12 ms·

My dad launched the quest to find alien intelligence

126 points by 8bitsrule 6y ago

jph 6y ago
Dr. Drake is especially famous for the Drake Equation (as the article mentions) which is a fascinating way to think about how many intelligent civilizations might be findable. https://exoplanets.nasa.gov/news/1350/are-we-alone-in-the-universe-revisiting-the-drake-equation/ https://exoplanets.nasa.gov/news/1350/are-we-alone-in-the-un...
- SirLJ 6y ago
  Sorry, but I always thought the equation meaningless...
  - taneq 6y ago
    I agree - it's basically just a way to arrive at a meaningless number by multiplying a whole lot of wild-ass guesses together. Do we have anything better, though?
    - JKCalhoun 6y ago
      Yeah, that's probably the point. You have to start somewhere. Personally I'm blown away that some parameters, like the fraction of those stars that have planets, we are able to capably plug values in for. I really never thought we'd be able to get statistics for things like that in my lifetime. I mean short of faster-than-light travel, I had assumed ignorantly that astronomy would be stuck more or less where it is for centuries to come.
      - cgriswald 6y ago
        I wrote a presentation for undergrad on the equation; and that was the focus. I went through each value and talked about the bounds for each value and arguments for those bounds. We’re still incredibly ignorant, but the bounds on the values have improved a lot. At the time the equation was written, it was assumed other stars had planets, but it wasn’t known and the value could have been anything. Now we know the f_p ≈ 1.
      - ArnoVW 6y ago
        Amazing isn't it? I really appreciated 'archives of the universe', which describes the chronological advancement of astronomy since the ancient Greek. Often by simply annotating the original works or papers. Amazing to see how humanity has gained insight piece by piece, thanks to the hard work of a select group op people. https://cmsw.mit.edu/archives-of-the-universe-marcia-bartusiak/ https://cmsw.mit.edu/archives-of-the-universe-marcia-bartusi...
    - eholk 6y ago
      I see it as a way of focusing the discussion. The numbers we could plug into it are mostly all wild guesses, but the exercise of plugging in different numbers can still be instructive. For example, we now know there are a huge number of planets out there, and even planets in the habitable zone. Yet we haven't found any extraterrestrial life, so that suggests maybe the other factors are smaller than we initially would have guessed.
  - lisper 6y ago
    Because....?
  - s1artibartfast 6y ago
    It is a fabulous equation which describes the factors that would contribute to alien life. It can inform how to think and pursue SETI and gauge our current knowledge. Any result that you see bandied about is meaningless because we don't know the inputs.
  - ekianjo 6y ago
    And deeply flawed...
- enjoyyourlife 6y ago
  https://xkcd.com/384/ https://xkcd.com/384/
  - chairmanwow1 6y ago
    The alt text is so great for this one
- zokula 6y ago
  I would bet a million dollars that there are no other intelligent civilizations in the universe.
  - deleted 6y ago
    [deleted]
  - s1artibartfast 6y ago
    I would take that bet. The observable universe is estimated to have 10^21 stars and the actual universe is infinite.
    - warent 6y ago
      I'm not sure what you mean by the "actual universe" but there's no proof that space is infinite. Unfathomably vast yes, but still finite.
      - internet_user 6y ago
        what's the proof it's finite?
        warent 6y ago
        Our senses are finite; we cannot directly know infinity through them. Because of that, I think the burden of proof is on the claim that it is infinite.
      - mnjn 6y ago
        Isn't space itself continuously expanding?
        mathdev 6y ago
        Expansion of space doesn’t preclude the universe being infinite.
      - s1artibartfast 6y ago
- jes5199 6y ago
  I’ve heard that the Drake equation was originally (?) intended to be a parable that makes you think about whether our civilization is likely to destroy itself before making a noticeable impact on the universe, in order to promote nuclear disarmament
  - EE84M3i 6y ago
    As far as I know, the concept of the 'great filter' was invented by (the now canceled) Robin Hanson.
    - jes5199 6y ago
      Hanson gave it that name in the 90s but it’s implied in Drake’s equations - I think people in the 1960s were aware of the subtext
  - cgriswald 6y ago
    I’ve studied this a lot but it’s been awhile. Drake et al we’re doing this during the Cold War and were definitely aware we could wipe ourselves out either with weapons or through ecological disaster. The L term is specifically about civilizations destroying themselves (although it can also be advances in technology which end radio-as-we-know-it). The great filter is an attempt to explain the Fermi Paradox. Fermi was there, but the paradox necessarily came after the Drake equation.
deleted 6y ago
[deleted]
SeekingMeaning 6y ago
http://archive.vn/fWFeM http://archive.vn/fWFeM
badRNG 6y ago
The silence from SETI is deafening. I'm not even amateurishly familiar with astronomy, but I remember setting up SETI@Home when I got my first computer, and remember slowly realizing that the universe seemingly isn't "teeming" with intelligent life. Maybe something is out there, but out of reach, or deliberately silent? Maybe we are alone in this huge universe? It does feel at least a little depressing that discovery of extraterrestrial intelligence seems unlikely in my lifetime. Maybe even out of the cards for humanity. I have to wonder if building communications devices (or "devices" in general) is a uniquely human thing that simply wouldn't matter to an intelligence that evolved some other way.
