pardon the convenient
| anthropomorphization, pointlessly larger structures, not
| doing anything in particular or having any particularly
| interesting properties beyond size. You get similarly
| large carbon structures in the soot of a fire, for
| instance.
|
| Compare with hemoglobin, just to pick a popular protein
| of moderate size: https://en.wikipedia.org/wiki/Hemoglobi
| n#Structure_of_heme This is a specific combination of 574
| amino acids, in the correct chirality. Some deviations
| are possible that will retain functionality, it isn't
| that _exact_ 574 amino acids, but there 's limited
| variation possible. "Things useful for life" are much
| more than just bare amino acids.
|
| This isn't something that should be downplayed; it is
| legitimately interesting, but at the same time, it
| doesn't materially move our probabilities on any
| particular theory of life because it was always
| predictable that amino acids would _exist_ elsewhere in
| the universe. At a bare minimum for excitement would be
| demonstrating some sort of significant chirality
| preference. That would turn some heads.
| trompetenaccoun wrote:
| It's common knowledge among those who're interested, most
| people simply don't care.
|
| >how is it not possible at least to say that we're not the
| only place in the universe where life exists?
|
| Almost every expert believes that. In fact, it's entirely
| possible life didn't originate on earth in the first place.
| Not that it necessarily has an origin outside the solar
| system, but who knows.
| fnordpiglet wrote:
| It's not possible because we've not yet observed it. It's
| possible to say it's very possible, but the strong
| assertion isn't valid without proof.
| Engineering-MD wrote:
| I think the conclusion is more amino acids form naturally
| without life rather than amino acid based life is
| widespread.
| MattPalmer1086 wrote:
| Indeed.
|
| It would actually be more surprising if it turned out the
| molecules we are built from do not arise easily and
| naturally.
|
| This doesn't mean that all life would be based off them
| though.
| hdjjhhvvhga wrote:
| Well, we know that we can produce some amino acids from the
| so-called "primordial soup" (which hit the news in the
| 50s). But there is still a wide gap between these simple
| chemicals and a simplest living organism.
| unixhero wrote:
| Exactly that's why I was perplexed I got the first comment
| on this thread and that nobody seems to care.
| bbarnett wrote:
| Sorry, that was me.
| darkerside wrote:
| It's this another point in favor of the panspermia hypothesis?
| mkl wrote:
| No, since this is not life or things definitely made by life.
| It's a point in favour of pseudo-panspermia
| (https://en.wikipedia.org/wiki/Pseudo-panspermia). Amino acids
| have been found in comets before, though it sounds like they
| found more here.
| perardi wrote:
| And what's quite interesting about the pseudo-panspermia
| hypothesis...
|
| https://en.wikipedia.org/wiki/Abiogenesis#Homochirality
|
| ...is the chirality of the molecules we've found on comets
| and meteorites. The amino acids and sugars out in space match
| what we find in Earth biology. That in way _proves_ that some
| of the building blocks of life on Earth were generated in the
| Solar System, but at least it's a plausible link.
| mekoka wrote:
| Finding amino acids on an asteroid confirms something we already
| knew. They can be available without showing evidence of life.
|
| The real mystery thus remains life itself. The fact that on Earth
| it used amino acids to express itself doesn't mean that it is
| necessarily limited to that single choice. It also doesn't mean
| that the same process would repeat in a different world, even if
| all the preconditions were met, i.e. the necessary for the
| presence of _life as we can recognize it_.
|
| For all our understanding of (earthly) biology, and the tools at
| our disposal that we use to decide that something is alive, we
| still don't _really_ know what life is, or how it begins. On
| another world it might as well kickstart the magic with a
| different medium than amino acids (e.g. more crystalline
| structures, some energy forms such as light or electricity, etc),
| with entirely different rules of replication and sustenance. It
| would probably make life look different to us, potentially not
| recognizable or even detectable.
|
| Heck, it could happen right here, under our nose and we'd be none
| the wiser.
| allemagne wrote:
| The possibility of extremely exotic new types of life has to be
| a given, but with Earthlike starting conditions turning out to
| be relatively prevalent and the robustness of convergent
| evolution (not to mention the possibility of some kind of
| panspermia event) there's just as good of an argument to be
| prepared for extra-terrestrial life to be similar to us in
| shocking ways.
| tgarv wrote:
| I've always wondered about this too, but kind of landed on
| something like this:
|
| Sure, there might be (and probably is) life out there that
| falls so far outside our definition of "life" that we would
| never detect it. If it's undetectable, and maybe even
| incomprehensible, to us, then what's the point in even thinking
| about it in the context of a "search for life"? What we really
| mean by the question "Is there life out there?" is "Is there
| life out there that's similar enough to the life we see on
| Earth that we could recognize it as such and interact with it?"
|
| I don't have a good way to phrase what I'm getting at without
| sounding dismissive - I do think it's interesting to think
| about other forms of "life", but it seems almost philosophical
| at that point and not scientific.
| mekoka wrote:
| There are certain questions that are so stubbornly elusive to
| science (as the study of nature), that they should _feel_ by
| now to belong to the realm of philosophy (e.g matter,
| consciousness, mathematics, an infinite universe). The study
| of life itself, not its manifestation in nature, has so far
| displayed all those fleeting qualities.
|
| But I guess science is stubborn too, so let's see where we
| get.
| CamperBob2 wrote:
| See the 'God of the Gaps' argument. At any given time,
| there has been a list of things considered to be the
| rightful domain of philosophers and theologians rather than
| logical positivists. So far, the list has only gotten
| smaller.
| nsv wrote:
| In other words - if you can't observe it, does it really
| exist?
| tsimionescu wrote:
| Honestly I think similarity is a bit of a red herring. The
| most interesting question is whether there are other beings
| we can communicate with in any sense of the word, so that we
| may learn from each other. For a somewhat trivial example, if
| we found robots on another planet, we would not consider them
| "life", but it would nevertheless be an incredibly important
| discovery.
|
| On the other hand, it's of course imaginable that there are
| beings that we would in principle consider intelligent
| agents, but who exist in a way that in practice we have no
| hope of recognizing as such. Again to pick a somewhat trivial
| example, if galaxies were in fact intelligent beings that
| take billions of years to form a single thought, we may both
| in principle be very interested in communicating with each
| other, but in practice could never even hope to recognize
| each other as sentient beings, because of the intense
| difference in time scale.
