25 ms·

Model predicts we're the only advanced civilization in the observable universe

319 points by sidcool 8y ago

lord_ring_111 8y ago
May be may be not. I wish my teachers would have accepted such answers in my high school
andbberger 8y ago
Why is this even still a question... every single time you boil a pot of water convection rolls form. According to equilibrium thermodynamics it is vanishingly improbable that Avogrado's numbers worth of molecules will conspire together to act in a coordinated fashion to form those rolls... yet it happens every time. The convection rolls win out over diffusion because they dissipate heat faster and there is only so much heat. Life is no different. A structured low entropy process that dissipates energy faster than diffusion - there's no paradox or anything about emergent complexity. The fundamental concepts here are pretty simple and any discussion concerning P(life) need to start by understanding what life is in the first place and how it can arise. Point being: life isn't a rare thing or a mystery, anywhere in the universe you find energy gradients you'll find life. There just isn't a conversation to have here. If we're alone it's because we're first. But we are almost certainly not alone. The universe is just really fucking big.
- em3rgent0rdr 8y ago
  Just because "a structured low entropy process that dissipates energy faster than diffusion" will win out every-time doesn't answer the question about how a self-replicating structured low entropy process will form in the first place. Once life starts then it will explode, but the problem is how to get life actually started.
  - millstone 8y ago
    Perhaps life is easy to start, but is also easily out-competed by non-living self-replicating organisms.
    - kaffeemitsahne 8y ago
      "non-living self-replicating organisms" Sounds like a contradiction to me ;)
      - bmc7505 8y ago
        Lots of things are self-replicating that we would not consider "living". https://en.wikipedia.org/wiki/Self-replication https://en.wikipedia.org/wiki/Self-replication
  - andbberger 8y ago
    Not claiming my above comment was the greatest argument ever, I didn't spend that much time on it - but that is precisely what the argument is about. I am arguing that the formation of life is not a rare thing at all.
- millstone 8y ago
  I want to understand this argument better. Are you claiming that any "structured low entropy process that dissipates energy" is alive? How are you defining life?
  - wool_gather 8y ago
    I may be putting words into the parent's mouth here, but I think the argument is just analogical. That there are emergent effects to physical processes that are difficult/nearly impossible to predict from basic physical law. And therefore we should withhold judgement about the difficulty of life forming, given that we so far have a limited understanding of the relevant physics.
    - andbberger 8y ago
      Nah I mean it pretty literally. You are very right that the necessary physics isn't really there, this is a really difficult thing to state rigorously. However I would argue that the underlying reasoning emerges out of fairly fundamental physics.. and that while difficult to state rigorously the core idea is kindof... obvious... to anyone with a strong physics background...
  - andbberger 8y ago
    Pretty much. I define life as any self-sustaining structured low entropy process that dissipates energy faster than diffusion. The low entropy part basically means that such a configuration is vanishingly improbable under _equilibrium_ statistical mechanics. Under this definition convection rolls, viruses and eukaryotes are all alive.
- teaspoons 8y ago
  this is a great comment, but what about Venus ? It has an energy gradient, so why no life ?
  - themagician 8y ago
    We don't know if there is no life there, we've never been. Almost every time we've assumed that an environment on Earth was "too harsh" to sustain life we have been proven wrong. We have no model for something that might live on the surface of Venus or below, but there could be something in the clouds.
    - dhdjc 8y ago
      “We’ve never been” As a species walking on the surface, no. But we have sent probes there as far back as the 60s.
SteveNuts 8y ago
I don't know what's a more terrifying thought; we're alone, or we're not alone.
- Spartan-S63 8y ago
  Additionally, the thought that we're not alone and we're not the most advanced species. If that's the case, then why haven't a more advanced species made contact yet?
  - thereau 8y ago
    Even if there are more advanced species, maybe they can't travel far enough to contact us. Or maybe they contacted other civilisations and we are just too far to bother.
  - econochoice 8y ago
    Why assume an alien species would value contact?
    - VvR-Ox 8y ago
      exactly, if they'd see what we do and were inteligent they would just leave us here to die :D
  - mirimir 8y ago
    Because they've seen enough TV to know that we're dangerous.
  - keithnz 8y ago
    well, our RF penetration of the galaxy is tiny... just over 100 years or so. and the galaxy is about 100k light years across.... so.....
  - Herodotus38 8y ago
    Read the book "The Three Body Problem" and the rest of the trilogy, it provides a very interesting and scary theory that I don't want to ruin.
tbodt 8y ago
The paper that this article is based off of was posted on HN a few days ago: https://news.ycombinator.com/item?id=17302924 https://news.ycombinator.com/item?id=17302924 Direct link to paper: https://arxiv.org/abs/1806.02404 https://arxiv.org/abs/1806.02404
rmm 8y ago
From the article; >In the end, the team’s conclusions do not mean that humanity is alone in the Universe, or that the odds of finding evidence of extra-terrestrial civilizations (both past and present) is unlikely. Instead, it simply means that we can say with greater confidence – based on what we know – that humanity is most likely the only intelligent species in the Milky Way Galaxy at present.
- itronitron 8y ago
  >> we can say with greater confidence – based on what we know if I know nothing, then I can say a lot of things with greater confidence, especially if I couch the statement with 'based on what we know.'
  - woogiewonka 8y ago
    Had exact same thought. "Based on what we know (which is not enough), I can say with greater confidence" ^^ oh really?
- yborg 8y ago
  Headline: "New model predicts that we’re probably the only advanced civilization in the observable universe." I'm trying to straight-up boycott sites that plain and simple use falsehoods to attract clicks, and everyone else should, too.
  - sosodaft 8y ago
    noble but futile
everdev 8y ago
The whole basis seems to be picking a range of values for the variables in the Drake equation rather than a single value for each variable. As a result, the variance multiplies significantly meaning that they find a 30% chance we're alone in the galaxy as the lower end of the deviation (and the higher end being the common notion that there should be abundant intelligent life everywhere we look). I hope they didn't spend too long making this "study" of tossing conservative estimates into a theoretical equation.
Pxtl 8y ago
> Claiming long-range settlement or communication are impossible requires assuming a surprisingly low technology ceiling. Whatever the answer is, it more or less has to be strange.” Considering the terrifying energies required for launching anything useful interstellarly, this quote is a bit off. I'm perfectly capable of believing that there is a tech ceiling preventing useful interstellar travel.
- scottLobster 8y ago
  Define "useful". Generation ships could be a thing, we're arguably close to that level of tech right now, and that's with a relative pittance spent on space-related tech for less than a century. Given enough R&D and raw resources it's probably an easier problem than curing cancer, and no one says that's impossible.
- adrianN 8y ago
  Roughly a century after discovering powered flight, we are pretty much capable of building spaceships that can reach Alpha Centauri in roughly 100 years. https://en.wikipedia.org/wiki/Nuclear_pulse_propulsion https://en.wikipedia.org/wiki/Nuclear_pulse_propulsion Single digit percentages of the speed of light are not that hard to achieve, but would probably be sufficient to launch some von Neumann probes (or generation ships) and start colonies.
  - labster 8y ago
    You are the children of a dead planet, EarthDeirdre, and this death we do not comprehend. We shall take you in, but may we ask this question--will we too catch the planetdeath disease? -- Lady Deirdre Skye, "Conversations With Planet"
    - dirkc 8y ago
      Now I want to play Alpha Centauri all over again!!
  - fhars 8y ago
    Getting there is easy. Stopping at the destination is the hard part.
frisco 8y ago
So, I read this paper and was pretty unconvinced. I think the premise of using a Monte Carlo analysis is flawed because of course multiplying together wide ~iid distributions that have big near-zero components asymptotes to zero; unless I'm misunderstanding something, this is essentially the central limit theorem. (All of the parameter samples below 1e0 drag the total outcome towards zero since probabilities are bounded >= 0) Thus, the real information is still strongly dominated by beliefs about the width and centering of the distributions, which we still don't know, and as long as enough of the parameters have high uncertainty with some potentially having near-zero values, the result will always tend towards zero. I think what this analysis tell us is that if you don't think it's possible to get better, more specific values for the parameters, the Drake Equation is just a bad tool. Also, the Drake Equation doesn't describe the number of alien civilizations, it describes the likely number of civilizations. Thus, extremely pessimistic estimates have to somehow correct for the fact that we know N is not zero, since we are here. That seems like a highly informative update that is not addressed in an interesting way.
- mcbutterbunz 8y ago
  I agree. Just because there might be a large number of stars without a habitable planet does not decrease the number of alien civilizations; it only reduces the likelihood that a given solar system would have such a civilization. Or to put it in other words, just because the haystack is large doesn't mean there is no needle present.
- aqsalose 8y ago
  > Thus, the real information is still strongly dominated by beliefs about the width and centering of the distributions, which we still don't know, and as long as enough of the parameters have high uncertainty with some potentially having near-zero values, the result will always tend towards zero. You state this like it is a problem. I think it's more like a feature? My take on the main point of the paper: it is commonplace to derive probabilities for being alone in the universe by plugging in point estimates into Drake Equation, but one should take into account that, in fact, we have lots uncertainty in our estimates for the parameters, and without quantifying that uncertainty, the Drake's Equation indeed will produce biased estimates. And if we quantify the uncertainty, we end up with wide distributions (that have some of their mass near zero). edit. Your point about N = 1 is interesting, though. edit2. Concerning N = 1: They don't elaborate on it in writing, but if I'm reading the sec 4.0.2 correctly, they do account for our existence in their spatial Poisson update: P(no detection | N, d) = 1 - exp(-(4/3) pi d^3 lambda) = 1 - P("number of civilizations in sphere of radius d when rate is lambda" = 0) = P("number of civilizations in sphere ..." > 0). edit3. wait, that does not make sense, does it. shouldn't P( no detection | N, d) be P("number of civilizations in sphere when rate is lambda" = 1) = (4/3) pi d^3 lambda exp(-(4/3) pi d^3 lambda), as per spatial Poisson process P(K = 1). now I'm just confused.