- usmannk 6y ago
  > Maybe something is out there, but out of reach, or deliberately silent? Have you read The Three Body Problem series by Cixin Liu? It's a terrific (and recently quite famous + awarded) sci fi trilogy that explores this idea. That all sufficiently advanced civilizations have learned to be extremely radio silent in order to escape detection. Reason being that they all eventually conclude that, from a game theoretic standpoint, the only reasonable thing to do when you detect another civilization is to eliminate them before they do you.
  - badRNG 6y ago
    I have not, I will definitely check that out, thanks for sharing. I feel that SETI is something I'm woefully uneducated on, and can't find good places to jump into research before sources seem to go wildly off the rails.
    - markus_zhang 6y ago
      Yeah I can testify that it's one of the best Sci-Fi novels these years. I read the original Chinese version but I heard that the translation of 1st and 3rd book (by same person) is excellent.
  - m3kw9 6y ago
    But earth debunks that theory, no body came to destroy us yet.
srwg 6y ago
then in my opinion your dad is most likely a victim of insane extrapolation and distraction and/or a brilliant cult leader. this way of thinking most resembles 'brainstorming' not science nor fact-checking and while it can seem super intelligent in spectacular ways, is dangerous when not kept in check. from a psychological and sociological perspective. especially when spoken by an authoritive figure or supposed credible source and taken for more than it is.
est31 6y ago
Thread about a similar topic from 1 day ago, 152 comments: https://news.ycombinator.com/item?id=23588469 https://news.ycombinator.com/item?id=23588469
yters 6y ago
I thought we cannot detect intelligent design?
cletus 6y ago
So I'm going to rehash somewhat some comments I've left on similar threads to this. The thought on this apparent lack of alien technological civilizations has advanced a lot since 1960 (when SETI began; from the article). I still see a lot of people stick to ideas that really don't hold up to scrutiny. The two core issues are: 1. We will find alien civilizations by their radio signals; and 2. The limiting factor on alien civilizations are Earthlike planets. (1) is the flaw in SETI. The general argument against this goes something like this: 1. Planets are efficient ways to store matter (in that gravity binds it together) but are highly inefficient in creating living area or collecting a star's energy; 2. Entering and leaving a gravity well is expensive (in energy terms); 3. Gravity can be trivially replicated with centrifugal force using materials we already have (eg stainless steel). 4. Within 1000 years we will be capable of building space habitats that solve the above 3 problems; 5. As a consequence of the above, the natural tendency for any growing civilization will be to encompass a star with orbiting habitats. 6. Artificial structures orbiting a star, even if they're just energy collectors, would be incredibly obvious to any observer from a huge distance and would be far easier to detect than radio transmissions similar to what we do today. The tl'dr of this is that the only way to get rid of heat in space is to radiate it away. The signature of this is a function of the temperature of the object and for a huge range of temperatures this is in the IR spectrum and this huge IR signature without a corresponding visible light output is what makes it "obvious". The first radio transmission occurred 120 years ago. In 1000 years (and possibly well before them) we'll be beyond them in terms of the signature alien civilizations would detect (in that, they'd see our IR signature first). This is of course the blink of a cosmological eye so what we're really doing is hoping to see civilizations who are at the same point we are, which is incredibly unlikely. This ties into (2). I even saw Neal degrasse Tyson make this mistake in a talk where he posits the answer to the Fermi Paradox is that civilizations run out of planets and die out. Planets are likely important as a cradle of life and the number of suitable planets is likely a filter of some sort but irrelevant in the long term. A star with no planetary system at all can easily be a home to a Kardashev-2 civilization. Matter can be extracted from stars directly (as a side note, extracting Helium to avoid the star going supernova is likely a useful side benefit) and/or constructed with particle accelerators (and all that energy). What I find compelling about this argument is that it's /almost/ just an engineering problem (albeit a huge one) rather than one requiring huge advances in technology and/or "new physics". Steel is sufficient to build O'Neil cylinders and solar power is a sufficient energy source for all this (ie it's not predicated on the viability of commercial fusion power generation, which I for one am not yet convinced of, and if it is viable everything gets a whole lot easier). The other attractive part of this is how it can be done.in a piecemeal fashion, meaning you can build one orbital, the another, and another and another. Certain