| Teever wrote:
| Can anyone point me in the right direction of a paper that talks
| more about this?
| xupybd wrote:
| I'm not sure if you're asking specifically about this data or
| the General topic. If it's the general topic the Wikipedia
| article links to a few. https://en.m.wikipedia.org/wiki/Pseudo-
| panspermia
| flobosg wrote:
| "Soluble Organic Compounds in Asteroid 162173 Ryugu":
| https://www.hou.usra.edu/meetings/lpsc2022/pdf/1781.pdf
| cletus wrote:
| We again return to the rabbit hole that is the Fermi Paradox [1].
| In short: there are so many stars and planets and we've had
| billions of years. Why aren't ther emore signs of technological
| life?
|
| A core idea of this is that there are various filters that
| separate a new planet from one hosting spacefaring life. There
| are lot of these filters proposed. One category is the Great
| Filter. These are where very few lifeforms are expected to pass.
|
| So what we're talking about here is an early filter where a
| planet forms in a relatively stable and suitable star system and
| single cellular life forms. Based on our own understanding of
| biochemistry, that pretty much requires amino acids. Now there
| might be other forms of life out there but they're all
| theoretical. We have one which is real (ie ours).
|
| We've had a lot of experimentals that show that amino acids can
| form in deep space on icy bodies. What we have here is direct
| evidence from an essentially random asteroid that it has amino
| acids on it. We can and will speculate as to the origins of
| these. Did they form on the asteroid? Elsewhere? When?
|
| You can't obviously draw too many conclusions from a single data
| point but to suggest we got _extremely_ lucky to find the a super
| rare asteroid with amino acids on it stretches incredulity.
|
| So the conditions that lead to life similar to ours forming being
| relatively common only gets stronger. This is similar to the
| number of expoplanets we've found. We've shown that planetary
| systems are exceedingly common, which was something we could only
| speculate about a mere 40 years ago.
|
| More planets, more conditions for life forming. This means more
| species are likely getting filtered further down the chain.
|
| [1]: https://en.wikipedia.org/wiki/Fermi_paradox
| throwawaycities wrote:
| > A core idea of this is that there are various filters that
| separate a new planet from one hosting spacefaring life.
|
| The most obvious, but least talked about filter is time.
|
| Let's assume there is a civilization just like us on the other
| end of the Milky Way galaxy, it's not like we can just "look
| out" and observe them. Assuming they blasted out radio signals,
| those radio signals would have to have been sent 100,000 years
| ago for us to detect them today. Alternatively for that same
| civilization to detect our earliest radio signals it take
| another 999,900 years.
|
| If this technologically advanced civilization was in the
| closest galaxy instead of the opposite end of the Milky Way,
| then our ability to detect one another's signals traveling at
| the speed of light would be separated by over 2.5M years.
| messe wrote:
| > The most obvious, but least talked about filter is time.
|
| For good reason: there's been a lot of it so far. Even at
| slower than light speeds, it would be possible for a
| sufficiently advanced civilization to send probes to ever
| star in the galaxy (or even colonize it) in just a few
| million years. So why don't we see any evidence of _any_
| prior civilization having done that? It would only take one.
| canaus wrote:
| I'm pulling information from an introductory astronomy
| class, but isn't the definition of what lot of time passing
| is, not agreed upon?
|
| /The Five Ages of the Universe/ by Adams and Laughlin
| theorize that new stars won't stop forming until trillions
| (possibly hundreds of trillions) of years after the
| universe's inception. We're currently on years 14-15
| billion. If their theories are true we'd be, arguably, one
| of the first instances of intelligent life in the universe.
|
| Now, some astronomers theorize that the universe will end
| in 5 - 15 billion years, so that would change the timeline
| substantially.
| pjmlp wrote:
| Cough, Egyptian pyramids, jump doors with runes,... :)
|
| Now seriously, maybe we have and they just weren't
| interested.
| cloverich wrote:
| How long would they have to last though? We don't just have
| to both be advanced but also overlap in time. When you
| consider there are hundred million+ years between advanced
| life forms and intelligent life, and even millions of years
| between humans and intelligent humans, any signals of any
| kind may have to last for millions of years or more to be
| detected.
|
| Then there's so much space, so it probably takes more than
| one. Perhaps a million+ more than one.
|
| Then the final but to me most important thing, is we often
| assume advanced life looks like us. I personally believe it
| generally does -- for a bit. But if we're just a stepping
| stone to AI and then (perhaps) we disappear, advanced life
| forms like us only exist for a blip anyways. We probably
| don't even know what to look for. The possibilities are
| fascinating and humbling.
| eloff wrote:
| I suspect that could be part of it, that we're the
| biological bootloader for AI and we last just a blink in
| that stage on the time scale of the universe.
|
| But then what does that AI do afterwards and why don't we
| see them. That doesn't really solve the dilemma.
| cloverich wrote:
| That is true although I suspect it might be like an ant
| and us -- the ant certainly interacts with us but does
| it, can it, know anything about us? Maybe the output of
| AI is all around us and we are simply (now and forever)
| incapable of "seeing" it. My other hunch is that
| communication at that level isn't actually required in
| the traditional sense, and anything that would need to be
| communicable is done so via truth seeking.
| whimsicalism wrote:
| It wouldn't have to be a signal, it could be physical
| artifacts.
| throwawaycities wrote:
| > ...it would be possible for a sufficiently advanced
| civilization to send probes to ever star in the galaxy (or
| even colonize it) in just a few million years.
|
| It's "possible", highlighted by the fact that we haven't
| sent a single probe to another star system. We have a grand
| total of 2 probes that have made it outside our solar
| system, and only 3 more on the way.
|
| There are an estimated hundred thousand million stars in
| the Milky Way. At a rounded cost of $1B for the Voyager
| missions, "possible" starts to meet reality.
|
| There are far to many assumptions. Not only does a
| technological civilization exist, but it had a few million
| years head start on us and used their time/technology to
| colonize every star system in the galaxy with physical
| probes, when so long as we are making assumptions and can
| assume they have/had the ability to collect all the same
| data/information locally at the speed of light.