interfixus 8y ago
The author seems possessed of a fairly creative unwillingness to spell the name Sandberg correctly.
Sniffnoy 8y ago
I'm going to repost the same comment I've made on this several times already: This is quite interesting. It certainly sounds like this does dissolve the Fermi paradox, as they say. However, I think the key idea in this paper is actually not what the authors say it is. They say the key idea is taking account of all our uncertainty rather than using point estimates. I think the key idea is actually realizing that the Drake equation and the Fermi observation don't conflict because they're answering different questions. That is to say: Where does this use of point estimates come from? Well, the Drake equation gives (under the assumption that certain things are uncorrelated) the expected number of civilizations we should expect to detect. Here's the thing -- if we grant the uncorrelatedness assumption (as the authors do), the use of point estimates is entirely valid for that purpose; summarizing one's uncertainty into point estimates will not alter the result. The thing is that the authors here have realized, it seems to me, that the expected value is fundamentally the wrong calculation for purposes of considering the Fermi observation. Sure, maybe the expected value is high -- but why would that conflict with our seeing nothing? The right question to ask, in terms of the Fermi observation, is not, what is the expected number of civilizations we would see, but rather, what is the probability we would see any number more than zero? They then note that -- taking into account all our uncertainty, as they say -- while the expected number may be high, this probability is actually quite low, and therefore does not conflict with the Fermi observation. But to my mind the key idea here isn't taking into account all our uncertainty, but asking about P(N>0) rather than E(N) in the first place, realizing that it's really P(N>0) and not E(N) that's the relevant question. It's only that switch from E(N) to P(N>0) that necessitates the taking into account of all our uncertainty, after all! [Note afterward: Over on Reddit, hxka points out that that should be P(N>1), not P(N>0). Or really it should be P(N>1|N>0)...]
- rzimmerman 8y ago
  I think this hits the real point. The expected value of the number of advanced civilizations may be high, but that could mean a very small probability of billions of advanced civilizations complemented with a very large probability of zero, one, or just a few.
phront 8y ago
It may be that an advanced civilization doesnt last long. So it is possible that we are somewhere on the very big graveyard.
sunstone 8y ago
Possibly, but not the way to bet. Live appeared on Earth very soon after it started to solidify. That would tend to imply that starting life was pretty easy or, life arrived by some kind of panspermia mechanism. There is a next to infinitesimal chance that life started very quickly by some kind of once in billions of years magical circumstance. To go from life to beings like humanity it's pretty clear that intelligence tends to increase as life goes on. For example some birds so exceptional abilities and they are dinosaurs according to most current understandings. Octopus can be remarkably clever and their lineage split from the "animals with backbones" line long before there were animals with backbones. Nerves and nervous systems seem to have been reinvented by evolution several different times. Putting this altogether, it seems there's an excellent chance that primitive uni-cellular life evolves pretty readily and multi-cellular animals tend towards increased intelligence soon there after. There's an assumption that "advanced civilizations" will be communicating with TV and Radio because that's the best we've got. On average most advanced civilizations would have had their technology for much more than 150 years and very likely communicate with methods we are not aware of yet. So when it's asked "Where are they?" the answer is they are out there, talking up a storm, they're just not still using electromagnetic "smoke signals" to do it.
- kungtotte 8y ago
  Two other factors that play a big role in not detecting life in the universe is: 1) it's a really big place. It's likely we can't see that far yet. 2) Will we be here a million years from now? Two million? Other civilizations could have come and gone dozens of times in our galaxy alone before we were here. And dozens may come and go after we're gone.
  - craftyguy 8y ago
    #1 is a lot crazier, and more like: "we can only look at specific places, our detectors can only detect things which degrade as distance increases, and we might not be listening at the right frequency. So even if there were a civilization in this tiny, tiny region of the universe we are looking at, if they are too far away/obscured by debris/gas clouds, using wavelengths we aren't actively monitoring, we don't see them.
billforsternz 8y ago
Being alone in the galaxy and being alone in the universe seem to be casually equated but are vastly different in every possible way (except perhaps any practical consequences).
herewegoagain90 8y ago
From a biblical perspective, this is just fine: Jesus can only die once, hence there is only one earth.
abakus 8y ago
It doesn't matter whether we are alone or not. The speed limit is so slow, the dilation is so quick, we will never be able to contact.
semasad 8y ago
Elon Musk is not sure about this: https://twitter.com/elonmusk/status/1011082171170242560?s=21 https://twitter.com/elonmusk/status/1011082171170242560?s=21
jcims 8y ago
Shouldn't the title be '..humanity may be the only detectable advanced civilization..'? After all, the last two terms of the Drake Equation are all about detectability, and what are the chances that a civilization outside the Milky Way would emit a signal that we could possibly detect? Just slapping a couple of internet calculators together, you'd get about 500dB of loss from Andromeda (our closest galactic neighbor) to us, requiring a 1x10^41 watt omnidirectional emission for us to receive a nanowatt signal. This is within a few orders of magnitude of a supernova. Even if you were to focus the beam, the transmitting civilization would likely scorch planets within a couple hundred light years just to say hi. The paper seemed to inconsistently pepper 'detectable' into the language and I lost interest before trying to figure out whether or not it included those terms (fc and L) in the final conclusion.
- em3rgent0rdr 8y ago
  Yeah. Also the successful advanced civilizations might not even be emitting any signals at all.
  - jcims 8y ago
    Exactly. The 'L' term at the end (length of time advanced civilization is transmitting detectable signals) may be a very small window for most civilizations. Energy is precious. If you have the technology to put the signal where you want it to be, why would you spew it all over the universe?
    - pattisapu 8y ago
      Good points--but you might still spew out your signal out all over the universe if you were still searching for advanced life.
- deleted 8y ago
  [deleted]
mbfg 8y ago
Let's cheat. Let's say that there's another Earth out there with human beings on it. Let's say they've been producing electrical noise for 200 years like us. Where would planet Earth #2 have to be in order for us to notice it?
- adamcharnock 8y ago
  I like this approach, but I don't think I like the answer. If Earth 2 has been producing noise for 200 years, that gives us an upper bound of 200 light years. However – for general terrestrial traffic – our detection range is only about 1 light year [1]. There are also no stars within that distance from Earth 1. So, at current levels of technology, Earth 2 would have to be a sad star-less frozen ball that just happens to drift into our neighbourhood within the appropriate 1 light year window on its eons-long journey. Given that, I think we got the best deal here on Earth 1. [1] https://physics.stackexchange.com/a/245562/4602 https://physics.stackexchange.com/a/245562/4602 (the author does mention interesting caveats regarding directional transmissions though) Edit: s/200 window/1 light year window/
  - mbfg 8y ago
    Exactly. Now remove the restriction that Earth #2 is active with life at the same time we are. Instead intelligent life existed 10 billion years ago. Now we've got a tiny band of space 10 billion light years away where that planet has to be located where we could have possibly detected it. It doesn't seem that unlikely that we haven't found intelligent life.
    - woogiewonka 8y ago
      If I had to bet on the right answer it would be this. The time scales of the universe are mind-fucking and we are just naive if we think we can maneuver around them.
    - vkou 8y ago
      The point of the paradox is that if intelligent civilization is only active for 200 years out of a 10 billion year timespan, there is something seriously wrong with the survival rates of such civilizations.
fipple 8y ago
Amazing how uncomfortable humans are with ignorance. Are we alone or not in the universe? Is there life after death? Is existence infinite? We'll never know. I wish we could be OK with that. "I don't know" is a toxic phrase for leaders to utter, so they prevaricate and confabulate.
- king_nothing 8y ago
  Spirituality, to the self, is largely a mechanism to sweep dukkha and its pointlessess, and lack of nuance in messy, real-world, imprecise interpretations under a rug of happy-clappy self-/mutually-reinforced delusions, blissful pseudosimplicity and sentimentality. The big, unanswerable questions include: 1. Reincarnation: yes/no? 1.5. If yes, are we all one or are there multiple perception entities? 2. Why are you you and me me? (1. asks “am I and you the same?” implicitly) 3. Does cognitive dissonance allow “good”-self-image people to live with their committing unspeakable horrors? 4. If cancers’ semi-“life” existence can be explained by increasing a host’s entropy, why don’t most “pathogens” improve a host’s fitness, enable the host to find, store or expend more energy, reproduce and extend the host’s lifespan? Since when thr host dies, the cancer dies. 5. Is there an absolute limit of entropy? 6. How much neural complexity is needed for self-awareness? 7. Does global intelligence have a maximum useful upper limit? 8. If each piece of a person were systematically-replaced with inorganic parts of close overall function, does the individual retain rights of an organic person? 8.1. Could they be sued for healing or modifying themselves because of intellectual property? 8.2. Could they be legally owned, bought, sold, etc.?
