13 ms·

Where are they? Why I hope the search for ET life finds nothing (2008)

78 points by godelmachine 8y ago

zamalek 8y ago
Human also occur in the earliest likely epoch of the universe: * We have, astronomically speaking, just entered the epoch where the universe can support life. We have the required abundance of elements and conditions that give rise to life (stellar nucleosynthesis). * Intelligence is an incredibly strange thing to evolve. Evolution is a gradient (the evolutionary whitening of the polar bear is probably the best example of this). There is no gradient to move down towards intelligence. You have it or you don't; you are reactive, instinctual, or intellectual. * Intelligent life has also been demonstrated to be unbelievably improbable. With nature as the best laboratory, out of all the species that have ever evolved, only one on Earth evolved intelligence. In layman terms, we are likely the "ancients," or rather we might be, as we could simply go extinct.
- mettamage 8y ago
  > * Intelligent life has also been demonstrated to be unbelievably improbable. With nature as the best laboratory, out of all the species that have ever evolved, only one on Earth evolved intelligence. I wonder whether this is actually true. Imagine the human society being transported to dolphin or shark bodies (they'd spawn there). Assume the following: food is not an issue in the short term and we retain our knowledge and we have quite a good control over our new bodies and can do what sharks or dolphins normally do. Even with these advantages, could we recreate what we made on land?
  - jonathankoren 8y ago
    No. Dolphins don’t have thumbs, and fire is a lot more problematical underwater.
  - zamalek 8y ago
    Good point. I would say that the defining feature of human intelligence is immediate and self-directed teaching. House training a dog takes many weeks and many rewards. Stopping smoking is a decision that a human makes and can immediately put into practice. Using sharks and dolphins as an example, both would learn to avoid fishing nets and communicate that danger (which is not unique to humans), remember it (which is) to each other and their offspring (again, unique to humans). What's not done is seemingly more important than what is, because beating opposable thumbs is pretty hard (as you've pointed out).
- paxys 8y ago
  > There is no gradient to move down towards intelligence. You have it or you don't; you are reactive, instinctual, or intellectual Disagree with this. You can compare the intelligence of various animals (humans, chimpanzees, dolphins, crows etc.) and see that there is a gradual scale rather than a binary (ternary?) switch.
- adrianN 8y ago
  Astronomical epochs are pretty long. While it's unlikely that extraterrestrial life has arisen billions of years before life on Earth, civilizations that are thousands or millions of years older than us should be as common as intelligent life in general. For example intelligent reptiles are not unthinkable, and their order had a hefty head start on mammals.
fernly 8y ago
There is currently an excellent podcast exploring these ideas: "The End of the World with Josh Clark"[1]. Nicely produced, fairly deep content -- including audio quotes from Nick Bostrom among others. This link is to episode 1, but for convenience in subscribing look it up on iTunes. [1] https://www.stuffyoushouldknow.com/podcasts/the-end-of-the-world-with-josh-clark-ep01-fermi-paradox.htm https://www.stuffyoushouldknow.com/podcasts/the-end-of-the-w...
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millstone 8y ago
> Humans have, to date, seen no sign of any extraterrestrial civilization. We do not know that and it may very well be false. Yeast was known of and observed for thousands of years, but was not discovered to be life until the 1800s. The signs of life were there, but were not recognized. It is just our human bias to envision complexity as only occurring on earth-like planets, on human-like time and size scales, communicating over the EM spectrum, formed of baryonic matter... We don't ask what Great Filter prevents the aliens from speaking English. But we might if English was the only language known on Earth. What languages other than DNA are spoken in the universe?
- caf 8y ago
  It is just our human bias to envision complexity as only occurring on earth-like planets, on human-like time and size scales, communicating over the EM spectrum, formed of baryonic matter... The argument works just as well if you stipulate that it covers only sufficiently human-like complex life. The speculated existence of life composed of galaxy-scale non-baryonic matter or something doesn't affect at all the question of where all the other more prosaic life is.
  - perl4ever 8y ago
    I vaguely recall an article describing reasons why really exotic (e.g. galaxy scale) life doesn't make a whole lot of sense. One problem is that no matter how it is organized or what it is made of, light speed prevents it from communicating rapidly. If it doesn't communicate rapidly within itself, it can't develop or evolve much in the lifespan of the universe, at least so far. You can deduce various constraints on "intelligent life" without making simplistic assumptions a priori that humans are normal, but rather starting with what we know about physics.
    - mysterypie 8y ago
      Since we're on the topic of really exotic, how about a complex proton arrangement inside a star having all the properties of intelligent life? This wouldn't suffer from light speed constraints. Would it violate other constraints from fundamental physics?
jim_bailie 8y ago
All I know is that if we're going to locate or communicate with any other advanced civilization out there, it's sure not going to be with radio waves. It will be with something a little more subtle that may not necessarily be constrained by gravity or the speed of light. Just my $0.02
- redial 8y ago
  How can someone claim to not know and yet be so, so sure and arrogant?
  - jim_bailie 8y ago
    I don't know
- paxys 8y ago
  It's likely that everything in the universe is constrained by the speed of light, so maybe radio waves are the best form of communication?
  - whydoineedthis 8y ago
    I think a lot of folks don't realize most real and hard science is done with radio waves. The tech is often associated with antiquated devices for music and news of erras by gone, but scientifically speaking, radio waves are pretty high tech. Electromagnetic Radiation has it's own brand problems though. We really new words not associated with early use cases.
    - redial 8y ago
      Sadly most people don't realize what they see is 'radio waves', hence OP's misguided comment.
      - jim_bailie 8y ago