| cletus wrote:
| The oldest stars in our galaxy are >12 billion years old.
| Ours is 4.5 billion years old. We obviously don't have a lot
| (meaning more than 1) of data points here but that one data
| point is that life _can_ evolve in 4 billion years.
|
| Whatever the variance is we've had ~3x that for other
| civilizations to arise in our galaxy alone.
|
| Yes we could be "first" (within our cone of spacetime). First
| of 3? That's possible. First of 1000? Way less likely.
| There's some BAyesian reasoning about probability spaces you
| can do here. The very fact that we can't seem to detect
| anyone else in our galaxy changes the probabilities making it
| much more likely (but not impossible of course) that we're
| effectively alone.
|
| Also the odds that another civilization evolves over 4B years
| and reaches spacefaring technology within 100,000 years of us
| is, statistically speaking, incredibly unlikely. It's way
| more likely they'll be way ahead of us or way behind us.
| spfzero wrote:
| Also, who knows how long the window would last where a
| civilization uses electromagnetic waves to communicate, in
| the ways we would look for them? We've only used them for a
| hundred-plus years or so, maybe in another hundred we will be
| using something else. That would mean there is only a
| 200-year period where we emitted detectible radiation, which
| is only detectible within a certain radius, and the detector
| would have to be within that radius and listening during that
| 200-year window at exactly the right distance and time to
| catch it.
| [deleted]
| hnuser123456 wrote:
| Consider factors like the age of the universe, stars growing
| more metallic as they form starting with elements that can only
| be made by others going supernova, and chances of the planet
| not being hit by a supernova strong enough to sterilize the
| planet for billions of years. The great filter isn't
| necessarily still yet to come.
| rococode wrote:
| Anyone interested in this topic should check out Stephen Webb's
| book, "If the Universe Is Teeming with Aliens ... Where Is
| Everybody?".
|
| It's not perfect, but it goes over a _lot_ of possible
| explanations (75 different explanations!) for the Fermi
| Paradox. It covers pretty much every theory I 've seen when
| people discuss the topic, aside from a government cover-up
| haha.
|
| Simulations, aliens hiding on Earth, von Neumann probes,
| signals that we don't understand, distances being
| insurmountable, self-destructiveness, inescapable planets,
| singularities, it's got it all! A lot of the explanations
| ultimately can't get over the "OK, but surely there are at
| least a few exceptions" problem, but it's very fun to think
| about nonetheless. A really engrossing read if you like
| thinking about this stuff!
|
| https://www.goodreads.com/en/book/show/180506.If_the_Univers...
| edgyquant wrote:
| The Fermi paradox is a joke (literally.) It's not meant to be
| taken seriously as science but as proof our understanding,
| specifically irt how we got complex life, is flawed. I really
| hate that there are entire media spheres dedicated to
| philosophizing about it.
|
| It also does little but derail every conversation about life in
| the universe into speculative science fiction.
| beej71 wrote:
| One thing that always struck me about humanlike intelligence on
| Earth is how quickly it came about.
|
| The dinosaurs had 180 million years or so to get it right, and
| we find no evidence of so much as a simple tool. Were they no
| smarter that crows? All that time?
|
| And Homo has been around, what, 2 million years? In just 2
| million years we've gone from basically zero tech to outer-
| freakin-space.
|
| Arguably, we've gone from nothing to outer-freakin-space in the
| last 6000 years, starting around the Bronze Age. That's
| astoundingly quick given how long life has existed on Earth.
|
| So it seems like as the dice were being thrown around we were
| just waiting for that magic run of all sixes that enabled us
| to, in the blink of an eye, become spacefaring.
|
| What was it? (Opposable thumbs? Language? War? Big brains?
| Etc?) And how likely are these things to happen in a magical
| combination? It took its sweet time here. Did we get lucky it
| only took 4 billion years? Or unlucky it took that long at all?
|
| But it never happened to the hapless dinos. Which is too bad,
| because space dinosaurs would be _awesome_.
|
| [Meme of dinosaurs looking up at the asteroid falling from the
| sky and one saying, "Oh fuck! The economy!"]
| skykooler wrote:
| Maybe intelligent dinosaurs had a very strong "no littering"
| policy.
| alchemist1e9 wrote:
| Silurian hypothesis is very intriguing.
|
| https://en.wikipedia.org/wiki/Silurian_hypothesis
| suzzer99 wrote:
| I've always wondered about this. Let's say civilization
| evolved a billion years ago on Mars or Venus to the level
| we are now. Would we ever be able to detect it? If they
| put up satellites, could some still be orbiting, or would
| they all have degraded by now? What if they really wanted
| to leave some sign they were there? What could they do?
| Venus would be really hard unless satellites work. But
| maybe Mars?
| CamperBob2 wrote:
| Remember that the crows _are_ dinosaurs in a sense. The
| dinosaurs are still in the game; don 't count them out yet.
| dzonga wrote:
| my uneducated take is maybe other civilizations existed on
| earth or other planets but then self-destructed or got
| destroyed by a asteroid just like the dinos. if human life on
| earth is a nano second in a day of the planet's life. surely
| these things can come and go without leaving any traces. poof
| just varnish into thin air.
| pwython wrote:
| Exponential growth [1]
|
| We went from the invention of radio in 1895 to a moon landing
| within 74 years. And 53 years later we have tech that is
| vastly superior to what we had in 1969.
|
| [1] https://en.wikipedia.org/wiki/Exponential_growth
| menacingly wrote:
| Is it possible that this presupposes the utility of
| inteligence for survival? It's an easy thing to assume, but a
| decent argument could be made for intelligence in sufficient
| quantity actually running counter to the fitness of a
| species.
|
| I would assume our style of intelligence isn't any kind of
| "goal", it just happened.
| spacebard wrote:
| How do you contend with the fact that humans dominate every
| ecosystem we enter? We don't just become the apex predator,
| we annihilate them all, entirely. Additionally, we find
| incredibly complex use cases for resources they ignored
| which increase wealth and prosperity across our
| civilization. To me, that suggests human intelligence is
| the most powerful force of survival in the known universe.
| lm28469 wrote:
| Destroying and consuming everything on earth for short
| term comfort and gains isn't what I'd call the smartest
| move.