other megastructures are much more "all or nothing" (eg ringworlds). The above is the classic Dyson Swarm, originally called a Dyson Sphere but Swarm tends to be the common name now as a bunch of people have assumed (incorrectly) that a Dyson Sphere is a rigid sphere. Dyson never suggested that and no known or even theorized material could support a rigid sphere that large. People tend to hone in to one issue or another with the above. A popular one is about waste heat. "What if they recycle it?" So with perfect recycling they've violated thermodynamics so we're just talking about increasing efficiency, at which point you've just reduced your IR signature, not eliminated it. The natural consequence of all this is that we are relatively alone and likely the only technological species at or above our technology level within our cone of effect in the Milky Way.
remir 6y ago
Drake reasoned that if planets like Earth orbited stars like the sun, then those worlds might be populated by civilizations advanced enough to broadcast their presence to the cosmos. His logic made sense: For the last century, Earthlings have been making these sorts of announcements all the time in the form of TV and radio broadcasts, military radar, and other communications that leak into space. His logic made sense in the context of an adolescent civilization. We broadcast stuff, so if there are other civilizations out there, surely they would do the same, right? Doubtful, because that's too risky. Why would anybody want to attract attention to themselves?
- w-ll 6y ago
  the light we get from our closest neighbors is lightyears away.
- danielheath 6y ago
  Not just risky; it's expensive. Our radio waves are much, much quieter as all the networks switch from analog broadcast to digital and from low-density-long-range to high-density-short-range.
  - phreeza 6y ago
    I think the most detectable radio signals would come from stuff like early warning radar, not communications, anyway. Not sure if those can be compressed in a meaningful way.
markus_zhang 6y ago
I actually have a theory about why we don't see (any) alien society at the moment. Step 1: recognize that all life needs to consume energy from somewhere (regardless of Carbon based or AI ones) Step 2: realize that albeit the total energy contained in the universe is probably going to be enough for any civilization out there, regardless of type, the total amount of energy that the CURRENT TECH LEVEL allows to harvester is never going to be really large enough to treat it as infinity. Step 3: assume that some individuals of any civilization wants to grab as much energy for itself as possible. Step 4: Combine 2 and 3, and we reach the conclusion that the said individuals will always try to bar others from gaining enough energy, which means an expansion of the gap between the "rich" and "poor", and most importantly lead to a shrink of education of the "poor"s can benefit from, and ultimately destroy the "tech base" of any civilization. The "tech base" is the least amount of individuals that can generate some tech/science genius like Einstein/Newton who can propel the civilization forward greatly. Step 5: I'd argue that this destruction of "tech base" almost surely occurs before the civilization reaches the point that general AI (or whatever that can substitute the original "tech base") arrives. Step 6: Tech/Science advances slowly afterwards and ultimately the civilization won't reach very far into the depth of the universe.
- teruakohatu 6y ago
  1500 years ago, or less, in Europe we see societies that were drastically poor (by modern standards), poorly educated/no formal education (the average person) and insanely unequal society (Kings and warlords vs. Serfs and slaves) where borders (resources) were being fought over and tech was very low relative to today and even relative to a few hundred years earlier (not to get into a dark ages dispute, but the Panethon would not have been able to be build in 500AD in Western Europe). Yet this society managed to advance just fine. We are as far away from them as a Sun harvesting civilization is away from us. Civilization finds a way. At some point great minds become less important. Cutting edge research today is not coming from Patent Office clerks, it comes from large research teams that are constrained by budgets not human resources.
  - jbay808 6y ago
    > Civilization finds a way. There's neither any strong guarantee of this, nor any shortage of historical counterexamples.
peteoria 6y ago
He should focus on the postal servers. Half of them are aliens, and the other half are retired man in black agents.
shahbaby 6y ago
I suspect that the answer to the fermi paradox is closely linked to AI.
- CRUDite 6y ago
  Consider when skynet goes live..the others will start talking to it!
TheOtherHobbes 6y ago
Ants can live in the middle of a city and have no idea what a city is, what humans are, or what human culture is - including the Internet. They're physically surrounded by a far more advanced civilisation and it's literally invisible to them because it's incomprehensible to the ant mind, and it doesn't communicate by leaving scent trails. We could be living inside the alien equivalent and we'd have no idea either, because we wouldn't be able to see it - never mind understand it. Maybe once every few million years something random and inexplicable would happen, but that would be all the evidence we'd get.
- kubanczyk 6y ago