        What you claim is indeed so very sad, but I wouldn't gnash teeth or loose any sleep over it.
cortesoft 8y ago
There are a number of flaws with this argument, but one major obvious one is the idea that finding life on mars would show the probability of life generating on a random planet is high. The premise of this argument relies on assuming life arising on Earth and Mars are stochastic processes that each occurred independently; on the contrary, there could be shared featured of Earth and Mars that make life more probable on those two planets than elsewhere. The 'great filter' could be shared between the two planets.
- rlpb 8y ago
  Earth and Mars are also close enough to have seeded each other: https://en.wikipedia.org/wiki/Martian_meteorite https://en.wikipedia.org/wiki/Martian_meteorite
  - starbeast 8y ago
    Given the amount of waterbears and the fact that they are small enough to get blown off the top of the atmosphere by solar winds, I suspect that perhaps one waterbear per century has the conditions to briefly wake up on Mars and wonder what the hell is going on before dying.
    - 8fingerlouie 8y ago
      Considering that they can survive the vacuum of space, 1000 times more radiation than other animals, few days at -200C (30 years at -20C), and they can be dehydrated for 10 years, i'd say they'd probably briefly wake up, wonder what the hell is going on, then doze off in a 30+ year hibernation state.
- tynpeddler 8y ago
  Finding life on Mars, or anywhere in the solar system, would be huge and would radically improve our ability to predict life elsewhere. If it's chemically different from earth life, that would revolutionize our knowledge of complex chemistries. If Mars life is chemically similar but independent of earth life, that would suggest that life tends to use common chemistry. If life on earth and mars has a common origin, that would tell us a lot about the early solar system. In short, N=2 doesn't sound great, but it is lightyears better than N=1.
DanielBMarkham 8y ago
This is an old argument, covering well-trod ground. Somewhere in the ocean there's an island with only one colony of ants. In that colony, there's a little ant-Enrico Fermi, doing little ant-things, writing in little ant-journals, wondering little ant-thoughts, including "Where are they?" You have to bring a great amount of hubris to bear on this problem to reach any kind of conclusions. After all, we only have an example of one Earth, with one species of humans on it. I'm not sure we'd know what an alien was if one were standing next to us (metaphorically, perhaps actually). We have no common frame of reference to reason about such things. The best we can do is string together a lot of terms representing concepts through multiplication. This gives us the unsurprising result that lots of things multiplied by each other tend to get either really large or really small really quickly. The question Fermi asked was a truly profound one. It was profound because it points the finger back at us, asking just what do we really know about the entirety of universe we live in? It's a great question. We will be fortunate to see little tiny pieces of the answer in our lifetimes.
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Inu 8y ago
> UFO‐spotters, Raelian cultists, and self‐certified alien abductees notwithstanding, humans have, to date, seen no sign of any extraterrestrial intelligent civilization. [...] If large telescopes, NASA satellites, and omplicated mathematical data analysis are involved, it becomes harder for outside observers to mistake the work for the ramblings of UFO‐nuts and other crackpots. The author makes it clear that for a serious scholar "UFOs" can a priori only be a subject of ridicule.
- kordlessagain 8y ago
  This behavior evidently started with Zeno of Elea's run on logic through reasoned argument. He's the reason we have the scientific method, basically. Fortunately, the scientific method produced technology that allows me to post this comment. Unfortunately, limiting a culture's philosophy to only discussing things we can attempt to disprove results in limiting the ability to discuss something as if it were true, before we know it to be true by proof. Example: I believe ʻOumuamua was a spacecraft. Can't prove it, but can't talk about it as a truth either, which sorta sucks given I figured (when I was a kid) aliens would be here by now. ;)
david-gpu 8y ago
Title needs a (2008) tag.
codechapin 8y ago
I think this is not giving enough thought on the topic of population growth. I believe in most rich/advanced countries population is declining, unless they have a lot of immigration, United States for example. Hans Rosling has some studies on this, his studies say that the world population won’t exceed 11 billion. Also, people are having less sex than before. https://www.theatlantic.com/magazine/archive/2018/12/the-sex-recession/573949/ https://www.theatlantic.com/magazine/archive/2018/12/the-sex... which obviously is going to affect population growth. Although, this could change if somehow we manage to live considerably longer lives. Then population would grow again. Which is the main promise of Scythe by Neal Shusterman. We would need a very good reason to spend the resources to go colonize other planets.
overgard 8y ago
There's an obvious possibility that people ignore because it's not very sexy: maybe life is common, but sending messages clearly over interstellar distances is pointless and extremely expensive. Maybe the energy cost of transmitting a signal that can be clearly heard over interstellar distances -- mixed with the time/distance barriers of interstellar travel and communication -- makes it kind of pointless outside of novelty. (Not to mention any communication would happen on the scale of rise and fall of civilizations -- how do you even have a coherent conversation across hundreds of years?). I mean maybe most societies that form just don't have the energy and willpower to colonize outside their solar system. They might also be like us where dominant civilisations and philosophy’s rise and fall every few years — meaning not enough stability for a 50000 year long conversation Perhaps the universe is silent simply because there's no reason to speak up.
- setr 8y ago
