[HN Gopher] 60 years later, is it time to update the Drake equat...
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60 years later, is it time to update the Drake equation?
Author : elorant
Score : 45 points
Date : 2021-05-18 17:20 UTC (5 hours ago)
(HTM) web link (phys.org)
(TXT) w3m dump (phys.org)
| 29athrowaway wrote:
| Drake equation needs to take in consideration more factors, for
| sure.
|
| Stars have lifecycles, and they can only support life in a stable
| manner in some stages of that lifecycle.
|
| I guess Drake just assumed that stars lifecycles have such a slow
| progression that for the purposes of determining alien life we
| can just assume it is constant.
| ProAm wrote:
| > Stars have lifecycles, and they can only support life in a
| stable manner in some stages of that lifecycle.
|
| That is what the 'L' is in the formula
| mFixman wrote:
| What I never understood about the Drake equation and the search
| for intelligent alien life is why people assume that
| "intelligence" is something special and not something inherently
| human. There's no reason to see human-like intelligence as one of
| the infinite amount of properties a life form can have.
|
| "Two possibilities exist: we are either the only things in the
| Universe that regularly speak Swedish or we are not. Both are
| equally terrifying".
| Grustaf wrote:
| No, it's time to scrap it, since it never made any sense. You
| can't talk about probabilities when there's only a single trial,
| the sample size is 1 and you have no possible way to determine
| the parameters in the first place.
| pitched wrote:
| You can't really get any precision out of it but I think the
| size of the error bars is interesting, where recent estimates
| come out somewhere between 10^-13 and 10^8. That makes it a bit
| more likely that we're alone than not.
|
| https://en.m.wikipedia.org/wiki/Drake_equation#Estimates
| Out_of_Characte wrote:
| While true that the last parameters are completely unknown (IE,
| wether a planet with life has intelligent life, and wether they
| have radio transmission capabilities) the other parameters are
| something we can most certainly estimate. The absense of
| precision in this case is why it was written in the first
| place.
|
| "As I planned the meeting, I realized a few day[s] ahead of
| time we needed an agenda. And so I wrote down all the things
| you needed to know _to predict how hard it 's going to be to
| detect extraterrestrial life._ And looking at them, it became
| pretty evident that if you multiplied all these together, you
| got a number, N, which is the number of detectable
| civilizations in our galaxy. This was aimed at the radio
| search, and not to search for primordial or primitive life
| forms."
|
| So the sample size isn't 1 and there are known ways to detect
| all but 2 or 3 parameters of the drake equation.
| jcranmer wrote:
| > So the sample size isn't 1 and there are known ways to
| detect all but 2 or 3 parameters of the drake equation.
|
| Actually, only 2 or 3 parameters of the Drake equation are
| estimable. (It depends on how you want to define "planets
| that can potentially support life"--you can argue that the
| answer is anywhere between 1 and 5 in our own solar system).
| Everything that talks about the possibility of life evolving,
| let alone speculating about _how_ it will evolve or the
| xenosociology of what that life will try to do, is pure
| conjecture: that 's the last 4 values of the equation, more
| than half of it.
| Grustaf wrote:
| Ok, you can say that the sample size is the number of
| planets, but there's only 1 trial.
|
| EDIT:
|
| If you go through the factors, only the first three even make
| sense to talk about. And the third, about "number of planets
| per star that can potentially support life" can only be
| discussed in terms of our particular form of life. We have no
| idea at all what other types of life there could be, much
| less under what conditions that might happen.
|
| The others are completely unknowable. For example:
|
| f_i: The fraction of planets with life that actually go on to
| develop intelligent life (civilizations)"
|
| I'm embarrassed even writing it out. How can anyone even
| start to think that they could come even with 10 orders of
| magnitude of the right answer, if it's even a well defined
| probability, which I doubt.
|
| We know of exactly one planet with life, and it has
| intelligent life that emits radio waves. Is that an
| inevitability, or a one in a trillion fluke?
|
| But what bother me the most is how you even think you can
| talk about probabilities when there's only one trial, and for
| the later factors, the sample size is most definitely 1. It's
| just inane.
| kelnos wrote:
| You absolutely can talk about probabilities, and it's an
| interesting thought experiment. You just can't -- yet -- plug
| in meaningful numbers derived from experimental data.
| Grustaf wrote:
| Yet? How could you ever hope to be able to say anything about
| the last five factors until you find another civilisation? By
| which time you have the answer anyway.
| mvzvm wrote:
| The Drake Equation always felt like gibberish to me. How can you
| have an equation "used to estimate the number of active,
| communicative extraterrestrial civilizations in the Milky Way
| galaxy" when we have nothing to test it with?
| sigg3 wrote:
| It's like rejecting quantum superpositions because you're fond
| of cats.
| neolog wrote:
| > nothing to test it with
|
| What do you mean here?
| delecti wrote:
| It's a thought experiment meant to highlight known unknowns. If
| we could perfectly measure each field, we would necessarily
| have an idea of the number of intelligent civilizations. Each
| term raises interesting questions, even if they can't be
| precisely measured (or even guessed at with any confidence).