  The ants have built pretty impressive detectors. Nevermind the humans. Where the heck are all the other anthills? It's quite scary there is only one in a very large detection radius.
  - rytis 6y ago
    The detectors still trying to find the distinctive scent. Which gets lost in all the fumes, dust, whatnot produced by humans...
- ajuc 6y ago
  Single ants don't have any idea, but anthills as a system probably have some kind of a working model of human activity. For example ants often feed off garbage cans so they know how the amount of garbage changes daily and weekly. I don't know how good ant systems are at generalizing and noticing patterns but if they are any good they probably know at least that about human civilization. Do they "think" of humans as another kind of anthill - probably not. But they certainly notice and react to changes in environment caused by human activity.
- rasz 6y ago
  "Eksperiment" by Janusz A. Zajdel. Polish sci-fi titan equal to Lem of 'Solaris' fame : https://translate.google.com/translate?hl=en&sl=pl&tl=en&u=https%3A%2F%2Fdocer.pl%2Fdoc%2Fe51v1s https://translate.google.com/translate?hl=en&sl=pl&tl=en&u=h... google translated ebook rip and similarly themed "He Who Shrank" by Henry Hasse https://en.wikipedia.org/wiki/He_Who_Shrank https://en.wikipedia.org/wiki/He_Who_Shrank
yyyk 6y ago
SETI never made much sense as a means to find aliens. As a means to get funding and interest in radioastronomy, by spinning more than a bit on the chances of it ever working, it made a lot of sense. A radio signal could be either intentional or unintentional. An unintentional signal being found is extremely unlikely. Radio isn't very useful for interplanetary communication, so the purpose must be local. But every civilization would have the desire to conserve energy, and it takes a very little time (compared to galaxy-scale distances) to improve it to the point it's very weak. Humanity switched very quickly from weak radio signals (because the power sources were weak) to very weak radio signals (because we knew better what we were doing) to digital. That's a very short time frame and a weak signal. Not likely to be detected. As for an intentional signal, well, if a powerful enough alien wants to be noticed, it will be. One could always come up with weird scenarios ("they want to test us so they're intentionally sending weak signals") but that's a very double edged sword ("they want to test us to see if they need to exterminate us") which doesn't justify SETI.
- lowmemcpu 6y ago
  > As a means to get funding and interest in radioastronomy, by spinning more than a bit on the chances of it ever working, it made a lot of sense. This sent me looking for the total half-century $ cost of SETI, but couldn't find it. Have any idea if that's been calculated?
  - deleted 6y ago
    [deleted]
  - yyyk 6y ago
    I didn't find much, but I have an idea for calculation: * Most of their projects have a relatively static cost[0] year-by-year. * The big variable is SETI@home. From the SETI PoV it's zero-cost, but that's not the case for society (compute, electricity, pollution). It's not difficult to find TFLOPS estimates via BOINC or wiki. Translating that back to cost is rather difficult, for me at least. Most people did not buy computers for this. Network bandwidth cost is also difficult to estimate. I suspect main component is power for processing. But electricity estimates vary widely depending on hardware used, I dunno how to estimate the average consumption per TLOPS. [0] https://www.quora.com/What-is-the-annual-cost-of-operating-SETI-Is-it-worth-the-money https://www.quora.com/What-is-the-annual-cost-of-operating-S...
coldtea 6y ago
So, will he return the taxpayer money?
CRUDite 6y ago
I have a pet idea that if star lifting or some stellar engineering is used and it were to alter emission spectra in some detectable way that we could look for clusters of stars with the same altered emission, or just clusters of stars with some non normal emissions. At least it would be possible to scan alot of the sky quickly with a method like this. I suppose i dont know enough about stellar spectra to know if fingerprints like this could be out there
- bena 6y ago
  You need to back that one up. You're basically saying: "Assume we can eventually manipulate stars, then this follows". And while that may be true, I'm not willing to grant you your first assumption. Why do you think anyone will be able to engineer a star? What do we have today that makes you think we can manipulate something that we can't even get within a million miles of.
RTV7 6y ago
s
gattr 6y ago
As regards frequency of civilizations occurring, I've read recently an interesting take: when we look at the Earth, each of the following milestones seems exponentially more difficult (i.e., probability density is far smaller for each): - simple unicellular organisms to eukaryotes (~2 billion years) - eukaryotes to multicellular lifeforms (~a few hundred million years) - humans + consciousness + language + prehensile limbs (only a couple of million / a few hundred thousand years ago?) In addition, if panspermia (exchange of biological material via meteorites/comets etc.) is in fact effective, the conclusion was: Earth-like planets may very well be (almost) universally covered (infested?) with one or another kind of unicellular goo; but only some tiny fraction has anything more interesting, and we could be one of the handful - or even the first technical civilization in the Milky Way.