|
| It's like burning your bed in winter because you're cold,
| it sure feels food for a few minutes but then you start
| breathing in the fumes and wondering where you'll sleep
| tomorrow
| dao- wrote:
| Annihilating the eco system we life in demonstrates that
| our intelligence isn't that good, and doesn't seem to
| showcase it's a powerful force for long-term survival.
| allemagne wrote:
| Of course there are plenty of metrics by which other
| species exceed humans, even some cognitive ones, and
| human intelligence in the end might just mean quick world
| domination followed by a quicker extinction, but the
| power and planetary supremacy that it endowed humans with
| in a cosmic blink of an eye is undeniable. No other
| species even comes close.
|
| Ecosystem-destroying catastrophic behavior isn't unique
| to humans, either. We are the only known form of life
| that can bring it about on a global scale, reason about
| it, and have the potential to consciously avert it.
| waitingforplum wrote:
| mywittyname wrote:
| Plenty of less-intelligent animals have been around since
| long before humans, and they will probably be around long
| after humans.
| snikeris wrote:
| Ultimately all less intelligent animals on this planet will
| perish due to heat death of the sun unless we bring them
| with us to other planets.
| tsimionescu wrote:
| You are assuming it is actually possible for human life
| to move to other solar systems.
|
| It's much more likely that we could send bacteria or
| extremophiles to another planet and have them become self
| sustaining there than it is for a colony of humans, given
| everything we know today about the limits of space travel
| (time scale VS resource requirements).
| lm28469 wrote:
| Ultimately all life will disappear due to the heat death
| of the universe so why bother.
|
| Humanity is fairly new, I doubt we'll make it to the heat
| death of the sun. Modern humans are 300 000 years old
| (anatomically, 50 000 behaviourally), the sun will run
| for another 5 000 000 000. We're running out of easy to
| use resources after not even 150 years of industrial
| progress, people are getting less and less healthy,
| fertility is going down thanks to pollution, many eco
| systems are on the verge of collapse with unpredictable
| consequences for us, &c.
|
| I think we have many things to focus on before saving
| animals from the heat death of the sun
| dragonwriter wrote:
| > We're running out of easy to use resources after not
| even 150 years of industrial progress,
|
| All of human civilization (and some pre-civilization
| time) has been industrial progress, and even if you are
| counting from the beginning of the popularly-named
| Industrial Revolution, that's fairly arbitrary but also
| 260+ years, not 150.
| vorpalhex wrote:
| > What was it?
|
| My lacking-evidence and very unverified theory is that it's
| something like bicameral mind theory. It wasn't until we
| developed a complex enough brain to have self metacognition
| that we started to take off as a species.
| everdrive wrote:
| My lacking-evidence theory is that this primarily evolved
| in mammals due to the requirements of child care imposed by
| mammalian birth.
| dekhn wrote:
| As for amino acids, I would just work on the assumption that
| they, and nucleosides, sort of people out of space organic
| chemistry on a regular basis, in a way that has nothing to do
| with life, but just basic chemistry/physics.
| JumpCrisscross wrote:
| > _more species are likely getting filtered further down the
| chain_
|
| My personal hunch is the filter is around multicellular life.
| We'll find lots of planets with single-celled goop. Many fewer
| with animals.
|
| The unions that created photosynthesis and mitochondria look to
| have happened only once (successfully) in Earth's history [1],
| and sound more like voodoo than science the more one thinks
| about it. (Cell ate another cell then changed its mind and
| adopted it for 1.45 billion years.)
|
| [1] https://www.nature.com/scitable/topicpage/the-origin-of-
| mito...
| cletus wrote:
| The earliest signs of life at >3.5B years old [1] while
| photosynthesis dates to ~3.4B years ago. That seems to be
| pretty quick (by some definition, ~100 million years with
| huge error bars is "quick").
|
| If photosynthesis only evolved once, another explanation is
| that it only needed to once because it was so wildly
| successful.
|
| Multicellular is interesting. That obviously took much longer
| but once it did? Holy crap did things take off. I kinda wish
| I could have a time machine just to visit the Cambrian
| Explosion era.
|
| [1]:
| https://en.wikipedia.org/wiki/Evolution_of_photosynthesis
| bmitc wrote:
| What observation methods would one use to detect life on Earth
| from even a moderate distance away? It is not known to me that
| we have the capability to even discover life on Earth if we
| were in another planet in another system.
|
| As far as I understand, exoplanet discovery and study is still
| incredibly rudimentary.
| cletus wrote:
| SETI began by looking for radio signals that were highly
| unlikely to be "random" because that fit what we ourselves
| were using at the time. As we've since discovered, this sort
| of communication was shortlived lasting just decades.
|
| So what could we observe instead? The answer is Dyson Swarms.
| These aren't rigid spheres as some seem to think (the
| original term was "Dyson Sphere" but is largely abandoned
| because of the confusion). It's merely a collection of
| orbitals to consume all the energy a star produces. Many
| (myself included) think this is the inevitable direction of
| our species.
|
| The only way to get rid of heat in space is to radiate it
| away. The frequency of the light emitted depends entirely on
| the temperature of the radiating object. This means a full
| Dyson Swarm would have a huge infrared signature. That sort
| of thing we could detect from a very far distance. A whole
| galaxy of these would be detectable from millions of light
| years away.
| bmitc wrote:
| I wasn't necessarily trying to address _what_ we can look
| for. I was trying to ask, what are things we are even
| _capable of_ looking for? I am aware of Dyson swarms, but
| is it not the case that the enumeration of objects that
| emit infrared large?
|
| The Fermi paradox is not really a paradox of sorts,
| especially given when it was formulated. Because if we
| aren't even capable of detecting life, then how can we ask
| where is it?
| cletus wrote:
| The Fermi Paradox isn't a paradox to many (including, I
| believe, Fermi). The answer many suspect (myself
| included) is that spacefaring life is incredibly rare so
| it's not really a "paradox" because there is nothing to
| detect.
| lumost wrote:
| While we're speculating, allow me to throw my 2 cents in.
|
| The biochemistry of life is likely to be common, the conditions
| for complex or even intelligent tool using life are likely to
| be rare.