| vimacs2 wrote:
| I have to disagree. It is useful to be able to quantify the
| exact state of ignorance that we currently have and as our
| observational reach expands, the values of the variables in the
| equation should become less and less fuzzy.
|
| The problem isn't with the Drake equation, it's with the pop
| science articles that extrapolated things from it way beyond
| the original intent or scope.
| treeman79 wrote:
| Several sets of unknown on an infinite universe, so we know
| know nothing.
|
| However thanks to speed of light the data set is not
| infinite, just absurd.
|
| So we know almost nothing.
|
| Given time the expansion of the universe will push all
| galaxies and stars away from us. The data set will be 1.
|
| We now know everything.
|
| As expansion continues all hydrogen items will eventually
| break apart. All life has ended.
|
| _Nothing_ now knows us.
| kelnos wrote:
| You can certainly have it, you just can't use it with any sense
| of accuracy until you have more data.
| nend wrote:
| Take a look at the article:
|
| "Rather than being an actual means for quantifying the number
| of intelligent species in our galaxy, the purpose of the
| equation was meant to frame the discussion on SETI. In addition
| to encapsulating the challenges facing scientists, it was
| intended to stimulate scientific dialog among those attending
| the meeting. As Drake would later remark:..."
|
| Then follows a video of Drake speaking.
| s1artibartfast wrote:
| But we do have ways of testing it. We can and do look for
| extraterrestrial civilizations coming from nearby planets and
| solar systems, and thereby place bonds on the output of the
| Drake Equation.
|
| For some combinations of parameters, we should expect to see
| life on most other bodies within the solar system. The search
| for life on the moon and mars are simple empirical tests of
| these predictions.
| TheOtherHobbes wrote:
| There's a missing term: "How much of our potential budget are we
| spending trying to fill in the other estimates?"
|
| SETI is _incredibly_ poorly funded compared to other science. For
| a long time it was barely funded at all. There 's been an uptick
| recently, but a project like Breakthrough Listen runs on $10m/yr
| and gets ridiculously constrained access to telescope time.
|
| The remaining SETI projects get by on less than $5m/yr. So SETI
| as a whole gets about as much funding as _one episode_ of The
| Mandalorian.
|
| No wonder we haven't found anything. We're barely even looking.
| [deleted]
| optimalsolver wrote:
| Learned about this equation from the late Michael Crichton's book
| "Sphere". A really great first contact science fiction story.
| blacktriangle wrote:
| Mandatory to mention when talking about Sphere: read the book
| first, then watch the movie if you feel so inclined. The book
| is very very good, the movie is okay but so much of the book
| takes place in the characters' heads that most of the plot is
| lost in the film.
| marze wrote:
| I think next year would be a better time to update the equation.
| myfavoritedog wrote:
| It seems odd to be conducting the search for extraterrestrial
| intelligence by looking for radio signals from distant planets.
|
| Maybe we should figure out what all these UFOs are here first.
|
| https://www.washingtonpost.com/nation/2021/05/17/ufo-sightin...
| jodrellblank wrote:
| I can't read that past the paywall, but what's your answer to
| https://xkcd.com/1235/ ?
| myfavoritedog wrote:
| I love the relevance of an XKCD as much as the next guy, but
| a clever graph doesn't compare to the admissions of the
| military and US government that these videos are not faked.
| They can't explain these craft that seem to be propelled in
| ways that are entirely unfamiliar to airforce personnel who
| are themselves familiar with cutting edge earthling aircraft.
|
| https://www.cbsnews.com/news/ufo-military-
| intelligence-60-mi...
|
| [edited for grammar]
| ud_0 wrote:
| I think (hope?) the Drake equation was never intended as a tool
| for making realistic estimations, I always thought it was more of
| a first approximation of how one might go about thinking about
| modeling when all you have is a sample of one.
|
| Specifically the rate of star formation has always been dubious,
| because there is such an enormous lag between star formation and
| the emergence of intelligent life (even if we turn out to be an
| extremely slow outlier), making it unsuitable for estimating the
| amount of civilizations active at a specific point in time.
|
| My personal drake equation would include only factors that are
| based on the current state of the galaxy. But that's the Drake
| equation doing its job: making people think about cosmic odds. It
| doesn't need an update, because I argue it shouldn't be taken
| literally in the first place.
|
| A few times a year, authors put out "new" estimations of the
| number of galactic civilizations, and to do that there is really
| not much alternative to chaining together these kinds of
| probabilities. While they sometimes may or more often may not use
| the _actual_ Drake equation to do it, its value lies in the basic
| structure, not in its specific implementation.
| derekp7 wrote:
| Is it valid to take a data point of one, combined with a time
| element to get an estimate? For example Earth started gaining
| life shortly (in geological time) after it was able to sustain
| it. That would indicate that either life arises easily, or that
| it pre existed the Earth and got seeded (panspermia).
|
| Then at the opposite end of the scale is the long time that it
| took for life to go multi-cellular, and for a space program to
| be formed by an instance of that life.