126 points by 8bitsrule 6y ago

jph 6y ago

Dr. Drake is especially famous for the Drake Equation (as the article mentions) which is a fascinating way to think about how many intelligent civilizations might be findable. https://exoplanets.nasa.gov/news/1350/are-we-alone-in-the-universe-revisiting-the-drake-equation/ https://exoplanets.nasa.gov/news/1350/are-we-alone-in-the-un...

SirLJ 6y ago
Sorry, but I always thought the equation meaningless...
- taneq 6y ago
  I agree - it's basically just a way to arrive at a meaningless number by multiplying a whole lot of wild-ass guesses together. Do we have anything better, though?
  - JKCalhoun 6y ago
    Yeah, that's probably the point. You have to start somewhere. Personally I'm blown away that some parameters, like the fraction of those stars that have planets, we are able to capably plug values in for. I really never thought we'd be able to get statistics for things like that in my lifetime. I mean short of faster-than-light travel, I had assumed ignorantly that astronomy would be stuck more or less where it is for centuries to come.
    - cgriswald 6y ago
      I wrote a presentation for undergrad on the equation; and that was the focus. I went through each value and talked about the bounds for each value and arguments for those bounds. We’re still incredibly ignorant, but the bounds on the values have improved a lot. At the time the equation was written, it was assumed other stars had planets, but it wasn’t known and the value could have been anything. Now we know the f_p ≈ 1.
    - ArnoVW 6y ago
      Amazing isn't it? I really appreciated 'archives of the universe', which describes the chronological advancement of astronomy since the ancient Greek. Often by simply annotating the original works or papers. Amazing to see how humanity has gained insight piece by piece, thanks to the hard work of a select group op people. https://cmsw.mit.edu/archives-of-the-universe-marcia-bartusiak/ https://cmsw.mit.edu/archives-of-the-universe-marcia-bartusi...
  - eholk 6y ago
    I see it as a way of focusing the discussion. The numbers we could plug into it are mostly all wild guesses, but the exercise of plugging in different numbers can still be instructive. For example, we now know there are a huge number of planets out there, and even planets in the habitable zone. Yet we haven't found any extraterrestrial life, so that suggests maybe the other factors are smaller than we initially would have guessed.
- lisper 6y ago
  Because....?
- s1artibartfast 6y ago
  It is a fabulous equation which describes the factors that would contribute to alien life. It can inform how to think and pursue SETI and gauge our current knowledge. Any result that you see bandied about is meaningless because we don't know the inputs.
- ekianjo 6y ago
  And deeply flawed...
enjoyyourlife 6y ago
https://xkcd.com/384/ https://xkcd.com/384/
- chairmanwow1 6y ago
  The alt text is so great for this one
zokula 6y ago
I would bet a million dollars that there are no other intelligent civilizations in the universe.
- deleted 6y ago
  [deleted]
- s1artibartfast 6y ago
  I would take that bet. The observable universe is estimated to have 10^21 stars and the actual universe is infinite.
  - warent 6y ago
    I'm not sure what you mean by the "actual universe" but there's no proof that space is infinite. Unfathomably vast yes, but still finite.
    - internet_user 6y ago
      what's the proof it's finite?
      - warent 6y ago
        Our senses are finite; we cannot directly know infinity through them. Because of that, I think the burden of proof is on the claim that it is infinite.
    - mnjn 6y ago
      Isn't space itself continuously expanding?
      - mathdev 6y ago
        Expansion of space doesn’t preclude the universe being infinite.
    - s1artibartfast 6y ago
jes5199 6y ago
I’ve heard that the Drake equation was originally (?) intended to be a parable that makes you think about whether our civilization is likely to destroy itself before making a noticeable impact on the universe, in order to promote nuclear disarmament
- EE84M3i 6y ago
  As far as I know, the concept of the 'great filter' was invented by (the now canceled) Robin Hanson.
  - jes5199 6y ago
    Hanson gave it that name in the 90s but it’s implied in Drake’s equations - I think people in the 1960s were aware of the subtext
- cgriswald 6y ago
  I’ve studied this a lot but it’s been awhile. Drake et al we’re doing this during the Cold War and were definitely aware we could wipe ourselves out either with weapons or through ecological disaster. The L term is specifically about civilizations destroying themselves (although it can also be advances in technology which end radio-as-we-know-it). The great filter is an attempt to explain the Fermi Paradox. Fermi was there, but the paradox necessarily came after the Drake equation.

deleted 6y ago

[deleted]