- woogiewonka 8y ago
  You can be OK with it and still seek answers.
rvn1045 8y ago
life forms are just collections of atoms from a few elements. these elements exist all over the universe, no reason to think they would not have somehow combined to form life forms else where. I personally don't like the attitude of thinking we are alone in the universe.
sidcool 8y ago
Elon Musk replied to this one: https://twitter.com/elonmusk/status/1011083630301536256?s=19 https://twitter.com/elonmusk/status/1011083630301536256?s=19
VvR-Ox 8y ago
This is a lie and you all know it! That's just like in the old days when people used to think that earth would be the center of the universe. Prove it or go on with this theory, I don't want to hear it anymore until this mystery is solved!
listenallyall 8y ago
Let's say we absolutely found another advanced civilization, and in fact somewhat close, reachable in just 500 years. Let's assume we can build a rather large spaceship, say the size of the Empire State Building, and can fill it with enough food and fuel for the journey. My question, what are the ethics of sending humans on such a trip? It would take 15 to 20 generations of human beings, living their entire lives confined to a prison, to complete this journey. An absolute nightmare of an existence, to be entirely disposable except to procreate in order to produce more prisoners like themselves for a few hundred more years. And when the ship did arrive, the living passengers would not be Earthlings, in the sense they would have little idea about the Earth, none would have ever been there or know anyone who had. We could provide them with every book, movie, etc that ever existed but they would still have no Earth-bound experiences. And it would likely depress them greatly, seeing and hearing things they will never experience. And finally, why would we expect anyone to ever return, to "complete" the mission? Their choice would be to make the best of life on their new planet or to once again volunteer for this bleak, suicidal journey to get back to Earth. Some may say that future tech, or ultra-advanced VR, or cryogenics, or "downloading" brains and sending inert bodies, may make such a journey possible, but no answers sound very convincing, in my opinion.
- gman83 8y ago
  I think we'd probably send robotic probes on missions such as this. The only way I can really see a multi-generational mission being done is for some kind of colonization mission.
  - Freestyler_3 8y ago
    And wouldn't we then send frozen egg and sperms, robots taking care of everything once the ship gets close, the humans get education etc. from robots
    - listenallyall 8y ago
      Nothing personal, but this is exactly what I was mentioning about "future tech" not being sufficient to solve these problems. In-vitro fertilization (test-tube babies) still requires a living uterus in which to gestate. And the idea that a robot could successfully raise a child from birth to even about 8 years old seems VERY far-fetched. I think the physics of velocity, acceleration, etc will be figured out well before the human aspect, as evidenced by our ability to send a rover to Mars but not a person.
tigerBL00D 8y ago
The title of this post if completely wrong. The article rather specifically states that: In the end, the team’s conclusions do not mean that humanity is alone in the Universe, or that the odds of finding evidence of extra-terrestrial civilizations (both past and present) is unlikely. Instead, it simply means that we can say with greater confidence – based on what we know – that humanity is most likely the only intelligent species in the Milky Way Galaxy at present.
makkesk8 8y ago
Have we seen any proof of life out there? Well, no... So if there's an alien race out there that's at the same level of technology as we are, could they prove that we exist? Well no... Let's think about that for a second, because to me, it's too early to tell since we don't possess the necessary technology for interstellar travel or any other technology that could prove it. And no other alien race might not either. Since we simply don't broadcast our location to half the galaxy that we exist we can't expect another race to it. Finding something that might not want to be found has proven to be tricky and I think drawing the conclusion that there's no other advanced life out there is arrogant at best.
- ben_w 8y ago
  From what I’ve read, we do have the technology, but not the desire to spend so much money on what would be a vanity project with no return on investment possible due to the timescales involved. Especially as we expect our costs to come down and our early ships to be overtaken. An alien civilisation with our technology and a million year headstart, trivial compared to the age of Earth, would have had time to build a K3 civilisation. (Assuming you can call things with that sort if time lag “a civilisation” rather than “a collection of civilisations the size of a K3”).
viach 8y ago
After reading the "The Three-Body Problem", I think it might be not that bad news after all.
krob 8y ago
How would someone living in the dark ages look for intelligent life if they can't imagine the existence of wireless communications beyond a mythical transference of thoughts from human to human. Most of this is theoretical, but all it proves is our lack of understanding is still ever present, and we're all still just a bunch of ignorant fools trying to make sense of it all. I think we should just focus our energy into bigger things, and allow the technological breakthroughs as they will come with time. We just have to put our focus on bigger better & more interesting pursuits and stop blowing people up. Stop destroying civilizations, and start to accept civilizations as they exist. The more we destroy ourselves the harder it becomes for us to overall advance enough people to create the ever necessary brain trust of the planet to build these new sophisticated technologies to maybe one day find a way to decode what was once maybe thought non-existent. Maybe neutrinos are already used to communicate from light-years away, we just don't have enough advanced technology to decode it. We're not there yet, maybe we need fusion technology before other technology makes more sense to us, maybe fusion technology is what brings us to insane speeds in space that we cannot replicate currently since we haven't mastered it yet. Once again, we argue about the unknown, and only create factions of people hating on others who don't realize they're just ignorant.
- ainiriand 8y ago
  Exactly, the better everyone else is doing, the better you can do.
- pattisapu 8y ago
  "Stop destroying civilizations, and start to accept civilizations as they exist." Civilizations, as they exist and have existed, unfortunately, appear almost inevitably to involve war.
  - erikpukinskis 8y ago
    Do they though?
    - pattisapu 8y ago
the6threplicant 8y ago
I love the Drake equation. It's like the shortest shorthand for "Where is your civilisation at?" If you go from left to right, each value determines where you are in the history of galactic civilisations: R* : you need to understand galaxies and star formation (1930-70s) fP : you need to have space telescopes (we are here) ne : we'll probably have this number in the next 10-20 years fe : might need at least 30 years before we can detect life via atmosphere spectroscopy fi : 100 years, maybe? fc : same as above but with more time since we need more than one other data point L : we're at a Star Trek level civilisation - we know of each civilisation's Shakespeare and Einstein, their history etc. Now we can learn how long technological civilisations last.
woogiewonka 8y ago
I have always had a sneaking suspicion that the time scale on which we seek answers is far too narrow for answers to be found. Is it not likely that the period during which advanced civilizations actually exists is so short that they never cross each other's paths? I mean, if this were the case, wouldn't it throw the entire Drake equation out the window?
- caf 8y ago
  That's the "L" term in the Drake equation. And indeed one of the oft-mooted possibilities is that L is quite small. Which is a bit of a worry.
jlebrech 8y ago
observable by us
huffmsa 8y ago
Didn't read it, but that it's taken us ~4 billion years on this rock to git gud enough to send interstellar transmissions, it's probably taken other civs that long (because we have no evidence to the contrary). Given that we're looking at systems thousands to millions and if "visible" literally billions of light years away, even if they beat us to interstellar radio, we're still getting messages from them which are hundreds, thousands, millions and billions of years old. So they might be there just like us, but the Pony Express can only run so fast.
MrRubbish 8y ago
It’s just us. Nothing else. No turtles. Nothing.
booleandilemma 8y ago
Does anyone have any book recommendations that are similar to the content in this comment thread? (speculation on alien life, and such)
- gregorymichael 8y ago
  Yes! The three body problem trilogy.
- arto 8y ago
  Stephen Baxter's "Manifold" trilogy deals head-on with the Fermi paradox: https://en.wikipedia.org/wiki/Time_(Baxter_novel) https://en.wikipedia.org/wiki/Time_(Baxter_novel)
- spookyuser 8y ago
  Can very highly recommend Three Body Problem. Also try not reading anything about the books beforehand if you haven't already.
earblast 8y ago
while(read(article)) { if(galaxy === universe) { clickbait++; break; }
posterboy 8y ago
Instead, should a model not aim to reach 0.5 probability, because we really do not know. Fermi Paradox or Drake equation express rather wishful thinking more than anything else.
kprostyakov 8y ago
Interstellar 'biomes' would operate on much slower clocks. Human perception time-scale of ~1s is mandated by fast-paced ecosystem of our gravity well. Maybe we just not had enough continuous data in ~50 yrs ~ 10e10s to recognise intersystem channel modulation as such. Economy cycle phase shift across the civilized area cant be much bigger than cycle duration, so for inter-system distances of ~1 ly we are looking at 10^6 years (1 a.u. @ 1 year financial year for humans right now). Any real economy involving Mars will already showcase the need for much slower finance clocks and longer plans than we have in current economy. I guess cryptocurrency clocks will split into temporal tiers according to systems served by that time.
ataturk 8y ago
I think about the millions of galaxies holding their billions of stars and wonder how it could be possible that our little solar system holds the only life in the universe while the building blocks and conditions for life must not be that unusual. Who writes this stuff?
andy_ppp 8y ago
You can write a model for things you can't measure if you like, but how can you know the accuracy of it or if it can predict future (impossible) measurements. It's almost nonsensical to try, unless some alien civilisation comes along with the data I don't see the point.
- minor3rd 8y ago
  The title is also clickbaity, since the conclusion is really just that "we can't deduce much of anything... yet".
- nautilus12 8y ago