| tsimionescu wrote:
| Well, we know life on earth is at least 3.7 billion years
| old, but it's not much clear how much older. Since the earth
| is 4.5 billion years old, that means that life could have
| appeared after ~17% of its life span so far, which is not
| THAT little. Furthermore, even if life appeared as early as
| the earliest estimate - just a few million years after the
| earth formed - we have no evidence that abiogenesis continued
| happening after an initial event, or that it happened
| anywhere except an initial location.
|
| Those two factors may mean that abiogenesis could be an
| extremely unlikely event that randomly happened to occur very
| early in the Earth's life span.
| ghaff wrote:
| >That would indicate that either life arises easily
|
| Not really. While suggestive, all it indicates is that it
| arose on _earth_ easily.
| s1artibartfast wrote:
| not even that. Life could have been incredibly unlikely to
| arise on earth, but still arise when it did as freak
| statistical occurrence. We only have one earth to examine,
| and the anthropic principle severely limits any conclusions
| we could draw from n=1.
| ghaff wrote:
| Yeah, happened to arise on earth quickly would probably
| be the better phrasing.
| pie420 wrote:
| Your line of thinking is exactly what's wrong. The fact that
| life emerged on earth shortly after being able to sustain
| life says absolutely nothing about likelihood. It could be a
| very likely thing. Or it could be a 1 in a 10^35 miracle that
| happened due to an insanely low probability event involving
| gamma rays hitting chemical reactions in just the right way.
| Until we solve abiogenesis and can demonstrably evolve life
| from abiotic matter, or observe other planets with life on
| them, this is all speculation.
| ghaff wrote:
| One of the challenges (I won't say problems) with the Drake
| Equation is we have some sense for some numbers and they're
| very very large. Which encourages people to use formulations
| for some of the other terms like "even if we assume this is one
| in a billion" and this is "one in a million," you still come up
| with a significant number of civilizations. When, in fact, some
| other term may be so vanishingly small that it's only happened
| once. (Or there may be something else, e.g. a great barrier,
| that's not being taken into account.)
|
| But, as others have written, it's not really intended to be
| used that way.
| lordnacho wrote:
| I'm a bit surprised at the criticism. I always thought of it as
| more of an equation template than a very specific equation. Of
| course if you take a specific version of it, there are things it
| won't capture that we discover over time. But the idea that we
| can take a very large number and whittle it down seems
| reasonable.
| _rpd wrote:
| Yes, it's inspired a lot of investigations and discussions,
| which was exactly its purpose. See also: 'solutions' to the
| Fermi Paradox.
|
| https://en.wikipedia.org/wiki/Fermi_paradox
| paxys wrote:
| > This would come to be known as the "Drake equation," which is
| considered by many to be one of the most renowned equations in
| the history of science.
|
| Uh, this might be a tad bit hyperbolic. Does anyone even consider
| it serious science?
| s1artibartfast wrote:
| Sure, why not?
|
| In terms of renown, it is probably it the top equations people
| would be able to recognize by name, and tell you what it is
| about. The only equations that might be more recognizable by
| name are the Pythagorean theorem, ideal gas law, and perhaps
| some Newtons laws of motion.
|
| In terms of scientific relevance, It is a tool for examining
| what many people consider the single most important questions
| ever asked.
| pie420 wrote:
| It's nowhere close. The quadratic equation, pthagorean
| theorem. Heros law, and a hundred other more simple equations
| are more famous.
| myfavoritedog wrote:
| It's interesting to see how much work people seem to think that
| framing the Drake equation as a "thought experiment" does.
|
| If it's a thought experiment, stop calling it an "equation".
| People hear that something is an equation and they think that
| there's real math and science involved. Call it the "Drake
| Conjecture" or something.
| BitwiseFool wrote:
| I think a journalist wanted to convey the concept of "well-
| known" coupled with a sense of respect. I sense the word choice
| made sense in a thesaurus.
| Dylan16807 wrote:
| It seems fine to me. Even if you don't think it's "serious"
| enough for you, it's a scientific way to organize an
| explanation of the world and it's very famous.
| labster wrote:
| Of course it's serious science, it's just thinking about
| statistics. Of course most of the values are unknown right now,
| as we are just starting our survey of exoplanets. But it raises
| lots of questions, and those are good for science.
| paxys wrote:
| I don't see how it meets even a single step of the scientific
| method. You can call it a somewhat scientific thought
| experiment, if such a thing even exists, but that's about it.
| s1artibartfast wrote:
| It is pretty easy to use it generate and test hypotheses,
| which is frequently done and published in the literature.
| Common examples include radio and other EM surveys for
| extraterrestrial signals.
| bpodgursky wrote:
| By your definition, "Calculus" is highly unscientific.
| analog31 wrote:
| Calculus owes some of its development to its use in
| scientific theories, but also stands alone as a branch of
| math. One can approach it as a pure exercise in symbol
| manipulation (as I did as a student).
|
| Without trying to precisely define scientific
| methodology, I think it always needs some connection to
| empirical evidence. This is the problem with the Drake
| equation, but also with some other speculative fields
| like string theory.
|
| So I'd say that the Drake equation is scientific in the
| sense that it's motivated by scientific speculation, but
| has not yet found a form that can be tested.