SeekingMeaning 6y ago

http://archive.vn/fWFeM http://archive.vn/fWFeM

badRNG 6y ago

The silence from SETI is deafening. I'm not even amateurishly familiar with astronomy, but I remember setting up SETI@Home when I got my first computer, and remember slowly realizing that the universe seemingly isn't "teeming" with intelligent life. Maybe something is out there, but out of reach, or deliberately silent? Maybe we are alone in this huge universe? It does feel at least a little depressing that discovery of extraterrestrial intelligence seems unlikely in my lifetime. Maybe even out of the cards for humanity. I have to wonder if building communications devices (or "devices" in general) is a uniquely human thing that simply wouldn't matter to an intelligence that evolved some other way.

usmannk 6y ago
> Maybe something is out there, but out of reach, or deliberately silent? Have you read The Three Body Problem series by Cixin Liu? It's a terrific (and recently quite famous + awarded) sci fi trilogy that explores this idea. That all sufficiently advanced civilizations have learned to be extremely radio silent in order to escape detection. Reason being that they all eventually conclude that, from a game theoretic standpoint, the only reasonable thing to do when you detect another civilization is to eliminate them before they do you.
- badRNG 6y ago
  I have not, I will definitely check that out, thanks for sharing. I feel that SETI is something I'm woefully uneducated on, and can't find good places to jump into research before sources seem to go wildly off the rails.
  - markus_zhang 6y ago
    Yeah I can testify that it's one of the best Sci-Fi novels these years. I read the original Chinese version but I heard that the translation of 1st and 3rd book (by same person) is excellent.
- m3kw9 6y ago
  But earth debunks that theory, no body came to destroy us yet.

srwg 6y ago

then in my opinion your dad is most likely a victim of insane extrapolation and distraction and/or a brilliant cult leader. this way of thinking most resembles 'brainstorming' not science nor fact-checking and while it can seem super intelligent in spectacular ways, is dangerous when not kept in check. from a psychological and sociological perspective. especially when spoken by an authoritive figure or supposed credible source and taken for more than it is.

est31 6y ago

Thread about a similar topic from 1 day ago, 152 comments: https://news.ycombinator.com/item?id=23588469 https://news.ycombinator.com/item?id=23588469

yters 6y ago

I thought we cannot detect intelligent design?

cletus 6y ago

So I'm going to rehash somewhat some comments I've left on similar threads to this. The thought on this apparent lack of alien technological civilizations has advanced a lot since 1960 (when SETI began; from the article). I still see a lot of people stick to ideas that really don't hold up to scrutiny. The two core issues are: 1. We will find alien civilizations by their radio signals; and 2. The limiting factor on alien civilizations are Earthlike planets. (1) is the flaw in SETI. The general argument against this goes something like this: 1. Planets are efficient ways to store matter (in that gravity binds it together) but are highly inefficient in creating living area or collecting a star's energy; 2. Entering and leaving a gravity well is expensive (in energy terms); 3. Gravity can be trivially replicated with centrifugal force using materials we already have (eg stainless steel). 4. Within 1000 years we will be capable of building space habitats that solve the above 3 problems; 5. As a consequence of the above, the natural tendency for any growing civilization will be to encompass a star with orbiting habitats. 6. Artificial structures orbiting a star, even if they're just energy collectors, would be incredibly obvious to any observer from a huge distance and would be far easier to detect than radio transmissions similar to what we do today. The tl'dr of this is that the only way to get rid of heat in space is to radiate it away. The signature of this is a function of the temperature of the object and for a huge range of temperatures this is in the IR spectrum and this huge IR signature without a corresponding visible light output is what makes it "obvious". The first radio transmission occurred 120 years ago. In 1000 years (and possibly well before them) we'll be beyond them in terms of the signature alien civilizations would detect (in that, they'd see our IR signature first). This is of course the blink of a cosmological eye so what we're really doing is hoping to see civilizations who are at the same point we are, which is incredibly unlikely. This ties into (2). I even saw Neal degrasse Tyson make this mistake in a talk where he posits the answer to the Fermi Paradox is that civilizations run out of planets and die out. Planets are likely important as a cradle of life and the number of suitable planets is likely a filter of some sort but irrelevant in the long term. A star with no planetary system at all can easily be a home to a Kardashev-2 civilization. Matter can be extracted from stars directly (as a side note, extracting Helium to avoid the star going supernova is likely a useful side benefit) and/or constructed with particle accelerators (and all that energy). What I find compelling about this argument is that it's /almost/ just an engineering problem (albeit a huge one) rather than one requiring huge advances in technology and/or "new physics". Steel is sufficient to build O'Neil cylinders and solar power is a sufficient energy source for all this (ie it's not predicated on the viability of commercial fusion power generation, which I for one am not yet convinced of, and if it is viable everything gets a whole lot easier). The other attractive part of this is how it can be done.in a piecemeal fashion, meaning you can build one orbital, the another, and another and another. Certain other megastructures are much more "all or nothing" (eg ringworlds). The above is the classic Dyson Swarm, originally called a Dyson Sphere but Swarm tends to be the common name now as a bunch of people have assumed (incorrectly) that a Dyson Sphere is a rigid sphere. Dyson never suggested that and no known or even theorized material could support a rigid sphere that large. People tend to hone in to one issue or another with the above. A popular one is about waste heat. "What if they recycle it?" So with perfect recycling they've violated thermodynamics so we're just talking about increasing efficiency, at which point you've just reduced your IR signature, not eliminated it. The natural consequence of all this is that we are relatively alone and likely the only technological species at or above our technology level within our cone of effect in the Milky Way.