|
| To have an earth, you need to have a moon comparable in mass to
| the planet to avoid atmospheric stripping. A temperature regime
| stable enough to support long term life development between 0
| and 100 C. A star that doesn't blasttge planet in radiation
| every few thousand years. Along with a reasonable balance of
| materials, and a stellar neighborhood which wont swing the
| balance too badly every few million years.
|
| Lastly, although untested, To have tool use, you likely need a
| planet with gravity thats strong enough for the atmosphere to
| be stable, but weak enough for organic molecules to hold
| together complex life and enable the construction of material
| objects. A super earth covered in algae is interesting, but may
| not be capable of traditional human intelligence.
| EForEndeavour wrote:
| > To have an earth, you need to have a moon comparable in
| mass to the planet to avoid atmospheric stripping.
|
| Could you elaborate on this? I'm aware that magnetospheres
| protect atmospheres from solar wind stripping (e.g.,
| https://science.nasa.gov/science-news/news-
| articles/earths-m...), but have never heard of the role of
| moons, and can't find anything via Google right now.
| noasaservice wrote:
| But you're assuming that life must contain good quantities of
| water, and in all 3 phases on the planet.
|
| Silicon life could definitely be a thing.. However silicon
| bonds are a lot lower energy than carbon bonds are, for most
| substances. (I would argue that oxygen would be toxic to
| silicon based beings, due to Si-O.). So, I'd theorize that
| silicon based living beings would have to be in an atmosphere
| of, say, methane. And the phasegraph of methane (
| https://www.engineeringtoolbox.com/methane-d_1420.html )
| would seem to show that -175c and around there would be ideal
| temps for silicon life.
|
| However, if we're exclusively only looking for
| carbon/oxygen/water based lifeforms, then I think the 0-100c
| is a reasonable assumption.
| lordnacho wrote:
| Don't you need carbon because the C-C bonds won't be
| disrupted by O2? I read that somewhere iirc in Larry
| Gonick's cartoon about chemistry.
| scrumbledober wrote:
| can't be disrupted by O2 if there's no O2 in your
| environment
| cletus wrote:
| The law of large numbers comes into play here.
|
| There are at least 100B stars in our galaxy. Over the last
| 20+ years we've gained a lot data on exoplanets. Exoplanetary
| systems seem to be _really_ common. So stability, the right
| elements, etc no doubt all play a role but we may be talking
| over WWhata trillion planetary bodies (including large
| moons).
|
| What's more, our understanding of where live can evolve,
| survive and thrive has greatly expanded in recent decades and
| now includes volcanic vents on the ocean floor, for example.
|
| So yes a lot of things have to go right but we're rolling an
| awful lot of dice.
| lumost wrote:
| Yes, but the fermi paradox focuses on intelligent life.
| Even if there are ~10 trillion of possible planets in the
| galaxy for intelligent life to evolve on, that is only
| 10^14th power. If each of the circumstances described above
| is a 1 in 100 event, then that leaves only 10^5 habitable
| planets for intelligent life to evolve across the _entire_
| galaxy. If you then consider that there is a 5 in 4.5
| billion chance that such a planet currently has an
| intelligent life form on it, then it 's quite possible that
| there are no other intelligent life forms in the galaxy.
| However there may be millions or billions of planets with
| evolved forms of algae.
|
| Now, I do not believe that these are uncorrelated
| probabilities - and as such I'd place the odds quite a bit
| higher. But the more we learn about planetary physics, the
| more unique earth appears to be. Meanwhile, it appears that
| the biochemistry of life is incredibly common.
| pasabagi wrote:
| My preferred speculation is simply that faster-than-light
| travel is impossible, so all the tool-using aliens out there
| are not visiting us because they can't, and we can't hear
| their signals because it gets lost against the background
| noise.
|
| I mean, would we be able to detect our own civilization from
| a few lightyears out? Apparently, unless you're pointing a
| radio telescope right at something, you woudn't be able to
| pick up human civilization levels of radio from more than a
| lightyear out. Say there's one smart tool-using civilization
| per 5000 lightyear volume, then they're unlikely to meet.
| spfzero wrote:
| Even if a civilization out there had faster-than-light
| travel, they would most likely not know we were here. They
| would need to decide to come explore near us, probably need
| to expensively slow down to sub-light speeds to look for
| signs of life near here and pick up our emissions on some
| old archaic piece of equipment they happened to bring
| along.
|
| Would a much more advanced civilization spend their
| exploration budget to look over uninteresting primitives
| like us, or would they go off in search of other more
| advanced civilizations like their own?
| corrral wrote:
| You also need plate tectonics. And exactly the right level of
| stellar radiation for the carbonate-silicate cycle to work,
| if you want photosynthesis, and without that you likely won't
| have anywhere near enough energy available for complex life.
|
| Get any of it wrong and life either won't develop, or will
| wreck its own biosphere in an unrecoverable way very early on
| and get wiped out (if there was ever life on Mars, that's my
| bet for why traces of it are elusive--it wasn't around very
| long, wasn't very complex, and it was a _very_ long time
| ago).
| lordnacho wrote:
| Can you elaborate? What's the reason it wouldn't work if
| all the plates were frozen?
| bbojan wrote:
| Plate tectonics helps with carbon recycling and
| regulating the temperature of the planet.
|
| Temperature drops, rainfall drops (less evaporation),
| rock weathering slows down (rock weathering normally
| removes CO2 from the atmosphere).
|
| With plate tectonics, volcanism continues to spew CO2 in
| the atmosphere, temperature eventually rises. Negative
| feedback.
|
| No plate tectonics, no volcanism, albedo increases,
| temperature drops further. Positive feedback.
| corrral wrote:
| Maybe not strictly necessary for _any_ life, but the
| broad principal is that any process that recycles
| material is going to be really helpful to life, with big
| bonus points for it working in a dynamic fashion so it
| tends to self-stabilize--plate tectonics don 't have that
| quality, but other processes do, like any chemical
| process where the concentration affects the rate at which
| the process occurs, or how our climate tends to find
| stable points rather than having runaway freezing or
| runaway heating.
|
| In the Earth's case, vulcanism is critical to balancing
| atmospheric CO2 levels. Over time (not on human
| timescales) carbon tends to get trapped in ways that make
| it unavailable to life, so you need something to undo
| that, and that's a major mechanism for it.