  Models like these only work when considering the order of magnitudes as a feasibility assessment. If you can determine a component reasonably has such a low probability that it pulls the entire thing down to infinitesimal probability then that observation is useful. However if the bounds of accuracy are too wide its not useful, this would be more useful with bounds.
- themodelplumber 8y ago
  You can measure the logic of using individual components of the model, and the combination of those components, by exposing them to social scrutiny. That's all measurements are: An agreed upon social standard based on shared subjective experiences. Plus, if any part of the model can be abstracted, there's a good chance you'll find leverage points to apply to other disciplines or problems. There's also a socio-political aspect: We are an emotion-driven species. Sharing this kind of stabbing-in-the-dark information may actually drive the advancement of far less speculative technology that could be beneficial to us all.
dharma1 8y ago
We've had EM comms for 100 years. Let's assume life, and civilisations capable of sending comms beyond their solar system have emerged multiple times during the history of the universe. If civilisations have a shelf life (for whatever reason) and don't exist indefinitely, it's extremely unlikely the timespan of someone transmitting and us receiving would overlap during those 100 years. Chances of existence/comms overlap are tiny even for the next 1 or 10 million years - even if Earth origin civilisation is still around then.
ramblerman 8y ago
For anyone interested in the various competing theories to explain the fermi paradox, waitbutwhy did a fantastic piece on this: https://waitbutwhy.com/2014/05/fermi-paradox.html https://waitbutwhy.com/2014/05/fermi-paradox.html
grigjd3 8y ago
The Drake equation gets too much attention in the popular press . First, the selection of factors is an arbitrary choice of basis that may not relate to what we can measure and second, we don't have good ideas of the values of most of those factors. It's a mental exercise and useful for showing certain concepts, but not a prediction based on observable data.
z3t4 8y ago
We are currently looking for smoke signals. We need to find a loop-hole in quantum theory and exploit it to send and listen for signals that wont be affected by the distance between the sender and receiver.
cvaidya1986 8y ago
What a comically arrogant species.
specialist 8y ago
Believe but cannot prove: Intelligent life on Earth is (effectively) unique. By "intelligent", I mean capable of purposefully leaving our gravity well. Residing in the goldilocks zone isn't enough. There needs to be external forces causing constant adaptation. Otherwise life will reach an equilibrium and evolve no further. Our Earth has seasons, plate tectonics, periodic mass extinction events (asteroid strikes). Other less frequent causes are likely nearby supernovae and possibly our galactic arm passing thru a gamma radiation beam. Even with constant evolution forcing habitats, a galaxy faring intelligence will be rare. As someone else noted, our saurian ancestors didn't stumble upon a tool building transmissible culture. There's just so many prerequisites. Compare us to the octopus, likely the next most potent intelligent being on Earth, and certainly alien (to us). They are frikkin brilliant. But they unfortunately have no way to transmit, share their knowledge. And their life spans are probably too brief, birth rate too low.
Arubis 8y ago
While it may be based on what is technically fiction, my views on the Drake Equation were modified to include a “caution in outbound communication factor” of fairly low probability after reading Cixin Liu’s “Dark Forest”. SPOILER ALERT for prior novel: it convincingly argues that, due to the impossibility of trust across otherwise unrelated civilizations, the rate of technological progress in any given civilization compared to the speed of travel between star systems, and the long-term understanding that resources are limited, and outgoing communication to another intelligent civilization inevitably results in attack and likely elimination of said civilization.
- peatmoss 8y ago
  Indeed this feels like the most satisfactory explanation for the Fermi paradox. I’m just starting on the third book, and am starting to think the eye-popping $1 billion that Amazon is rumored to be paying / have paid to allow them to make this into a TV series might not be entirely insane.
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rgomez 8y ago
Yep. The ugly truth: We are kind of alone out there. There's no one, or there's no one who wants to openly communicate with us, at least not yet. Get over it.
riazrizvi 8y ago
> Instead, it simply means that we can say with greater confidence – based on what we know – that humanity is most likely the only intelligent species in the Milky Way Galaxy at present. The article is light years away from its title.
daodedickinson 8y ago
What do you even mean by "we"?
ianamartin 8y ago
My pet theory about Fermi’s paradox is that there was only ever a very brief moment in the history of our civilization where attempted contact was politically and socially viable. Think about the Voyager project right now. Assembling a rep sample of all of human existence onto a single golden record and including the instructions to decode it in math. This. Could. Never. Happen. Today. No one could agree on what to include or exclude or how to execute it. There was an incredibly brief window of opportunity where we had the technology and the social capacity to reach out to interstellar neighbors. There are tons of other civilizations close by us. They just missed that very tiny window of a chance to say hello.
ezioamf 8y ago
We could just be a pet civilization from an nearby advanced civilization that blocks all signals coming to us.
ravenstine 8y ago
On a bit of a tangent from the core content of the article and the discussion here, I take issue with how easily even the smartest of people will take one example of a phenomenon and extrapolate the frequency(or replicability) of said phenomenon. All we really know about life, as we define it, is that it's possible to occur, because we're here, but we don't have any actual information about whether we're a fluke or an unknowing part of a greater community of intergalactic life. Pointing to billions and billions of stars and saying "there must be life out there" is unfounded at this point because we still aren't even close to understanding exactly how life came to be on Earth, as well as why it happened when it did. What the equation of predicting life is missing is the variable of time; without having at least two examples of life occurring independently, there's no way that I'm aware of that we can come up with a useful probability of life occurring anywhere. That is, unless we can create simulations to test theories outside of real time, which will probably be a required next step in science for getting a better understanding of our universe.
themagician 8y ago
Almost all of these models assume that an "advanced civilization" must have language and radio astronomy and I've always felt that's a rather odd set of parameters. It's completely possible that we haven't found anyone else because we are looking for the wrong things. We are looking for ourselves in the stars and fail to realize that we aren't "it". We may not even be the most advanced species on Earth. When all the dolphins rise out of the ocean and into the sky maybe then we'll realize, but it will be too late.
geebee 8y ago
It seems like we have an equation with a bunch of variables that are either extremely close to 1 or extremely close to zero. And really, these variables seem to group together into two essential variables, which are either almost 1 or almost 0. And we're trying to figure out whether, when you multiply them together, you get almost 1 or almost 0. So, what does (almost_1 * almost_0) equal? It requires more knowledge about "almost" than are able to obtain.
- sixdimensional 8y ago
  Your question reminded me of MAYBE. I often joke about the MAYBE logical operator with friends. It's based on the concept of three valued logic [1]. It always came up for me in SQL where you have a cell in a result that can be NULL, NOT NULL or a value. I also use it to refer to spaghetti or complex code where the outcome on first glance is "maybe this or maybe that, or maybe something in the middle". Again, I use it as a joke when it is a totally real concept. It seems like increasingly we are trying to extract approximate answers from machine learning, statistics, etc. because in so many cases it seems difficult to get to TRUE or FALSE for a given hypothesis. We want "MAYBE" with enough accuracy to believe it is mostly TRUE or 100% TRUE (but often 95% confidence - heck even 85% is still amazingly valuable when you aren't sure at all). I believe there is a programming language that handles this (I forget which one though - anyone?). I know quantum processors potentially could handle it since they have multiple states for a qubit which could represent different states of "in-between" TRUE and FALSE. [1] https://en.wikipedia.org/wiki/Three-valued_logic https://en.wikipedia.org/wiki/Three-valued_logic
  - mitchty 8y ago
    This basically exists in Haskell/Idris as the Maybe type. It is used slightly differently than what you're saying but in essence it lets you say: - The thing doesn't exist, return Nothing (unit in a way) - The inputs produced Just the thing you wanted You have to cover both "didn't work" and "here you go" but its highly useful to not have to worry about NULL versus NOT NULL. https://stackoverflow.com/questions/29456824/what-is-the-maybe-type-and-how-does-it-work https://stackoverflow.com/questions/29456824/what-is-the-may... Your function that decides if something exists or not, could be the thing determining the percentage spiel. Aka a function returning Maybe Bool could return: a Bool with true/false, or Nothing. Nothing being "its not a bool, your inputs are insane/nonsensical", but if it returns a Just Bool, you just unbox the Bool and voila. Just thought you might want to know this is a real thing and is super useful.
turdnagel 8y ago
I've seen that we search for exoplanets with life by using spectral analysis to estimate the temperature, atmospheric composition, etc. of these planets, and seeing whether or not they fall within a range that is similar to Earth's. I wonder if it would also be instructive to search for planets who exhibit signs of a man-made apocalypse, like massive nuclear fallout.
didibus 8y ago
Curious what a similar model would show if applied to earth pre the discovery of the other continents.
sliken 8y ago
If we started the colonization of the galaxy in the year 2500 with 10 planets I suspect we would just wait and see if we came across a society with the level of technology we have today. After all, why take the risk of meeting a war like society that lobs nukes at each other? Just leave a few probes nearby to keep tabs on them and see if they advance to a level that's interesting.... or scary.
oooooof 8y ago
That means that Trump is the most powerful person in the universe.
089723645897236 8y ago
Not enough data to make this conclusion in any actionable way.