  Presumably any space-faring civilization would be interested in knowing if others exist; at a minimum, first contact (should they have any expectation of external life) would likely offer an extreme advantage in whatever competition they have locally (eg technological gifts, information exchange, prinary point of contact, etc). Furthermore, if they are spacefaring, they will require long-range transmissions regardless: it would be odd to think they’d send ships into multi-year journeys without being able to phone home, or having the tech and not utilizing it (a lost ship is likely costlier than transmission). A civilization not capable of spaceflight might be in your position, incapable of producing transmission cheap enough, and not being curious enough to cast it into the void, but otherwise, any being capable (and willing) of long-distance travel should find sufficient use for long-distance communication to utilize it, independent of a search for alternate life. That is, advanced civilization should be noisy for their own sake. (Though perhaps in a manner we can’t detect, or don’t expect).
  - mcv 8y ago
    Communication within a civilisation is quite a bit different from highly speculative permanent signals to billions of starts in the hope that someone is listening. And even if someone is listening, they might not be able to answer. So this sounds rather unlikely to me. A bigger issue is: would they actually send spaceships on multi-year journeys to other solar systems? If they would, then why aren't they already here? Some of those civilisations must have a million or billion year head start on us. Plenty to colonise the galaxy, yet we see no trace of them here. So the odds of there being interstellar civilisations out there is extremely slim. I think our best bet to find alien civilisations is by detecting the signature of alien megastructures; Dyson Spheres and the like. Tabby's Star sounds to me like the most likely way we might find alien life.
mooreds 8y ago
If you liked this, you might enjoy "Light of the Same", which examines the Drake equation and seti in the light of all the planets that have been discovered. https://www.goodreads.com/book/show/36236156-light-of-the-stars https://www.goodreads.com/book/show/36236156-light-of-the-st...
nickysielicki 8y ago
Highlighting text on a webpage so that you can focus on a particular sentence should never move the text and make you lose your place. I like the idea but don't make it a pop-in sidebar that moves the page.
- mooreds 8y ago
  Yes, the ux was horrible, especially on mobile.
  - michaelmrose 8y ago
    On firefox I couldn't even enable reader mode on this page.
- mysterypie 8y ago
  For an article that looks like typewritten pages, you'd think it would be perfect for printing. But it gets horribly butchered if you try to print it or save it as a PDF. Modern web development has robbed us of the beauty and simplicity of plain text.
vorg 8y ago
Our own DNA-based life may actually be the von Neumann probes the author mentions -- self-replicating spacecraft, controlled by AI and capable of interstellar travel via "Panspemia".
mooreds 8y ago
I wonder if the availability of fossil fuels is the great filter? My understanding is that all that plant matter didn't decay only because fungi hadn't evolved thr ability to break it down, and thus fossil fuels are a one time burst of energy that isn't going to ever be available again.
- c22 8y ago
  Do you have a citation for this understanding? I hadn't heard this before so I did a brief search and found [0], but this seems to apply just to coal which goes through a lignite phase during its formation [1]. I'm not familiar the details of how other fossil fuels are formed, but I was under the impression it usually happens under the seafloor, are the same mechanisms at play in an undersea environment? It seems like fungi are more common on land than at sea [2]. [0] https://clarknow.clarku.edu/2012/06/28/findings-point-to-fungi-as-prime-suspects-in-fossil-fuel-mystery/ https://clarknow.clarku.edu/2012/06/28/findings-point-to-fun... [1] https://en.wikipedia.org/wiki/Coal https://en.wikipedia.org/wiki/Coal [2] https://sciencing.com/types-fungi-grow-ocean-8467074.html https://sciencing.com/types-fungi-grow-ocean-8467074.html
  - mooreds 8y ago
    Ah, TIL. I am wrong. I was unable to find any source for this, and, like you, found some countervailing posts, like this one: http://www.abc.net.au/science/articles/2013/02/18/3691317.htm http://www.abc.net.au/science/articles/2013/02/18/3691317.ht... So, please consider the above comment retracted.
mannykannot 8y ago
Bostrom dismisses, as a fallacy, the idea that the relatively rapid appearance of life on Earth is evidence for it being somewhat probable, yet it is just about as fallacious to think that the absence of life on Mars would be evidence for humanity having long-term prospects.
phkahler 8y ago
I'm picking up a lot of existential angst in this one. The author hopes we are the only intelligent species in the universe because why? I think spending so much time on the nature of ones own existence is to neglect the here and now. I say this as someone who confronted his own existential angst - it can drive you in any number of directions, none of which really matter for someone with an expected lifespan of 70 years. If life is so precious, why not go experience it while you can?
- AgentME 8y ago
  >The author hopes we are the only intelligent species in the universe because why? Because if there is other life in the universe, then it's more likely that the Great Filter is ahead of us and that human civilization will end sooner. If we are the only intelligent species, then it's more likely that the Great Filter is behind us and humanity is more likely to spread across planets.
caller9 8y ago
It's because the simulation was built to simulate a culture that wasn't yet aware of aliens and alien interaction isn't part of the experiment. It's also less expensive in compute resources.
state_less 8y ago
The possibilities that come to mind are: 1. We happen to be first. 2. They are on their way. 3. They are within reach and are not malevolent, nor allow the spread of malevolence, given the 'typical' billions years gestation period.
- ianai 8y ago
  Or they exist but because the universe is huge and sparse we’ll never encounter each other. My hunch is that life is actually prolific. It’s in the oceans of Encledeus (sp), may be in extremes on mars, and possibly more in other places. But it’s not industrial the ways we are.
  - state_less 8y ago
    > Or they exist but because the universe is huge and sparse we’ll never encounter each other. That's a good hunch. As we've learned more, the universe has appeared to be larger over the years. This could keep destructive contagions from spreading. If destructive contagions are likely, we probably wouldn't be here. I sort of file it under 1. where they are causally unreachable and we are singular in our sphere of influence. Or maybe 2., but over time even if space is vast, we ought to bump into each other eventually. Folks won't rest until they probe under every rock. So maybe they are out there, maybe even prolific and they (or we) are on the way to meeting each other. Humanity ought to make itself durable to see it through.