|
| Life may be (probably is) possible without some elements
| of what makes life work on Earth, but with the wrong
| environment may destroy itself relatively quickly (as
| life on Earth nearly did, during the oxygenation crisis)
| or fail to capture enough energy for the development of
| complex life (think: a planet where the only energy
| available to life comes from a few undersea vents,
| photosynthesis being impossible for any of several
| reasons).
|
| For this reason, a planet being in the "Goldilocks zone"
| around its host star is just the bare minimum required
| for widespread, complex life. The planet itself must also
| be more-or-less the right size, and must have the right
| composition of surface and atmosphere _and_ various
| processes occurring (geological and otherwise) to keep
| those in balance, and so on. It 's possible there are
| certain very hardy chemistries possible for life that we
| simply don't see on Earth because they're easily
| outcompeted by what we've already got, but those pretty
| much by definition won't provide as much energy to the
| host body's biosphere, so complex life is less likely.
| It's also possible there are planets far _more_ amenable
| to life than Earth (though perhaps wholly incompatible
| with Earth-like life), with unknown-to-us chemistries
| that are only viable in that kind of even-better
| environment.
| lumost wrote:
| A good way to understand this is through an ocean world
| thought experiment. If a hypothetical planet existed
| which was covered in a 100km deep ocean, all nutrients
| would steadily fall to the bottom of the ocean - where
| there would be minimal to no energy to make use of the
| nutrients. You'd eventually be left with a surface layer
| containing only the minimal amounts of nutrients which
| diffusion pulls back up to the surface.
|
| In order for this hypothetical water world to host a
| thriving ecosystem, you would need a large moon or heavy
| vulcanism to ensure that the oceans remain mixed.
| saiya-jin wrote:
| The list of prerequisites is much longer. Right amount of
| radiation, rotating molten metallic core (that probably
| came from collision with another planet!), jupiter-like
| vacuum cleaner to not have massive asteroid impacts too
| often - but sometimes they may help, like for us. Stable,
| boring star.
|
| The list is probably much longer, ie chemistry part mixed
| with geology, astronomy and other topics.
| tediousdemise wrote:
| The universe is infinite and continuously expanding. This
| cosmological scale, the monumental distance between celestial
| objects in deep space, would make it quite literally impossible
| for any extraterrestrial to feasibly be aware of or make
| contact with humans and vice versa. Even if we could travel
| beyond the speed of light, we'd still probably never make
| contact; there would be too many things that could go wrong.
| It's depressing to think about.
|
| Space limits everything, and is the simplest solution to the
| Fermi paradox (following Occam's razor).
|
| Source: I am a software engineer who works on cool space stuff
| gibolt wrote:
| Lots of child comments have made statements about what life
| 'needs' and why that would make things difficult.
|
| We don't know what conditions life 'needs' since we only have a
| sample size of 1. We can speculate, but nothing yet is a known
| fact.
| stormfather wrote:
| Right. It's not like we would theorize the existence of
| biological life on earth from first principles if we didn't
| know about it beforehand. It's such a magical, complex thing.
| We have no idea what other kinds of incomprehensibly
| complicated reactions might occur.
| BurningFrog wrote:
| Robin Hanson, who coined the term "Great Filter", presented a
| theory in 2021 to explain the Fermi Paradox. It's known as the
| "Grabby Aliens Theory".
|
| This 12 minute video does a good job of explaining the fairly
| non intuitive reasoning:
| https://www.youtube.com/watch?v=l3whaviTqqg
|
| As I understand it (it's not an easy theory to wrap your - or
| at least my - mind around), the reason we don't see any other
| civilizations is that we're among the first ones.
|
| This seems very unlikely, but is actually not. Because a
| successful hi tech civilization would likely be inclined to
| expand ("be grabby") and fill up the galaxy in ~100 million
| years, as Fermi pointed out. That would mean all habitable
| planets would then be taken, and no more civilizations would
| rise up from primordial goo like ours.
|
| That means - and it's a weird mental leap, but I think it's
| correct - that almost all civilizations arising "naturally"
| would have the same experience we have: The universe seems
| weirdly empty.
|
| I guess it also means that the galaxy is ours for the taking!
| PKop wrote:
| I'm missing something in these videos. Is it that the
| perception we're early implies an implausible scenario
| because "grabby" (I would just call them expansionist)
| civilizations would also be cloaking their signals (he seems
| to gloss over this point)? I.e. "they're out there" we just
| can't see them, or is he saying _that_ would be implausible
| because we should have been invaded by now by these
| expansionist empires, therefore since we haven 't we _are_
| early?
|
| You seem to be saying the theory implies we are early when in
| the first video I got the impression that is statistically
| implausible.
|
| I guess my main confusion is, if they are grabby, why haven't
| we been grabbed?
|
| edit: watched the second video further, I think I get it a
| little better now. We are generally early and/or somehow
| advanced aliens expand quickly, otherwise we'd see signals
| because the signals would propagate faster than their
| expansion, whereas if they expand quickly, they'll invade us
| before we see signals, and dominate a larger portion of
| visible universe.
| BurningFrog wrote:
| My interpretation, which I'm only 90% sure of, is that if
| we weren't early we'd be dead, since an earlier
| civilization would have colonized Earth for their own
| purposes.
|
| So seeing no one else out there is to be expected.
|
| It's a bit like how it's _NOT_ weird that we happened to
| evolve on a planet that is so extremely favorable to our
| form of life.
| kabdib wrote:
| If we're the forerunners, it's our responsibility to leave
| behind huge and mysterious artifacts containing the secrets
| of the universe, filled with traps for the unwary.
|
| "Figby, get those doom-chompers synchronized with the
| shooting flames!"
|
| "Yes sir!"
|
| "And think of something more profound than 'Be nice to other
| beings and remember to call your mother(s)' for that final
| secret. Maybe get someone in the art department to help out."
|
| It's not easy being the Elder Race, but someone has to do it.
| cletus wrote:
| That's not that new an idea. Even at 1% of c we could fully
| colonize the Milky Way in 10 million years, which is a blink
| of an eye compared to the >4B years the EArth has been here.
|
| The second issue is that planets don't really matter other
| than being essentially "mass repositories". They're a highly
| inefficient way of creating living area. I'm speaking of
| course of Dyson Swarms as a highly likely alternative. I saw
| "highly likely" because it requires no new physics, no new
| materials beyond what we already have, is orders of magnitude
| more efficient (in living space per unit mass terms) and is
| essentially just an engineering problem (obviously a big
| one).