remir 6y ago

Drake reasoned that if planets like Earth orbited stars like the sun, then those worlds might be populated by civilizations advanced enough to broadcast their presence to the cosmos. His logic made sense: For the last century, Earthlings have been making these sorts of announcements all the time in the form of TV and radio broadcasts, military radar, and other communications that leak into space. His logic made sense in the context of an adolescent civilization. We broadcast stuff, so if there are other civilizations out there, surely they would do the same, right? Doubtful, because that's too risky. Why would anybody want to attract attention to themselves?

w-ll 6y ago
the light we get from our closest neighbors is lightyears away.
danielheath 6y ago
Not just risky; it's expensive. Our radio waves are much, much quieter as all the networks switch from analog broadcast to digital and from low-density-long-range to high-density-short-range.
- phreeza 6y ago
  I think the most detectable radio signals would come from stuff like early warning radar, not communications, anyway. Not sure if those can be compressed in a meaningful way.

markus_zhang 6y ago

I actually have a theory about why we don't see (any) alien society at the moment. Step 1: recognize that all life needs to consume energy from somewhere (regardless of Carbon based or AI ones) Step 2: realize that albeit the total energy contained in the universe is probably going to be enough for any civilization out there, regardless of type, the total amount of energy that the CURRENT TECH LEVEL allows to harvester is never going to be really large enough to treat it as infinity. Step 3: assume that some individuals of any civilization wants to grab as much energy for itself as possible. Step 4: Combine 2 and 3, and we reach the conclusion that the said individuals will always try to bar others from gaining enough energy, which means an expansion of the gap between the "rich" and "poor", and most importantly lead to a shrink of education of the "poor"s can benefit from, and ultimately destroy the "tech base" of any civilization. The "tech base" is the least amount of individuals that can generate some tech/science genius like Einstein/Newton who can propel the civilization forward greatly. Step 5: I'd argue that this destruction of "tech base" almost surely occurs before the civilization reaches the point that general AI (or whatever that can substitute the original "tech base") arrives. Step 6: Tech/Science advances slowly afterwards and ultimately the civilization won't reach very far into the depth of the universe.

teruakohatu 6y ago
1500 years ago, or less, in Europe we see societies that were drastically poor (by modern standards), poorly educated/no formal education (the average person) and insanely unequal society (Kings and warlords vs. Serfs and slaves) where borders (resources) were being fought over and tech was very low relative to today and even relative to a few hundred years earlier (not to get into a dark ages dispute, but the Panethon would not have been able to be build in 500AD in Western Europe). Yet this society managed to advance just fine. We are as far away from them as a Sun harvesting civilization is away from us. Civilization finds a way. At some point great minds become less important. Cutting edge research today is not coming from Patent Office clerks, it comes from large research teams that are constrained by budgets not human resources.
- jbay808 6y ago
  > Civilization finds a way. There's neither any strong guarantee of this, nor any shortage of historical counterexamples.

peteoria 6y ago

He should focus on the postal servers. Half of them are aliens, and the other half are retired man in black agents.

shahbaby 6y ago

I suspect that the answer to the fermi paradox is closely linked to AI.

CRUDite 6y ago
Consider when skynet goes live..the others will start talking to it!