  - gnulinux 8y ago
    > But it’s not industrial the ways we are. I find this very unlikely. If you do some computer simulations, you can see that if "life" has minimal amount of freedom to get modified, it diverges to really interesting objects and exploits a lot of phenomenon happening in its virtual universe. Something as absurdly unlikely and crazy as symbiogenesis occured multiple times in our planet. It's unlikely if there is life out there, it'd stay simple and invisible. My hunch is that life is extremely rare, if it exists at all. We know from computer science that evolution is a very good method to find ever-improving local optimas, so to me it's very likely if life exists, it'll evolve to galactic empires in a few billion years. And thus thanks to Fermi paradox, this convinces me that life must be extremely rare, or the Great Filter must be very effective or intergalactic communication/travel must be extremely expensive.
c-smile 8y ago
If to expand that line of thought even further we shall conclude that we are alone in observable Universe. Life as we know it tends to preserve itself - the instinct of self-preservation is the main feature of life. Others are just consequences. "Hi-order" life will preserve not only one particular incarnation of it but various others too. So as soon one civilization will pass the filter - it should help others to pass it. And if we do not see that other hi-order one yet then it means this role is ours and no one is out there. For humanity "hi-order" state of life is definitely far ahead - long way to go. If not the filter is ahead of us :)
- gremlinsinc 8y ago
  >> So as soon one civilization will pass the filter - it should help others to pass it.... unless neither civilization knows 'when' the great filter is...and continues to expect it's in the future... this could cause fear of each other... fear leads to the dark side... Interstellar war probably isn't good for the less advanced civilization. Let's hope when the time comes we're not the less advanced civilization...or the other one will become our great filter.. The great filter also could be a predatory civ that snuffs out any sign of life after they find it. For this reason many civs could be afraid to do anything to draw attention.
gremlinsinc 8y ago
Why does there have to be 'one' great filter... I think it's more a 'tiered' system... I mean on any given planet getting to eukaryotes is difficult..once you do, you've made it past 'a great filter'.... onto the next... Everything in life is a battle to survive - even evolution. I don't think there even being a great filter means that we necessarily wouldn't pass through it... -- I guarantee you there's a great filter...if we never become space faring this world will die -- the sun will supernova. If humans survive to that day, and never leave the solar system then all life here will be snuffed out... If we do survive eons past the end of this solar system at some point the entire universe could contract, entropy could run out and all life would be snuffed out... On a long enough time line -- everything in this universe will be filtered out.
- eloff 8y ago
  Not to detract from your other points, which I agree with, but our star won't supernova. It doesn't have enough mass. It will go red giant and toast our planet.
caf 8y ago
The idea that we'd most likely encounter a colonising civilisation in the form of von Neumann probes seems reasonable. Imagine there was one (or even a few dozen) such probe currently occupying an asteroid somewhere in our solar system, slowly completing the millenia-long task of replicating itself. Would we have noticed yet?
brazzy 8y ago
Charlie Stross' "Accelerando" floats an interesting idea: Post-Tech-Singularity civilizations might naturally become isolationist because consciousness becomes tied to computing hardware that is dependant on abundant energy and low communication latency that you don't have unless you all cluster closely around a star, i.e. a small Dyson sphere. Leaving those ideal circumstances becomes unthinkable for the individual because it would mean lobotomizing yourself. However, we should be able to see those Dyson spheres, and we don't.
- ludos 8y ago
  Isnt the purpose of a Dyson sphere to keep all Energy inside? If thats the case, how would you detect such a sphere? Maybe that's where the dark matter is. 80% of the universe, packed into small Dyson Spheres, where live is sprawling and we just cant see it. ;-)
  - HappySweeney 8y ago
    They would glow in infrared.
  - brazzy 8y ago
    > Isnt the purpose of a Dyson sphere to keep all Energy inside? No, because that would be both impossible (see "black body radiation") and useless. The purpose is to use all energy produced by the star. But "using" energy doesn't mean it's gone (see conservation of energy) or that you have to trap it. What it really means is you want to use the low entropy inherent in a concentrated source of energy to perform work.
ulisesrmzroche 8y ago
My latest favorite tin foil hats are The Watchers & The Cosmic War because otherwise perhaps we're going thru a Great Filter right now with global warming due to energy consumption, etcetera & I dunno if we're gonna make it at all
shireboy 8y ago
I've thought along these lines before, and am writing a hard science fiction novel with this premise. I love thinking about the possibility of other advanced civilizations etc as much as the next guy, but it does seem like the _other_ possibility is less represented in sci-fi and maybe in current thought in general. It's so fun to think about life existing and those implications, less time is given to thinking about life _not_ existing elsewhere and what that would mean. I get that to a degree. I feel like Debbie Downer just saying it, but in order of likelihood based on current observation, I would arrange the scenarios like this: * Intelligent life only exists on Earth. This is what we have observed so far, so in absence of other evidence this is "most likely" with a large margin of error ;) * Intelligent life does exist and is abundant, but we are among the most advanced. Hard limits in physics mean it is impractical to travel out of one's solar system, much less galaxy. * We're among the most advanced because of a "great filter" after our current stage. * We're among the most advanced because of a "great filter" before our current stage. * We are a simulation
dreamcompiler 8y ago
It's very hard to read these not-HTML and not-quite-PDF sites on mobile, especially with all the popups. Author might have something interesting to say but I can't tell.
zygotic12 8y ago
Space is BIG with a capital BIG !!! Small is human.