319 points by sidcool 8y ago

May be may be not. I wish my teachers would have accepted such answers in my high school

Why is this even still a question... every single time you boil a pot of water convection rolls form. According to equilibrium thermodynamics it is vanishingly improbable that Avogrado's numbers worth of molecules will conspire together to act in a coordinated fashion to form those rolls... yet it happens every time. The convection rolls win out over diffusion because they dissipate heat faster and there is only so much heat. Life is no different. A structured low entropy process that dissipates energy faster than diffusion - there's no paradox or anything about emergent complexity. The fundamental concepts here are pretty simple and any discussion concerning P(life) need to start by understanding what life is in the first place and how it can arise. Point being: life isn't a rare thing or a mystery, anywhere in the universe you find energy gradients you'll find life. There just isn't a conversation to have here. If we're alone it's because we're first. But we are almost certainly not alone. The universe is just really fucking big.

em3rgent0rdr 8y ago
Just because "a structured low entropy process that dissipates energy faster than diffusion" will win out every-time doesn't answer the question about how a self-replicating structured low entropy process will form in the first place. Once life starts then it will explode, but the problem is how to get life actually started.
- millstone 8y ago
  Perhaps life is easy to start, but is also easily out-competed by non-living self-replicating organisms.
  - kaffeemitsahne 8y ago
    "non-living self-replicating organisms" Sounds like a contradiction to me ;)
    - bmc7505 8y ago
      Lots of things are self-replicating that we would not consider "living". https://en.wikipedia.org/wiki/Self-replication https://en.wikipedia.org/wiki/Self-replication
- andbberger 8y ago
  Not claiming my above comment was the greatest argument ever, I didn't spend that much time on it - but that is precisely what the argument is about. I am arguing that the formation of life is not a rare thing at all.
millstone 8y ago
I want to understand this argument better. Are you claiming that any "structured low entropy process that dissipates energy" is alive? How are you defining life?
- wool_gather 8y ago
  I may be putting words into the parent's mouth here, but I think the argument is just analogical. That there are emergent effects to physical processes that are difficult/nearly impossible to predict from basic physical law. And therefore we should withhold judgement about the difficulty of life forming, given that we so far have a limited understanding of the relevant physics.
  - andbberger 8y ago
    Nah I mean it pretty literally. You are very right that the necessary physics isn't really there, this is a really difficult thing to state rigorously. However I would argue that the underlying reasoning emerges out of fairly fundamental physics.. and that while difficult to state rigorously the core idea is kindof... obvious... to anyone with a strong physics background...
- andbberger 8y ago
  Pretty much. I define life as any self-sustaining structured low entropy process that dissipates energy faster than diffusion. The low entropy part basically means that such a configuration is vanishingly improbable under _equilibrium_ statistical mechanics. Under this definition convection rolls, viruses and eukaryotes are all alive.
teaspoons 8y ago
this is a great comment, but what about Venus ? It has an energy gradient, so why no life ?
- themagician 8y ago
  We don't know if there is no life there, we've never been. Almost every time we've assumed that an environment on Earth was "too harsh" to sustain life we have been proven wrong. We have no model for something that might live on the surface of Venus or below, but there could be something in the clouds.
  - dhdjc 8y ago
    “We’ve never been” As a species walking on the surface, no. But we have sent probes there as far back as the 60s.

SteveNuts 8y ago

I don't know what's a more terrifying thought; we're alone, or we're not alone.

Spartan-S63 8y ago
Additionally, the thought that we're not alone and we're not the most advanced species. If that's the case, then why haven't a more advanced species made contact yet?
- thereau 8y ago
  Even if there are more advanced species, maybe they can't travel far enough to contact us. Or maybe they contacted other civilisations and we are just too far to bother.
- econochoice 8y ago
  Why assume an alien species would value contact?
  - VvR-Ox 8y ago
    exactly, if they'd see what we do and were inteligent they would just leave us here to die :D
- mirimir 8y ago
  Because they've seen enough TV to know that we're dangerous.
- keithnz 8y ago
  well, our RF penetration of the galaxy is tiny... just over 100 years or so. and the galaxy is about 100k light years across.... so.....
- Herodotus38 8y ago
  Read the book "The Three Body Problem" and the rest of the trilogy, it provides a very interesting and scary theory that I don't want to ruin.

tbodt 8y ago

The paper that this article is based off of was posted on HN a few days ago: https://news.ycombinator.com/item?id=17302924 https://news.ycombinator.com/item?id=17302924 Direct link to paper: https://arxiv.org/abs/1806.02404 https://arxiv.org/abs/1806.02404

rmm 8y ago

From the article; >In the end, the team’s conclusions do not mean that humanity is alone in the Universe, or that the odds of finding evidence of extra-terrestrial civilizations (both past and present) is unlikely. Instead, it simply means that we can say with greater confidence – based on what we know – that humanity is most likely the only intelligent species in the Milky Way Galaxy at present.

itronitron 8y ago
>> we can say with greater confidence – based on what we know if I know nothing, then I can say a lot of things with greater confidence, especially if I couch the statement with 'based on what we know.'
- woogiewonka 8y ago
  Had exact same thought. "Based on what we know (which is not enough), I can say with greater confidence" ^^ oh really?
yborg 8y ago
Headline: "New model predicts that we’re probably the only advanced civilization in the observable universe." I'm trying to straight-up boycott sites that plain and simple use falsehoods to attract clicks, and everyone else should, too.
- sosodaft 8y ago
  noble but futile

everdev 8y ago

The whole basis seems to be picking a range of values for the variables in the Drake equation rather than a single value for each variable. As a result, the variance multiplies significantly meaning that they find a 30% chance we're alone in the galaxy as the lower end of the deviation (and the higher end being the common notion that there should be abundant intelligent life everywhere we look). I hope they didn't spend too long making this "study" of tossing conservative estimates into a theoretical equation.

Pxtl 8y ago

> Claiming long-range settlement or communication are impossible requires assuming a surprisingly low technology ceiling. Whatever the answer is, it more or less has to be strange.” Considering the terrifying energies required for launching anything useful interstellarly, this quote is a bit off. I'm perfectly capable of believing that there is a tech ceiling preventing useful interstellar travel.

scottLobster 8y ago
Define "useful". Generation ships could be a thing, we're arguably close to that level of tech right now, and that's with a relative pittance spent on space-related tech for less than a century. Given enough R&D and raw resources it's probably an easier problem than curing cancer, and no one says that's impossible.
adrianN 8y ago
Roughly a century after discovering powered flight, we are pretty much capable of building spaceships that can reach Alpha Centauri in roughly 100 years. https://en.wikipedia.org/wiki/Nuclear_pulse_propulsion https://en.wikipedia.org/wiki/Nuclear_pulse_propulsion Single digit percentages of the speed of light are not that hard to achieve, but would probably be sufficient to launch some von Neumann probes (or generation ships) and start colonies.
- labster 8y ago
  You are the children of a dead planet, EarthDeirdre, and this death we do not comprehend. We shall take you in, but may we ask this question--will we too catch the planetdeath disease? -- Lady Deirdre Skye, "Conversations With Planet"
  - dirkc 8y ago
    Now I want to play Alpha Centauri all over again!!
- fhars 8y ago
  Getting there is easy. Stopping at the destination is the hard part.

frisco 8y ago

So, I read this paper and was pretty unconvinced. I think the premise of using a Monte Carlo analysis is flawed because of course multiplying together wide ~iid distributions that have big near-zero components asymptotes to zero; unless I'm misunderstanding something, this is essentially the central limit theorem. (All of the parameter samples below 1e0 drag the total outcome towards zero since probabilities are bounded >= 0) Thus, the real information is still strongly dominated by beliefs about the width and centering of the distributions, which we still don't know, and as long as enough of the parameters have high uncertainty with some potentially having near-zero values, the result will always tend towards zero. I think what this analysis tell us is that if you don't think it's possible to get better, more specific values for the parameters, the Drake Equation is just a bad tool. Also, the Drake Equation doesn't describe the number of alien civilizations, it describes the likely number of civilizations. Thus, extremely pessimistic estimates have to somehow correct for the fact that we know N is not zero, since we are here. That seems like a highly informative update that is not addressed in an interesting way.

mcbutterbunz 8y ago
I agree. Just because there might be a large number of stars without a habitable planet does not decrease the number of alien civilizations; it only reduces the likelihood that a given solar system would have such a civilization. Or to put it in other words, just because the haystack is large doesn't mean there is no needle present.
aqsalose 8y ago
> Thus, the real information is still strongly dominated by beliefs about the width and centering of the distributions, which we still don't know, and as long as enough of the parameters have high uncertainty with some potentially having near-zero values, the result will always tend towards zero. You state this like it is a problem. I think it's more like a feature? My take on the main point of the paper: it is commonplace to derive probabilities for being alone in the universe by plugging in point estimates into Drake Equation, but one should take into account that, in fact, we have lots uncertainty in our estimates for the parameters, and without quantifying that uncertainty, the Drake's Equation indeed will produce biased estimates. And if we quantify the uncertainty, we end up with wide distributions (that have some of their mass near zero). edit. Your point about N = 1 is interesting, though. edit2. Concerning N = 1: They don't elaborate on it in writing, but if I'm reading the sec 4.0.2 correctly, they do account for our existence in their spatial Poisson update: P(no detection | N, d) = 1 - exp(-(4/3) pi d^3 lambda) = 1 - P("number of civilizations in sphere of radius d when rate is lambda" = 0) = P("number of civilizations in sphere ..." > 0). edit3. wait, that does not make sense, does it. shouldn't P( no detection | N, d) be P("number of civilizations in sphere when rate is lambda" = 1) = (4/3) pi d^3 lambda exp(-(4/3) pi d^3 lambda), as per spatial Poisson process P(K = 1). now I'm just confused.

interfixus 8y ago

The author seems possessed of a fairly creative unwillingness to spell the name Sandberg correctly.