| thaumasiotes wrote:
| > Does anyone even consider it serious science?
|
| Yes, just like there are people who consider Crystal Power
| serious science. A lot of people are deeply impressed by the
| Drake Equation, presumably because they can't understand it.
| neolog wrote:
| What's unserious about it?
| thaumasiotes wrote:
| Literally every part of it.
| jandrese wrote:
| I always thought it was a bit of a lark. You multiply a whole
| bunch of unknowns with huge errors bars together to get a
| totally new unknown with universe sized error bars.
| pie420 wrote:
| Yep, it's really silly. It's really just saying we don't
| know, and here's a breakdown of all the reasons that we don't
| know.
| jawns wrote:
| I don't have any philosophic objections to the existence of
| extraterrestrial life, but what does bug me is when people claim
| that simply because the universe is so big, that somehow makes it
| not only likely but practically certain that life has developed
| on other planets or in other solar systems or galaxies. That kind
| of thinking presumes some very important information that we just
| don't have. We are currently unable to enter any coherent value
| into the portion of the Drake Equation that pertains to how
| frequently life arises from non-life.
|
| We have an admittedly very limited knowledge of events outside of
| our own planet, but so far as we know, abiogenesis has occurred
| only once, and from that one event, all life on Earth proceeded.
| (It's possible that abiogenesis occurred independently multiple
| times during the beginning of life on Earth, but I don't think we
| yet have a compelling argument that it must have happened more
| than once.)
|
| My favorite analogy:
|
| Suppose you see a number with this pattern:
|
| 0.1001000101001000101001000___
|
| What would you say is the likelihood that a 1 is the next number
| in the sequence? Not that hard to compute a probability, is it?
|
| But suppose you see a number with this pattern:
|
| 0.1000000000000000000000000___
|
| What is the likelihood that a 1 is the next number in the
| sequence? You could say the odds are 1-in-25, but that doesn't
| takes into account the clear pattern we see in the sequence.
| Unless and until we start to see some more ones pop up, it's
| reasonable to assume that this is a sequence of infinite zeroes,
| or at the very least that it could perfectly well be a sequence
| of infinite zeroes. Suppose the sequence goes on for many
| trillions of numerals. No one's going to say, "Well, if there are
| trillions of 0s, it's highly unlikely that there won't be some 1s
| sprinkled in there somewhere."
| kadoban wrote:
| If there are no more 1s, then we need to answer why our
| position in the universe is unique. That seems like a hard
| question to answer. It just seems like a _much_ better bet that
| we aren't the only 1.
| jawns wrote:
| The "why" might be more of a philosophical question than a
| scientific question, but in terms of the science, I don't
| think it's hard to reason about.
|
| Ultimately, the frequency at which abiogenesis occurs is 1/N.
|
| It may be the case that N is small enough that the universe
| is positively teaming with life.
|
| Or it may be the case that N is so unfathomably large that
| the odds are exceedingly small that abiogenesis occurs even
| once during the lifetime of the universe, and the universe
| just happened to get lucky.
|
| But until we have some other confirmed, observed instance of
| abiogenesis, we can say nothing about N other than its lower
| bound is pretty large.
|
| And I don't think we can pile probabilities on top of
| probabilities to say, "Well, we have no way of knowing how
| large N is, so I'm going to just bet that it's medium-sized."
| Smithalicious wrote:
| This reasoning seems flawed, how is it that an answer that
| doesn't lead to difficult questions is more likely (rather
| than simply more convenient)?
| tsimionescu wrote:
| There doesn't have to be an answer. We could just be "the
| first"[0] life to evolve - someone always has to be. Now, if
| we were to say that ours is the only life to exist in the
| entire past and future history of the universe, that would
| probably require a more specific explanation.
|
| [0] to the extent that events across vast spans of space can
| be said to be ordered
| kadoban wrote:
| If we're the first, that also requires just about as much
| explanation really. There are how many galaxies, and how
| many systems per galaxy, and how many planets per galaxy?
| If the chance of life per planet is anything more than on
| the order of 1/trillion, laws of big numbers suggest we
| just _can't_ be the first or only.
|
| None of this is any kind of _hard_ proof of course, it's
| just attempting to reason through what we expect without
| having enough data to prove either way.
| tsimionescu wrote:
| Again, some civilization will be the first, that is a
| certainty. Now, you may ask 'why did civilization only
| arise X billion years in the universe' s history'
| perhaps, but not 'why are we the first and not someone
| else' (assuming we were, which I have no opinion on).
| colordrops wrote:
| Question: is it possible that the universe is geared for DNA
| based life to emerge through abiogenesis? Just as the same
| crystals form under the same circumstances no matter where you
| are, perhaps DNA based life is the same, just a fundamental
| standard pattern you can find through abiogenesis at multiple
| points in time and location. Why do we presume that our form of
| life is so special?
| jawns wrote:
| I don't think it entails presumption that our form of life is
| special to say, "You can't determine frequency based on a
| single data point."