78 points by godelmachine 8y ago

Human also occur in the earliest likely epoch of the universe: * We have, astronomically speaking, just entered the epoch where the universe can support life. We have the required abundance of elements and conditions that give rise to life (stellar nucleosynthesis). * Intelligence is an incredibly strange thing to evolve. Evolution is a gradient (the evolutionary whitening of the polar bear is probably the best example of this). There is no gradient to move down towards intelligence. You have it or you don't; you are reactive, instinctual, or intellectual. * Intelligent life has also been demonstrated to be unbelievably improbable. With nature as the best laboratory, out of all the species that have ever evolved, only one on Earth evolved intelligence. In layman terms, we are likely the "ancients," or rather we might be, as we could simply go extinct.

mettamage 8y ago
> * Intelligent life has also been demonstrated to be unbelievably improbable. With nature as the best laboratory, out of all the species that have ever evolved, only one on Earth evolved intelligence. I wonder whether this is actually true. Imagine the human society being transported to dolphin or shark bodies (they'd spawn there). Assume the following: food is not an issue in the short term and we retain our knowledge and we have quite a good control over our new bodies and can do what sharks or dolphins normally do. Even with these advantages, could we recreate what we made on land?
- jonathankoren 8y ago
  No. Dolphins don’t have thumbs, and fire is a lot more problematical underwater.
- zamalek 8y ago
  Good point. I would say that the defining feature of human intelligence is immediate and self-directed teaching. House training a dog takes many weeks and many rewards. Stopping smoking is a decision that a human makes and can immediately put into practice. Using sharks and dolphins as an example, both would learn to avoid fishing nets and communicate that danger (which is not unique to humans), remember it (which is) to each other and their offspring (again, unique to humans). What's not done is seemingly more important than what is, because beating opposable thumbs is pretty hard (as you've pointed out).
paxys 8y ago
> There is no gradient to move down towards intelligence. You have it or you don't; you are reactive, instinctual, or intellectual Disagree with this. You can compare the intelligence of various animals (humans, chimpanzees, dolphins, crows etc.) and see that there is a gradual scale rather than a binary (ternary?) switch.
adrianN 8y ago
Astronomical epochs are pretty long. While it's unlikely that extraterrestrial life has arisen billions of years before life on Earth, civilizations that are thousands or millions of years older than us should be as common as intelligent life in general. For example intelligent reptiles are not unthinkable, and their order had a hefty head start on mammals.

fernly 8y ago

There is currently an excellent podcast exploring these ideas: "The End of the World with Josh Clark"[1]. Nicely produced, fairly deep content -- including audio quotes from Nick Bostrom among others. This link is to episode 1, but for convenience in subscribing look it up on iTunes. [1] https://www.stuffyoushouldknow.com/podcasts/the-end-of-the-world-with-josh-clark-ep01-fermi-paradox.htm https://www.stuffyoushouldknow.com/podcasts/the-end-of-the-w...

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millstone 8y ago

> Humans have, to date, seen no sign of any extraterrestrial civilization. We do not know that and it may very well be false. Yeast was known of and observed for thousands of years, but was not discovered to be life until the 1800s. The signs of life were there, but were not recognized. It is just our human bias to envision complexity as only occurring on earth-like planets, on human-like time and size scales, communicating over the EM spectrum, formed of baryonic matter... We don't ask what Great Filter prevents the aliens from speaking English. But we might if English was the only language known on Earth. What languages other than DNA are spoken in the universe?

caf 8y ago
It is just our human bias to envision complexity as only occurring on earth-like planets, on human-like time and size scales, communicating over the EM spectrum, formed of baryonic matter... The argument works just as well if you stipulate that it covers only sufficiently human-like complex life. The speculated existence of life composed of galaxy-scale non-baryonic matter or something doesn't affect at all the question of where all the other more prosaic life is.
- perl4ever 8y ago
  I vaguely recall an article describing reasons why really exotic (e.g. galaxy scale) life doesn't make a whole lot of sense. One problem is that no matter how it is organized or what it is made of, light speed prevents it from communicating rapidly. If it doesn't communicate rapidly within itself, it can't develop or evolve much in the lifespan of the universe, at least so far. You can deduce various constraints on "intelligent life" without making simplistic assumptions a priori that humans are normal, but rather starting with what we know about physics.
  - mysterypie 8y ago
    Since we're on the topic of really exotic, how about a complex proton arrangement inside a star having all the properties of intelligent life? This wouldn't suffer from light speed constraints. Would it violate other constraints from fundamental physics?

jim_bailie 8y ago

All I know is that if we're going to locate or communicate with any other advanced civilization out there, it's sure not going to be with radio waves. It will be with something a little more subtle that may not necessarily be constrained by gravity or the speed of light. Just my $0.02

redial 8y ago
How can someone claim to not know and yet be so, so sure and arrogant?
- jim_bailie 8y ago
  I don't know
paxys 8y ago
It's likely that everything in the universe is constrained by the speed of light, so maybe radio waves are the best form of communication?
- whydoineedthis 8y ago
  I think a lot of folks don't realize most real and hard science is done with radio waves. The tech is often associated with antiquated devices for music and news of erras by gone, but scientifically speaking, radio waves are pretty high tech. Electromagnetic Radiation has it's own brand problems though. We really new words not associated with early use cases.
  - redial 8y ago
    Sadly most people don't realize what they see is 'radio waves', hence OP's misguided comment.
    - jim_bailie 8y ago
      What you claim is indeed so very sad, but I wouldn't gnash teeth or loose any sleep over it.