Sniffnoy 8y ago

I'm going to repost the same comment I've made on this several times already: This is quite interesting. It certainly sounds like this does dissolve the Fermi paradox, as they say. However, I think the key idea in this paper is actually not what the authors say it is. They say the key idea is taking account of all our uncertainty rather than using point estimates. I think the key idea is actually realizing that the Drake equation and the Fermi observation don't conflict because they're answering different questions. That is to say: Where does this use of point estimates come from? Well, the Drake equation gives (under the assumption that certain things are uncorrelated) the expected number of civilizations we should expect to detect. Here's the thing -- if we grant the uncorrelatedness assumption (as the authors do), the use of point estimates is entirely valid for that purpose; summarizing one's uncertainty into point estimates will not alter the result. The thing is that the authors here have realized, it seems to me, that the expected value is fundamentally the wrong calculation for purposes of considering the Fermi observation. Sure, maybe the expected value is high -- but why would that conflict with our seeing nothing? The right question to ask, in terms of the Fermi observation, is not, what is the expected number of civilizations we would see, but rather, what is the probability we would see any number more than zero? They then note that -- taking into account all our uncertainty, as they say -- while the expected number may be high, this probability is actually quite low, and therefore does not conflict with the Fermi observation. But to my mind the key idea here isn't taking into account all our uncertainty, but asking about P(N>0) rather than E(N) in the first place, realizing that it's really P(N>0) and not E(N) that's the relevant question. It's only that switch from E(N) to P(N>0) that necessitates the taking into account of all our uncertainty, after all! [Note afterward: Over on Reddit, hxka points out that that should be P(N>1), not P(N>0). Or really it should be P(N>1|N>0)...]

rzimmerman 8y ago
I think this hits the real point. The expected value of the number of advanced civilizations may be high, but that could mean a very small probability of billions of advanced civilizations complemented with a very large probability of zero, one, or just a few.

phront 8y ago

It may be that an advanced civilization doesnt last long. So it is possible that we are somewhere on the very big graveyard.

sunstone 8y ago

Possibly, but not the way to bet. Live appeared on Earth very soon after it started to solidify. That would tend to imply that starting life was pretty easy or, life arrived by some kind of panspermia mechanism. There is a next to infinitesimal chance that life started very quickly by some kind of once in billions of years magical circumstance. To go from life to beings like humanity it's pretty clear that intelligence tends to increase as life goes on. For example some birds so exceptional abilities and they are dinosaurs according to most current understandings. Octopus can be remarkably clever and their lineage split from the "animals with backbones" line long before there were animals with backbones. Nerves and nervous systems seem to have been reinvented by evolution several different times. Putting this altogether, it seems there's an excellent chance that primitive uni-cellular life evolves pretty readily and multi-cellular animals tend towards increased intelligence soon there after. There's an assumption that "advanced civilizations" will be communicating with TV and Radio because that's the best we've got. On average most advanced civilizations would have had their technology for much more than 150 years and very likely communicate with methods we are not aware of yet. So when it's asked "Where are they?" the answer is they are out there, talking up a storm, they're just not still using electromagnetic "smoke signals" to do it.

kungtotte 8y ago
Two other factors that play a big role in not detecting life in the universe is: 1) it's a really big place. It's likely we can't see that far yet. 2) Will we be here a million years from now? Two million? Other civilizations could have come and gone dozens of times in our galaxy alone before we were here. And dozens may come and go after we're gone.
- craftyguy 8y ago
  #1 is a lot crazier, and more like: "we can only look at specific places, our detectors can only detect things which degrade as distance increases, and we might not be listening at the right frequency. So even if there were a civilization in this tiny, tiny region of the universe we are looking at, if they are too far away/obscured by debris/gas clouds, using wavelengths we aren't actively monitoring, we don't see them.

billforsternz 8y ago

Being alone in the galaxy and being alone in the universe seem to be casually equated but are vastly different in every possible way (except perhaps any practical consequences).

herewegoagain90 8y ago

From a biblical perspective, this is just fine: Jesus can only die once, hence there is only one earth.

abakus 8y ago

It doesn't matter whether we are alone or not. The speed limit is so slow, the dilation is so quick, we will never be able to contact.

semasad 8y ago

Elon Musk is not sure about this: https://twitter.com/elonmusk/status/1011082171170242560?s=21 https://twitter.com/elonmusk/status/1011082171170242560?s=21

jcims 8y ago

Shouldn't the title be '..humanity may be the only detectable advanced civilization..'? After all, the last two terms of the Drake Equation are all about detectability, and what are the chances that a civilization outside the Milky Way would emit a signal that we could possibly detect? Just slapping a couple of internet calculators together, you'd get about 500dB of loss from Andromeda (our closest galactic neighbor) to us, requiring a 1x10^41 watt omnidirectional emission for us to receive a nanowatt signal. This is within a few orders of magnitude of a supernova. Even if you were to focus the beam, the transmitting civilization would likely scorch planets within a couple hundred light years just to say hi. The paper seemed to inconsistently pepper 'detectable' into the language and I lost interest before trying to figure out whether or not it included those terms (fc and L) in the final conclusion.

em3rgent0rdr 8y ago
Yeah. Also the successful advanced civilizations might not even be emitting any signals at all.
- jcims 8y ago
  Exactly. The 'L' term at the end (length of time advanced civilization is transmitting detectable signals) may be a very small window for most civilizations. Energy is precious. If you have the technology to put the signal where you want it to be, why would you spew it all over the universe?
  - pattisapu 8y ago
    Good points--but you might still spew out your signal out all over the universe if you were still searching for advanced life.
deleted 8y ago
[deleted]

mbfg 8y ago

Let's cheat. Let's say that there's another Earth out there with human beings on it. Let's say they've been producing electrical noise for 200 years like us. Where would planet Earth #2 have to be in order for us to notice it?

adamcharnock 8y ago
I like this approach, but I don't think I like the answer. If Earth 2 has been producing noise for 200 years, that gives us an upper bound of 200 light years. However – for general terrestrial traffic – our detection range is only about 1 light year [1]. There are also no stars within that distance from Earth 1. So, at current levels of technology, Earth 2 would have to be a sad star-less frozen ball that just happens to drift into our neighbourhood within the appropriate 1 light year window on its eons-long journey. Given that, I think we got the best deal here on Earth 1. [1] https://physics.stackexchange.com/a/245562/4602 https://physics.stackexchange.com/a/245562/4602 (the author does mention interesting caveats regarding directional transmissions though) Edit: s/200 window/1 light year window/
- mbfg 8y ago
  Exactly. Now remove the restriction that Earth #2 is active with life at the same time we are. Instead intelligent life existed 10 billion years ago. Now we've got a tiny band of space 10 billion light years away where that planet has to be located where we could have possibly detected it. It doesn't seem that unlikely that we haven't found intelligent life.
  - woogiewonka 8y ago
    If I had to bet on the right answer it would be this. The time scales of the universe are mind-fucking and we are just naive if we think we can maneuver around them.
  - vkou 8y ago
    The point of the paradox is that if intelligent civilization is only active for 200 years out of a 10 billion year timespan, there is something seriously wrong with the survival rates of such civilizations.

fipple 8y ago

Amazing how uncomfortable humans are with ignorance. Are we alone or not in the universe? Is there life after death? Is existence infinite? We'll never know. I wish we could be OK with that. "I don't know" is a toxic phrase for leaders to utter, so they prevaricate and confabulate.

king_nothing 8y ago
Spirituality, to the self, is largely a mechanism to sweep dukkha and its pointlessess, and lack of nuance in messy, real-world, imprecise interpretations under a rug of happy-clappy self-/mutually-reinforced delusions, blissful pseudosimplicity and sentimentality. The big, unanswerable questions include: 1. Reincarnation: yes/no? 1.5. If yes, are we all one or are there multiple perception entities? 2. Why are you you and me me? (1. asks “am I and you the same?” implicitly) 3. Does cognitive dissonance allow “good”-self-image people to live with their committing unspeakable horrors? 4. If cancers’ semi-“life” existence can be explained by increasing a host’s entropy, why don’t most “pathogens” improve a host’s fitness, enable the host to find, store or expend more energy, reproduce and extend the host’s lifespan? Since when thr host dies, the cancer dies. 5. Is there an absolute limit of entropy? 6. How much neural complexity is needed for self-awareness? 7. Does global intelligence have a maximum useful upper limit? 8. If each piece of a person were systematically-replaced with inorganic parts of close overall function, does the individual retain rights of an organic person? 8.1. Could they be sued for healing or modifying themselves because of intellectual property? 8.2. Could they be legally owned, bought, sold, etc.?
woogiewonka 8y ago
You can be OK with it and still seek answers.