|
| If you accept that premise then it's even less likely there
| are other spacefaring civilizations within our light cone
| because they would stick out like a sore thumb. Certainly a
| whole galaxy of these would be detectable by us currently
| from millions of light years away.
| lm28469 wrote:
| > we've had billions of years. Why aren't ther emore signs of
| technological life?
|
| I think the "billions of years" part is key.
|
| Humanity might die in the next centuries, or at least stop
| progressing technologically due to our lack of sustainable
| planning. If a human like life existed 100m years ago in a
| nearby planet we wouldn't now even if we sent basic probes,
| you'd need to dig just like we need to dig to find dino bones.
|
| Modern civilisation are maybe 5000-7000 years old, that's not
| even a blip in the universe history. The universe could develop
| millions of technologically advanced civilisations on different
| planets with no time overlap
|
| I also feel like lots of people are too much into sci fi,
| nothing guarantees technological progress can go much further
| than what we have and allow for large scale space exploration.
| We might not see signs of technological life because the most
| advanced thing they came up with are a few probes and some
| radio signals sent from so far away that you statistically will
| not find even if you look for them.
|
| The universe physical and time scale raise the fermi paradox,
| but the same physical and time scale give you an answer as to
| why we might not be able detect life
| belter wrote:
| The most likely reason is the one show in the simulation made
| in this paper, I recently posted here.
|
| "Possible CETIs Within Our Galaxy and Communication Probability
| Among CETIs ": https://news.ycombinator.com/item?id=31449404"
|
| "...human beings need to survive 50 (+250 -49) Myr to receive
| one signal from other CETIs. Our results may quantitatively
| explain why we have not detected any alien signals so far. The
| uncertainty of the results has been discussed in detail and
| would be alleviated with the further improvement of our
| astronomical observation ability in the future..."
|
| The universe is a big, big place and civilizations come and go.
| We would need to be around for 50 million years, to have a good
| chance to catch a window that would match another civilization.
| We are barely around as a species for 2 million years and
| civilization is maybe 10,000 years old...
| marklubi wrote:
| I've always held the belief that given the vastness of space,
| and the age of time, it's not just a question of if other
| intelligent life can exist, but whether or not we we will be
| in the same place at the same time.
| zinclozenge wrote:
| What if the probability of life forming on any given planet
| was so infinitesimally tiny that it happening on earth is
| already a fluke?
| marklubi wrote:
| I would think that it's shortsighted. Just on Earth,
| we've been through several millions of years of various
| evolutions. We've had fauna, mega fauna, mega flora,
| dinosaurs, so many things have occurred over millions of
| years. It's hard to believe that none of this has
| possibly occurred elsewhere.
|
| Edit: for clarity
| stormfather wrote:
| The flaw in our approach to the Fermi paradox is that we are
| looking for intelligent life which resembles us as we are now.
| Big, corporal bodies made of proteins communicating with big,
| inefficient, slow frequency vibrations. But this is just a
| transitory phase in our evolution which will pass in the
| astronomical blink of an eye.
|
| Consider if you agree with these propositions:
|
| - Consciousness is an emergent property of computation
|
| - Computation is possible in any media
|
| - Computation is more efficient in smaller, less massy media
|
| - We are already beginning to fiddle with our own brains and
| this will accelerate
|
| - Our bodies in general have huge room for optimization and
| eventually will be completely unrecognizable or even
| unnecessary as we currently imagine them
|
| - Progress is exponential as our population grows in education,
| size and free time
|
| If these are true, what does that mean for our destiny as a
| species in 100k years? 1M years?
|
| I think we can all agree we will become cyborgs, but I think we
| still imagine our bodies having the same form factor. But
| that's the flawed assumption. Really we will shrink down. And
| what's the limit to how far down we shrink and how efficient
| and massless our bodies/brains get? How would we even be
| communicating in 1M years? Through entangled qubits? Vibrations
| in subspace? Who knows, but it's probably not something 21st
| century earth would even notice with a radio telescope.
|
| So the answer to the Fermi paradox isn't that intelligent life
| snuffs itself out after a few million years. That's terribly
| unimaginative. The answer is that from our perspective
| intelligent civilizations disappear because they change
| themselves so radically that they transcend our concept of what
| to look for.
| cletus wrote:
| > Consciousness is an emergent property of computation
|
| It's interesting to see the negative comments about this here
| because I agree with you. "Consciousness" or even "sentience"
| is notoriously difficult to define. Even defining what an
| organism is isn't entirely obvious (eg some might consider a
| colony of ants or bees as being organism-like). Our views
| tend to be extremely human-centric because we can relate. I
| imagine once we actually invent an AGI many will debate if
| it's truly sentient or conscious for a long, long time
| afterwards.
|
| > Computation is more efficient in smaller, less massy media
|
| There are physical limits on computation. A smaller package
| ultimately has a lower limit. That alone will (IMHO) keep a
| space for very large computational units. At the top end of
| this is Matrioshka Brains [1].
|
| A digital existence looks highly likely in the black hole era
| of the universe [2]. This is the era after all the stars have
| faded out and will be _much_ longer (based on current
| understanding) than the stellar era, so much so that the
| 13-14B year lifetime of the universe thus far will be like
| the blink of an eye.
|
| As for detecting communication, that's too narrow a focus.
| Whether we're miniscule cyborgs that communicate with qubits
| or living as virtual beings in a world-sized computer, the
| ultimate limits of what any such civilization can do is is
| the amount of energy they can consume. More energy means more
| is possible.
|
| So even if we end up living as a K2 civilization in a billion
| orbitals around our Sun or one of the alternatives or build a
| Matrioshka Brain or simply collect all the power with
| satellites, all of these will have a similar IR signature
| that will be extremely detectable.