| saas_sam wrote:
| I don't think this is a very good analogy because we know far
| more about the nature of life, what is required to make it, and
| the abundance of those ingredients throughout the cosmos. Life
| isn't a lengthy, specific sequence of precise things. It's a
| phenomenon that occurs when certain _kinds_ of things come
| together in certain _kinds_ of ways -- many variations of these
| ingredients and permutations exist on Earth alone.
|
| Your perspective reminds me of the anthropic principle:
| https://en.wikipedia.org/wiki/Anthropic_principle
|
| The popular conception is the "puddle analogy." You can imagine
| a rain puddle becoming conscious, seeing the intricacies of its
| perfect fit with the pavement that surrounds it and concluding
| "wow, this hole fits me SO perfectly, it must have been made
| for me."
| [deleted]
| tsimionescu wrote:
| > many variations of these ingredients and permutations exist
| on Earth alone.
|
| Apart from cells, what are you referring to here? Especially,
| is there anything that can be considered "somewhat living"
| that is not a by-product of regular life, which as far as we
| know has only ever appeared (or thrived) once Earth's
| history?
| saas_sam wrote:
| Let's take a different naturally-occurring type of object
| that has only ever been found on Earth: waterfalls. To get
| a waterfall, you need a set of ingredients and
| circumstances to occur in a particular way that a waterfall
| results. We've only ever seen this on Earth. They come in
| many forms: Niagara Falls, jungle waterfalls, small
| waterfalls, even frozen waterfalls and underground
| waterfalls. They even have different colors, chemical
| characteristics, and each one can be said to be very unique
| from all the others.
|
| We know of no other planet that has waterfalls.
|
| Yet, because we have seen enough waterfalls on Earth we
| have an evidence-based scientific belief that waterfalls
| cannot be Earth-specific because all that is required for
| one: water, erosion, gravity -- exists throughout the
| cosmos in very large amounts.
|
| Life is the same. We have seen enough of it in enough
| variety to know that it can take on many forms, including
| exotic forms that are impossible on Earth but would be
| possible elsewhere. The abundance of the ingredients and
| time are all that's required.
| cwkoss wrote:
| > Life is the same. We have seen enough of it in enough
| variety to know that it can take on many forms, including
| exotic forms that are impossible on Earth but would be
| possible elsewhere.
|
| What forms of life that are impossible on earth do we
| know about?
| saas_sam wrote:
| Silicon based for one.
| tsimionescu wrote:
| That's a conjecture, not a known form of life that
| couldn't occur on Earth. There is no proof that silicon
| based life could exist, we barely know if silicon organic
| chemistry could actually exist.
| tsimionescu wrote:
| I understand the concept, but I don't think it applies to
| life specifically. Even the simplest cell is more complex
| than any other naturally occurring formation we have ever
| seen in the universe.
|
| Furthermore, unlike waterfalls, we actually have no idea
| how life appeared and, despite trying for many years,
| have been entirely unable to produce life from non-living
| things, and we have never observed this process occurring
| naturally either.
|
| Furthermore, every living thing we've ever looked at has
| been a relative of other living things - as far as we've
| been able to determine, all of the life on Earth has a
| single origin, a single original RNA/DNA code which must
| have been present in a single population of organisms, at
| a single location. This is a strong suggestion that the
| conditions that allowed life to appear on Earth may have
| been extraordinarily specific - otherwise, we would
| expect many unrelated beings sharing the planet (or at
| least it means that a particular for of life was
| overwhelmingly more adaptive and entirely wiped out all
| of the others).
|
| Even worse, there is another phenomenon for which we only
| have evidence of one instance happening in the history of
| the Earth: all eukaryotic life has a single common
| ancestor, and there are no complex multicellular
| organisms which are not eukaryotes.
|
| So, not only did life arise only once on the one planet
| we know it can thrive in, but complex life only arose
| once from simpler life.
|
| So, while we can't say that it's plausible life will
| never again arise in the universe, we can say that for
| any particular moment of time, it is plausible that no
| new life is being formed anywhere else in the universe.
| CorrectHorseBat wrote:
| I don't think that's a good analogy, all those waterfalls
| developed independent of each other.
|
| As far as we know all life is related and has the same
| ancestor. Even on earth the emergence of life seems to be
| a freak accident.
| saas_sam wrote:
| Sigh. Analogies are hard.
| tsimionescu wrote:
| I don't think this is just a limitation of the analogy,
| but it is the key point: for any structure where we know
| the process that forms it (like waterfalls or snow
| flakes), we can have some informed opinion about the
| chances of it happening elsewhere in the universe, even
| if we have only observed one instance of it happening.
|
| However, for structures where we have no idea of the
| process by which they are formed (like cells), we can't
| have any opinion on how likely they are to happen
| elsewhere, unless we see more examples.
| saas_sam wrote:
| I think we know more about abiogenesis than you are
| giving us credit for.
| tsimionescu wrote:
| We know a few things about the formation of organic
| compounds that life uses from inorganic compounds, and
| how some specific organic compounds crucial to life
| appeared, but not much more than that. Nothing even close
| to the formation of a simple self-replicating cell, for
| example.