rvn1045 8y ago

life forms are just collections of atoms from a few elements. these elements exist all over the universe, no reason to think they would not have somehow combined to form life forms else where. I personally don't like the attitude of thinking we are alone in the universe.

sidcool 8y ago

Elon Musk replied to this one: https://twitter.com/elonmusk/status/1011083630301536256?s=19 https://twitter.com/elonmusk/status/1011083630301536256?s=19

VvR-Ox 8y ago

This is a lie and you all know it! That's just like in the old days when people used to think that earth would be the center of the universe. Prove it or go on with this theory, I don't want to hear it anymore until this mystery is solved!

listenallyall 8y ago

Let's say we absolutely found another advanced civilization, and in fact somewhat close, reachable in just 500 years. Let's assume we can build a rather large spaceship, say the size of the Empire State Building, and can fill it with enough food and fuel for the journey. My question, what are the ethics of sending humans on such a trip? It would take 15 to 20 generations of human beings, living their entire lives confined to a prison, to complete this journey. An absolute nightmare of an existence, to be entirely disposable except to procreate in order to produce more prisoners like themselves for a few hundred more years. And when the ship did arrive, the living passengers would not be Earthlings, in the sense they would have little idea about the Earth, none would have ever been there or know anyone who had. We could provide them with every book, movie, etc that ever existed but they would still have no Earth-bound experiences. And it would likely depress them greatly, seeing and hearing things they will never experience. And finally, why would we expect anyone to ever return, to "complete" the mission? Their choice would be to make the best of life on their new planet or to once again volunteer for this bleak, suicidal journey to get back to Earth. Some may say that future tech, or ultra-advanced VR, or cryogenics, or "downloading" brains and sending inert bodies, may make such a journey possible, but no answers sound very convincing, in my opinion.

gman83 8y ago
I think we'd probably send robotic probes on missions such as this. The only way I can really see a multi-generational mission being done is for some kind of colonization mission.
- Freestyler_3 8y ago
  And wouldn't we then send frozen egg and sperms, robots taking care of everything once the ship gets close, the humans get education etc. from robots
  - listenallyall 8y ago
    Nothing personal, but this is exactly what I was mentioning about "future tech" not being sufficient to solve these problems. In-vitro fertilization (test-tube babies) still requires a living uterus in which to gestate. And the idea that a robot could successfully raise a child from birth to even about 8 years old seems VERY far-fetched. I think the physics of velocity, acceleration, etc will be figured out well before the human aspect, as evidenced by our ability to send a rover to Mars but not a person.

tigerBL00D 8y ago

The title of this post if completely wrong. The article rather specifically states that: In the end, the team’s conclusions do not mean that humanity is alone in the Universe, or that the odds of finding evidence of extra-terrestrial civilizations (both past and present) is unlikely. Instead, it simply means that we can say with greater confidence – based on what we know – that humanity is most likely the only intelligent species in the Milky Way Galaxy at present.

makkesk8 8y ago

Have we seen any proof of life out there? Well, no... So if there's an alien race out there that's at the same level of technology as we are, could they prove that we exist? Well no... Let's think about that for a second, because to me, it's too early to tell since we don't possess the necessary technology for interstellar travel or any other technology that could prove it. And no other alien race might not either. Since we simply don't broadcast our location to half the galaxy that we exist we can't expect another race to it. Finding something that might not want to be found has proven to be tricky and I think drawing the conclusion that there's no other advanced life out there is arrogant at best.

ben_w 8y ago
From what I’ve read, we do have the technology, but not the desire to spend so much money on what would be a vanity project with no return on investment possible due to the timescales involved. Especially as we expect our costs to come down and our early ships to be overtaken. An alien civilisation with our technology and a million year headstart, trivial compared to the age of Earth, would have had time to build a K3 civilisation. (Assuming you can call things with that sort if time lag “a civilisation” rather than “a collection of civilisations the size of a K3”).

viach 8y ago

After reading the "The Three-Body Problem", I think it might be not that bad news after all.

krob 8y ago

How would someone living in the dark ages look for intelligent life if they can't imagine the existence of wireless communications beyond a mythical transference of thoughts from human to human. Most of this is theoretical, but all it proves is our lack of understanding is still ever present, and we're all still just a bunch of ignorant fools trying to make sense of it all. I think we should just focus our energy into bigger things, and allow the technological breakthroughs as they will come with time. We just have to put our focus on bigger better & more interesting pursuits and stop blowing people up. Stop destroying civilizations, and start to accept civilizations as they exist. The more we destroy ourselves the harder it becomes for us to overall advance enough people to create the ever necessary brain trust of the planet to build these new sophisticated technologies to maybe one day find a way to decode what was once maybe thought non-existent. Maybe neutrinos are already used to communicate from light-years away, we just don't have enough advanced technology to decode it. We're not there yet, maybe we need fusion technology before other technology makes more sense to us, maybe fusion technology is what brings us to insane speeds in space that we cannot replicate currently since we haven't mastered it yet. Once again, we argue about the unknown, and only create factions of people hating on others who don't realize they're just ignorant.

ainiriand 8y ago
Exactly, the better everyone else is doing, the better you can do.
pattisapu 8y ago
"Stop destroying civilizations, and start to accept civilizations as they exist." Civilizations, as they exist and have existed, unfortunately, appear almost inevitably to involve war.
- erikpukinskis 8y ago
  Do they though?
  - pattisapu 8y ago

the6threplicant 8y ago

I love the Drake equation. It's like the shortest shorthand for "Where is your civilisation at?" If you go from left to right, each value determines where you are in the history of galactic civilisations: R* : you need to understand galaxies and star formation (1930-70s) fP : you need to have space telescopes (we are here) ne : we'll probably have this number in the next 10-20 years fe : might need at least 30 years before we can detect life via atmosphere spectroscopy fi : 100 years, maybe? fc : same as above but with more time since we need more than one other data point L : we're at a Star Trek level civilisation - we know of each civilisation's Shakespeare and Einstein, their history etc. Now we can learn how long technological civilisations last.

woogiewonka 8y ago

I have always had a sneaking suspicion that the time scale on which we seek answers is far too narrow for answers to be found. Is it not likely that the period during which advanced civilizations actually exists is so short that they never cross each other's paths? I mean, if this were the case, wouldn't it throw the entire Drake equation out the window?

caf 8y ago
That's the "L" term in the Drake equation. And indeed one of the oft-mooted possibilities is that L is quite small. Which is a bit of a worry.

jlebrech 8y ago

observable by us

huffmsa 8y ago

Didn't read it, but that it's taken us ~4 billion years on this rock to git gud enough to send interstellar transmissions, it's probably taken other civs that long (because we have no evidence to the contrary). Given that we're looking at systems thousands to millions and if "visible" literally billions of light years away, even if they beat us to interstellar radio, we're still getting messages from them which are hundreds, thousands, millions and billions of years old. So they might be there just like us, but the Pony Express can only run so fast.

MrRubbish 8y ago

It’s just us. Nothing else. No turtles. Nothing.

booleandilemma 8y ago

Does anyone have any book recommendations that are similar to the content in this comment thread? (speculation on alien life, and such)

gregorymichael 8y ago
Yes! The three body problem trilogy.
arto 8y ago
Stephen Baxter's "Manifold" trilogy deals head-on with the Fermi paradox: https://en.wikipedia.org/wiki/Time_(Baxter_novel) https://en.wikipedia.org/wiki/Time_(Baxter_novel)
spookyuser 8y ago
Can very highly recommend Three Body Problem. Also try not reading anything about the books beforehand if you haven't already.

earblast 8y ago

while(read(article)) { if(galaxy === universe) { clickbait++; break; }

posterboy 8y ago

Instead, should a model not aim to reach 0.5 probability, because we really do not know. Fermi Paradox or Drake equation express rather wishful thinking more than anything else.

kprostyakov 8y ago

Interstellar 'biomes' would operate on much slower clocks. Human perception time-scale of ~1s is mandated by fast-paced ecosystem of our gravity well. Maybe we just not had enough continuous data in ~50 yrs ~ 10e10s to recognise intersystem channel modulation as such. Economy cycle phase shift across the civilized area cant be much bigger than cycle duration, so for inter-system distances of ~1 ly we are looking at 10^6 years (1 a.u. @ 1 year financial year for humans right now). Any real economy involving Mars will already showcase the need for much slower finance clocks and longer plans than we have in current economy. I guess cryptocurrency clocks will split into temporal tiers according to systems served by that time.

ataturk 8y ago

I think about the millions of galaxies holding their billions of stars and wonder how it could be possible that our little solar system holds the only life in the universe while the building blocks and conditions for life must not be that unusual. Who writes this stuff?

andy_ppp 8y ago

You can write a model for things you can't measure if you like, but how can you know the accuracy of it or if it can predict future (impossible) measurements. It's almost nonsensical to try, unless some alien civilisation comes along with the data I don't see the point.