|
| [1]: https://www.youtube.com/watch?v=Ef-mxjYkllw
|
| [2]: https://www.youtube.com/watch?v=Qam5BkXIEhQ
| mentos wrote:
| I imagine civilization will just be a solar powered server
| box floating through space running unreal engine 6.0x10^27
| stormfather wrote:
| inshallah
| tsimionescu wrote:
| > Our bodies in general have huge room for optimization and
| eventually will be completely unrecognizable or even
| unnecessary as we currently imagine them
|
| I think this is a huge leap, especially when it comes to
| computation. As far we can tell, the brain is amazingly
| energy efficient compared to to any electronic chip. It's
| hard to estimate exactly what kinds of computation our brains
| are doing so that we could compare in terms of teraflops, but
| the energy consumption is many times better than any
| processor that could come close in any reasonable estimation.
| nycdotnet wrote:
| > I think we can all agree we will become cyborgs
|
| Sent from my iPhone
| blizdiddy wrote:
| > I think we can all agree we will become cyborgs,
|
| Well, obviously! Who could imagine any other scenarios?! My
| mom just called me asking if i could replace her right foot
| with a hoverboard. I cant wait until I can no longer feel
| sunshine or grass. Living forever as a process in a virtual
| machine... my ancestors could have never dreamt of having
| such fulfillment.
| stormfather wrote:
| I think the fact that we will start to augment our bodies
| is a safe assumption. It's just too useful, and you will
| need to do it to compete. How will one get by without their
| AR retinal implants, brain chip and exoskeleton? Sure, it's
| dehumanizing but do you really think you will reject it?
| You are talking to me on a computer already... it won't
| always be external. When you age, you won't feel so
| sentimental about your teeth and spine anymore...
|
| Now, if we let it rob us of sensations is another matter,
| and I think assuming that it will is the bigger leap. I
| imagine that in 10k years we will be able to integrate new
| parts with our nervous system. Think augmentation, not
| replacement, until the whole of the human body is replaced
| in form, but not necessarily function, like Theseus' ship,
| but without changing our experience too much.
| rpearl wrote:
| Your fundamental experiences as a human are already
| augmented by technologies so deeply integrated that our
| brains have changed to accommodate for them. For example:
| writing and speech.
|
| What makes you think that "cyborg" means "foot replaced
| with hoverboard" and not things like "memory augmented with
| curated database" or "though process augmented with
| numeric-error-free calculation"?
| tsimionescu wrote:
| Speech is not "a technology", it is a natural human
| ability. Our ability to form thoughts in the form of
| language and then communicate them (through speech or
| other ways, such as sign languages) is very likely of the
| same nature as our ability to see and interpret the world
| as objects.
|
| Note that children do need interaction to learn to speak,
| but it is not taught to them in the sense that writing
| is, it is a natural instinct that they need social
| interaction to exercise (and they of course need to learn
| a particular firm of speech, i.e. one or more spoken or
| signed languages).
|
| Though such experiments can't be carried out because they
| would risk being monstrous, it's quite possible that a
| group of babies growing up together with no spoken or
| signed interactions from their parents would still create
| a language of their own.
| ewindal wrote:
| You can only feel sunshine and grass because your brain
| interprets sensory signals from your body. It's easy to
| imagine a world where your cyborg body can deliver those
| same signals. If the sensation is the same, why would you
| _not_ exhchange your fragile meat sack of a body with a far
| more versatile mechanical one?
| 20after4 wrote:
| Mechanical devices don't repair themselves. Living bodies
| do. I think you underestimate the highly optimized and
| resilient nature of a meat-sack body.
| CamperBob2 wrote:
| _Mechanical devices don 't repair themselves._
|
| Only because we haven't bothered building any that do. A
| cynical take would be that it would be bad for the
| economy.
| ewindal wrote:
| Perhaps, but imagine no need for surgery, no need for
| anesthesia, all wounds, illnesses and ailments fixed
| simply by switching the damaged part, or switching bodies
| entirely.
| yieldcrv wrote:
| > I think we can all agree we will become cyborgs
|
| That was a leap.
|
| I think we will become more like mycelium, or a root system
| connected in the ground. Still limiting us to terrestrial
| communication on the planet the network is placed on, but an
| optional ability to blast messages out if necessary.
| encoderer wrote:
| The matrix. You're describing the matrix.
| yieldcrv wrote:
| The closest pop culture reference I've seen was depicted
| in Avatar, where the planet wide root system could be
| used for consciousness transfer.
|
| I'm describing that as there are various large networks
| on our planet already, whether fungi or plants, with some
| insect colonies acting similarly as a large single
| organism network.
|
| The matrix didn't have communication between the organic
| nodes in the world they physically existed on, and is
| primarily focused on a simulated world. I'm not
| describing that at all, but I can see how its the nearest
| skeumorph barring any other examples.
| stormfather wrote:
| You don't think we're gonna want to move around?
| jimmygrapes wrote:
| Have you seen the backlash to people being recalled to
| the office? Doesn't seem so far fetched to me...
| yieldcrv wrote:
| We have need for stimuli not a need for movement. The
| movement being a surrogate for the need for stimuli or
| accessing where the stimuli is. We can reduce it directly
| to stimuli if that remains a need.
| stormfather wrote:
| I think we're gonna want to explore the cosmos though. I
| could imagine doing that via sensors that travel while we
| sit here, but you could just say that's an extension of
| our artificial body.
| foobarian wrote:
| > - Consciousness is an emergent property of computation
|
| That is quite a leap. I hope it is true but you never know
| what kind of quantum/other shenanigans sneaky evolution has
| latched on to to end up with the brains of today.
| stormfather wrote:
| Yeah, we don't know the first thing about consciousness
| really. But I imagine with enough time we will be able to
| build an artificial neuron that's smaller. And induct from
| there.
| rmah wrote:
| We know one very important thing: consciousness is not a
| binary state. We have learned that different animals
| experience sensations, emotions at varying degrees. That
| different animals can solve problems of varying
| difficulty. And more advanced animals can communicate at
| varying levels of richness. When you stop thinking of
| consciousness, intellect and awareness as binary states
| but gradients (perhaps multidimensional), then you can
| more easily accept the premise that consciousness is an
| emergent property of the complex biological systems.
| [deleted]
| BurningFrog wrote:
| My intuition is that life was formed using amino acids because
| they are common substances that occur naturally where liquid
| water is around.
|
| Not because they have any unique lifeforming property.
| LightG wrote:
| I just have to say it ... Hayabusa is such a cool name ... just
| is.
| madduci wrote:
| Like the Suzuki motorcycle
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