TheOtherHobbes 6y ago

Ants can live in the middle of a city and have no idea what a city is, what humans are, or what human culture is - including the Internet. They're physically surrounded by a far more advanced civilisation and it's literally invisible to them because it's incomprehensible to the ant mind, and it doesn't communicate by leaving scent trails. We could be living inside the alien equivalent and we'd have no idea either, because we wouldn't be able to see it - never mind understand it. Maybe once every few million years something random and inexplicable would happen, but that would be all the evidence we'd get.

kubanczyk 6y ago
The ants have built pretty impressive detectors. Nevermind the humans. Where the heck are all the other anthills? It's quite scary there is only one in a very large detection radius.
- rytis 6y ago
  The detectors still trying to find the distinctive scent. Which gets lost in all the fumes, dust, whatnot produced by humans...
ajuc 6y ago
Single ants don't have any idea, but anthills as a system probably have some kind of a working model of human activity. For example ants often feed off garbage cans so they know how the amount of garbage changes daily and weekly. I don't know how good ant systems are at generalizing and noticing patterns but if they are any good they probably know at least that about human civilization. Do they "think" of humans as another kind of anthill - probably not. But they certainly notice and react to changes in environment caused by human activity.
rasz 6y ago
"Eksperiment" by Janusz A. Zajdel. Polish sci-fi titan equal to Lem of 'Solaris' fame : https://translate.google.com/translate?hl=en&sl=pl&tl=en&u=https%3A%2F%2Fdocer.pl%2Fdoc%2Fe51v1s https://translate.google.com/translate?hl=en&sl=pl&tl=en&u=h... google translated ebook rip and similarly themed "He Who Shrank" by Henry Hasse https://en.wikipedia.org/wiki/He_Who_Shrank https://en.wikipedia.org/wiki/He_Who_Shrank

yyyk 6y ago

SETI never made much sense as a means to find aliens. As a means to get funding and interest in radioastronomy, by spinning more than a bit on the chances of it ever working, it made a lot of sense. A radio signal could be either intentional or unintentional. An unintentional signal being found is extremely unlikely. Radio isn't very useful for interplanetary communication, so the purpose must be local. But every civilization would have the desire to conserve energy, and it takes a very little time (compared to galaxy-scale distances) to improve it to the point it's very weak. Humanity switched very quickly from weak radio signals (because the power sources were weak) to very weak radio signals (because we knew better what we were doing) to digital. That's a very short time frame and a weak signal. Not likely to be detected. As for an intentional signal, well, if a powerful enough alien wants to be noticed, it will be. One could always come up with weird scenarios ("they want to test us so they're intentionally sending weak signals") but that's a very double edged sword ("they want to test us to see if they need to exterminate us") which doesn't justify SETI.

lowmemcpu 6y ago
> As a means to get funding and interest in radioastronomy, by spinning more than a bit on the chances of it ever working, it made a lot of sense. This sent me looking for the total half-century $ cost of SETI, but couldn't find it. Have any idea if that's been calculated?
- deleted 6y ago
  [deleted]
- yyyk 6y ago
  I didn't find much, but I have an idea for calculation: * Most of their projects have a relatively static cost[0] year-by-year. * The big variable is SETI@home. From the SETI PoV it's zero-cost, but that's not the case for society (compute, electricity, pollution). It's not difficult to find TFLOPS estimates via BOINC or wiki. Translating that back to cost is rather difficult, for me at least. Most people did not buy computers for this. Network bandwidth cost is also difficult to estimate. I suspect main component is power for processing. But electricity estimates vary widely depending on hardware used, I dunno how to estimate the average consumption per TLOPS. [0] https://www.quora.com/What-is-the-annual-cost-of-operating-SETI-Is-it-worth-the-money https://www.quora.com/What-is-the-annual-cost-of-operating-S...

coldtea 6y ago

So, will he return the taxpayer money?

CRUDite 6y ago

I have a pet idea that if star lifting or some stellar engineering is used and it were to alter emission spectra in some detectable way that we could look for clusters of stars with the same altered emission, or just clusters of stars with some non normal emissions. At least it would be possible to scan alot of the sky quickly with a method like this. I suppose i dont know enough about stellar spectra to know if fingerprints like this could be out there

bena 6y ago
You need to back that one up. You're basically saying: "Assume we can eventually manipulate stars, then this follows". And while that may be true, I'm not willing to grant you your first assumption. Why do you think anyone will be able to engineer a star? What do we have today that makes you think we can manipulate something that we can't even get within a million miles of.

RTV7 6y ago

gattr 6y ago

As regards frequency of civilizations occurring, I've read recently an interesting take: when we look at the Earth, each of the following milestones seems exponentially more difficult (i.e., probability density is far smaller for each): - simple unicellular organisms to eukaryotes (~2 billion years) - eukaryotes to multicellular lifeforms (~a few hundred million years) - humans + consciousness + language + prehensile limbs (only a couple of million / a few hundred thousand years ago?) In addition, if panspermia (exchange of biological material via meteorites/comets etc.) is in fact effective, the conclusion was: Earth-like planets may very well be (almost) universally covered (infested?) with one or another kind of unicellular goo; but only some tiny fraction has anything more interesting, and we could be one of the handful - or even the first technical civilization in the Milky Way.