| rektide wrote:
| The amazing thing about the Drake Equation is that it's a
| funneling pipeline where we're spitballing numbers with huge
| orders of magnitudes difference across different people's
| guesses. They're just random guesses, where one person says one
| particular odds are one in a million, the other guy says one in
| a billion, the other gal says one in a trillion. Yet in spite
| of a huge range, for each of the winnowing factors in this
| funnel, the odds of there being life are often significant.
|
| Which is to say, two things are certainly true:
|
| The universe is incredibly fantastically basically unimaginably
| vast. Practically countless (~10 million estimated) super-
| clusters of galaxies dot the heavens. There's just so many
| chances, so many opportunities, so much probability that, if
| you believe in life arising from a primordial soup, seem almost
| certain to be replicated.
|
| Sometimes chaos, in it's fumbling teaming randomness, happens
| upon patterns. Patterns which sometimes stick, which sometimes
| reproduce, which sometimes grow. Entropy amid complex systems
| sometimes produces it's own enclaves of stability, sometimes.
|
| The other true fact is that time is long and deep. Life on
| earth is not a flash in the pan, not an instant thing; it
| emerged slowly, over time, in differing waves, across time. The
| promise that life, once began, has a chance to ride these waves
| of time & to become significant, that it grows to fill rich
| biodiverse roles, grows to complete, that it thrives: if we
| believe in the soup of life, believe in the complex chemistries
| that powers cells, and believe in time, then a belief in other
| life seems not certain, but to me, highly highly probable.
| CoolGuySteve wrote:
| We have another datapoint though, the age of the Earth. Life
| started fairly early after the Earth cooled, about a billion
| years after initial formation. This implies that abiogensis
| could have happened several times since then and died out;
| created the same chemical system independently; was out-
| competed by regular DNA life; or they're around but we just
| haven't discovered alternative forms of life on earth.
|
| But life capable of communicating across space didn't arrive
| until 4.5 billions years and after several mass extinctions.
| Even on a cosmic scale that's a very long time.
| jcadam wrote:
| Personally, I'm starting to lean toward the Rare Earth
| hypothesis.
|
| I do, however, like the "solution" posited in the short story
| "The Crystal Spheres":
| https://en.wikipedia.org/wiki/The_Crystal_Spheres
| hackeraccount wrote:
| Everything I've read makes me think life almost certainly
| exists outside of the Earth, I'm even open to the idea that it
| exists within the solar system. Complex eukaryotic type life?
| I'd be that's a lot more rare - consider that prokaryotes look
| to have popped almost as soon was possible but then it
| apparently to several billion years for eukaryotes.
| cletus wrote:
| "Equation" is an unfortunate name because some view that like the
| Drake Equation is meant to produce a quantifiable number. It
| isn't and never was. It's a thought experiment and a way to frame
| the problem (the article states this explicitly).
|
| What has changed is the assumptions about how we would detect a
| starfaring civilization. 60 years ago we were assuming radio
| communications because that seemed to be where our future was
| and, by extension, what we might expect other civilizations to
| do.
|
| Obviously the values in the equation are unknown. We use such
| things to frame problems that involve unknowns like this. A good
| example: the anthropic principle [1].
|
| Anyway, the more prevalent line of thinking now is that
| starfaring civilizations are likely to end up building Dyson
| swarms. This is a long and complex discussion. There are many
| objections but those objections tend to suffer from the problem
| that, if that objection is true, there should be more not less
| starfaring life (eg any form of FTL).
|
| If matter is the ultimate limiter to civilizations then it makes
| sense that civilizations will try and amass as much of it as
| possible. It doesn't matter if not every civilization goes this
| route because even one such galaxy-spanning civilization within a
| million light years will stand out (based on the IR signature).
|
| Even without that it probably wouldn't take more than about 10M
| years for humanity to colonize the Milky Way.
|
| [1]: https://en.wikipedia.org/wiki/Anthropic_principle
| LatteLazy wrote:
| Wait, do people actually think Dyson swarms are a thing? The
| amount of time and energy needed to build them always seemed
| ridiculous to me. Especially as all you gain is energy (which
| hasn't proven limiting) and you lose almost everything else
| (gravity and atmosphere for a start)...
| the8472 wrote:
| > Especially as all you gain is energy (which hasn't proven
| limiting)
|
| What? Civilization runs on cheap, abundant energy. Before the
| industrial revolution we had to use labor animals, slaves and
| the occasionally water and wind mill. Providing light was
| expensive. Global supply chains (transportation), aluminium
| smelting, fixing nitrogen for fertilizer or calcination for
| cement consume stupendous amounts of energy.
|
| If energy became cheaper then creating green fuel for
| airplanes and rockets, electrorefining all metals,
| desalination or perhaps mining and crushing olivine rocks for
| carbon sequestration would become more feasible.
|
| Whenever vertical farming is discussed here the main counter-
| argument boils down to energy not being cheap enough. It's
| hard to compete with the sun delivering it to plants for
| free.
| Grustaf wrote:
| None of those things are necessary for civilisation, or
| radio communication. They just improve things on the
| margin.