cortesoft 8y ago

There are a number of flaws with this argument, but one major obvious one is the idea that finding life on mars would show the probability of life generating on a random planet is high. The premise of this argument relies on assuming life arising on Earth and Mars are stochastic processes that each occurred independently; on the contrary, there could be shared featured of Earth and Mars that make life more probable on those two planets than elsewhere. The 'great filter' could be shared between the two planets.

rlpb 8y ago
Earth and Mars are also close enough to have seeded each other: https://en.wikipedia.org/wiki/Martian_meteorite https://en.wikipedia.org/wiki/Martian_meteorite
- starbeast 8y ago
  Given the amount of waterbears and the fact that they are small enough to get blown off the top of the atmosphere by solar winds, I suspect that perhaps one waterbear per century has the conditions to briefly wake up on Mars and wonder what the hell is going on before dying.
  - 8fingerlouie 8y ago
    Considering that they can survive the vacuum of space, 1000 times more radiation than other animals, few days at -200C (30 years at -20C), and they can be dehydrated for 10 years, i'd say they'd probably briefly wake up, wonder what the hell is going on, then doze off in a 30+ year hibernation state.
tynpeddler 8y ago
Finding life on Mars, or anywhere in the solar system, would be huge and would radically improve our ability to predict life elsewhere. If it's chemically different from earth life, that would revolutionize our knowledge of complex chemistries. If Mars life is chemically similar but independent of earth life, that would suggest that life tends to use common chemistry. If life on earth and mars has a common origin, that would tell us a lot about the early solar system. In short, N=2 doesn't sound great, but it is lightyears better than N=1.

DanielBMarkham 8y ago

This is an old argument, covering well-trod ground. Somewhere in the ocean there's an island with only one colony of ants. In that colony, there's a little ant-Enrico Fermi, doing little ant-things, writing in little ant-journals, wondering little ant-thoughts, including "Where are they?" You have to bring a great amount of hubris to bear on this problem to reach any kind of conclusions. After all, we only have an example of one Earth, with one species of humans on it. I'm not sure we'd know what an alien was if one were standing next to us (metaphorically, perhaps actually). We have no common frame of reference to reason about such things. The best we can do is string together a lot of terms representing concepts through multiplication. This gives us the unsurprising result that lots of things multiplied by each other tend to get either really large or really small really quickly. The question Fermi asked was a truly profound one. It was profound because it points the finger back at us, asking just what do we really know about the entirety of universe we live in? It's a great question. We will be fortunate to see little tiny pieces of the answer in our lifetimes.

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Inu 8y ago

> UFO‐spotters, Raelian cultists, and self‐certified alien abductees notwithstanding, humans have, to date, seen no sign of any extraterrestrial intelligent civilization. [...] If large telescopes, NASA satellites, and omplicated mathematical data analysis are involved, it becomes harder for outside observers to mistake the work for the ramblings of UFO‐nuts and other crackpots. The author makes it clear that for a serious scholar "UFOs" can a priori only be a subject of ridicule.

kordlessagain 8y ago
This behavior evidently started with Zeno of Elea's run on logic through reasoned argument. He's the reason we have the scientific method, basically. Fortunately, the scientific method produced technology that allows me to post this comment. Unfortunately, limiting a culture's philosophy to only discussing things we can attempt to disprove results in limiting the ability to discuss something as if it were true, before we know it to be true by proof. Example: I believe ʻOumuamua was a spacecraft. Can't prove it, but can't talk about it as a truth either, which sorta sucks given I figured (when I was a kid) aliens would be here by now. ;)

david-gpu 8y ago

Title needs a (2008) tag.

codechapin 8y ago

I think this is not giving enough thought on the topic of population growth. I believe in most rich/advanced countries population is declining, unless they have a lot of immigration, United States for example. Hans Rosling has some studies on this, his studies say that the world population won’t exceed 11 billion. Also, people are having less sex than before. https://www.theatlantic.com/magazine/archive/2018/12/the-sex-recession/573949/ https://www.theatlantic.com/magazine/archive/2018/12/the-sex... which obviously is going to affect population growth. Although, this could change if somehow we manage to live considerably longer lives. Then population would grow again. Which is the main promise of Scythe by Neal Shusterman. We would need a very good reason to spend the resources to go colonize other planets.

overgard 8y ago

There's an obvious possibility that people ignore because it's not very sexy: maybe life is common, but sending messages clearly over interstellar distances is pointless and extremely expensive. Maybe the energy cost of transmitting a signal that can be clearly heard over interstellar distances -- mixed with the time/distance barriers of interstellar travel and communication -- makes it kind of pointless outside of novelty. (Not to mention any communication would happen on the scale of rise and fall of civilizations -- how do you even have a coherent conversation across hundreds of years?). I mean maybe most societies that form just don't have the energy and willpower to colonize outside their solar system. They might also be like us where dominant civilisations and philosophy’s rise and fall every few years — meaning not enough stability for a 50000 year long conversation Perhaps the universe is silent simply because there's no reason to speak up.