minor3rd 8y ago
The title is also clickbaity, since the conclusion is really just that "we can't deduce much of anything... yet".
nautilus12 8y ago
Models like these only work when considering the order of magnitudes as a feasibility assessment. If you can determine a component reasonably has such a low probability that it pulls the entire thing down to infinitesimal probability then that observation is useful. However if the bounds of accuracy are too wide its not useful, this would be more useful with bounds.
themodelplumber 8y ago
You can measure the logic of using individual components of the model, and the combination of those components, by exposing them to social scrutiny. That's all measurements are: An agreed upon social standard based on shared subjective experiences. Plus, if any part of the model can be abstracted, there's a good chance you'll find leverage points to apply to other disciplines or problems. There's also a socio-political aspect: We are an emotion-driven species. Sharing this kind of stabbing-in-the-dark information may actually drive the advancement of far less speculative technology that could be beneficial to us all.

dharma1 8y ago

We've had EM comms for 100 years. Let's assume life, and civilisations capable of sending comms beyond their solar system have emerged multiple times during the history of the universe. If civilisations have a shelf life (for whatever reason) and don't exist indefinitely, it's extremely unlikely the timespan of someone transmitting and us receiving would overlap during those 100 years. Chances of existence/comms overlap are tiny even for the next 1 or 10 million years - even if Earth origin civilisation is still around then.

ramblerman 8y ago

For anyone interested in the various competing theories to explain the fermi paradox, waitbutwhy did a fantastic piece on this: https://waitbutwhy.com/2014/05/fermi-paradox.html https://waitbutwhy.com/2014/05/fermi-paradox.html

grigjd3 8y ago

The Drake equation gets too much attention in the popular press . First, the selection of factors is an arbitrary choice of basis that may not relate to what we can measure and second, we don't have good ideas of the values of most of those factors. It's a mental exercise and useful for showing certain concepts, but not a prediction based on observable data.

z3t4 8y ago

We are currently looking for smoke signals. We need to find a loop-hole in quantum theory and exploit it to send and listen for signals that wont be affected by the distance between the sender and receiver.

cvaidya1986 8y ago

What a comically arrogant species.

specialist 8y ago

Believe but cannot prove: Intelligent life on Earth is (effectively) unique. By "intelligent", I mean capable of purposefully leaving our gravity well. Residing in the goldilocks zone isn't enough. There needs to be external forces causing constant adaptation. Otherwise life will reach an equilibrium and evolve no further. Our Earth has seasons, plate tectonics, periodic mass extinction events (asteroid strikes). Other less frequent causes are likely nearby supernovae and possibly our galactic arm passing thru a gamma radiation beam. Even with constant evolution forcing habitats, a galaxy faring intelligence will be rare. As someone else noted, our saurian ancestors didn't stumble upon a tool building transmissible culture. There's just so many prerequisites. Compare us to the octopus, likely the next most potent intelligent being on Earth, and certainly alien (to us). They are frikkin brilliant. But they unfortunately have no way to transmit, share their knowledge. And their life spans are probably too brief, birth rate too low.

Arubis 8y ago

While it may be based on what is technically fiction, my views on the Drake Equation were modified to include a “caution in outbound communication factor” of fairly low probability after reading Cixin Liu’s “Dark Forest”. SPOILER ALERT for prior novel: it convincingly argues that, due to the impossibility of trust across otherwise unrelated civilizations, the rate of technological progress in any given civilization compared to the speed of travel between star systems, and the long-term understanding that resources are limited, and outgoing communication to another intelligent civilization inevitably results in attack and likely elimination of said civilization.

peatmoss 8y ago
Indeed this feels like the most satisfactory explanation for the Fermi paradox. I’m just starting on the third book, and am starting to think the eye-popping $1 billion that Amazon is rumored to be paying / have paid to allow them to make this into a TV series might not be entirely insane.

deleted 8y ago

[deleted]

rgomez 8y ago

Yep. The ugly truth: We are kind of alone out there. There's no one, or there's no one who wants to openly communicate with us, at least not yet. Get over it.

riazrizvi 8y ago

> Instead, it simply means that we can say with greater confidence – based on what we know – that humanity is most likely the only intelligent species in the Milky Way Galaxy at present. The article is light years away from its title.

daodedickinson 8y ago

What do you even mean by "we"?

ianamartin 8y ago

My pet theory about Fermi’s paradox is that there was only ever a very brief moment in the history of our civilization where attempted contact was politically and socially viable. Think about the Voyager project right now. Assembling a rep sample of all of human existence onto a single golden record and including the instructions to decode it in math. This. Could. Never. Happen. Today. No one could agree on what to include or exclude or how to execute it. There was an incredibly brief window of opportunity where we had the technology and the social capacity to reach out to interstellar neighbors. There are tons of other civilizations close by us. They just missed that very tiny window of a chance to say hello.

ezioamf 8y ago

We could just be a pet civilization from an nearby advanced civilization that blocks all signals coming to us.

ravenstine 8y ago

On a bit of a tangent from the core content of the article and the discussion here, I take issue with how easily even the smartest of people will take one example of a phenomenon and extrapolate the frequency(or replicability) of said phenomenon. All we really know about life, as we define it, is that it's possible to occur, because we're here, but we don't have any actual information about whether we're a fluke or an unknowing part of a greater community of intergalactic life. Pointing to billions and billions of stars and saying "there must be life out there" is unfounded at this point because we still aren't even close to understanding exactly how life came to be on Earth, as well as why it happened when it did. What the equation of predicting life is missing is the variable of time; without having at least two examples of life occurring independently, there's no way that I'm aware of that we can come up with a useful probability of life occurring anywhere. That is, unless we can create simulations to test theories outside of real time, which will probably be a required next step in science for getting a better understanding of our universe.

themagician 8y ago

Almost all of these models assume that an "advanced civilization" must have language and radio astronomy and I've always felt that's a rather odd set of parameters. It's completely possible that we haven't found anyone else because we are looking for the wrong things. We are looking for ourselves in the stars and fail to realize that we aren't "it". We may not even be the most advanced species on Earth. When all the dolphins rise out of the ocean and into the sky maybe then we'll realize, but it will be too late.

geebee 8y ago

It seems like we have an equation with a bunch of variables that are either extremely close to 1 or extremely close to zero. And really, these variables seem to group together into two essential variables, which are either almost 1 or almost 0. And we're trying to figure out whether, when you multiply them together, you get almost 1 or almost 0. So, what does (almost_1 * almost_0) equal? It requires more knowledge about "almost" than are able to obtain.

sixdimensional 8y ago
Your question reminded me of MAYBE. I often joke about the MAYBE logical operator with friends. It's based on the concept of three valued logic [1]. It always came up for me in SQL where you have a cell in a result that can be NULL, NOT NULL or a value. I also use it to refer to spaghetti or complex code where the outcome on first glance is "maybe this or maybe that, or maybe something in the middle". Again, I use it as a joke when it is a totally real concept. It seems like increasingly we are trying to extract approximate answers from machine learning, statistics, etc. because in so many cases it seems difficult to get to TRUE or FALSE for a given hypothesis. We want "MAYBE" with enough accuracy to believe it is mostly TRUE or 100% TRUE (but often 95% confidence - heck even 85% is still amazingly valuable when you aren't sure at all). I believe there is a programming language that handles this (I forget which one though - anyone?). I know quantum processors potentially could handle it since they have multiple states for a qubit which could represent different states of "in-between" TRUE and FALSE. [1] https://en.wikipedia.org/wiki/Three-valued_logic https://en.wikipedia.org/wiki/Three-valued_logic
- mitchty 8y ago
  This basically exists in Haskell/Idris as the Maybe type. It is used slightly differently than what you're saying but in essence it lets you say: - The thing doesn't exist, return Nothing (unit in a way) - The inputs produced Just the thing you wanted You have to cover both "didn't work" and "here you go" but its highly useful to not have to worry about NULL versus NOT NULL. https://stackoverflow.com/questions/29456824/what-is-the-maybe-type-and-how-does-it-work https://stackoverflow.com/questions/29456824/what-is-the-may... Your function that decides if something exists or not, could be the thing determining the percentage spiel. Aka a function returning Maybe Bool could return: a Bool with true/false, or Nothing. Nothing being "its not a bool, your inputs are insane/nonsensical", but if it returns a Just Bool, you just unbox the Bool and voila. Just thought you might want to know this is a real thing and is super useful.

turdnagel 8y ago

I've seen that we search for exoplanets with life by using spectral analysis to estimate the temperature, atmospheric composition, etc. of these planets, and seeing whether or not they fall within a range that is similar to Earth's. I wonder if it would also be instructive to search for planets who exhibit signs of a man-made apocalypse, like massive nuclear fallout.

didibus 8y ago

Curious what a similar model would show if applied to earth pre the discovery of the other continents.

sliken 8y ago

If we started the colonization of the galaxy in the year 2500 with 10 planets I suspect we would just wait and see if we came across a society with the level of technology we have today. After all, why take the risk of meeting a war like society that lobs nukes at each other? Just leave a few probes nearby to keep tabs on them and see if they advance to a level that's interesting.... or scary.

oooooof 8y ago

That means that Trump is the most powerful person in the universe.

089723645897236 8y ago

Not enough data to make this conclusion in any actionable way.