|
| Besides, surely it must be simpler to build a fusion
| reactor on earth than harvesting enough material to cover
| the sun in solar panels. Would the solar system even have
| enough resources for that?
| [deleted]
| the8472 wrote:
| > None of those things are necessary for civilisation
|
| That's only true for low values of civilization. Even
| bronze age tech consumes more than hunter-gatherers which
| consume more than monkeys.
|
| > Besides, surely it must be simpler to build a fusion
| reactor on earth than harvesting enough material to cover
| the sun in solar panels.
|
| Dyson swarms sit higher on the kardashev scale than
| harvesting whatever you can get on a single planet. At
| some point waste heat rather than fuel will also become a
| real problem. Fusion reactors are ultimately thermal
| power stations, glorified steam engines.
|
| > Would the solar system even have enough resources for
| that?
|
| You'd start small with asteroids. And then disassemble
| some moons with shallow gravity wells. Which of course
| again requires stupendous amounts of energy just to move
| the material around but the sun still has billions of
| years left so there will be time to recoup that
| investment.
| pie420 wrote:
| The sun is a large fusion reactor. Eventually you will
| run out of mass in the solar system to put in your fusion
| reactor, and then you'll resort to extracting energy from
| the natural fusion reactor. A Dyson sphere is a fusion
| reactor of sorts.
| LatteLazy wrote:
| I don't want to doubt we will find some use for more energy
| but... I think I have all the energy I need to be honest.
|
| I don't lack for aluminium or even transatlantic flights
| (the most energy intensive think I could think of buying).
| If I really want to go to X I do. Price doesn't really
| bother me.
|
| Maybe we can use 10x the current supply so everyone can
| have my lifestyle. But that's still vastly less than a
| Dyson sphere would produce.
|
| For a long time energy was a limiting factor on human
| development. But I don't think that's true for the average
| westerner anymore. I want time off and less stress and
| relationships. Those mostly come down to social structures
| and information, not GJs...
| pixl97 wrote:
| >I think I have all the energy I need to be honest.
|
| You don't. You only think you do because you are living
| on borrowed energy, _massive_ amounts of energy stored in
| carbon over the last billion years. Unleashing this
| stored energy is going to burn down our planet.
|
| So yes, we need way more energy that is not tied to
| digging up dead dinosaurs. Even more energy if we want to
| put them back in the ground. And even more if everyone
| wants clean water. Everyone else that is not a westerner
| wants lights and water and food too.
| ben_w wrote:
| PV can give us about 10,000 times our current power even
| without building a Dyson swarm. Ten billion humans each
| regularly using a thousand times the power of the average
| current American could happen, but it's ten times greater
| a change to how people live than was reaching modern day
| American power use relative to the day before the
| invention of fire (or domestication, whichever came
| first).
| cletus wrote:
| > Wait, do people actually think Dyson swarms are a thing?
|
| Yes, absolutely. The main reason is that building orbitals is
| largely an engineering problem. You need a material no
| stronger than stainless steel. If graphite is feasible, it
| allows you to build bigger orbitals but it's not necessary.
|
| Compare this to a lot of other proposed megastructures like
| space elevators, which would take a material to build that
| doesn't currently exist.
|
| Also, to be clear, we're talking about Dyson _Swarms_. This
| is the original design idea that was called Dyson Spheres but
| that name is often not used because people mistakenly think
| we're talking about a rigid shell that encompasses a star.
| That is not and never was the intent. It's also impossible
| for many reasons.
|
| A Dyson swarm is simply a collection of orbitals. The great
| thing about it is you can also build it incrementally.
|
| Note that since these are spinning orbitals they have (spin)
| gravity and atmospheres.
|
| Energy is absolutely a factor here.
| UI_at_80x24 wrote:
| >Also, to be clear, we're talking about Dyson _Swarms_.
| This is the original design idea that was called Dyson
| Spheres but that name is often not used because people
| mistakenly think we're talking about a rigid shell that
| encompasses a star. That is not and never was the intent.
| It's also impossible for many reasons.
|
| Thank-you for clearing this up for me. I made a post after
| you, but you addressed the issues that I discarded. I now
| know more then I did. Thanks!
| LatteLazy wrote:
| How do such small objects maintain their atmospheres?
|
| Also, to remain in a stable orbit, wouldn't the spin force
| have to match the gravity of the star? So there would be no
| effective force left to provide gravity would there?
| (Similar to how people on the ISS are weightless despite
| still being within earth's gravity well).
| ben_w wrote:
| The problem with spin-gravity and stable orbit is
| specifically an issue for Niven Rings rather than all
| possible space habitats.
| pixl97 wrote:
| The vast majority of devices in a theoretical dyson
| sphere are energy collectors. These would be mostly flat
| with no atmosphere or gravity. Much larger 'space
| stations' could be built throughout the swarm that would
| have induced gravity or internal atmosphere.
| jerf wrote:
| In fact, you can say with a straight face that we've
| _already started_ to build our own Dyson swarm. We have
| things in orbit around our sun. All we have to do is just
| keep going!
| UI_at_80x24 wrote:
| I liked that Ringworld addresses this.