setr 8y ago
Presumably any space-faring civilization would be interested in knowing if others exist; at a minimum, first contact (should they have any expectation of external life) would likely offer an extreme advantage in whatever competition they have locally (eg technological gifts, information exchange, prinary point of contact, etc). Furthermore, if they are spacefaring, they will require long-range transmissions regardless: it would be odd to think they’d send ships into multi-year journeys without being able to phone home, or having the tech and not utilizing it (a lost ship is likely costlier than transmission). A civilization not capable of spaceflight might be in your position, incapable of producing transmission cheap enough, and not being curious enough to cast it into the void, but otherwise, any being capable (and willing) of long-distance travel should find sufficient use for long-distance communication to utilize it, independent of a search for alternate life. That is, advanced civilization should be noisy for their own sake. (Though perhaps in a manner we can’t detect, or don’t expect).
- mcv 8y ago
  Communication within a civilisation is quite a bit different from highly speculative permanent signals to billions of starts in the hope that someone is listening. And even if someone is listening, they might not be able to answer. So this sounds rather unlikely to me. A bigger issue is: would they actually send spaceships on multi-year journeys to other solar systems? If they would, then why aren't they already here? Some of those civilisations must have a million or billion year head start on us. Plenty to colonise the galaxy, yet we see no trace of them here. So the odds of there being interstellar civilisations out there is extremely slim. I think our best bet to find alien civilisations is by detecting the signature of alien megastructures; Dyson Spheres and the like. Tabby's Star sounds to me like the most likely way we might find alien life.

mooreds 8y ago

If you liked this, you might enjoy "Light of the Same", which examines the Drake equation and seti in the light of all the planets that have been discovered. https://www.goodreads.com/book/show/36236156-light-of-the-stars https://www.goodreads.com/book/show/36236156-light-of-the-st...

nickysielicki 8y ago

Highlighting text on a webpage so that you can focus on a particular sentence should never move the text and make you lose your place. I like the idea but don't make it a pop-in sidebar that moves the page.

mooreds 8y ago
Yes, the ux was horrible, especially on mobile.
- michaelmrose 8y ago
  On firefox I couldn't even enable reader mode on this page.
mysterypie 8y ago
For an article that looks like typewritten pages, you'd think it would be perfect for printing. But it gets horribly butchered if you try to print it or save it as a PDF. Modern web development has robbed us of the beauty and simplicity of plain text.

vorg 8y ago

Our own DNA-based life may actually be the von Neumann probes the author mentions -- self-replicating spacecraft, controlled by AI and capable of interstellar travel via "Panspemia".

mooreds 8y ago

I wonder if the availability of fossil fuels is the great filter? My understanding is that all that plant matter didn't decay only because fungi hadn't evolved thr ability to break it down, and thus fossil fuels are a one time burst of energy that isn't going to ever be available again.

c22 8y ago
Do you have a citation for this understanding? I hadn't heard this before so I did a brief search and found [0], but this seems to apply just to coal which goes through a lignite phase during its formation [1]. I'm not familiar the details of how other fossil fuels are formed, but I was under the impression it usually happens under the seafloor, are the same mechanisms at play in an undersea environment? It seems like fungi are more common on land than at sea [2]. [0] https://clarknow.clarku.edu/2012/06/28/findings-point-to-fungi-as-prime-suspects-in-fossil-fuel-mystery/ https://clarknow.clarku.edu/2012/06/28/findings-point-to-fun... [1] https://en.wikipedia.org/wiki/Coal https://en.wikipedia.org/wiki/Coal [2] https://sciencing.com/types-fungi-grow-ocean-8467074.html https://sciencing.com/types-fungi-grow-ocean-8467074.html
- mooreds 8y ago
  Ah, TIL. I am wrong. I was unable to find any source for this, and, like you, found some countervailing posts, like this one: http://www.abc.net.au/science/articles/2013/02/18/3691317.htm http://www.abc.net.au/science/articles/2013/02/18/3691317.ht... So, please consider the above comment retracted.

mannykannot 8y ago

Bostrom dismisses, as a fallacy, the idea that the relatively rapid appearance of life on Earth is evidence for it being somewhat probable, yet it is just about as fallacious to think that the absence of life on Mars would be evidence for humanity having long-term prospects.

phkahler 8y ago

I'm picking up a lot of existential angst in this one. The author hopes we are the only intelligent species in the universe because why? I think spending so much time on the nature of ones own existence is to neglect the here and now. I say this as someone who confronted his own existential angst - it can drive you in any number of directions, none of which really matter for someone with an expected lifespan of 70 years. If life is so precious, why not go experience it while you can?

AgentME 8y ago
>The author hopes we are the only intelligent species in the universe because why? Because if there is other life in the universe, then it's more likely that the Great Filter is ahead of us and that human civilization will end sooner. If we are the only intelligent species, then it's more likely that the Great Filter is behind us and humanity is more likely to spread across planets.

caller9 8y ago

It's because the simulation was built to simulate a culture that wasn't yet aware of aliens and alien interaction isn't part of the experiment. It's also less expensive in compute resources.

state_less 8y ago

The possibilities that come to mind are: 1. We happen to be first. 2. They are on their way. 3. They are within reach and are not malevolent, nor allow the spread of malevolence, given the 'typical' billions years gestation period.