|
| What Dyson Sphere's excel at is hiding their location* and
| capturing 100% of a stars output. At those sizes, a
| civilization MUST have already conquered the energy problem.
| It'd be impossible to construct without "free energy",
| because you need to convert that energy into matter to
| make/engineer enough material to create a sphere the size of
| the Goldilocks zone.
|
| And as you said, you'd lose atmosphere & gravity* would be
| wonky.
|
| But to address the fine article, the equation was a thought
| experiment. We now have hard data on the number of stars that
| we've looked at that have planets. And of those we have a
| hard number that have planets in the habitable zone. The
| Drake Equation presumes that you guess TINY numbers for those
| values. Well using known numbers and extrapolating the number
| of possible worlds with intelligent life jumps from
| staggering large, to incomprehensible.
|
| As humans, we can barely communicate with others of our own
| species. Let's frame the problem another way.
|
| Put two Americans in a room. One is deaf, the other is blind.
| How long does it take for them to agree on what to eat for
| dinner?
|
| Context depends on language. We may have been bombarded by
| intelligent alien life for centuries; we just don't know that
| somebody is talking.
|
| *Everybody forgets about gravity.
| the8472 wrote:
| > A civilization MUST have already conquered the energy
| problem
|
| There possibly are ever more exotic applications that
| require more energy. Energy to matter conversion which you
| mention (and which also conveniently produces antimatter)
| requires very very large amounts of energy. The mass defect
| of the Tsar Bomba is merely 2.6kg, which also happens to be
| roughly equivalent the energy the sun that hits the whole
| planet each second. And then there are speculative things
| like the alcubierre drive or anything that involves moving
| entire stars.
| mgolawala wrote:
| I am not at all well informed about this but I imagined a
| Dyson swarm would sort of grow and evolve organically over
| time. Not as an end goal in themselves.
|
| For example, if you start building space habitats (even if
| they are enclosed cylinders such that they hold an atmosphere
| and provide gravity via rotation) you need to put them
| somewhere. It makes sense to throw them in orbit around the
| star at some optimal distance (for example at 1AU +/- some
| amount), if you continue to put more and more such habitats
| around a star in similar orbits over time, in sufficient
| numbers, wouldn't they start to resemble a Dyson swarm?
| the8472 wrote:
| _Dissolving the Fermi Paradox_ [0] is a great and easy to read
| paper to disabuse anyone of the idea of multiplying point
| estimates when you could convolve probability distributions
| instead.
|
| [0] https://arxiv.org/abs/1806.02404
| floxy wrote:
| I think this paper should be a top level HN discussion
| thread.
| the8472 wrote:
| has been https://news.ycombinator.com/item?id=17560462
| analog31 wrote:
| >>> 60 years ago we were assuming radio communications because
| that seemed to be where our future was and, by extension, what
| we might expect other civilizations to do.
|
| Indeed, and today, the bulk of our communications are via
| enclosed waveguides -- fiber optics. And our remaining wireless
| communications are quickly evolving towards both decreasing
| power use and signal formats that are nearly indistinguishable
| from noise. Our period of "hot" radio emissions may only span
| roughly a century.
| gus_massa wrote:
| Once we go interplanetary, we will need to turn on the radio
| again.
| JoeAltmaier wrote:
| Geometric growth would put it at far less than 10M years? On
| the order of hundreds of thousands I would think.
| jfengel wrote:
| The Drake equation is an example of a more general issue in
| science: what are we going to spend money on?
|
| The Drake equation is treated as fodder for late-night Cheetos-
| driven college sophomore discussions. But we use it, and
| siblings, to estimate the inestimable: how much value do we get
| out of a dollar put towards actually investigating this?
|
| No matter what the field, it's always all over the map. Do we
| want to spend gigabucks on an LHC successor in the hopes of a
| vast payoff? Do we want to spend megabucks on this specific line
| of cancer research? Or should we spend the same money on
| thousands of kilobuck experiments in everything from economics to
| psychology to polymer chemistry?
|
| It's even harder when there isn't actually a dollar value
| attached. Even if we discover alien life, what's the merit of
| that? Economically, perhaps nothing, other than sales of "I
| wanted to believe/and I was right" tee shirts. But in terms of
| satisfaction, perhaps more than all of the movies and video games
| ever made put together.
|
| That's why we spend so much effort trying to estimate priors that
| we know are too wild to be of actual value in that calculation.
| Playing with the Drake equation is fun. That's all. But it does
| also ultimately inform the expenditure of some resources, even if
| we don't actually do the math.
| redis_mlc wrote:
| > late-night Cheetos-driven college sophomore
|
| Welcome to HN!
|
| > starfaring civilization
|
| Reinforces the point - fanbois confusing scifi with reality.
| s1artibartfast wrote:
| Why do anything?
|
| Any questions of resource allocation ultimately come down to a
| question individual and social values, or merit, as you phrased
| it.
|
| Merit is inherently arbitrary. Some people can and do think
| answering the question of the existence of extraterrestrial
| life has intrinsic merit and is the single most important
| society could do. More important than improving global
| prosperity or even continuation of the species.
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