ianai 8y ago
Or they exist but because the universe is huge and sparse we’ll never encounter each other. My hunch is that life is actually prolific. It’s in the oceans of Encledeus (sp), may be in extremes on mars, and possibly more in other places. But it’s not industrial the ways we are.
- state_less 8y ago
  > Or they exist but because the universe is huge and sparse we’ll never encounter each other. That's a good hunch. As we've learned more, the universe has appeared to be larger over the years. This could keep destructive contagions from spreading. If destructive contagions are likely, we probably wouldn't be here. I sort of file it under 1. where they are causally unreachable and we are singular in our sphere of influence. Or maybe 2., but over time even if space is vast, we ought to bump into each other eventually. Folks won't rest until they probe under every rock. So maybe they are out there, maybe even prolific and they (or we) are on the way to meeting each other. Humanity ought to make itself durable to see it through.
- gnulinux 8y ago
  > But it’s not industrial the ways we are. I find this very unlikely. If you do some computer simulations, you can see that if "life" has minimal amount of freedom to get modified, it diverges to really interesting objects and exploits a lot of phenomenon happening in its virtual universe. Something as absurdly unlikely and crazy as symbiogenesis occured multiple times in our planet. It's unlikely if there is life out there, it'd stay simple and invisible. My hunch is that life is extremely rare, if it exists at all. We know from computer science that evolution is a very good method to find ever-improving local optimas, so to me it's very likely if life exists, it'll evolve to galactic empires in a few billion years. And thus thanks to Fermi paradox, this convinces me that life must be extremely rare, or the Great Filter must be very effective or intergalactic communication/travel must be extremely expensive.

c-smile 8y ago

If to expand that line of thought even further we shall conclude that we are alone in observable Universe. Life as we know it tends to preserve itself - the instinct of self-preservation is the main feature of life. Others are just consequences. "Hi-order" life will preserve not only one particular incarnation of it but various others too. So as soon one civilization will pass the filter - it should help others to pass it. And if we do not see that other hi-order one yet then it means this role is ours and no one is out there. For humanity "hi-order" state of life is definitely far ahead - long way to go. If not the filter is ahead of us :)

gremlinsinc 8y ago
>> So as soon one civilization will pass the filter - it should help others to pass it.... unless neither civilization knows 'when' the great filter is...and continues to expect it's in the future... this could cause fear of each other... fear leads to the dark side... Interstellar war probably isn't good for the less advanced civilization. Let's hope when the time comes we're not the less advanced civilization...or the other one will become our great filter.. The great filter also could be a predatory civ that snuffs out any sign of life after they find it. For this reason many civs could be afraid to do anything to draw attention.

gremlinsinc 8y ago

Why does there have to be 'one' great filter... I think it's more a 'tiered' system... I mean on any given planet getting to eukaryotes is difficult..once you do, you've made it past 'a great filter'.... onto the next... Everything in life is a battle to survive - even evolution. I don't think there even being a great filter means that we necessarily wouldn't pass through it... -- I guarantee you there's a great filter...if we never become space faring this world will die -- the sun will supernova. If humans survive to that day, and never leave the solar system then all life here will be snuffed out... If we do survive eons past the end of this solar system at some point the entire universe could contract, entropy could run out and all life would be snuffed out... On a long enough time line -- everything in this universe will be filtered out.

eloff 8y ago
Not to detract from your other points, which I agree with, but our star won't supernova. It doesn't have enough mass. It will go red giant and toast our planet.

caf 8y ago

The idea that we'd most likely encounter a colonising civilisation in the form of von Neumann probes seems reasonable. Imagine there was one (or even a few dozen) such probe currently occupying an asteroid somewhere in our solar system, slowly completing the millenia-long task of replicating itself. Would we have noticed yet?

brazzy 8y ago

Charlie Stross' "Accelerando" floats an interesting idea: Post-Tech-Singularity civilizations might naturally become isolationist because consciousness becomes tied to computing hardware that is dependant on abundant energy and low communication latency that you don't have unless you all cluster closely around a star, i.e. a small Dyson sphere. Leaving those ideal circumstances becomes unthinkable for the individual because it would mean lobotomizing yourself. However, we should be able to see those Dyson spheres, and we don't.

ludos 8y ago
Isnt the purpose of a Dyson sphere to keep all Energy inside? If thats the case, how would you detect such a sphere? Maybe that's where the dark matter is. 80% of the universe, packed into small Dyson Spheres, where live is sprawling and we just cant see it. ;-)
- HappySweeney 8y ago
  They would glow in infrared.
- brazzy 8y ago
  > Isnt the purpose of a Dyson sphere to keep all Energy inside? No, because that would be both impossible (see "black body radiation") and useless. The purpose is to use all energy produced by the star. But "using" energy doesn't mean it's gone (see conservation of energy) or that you have to trap it. What it really means is you want to use the low entropy inherent in a concentrated source of energy to perform work.

ulisesrmzroche 8y ago

My latest favorite tin foil hats are The Watchers & The Cosmic War because otherwise perhaps we're going thru a Great Filter right now with global warming due to energy consumption, etcetera & I dunno if we're gonna make it at all

shireboy 8y ago

I've thought along these lines before, and am writing a hard science fiction novel with this premise. I love thinking about the possibility of other advanced civilizations etc as much as the next guy, but it does seem like the _other_ possibility is less represented in sci-fi and maybe in current thought in general. It's so fun to think about life existing and those implications, less time is given to thinking about life _not_ existing elsewhere and what that would mean. I get that to a degree. I feel like Debbie Downer just saying it, but in order of likelihood based on current observation, I would arrange the scenarios like this: * Intelligent life only exists on Earth. This is what we have observed so far, so in absence of other evidence this is "most likely" with a large margin of error ;) * Intelligent life does exist and is abundant, but we are among the most advanced. Hard limits in physics mean it is impractical to travel out of one's solar system, much less galaxy. * We're among the most advanced because of a "great filter" after our current stage. * We're among the most advanced because of a "great filter" before our current stage. * We are a simulation

dreamcompiler 8y ago

It's very hard to read these not-HTML and not-quite-PDF sites on mobile, especially with all the popups. Author might have something interesting to say but I can't tell.

zygotic12 8y ago

Space is BIG with a capital BIG !!! Small is human.