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July 21, 2015 10:49 PM   Subscribe

 
I'm beginning to think that the reason we haven't found them yet is that they are smart enough to hide from us.
posted by markkraft at 11:03 PM on July 21, 2015 [4 favorites]


Can Fermat's paradox be resolved with the discovery that we aren't actually intelligent?
posted by BrotherCaine at 11:18 PM on July 21, 2015 [11 favorites]


Read this recently: If the sun were the size of a white blood cell, the Milky Way galaxy would be the size of North America - and we're out at the edge of it. There's life out there, that's certain. It's likely that there's a whole interstellar community close in to the Milky Way core.

What's really depressing is that any civilization advanced enough to know that we're here would not give a shit - it would be the equivalent of positing that someone in New York should head out to the Yukon to see a new bacterium under a rock that had once made it to the next rock over. No thanks.
posted by jimmythefish at 11:38 PM on July 21, 2015 [8 favorites]


What's really depressing is that any civilization advanced enough to know that we're here would not give a shit

That's not true, or more accurately it's very probably not true. We're advanced enough to detect if some alien life exists (which is the whole point of SETI) and we'd certainly care. So every galactic civilization of which we are aware contradicts your statement (n=1).
posted by Justinian at 11:48 PM on July 21, 2015 [5 favorites]


We're advanced enough to detect if some alien life exists (which is the whole point of SETI) and we'd certainly care.

And why would "we" care? What would humanity actually do with this information at the present time? I mean say there is a press conference where they announce that the project has identified the signals from several light years away which could possibly be the ancient transmissions from a civilisation which may or may not still exist. What then? Build spaceships to visit the new neighbors or warships to defend against them?
posted by three blind mice at 12:28 AM on July 22, 2015 [2 favorites]


It's likely that there's a whole interstellar community close in to the Milky Way core.

I dunno, the core is full of activity - young stars going supernova, lots of heat and radiation etc etc. I would think life would be more prevalent on the edges where it's a bit "quieter".
posted by PenDevil at 12:36 AM on July 22, 2015 [11 favorites]


We'd KNOW there are or were other lifeforms, which would profoundly change us.

Plus we'd seriously start figuring out how to visit.
posted by Brandon Blatcher at 12:37 AM on July 22, 2015 [2 favorites]


Given the age of the galaxy, and the distances involved, a hypothetical interstellar community could have detected life on earth and send a probe by now.

Life oxygenated our atmosphere 2.3 billion years ago, which is enough time for even our own Voyager 1 to cross the galaxy.
posted by ryanrs at 12:49 AM on July 22, 2015 [1 favorite]


What then? Build spaceships to visit the new neighbors or warships to defend against them?

Optimistically, the biggest national defence boondoggle of all time might actually have some beneficial side-effects in this case.
posted by justsomebodythatyouusedtoknow at 12:52 AM on July 22, 2015


And why would "we" care? What would humanity actually do with this information at the present time?

Well shit, just think about the content of that message. We'd decode the hell out of that. Can you imagine the boon just to linguistics? How about just signal encoding technology itself? I assume we'd spend time to lock on to the source and start getting a stream of data. If we ever managed to decode it, we would have an unprecedented view into a far remote world. We might learn a thing or two...
posted by smidgen at 12:55 AM on July 22, 2015 [1 favorite]


I think it's far more likely that we'll become a thriving interstellar community, rather than be discovered by one.

If you look at the evolution required to grow a cyanobacterial mat into a galaxy-spanning civilization, we're like 95% there. Really.
posted by ryanrs at 12:56 AM on July 22, 2015 [10 favorites]


And why would "we" care? What would humanity actually do with this information at the present time?

Does it matter? I would just like to know.
posted by Pre-Taped Call In Show at 1:00 AM on July 22, 2015 [5 favorites]


Yeah it would only be the single most world-shaking piece of information in the history of mankind but why would we care...?

Intelligent life would be, anyway.
posted by Justinian at 1:09 AM on July 22, 2015 [3 favorites]


If you look at the evolution required to grow a cyanobacterial mat into a galaxy-spanning civilization, we're like 95% there.

This presumes that evolution has a preferred direction, a dubious proposition at best. It also presumes that civilization is an evolutionarily stable form, which is an idea sadly wanting for evidence.
posted by flabdablet at 1:20 AM on July 22, 2015 [11 favorites]


At this point our technological evolution is a lot more relevant than biological evolution. So yes, there is a preferred direction. We advance in areas we chose to research. One of those is space travel.
posted by ryanrs at 1:32 AM on July 22, 2015 [1 favorite]


Just wait, all we'll pick up is their daytime television.

As Kepler-186f Turns.
O͝p͢r̴ah̢t͞h̛l͡u̧ W̢infre̶y͘b͡zxg͘h̨.
And Dr. Phil, only he's got a spiny carapace and breathes ammonia.
posted by Wemmick at 2:49 AM on July 22, 2015 [4 favorites]


The hypothesis I've always liked is that some regular cosmological event kills off civilizations before they become significantly spacefaring; but the event frequency may change as the universe expands, and assuming we are typical it's getting less frequent.

So as soon as one civilization becomes spacefaring on an interstellar scale, millions will crop up. The time will be right.
posted by solarion at 3:14 AM on July 22, 2015 [4 favorites]


Far out in the uncharted backwaters of the unfashionable end of the western spiral arm of the Galaxy lies a small unregarded yellow sun. Orbiting this at a distance of roughly ninety-two million miles is an utterly insignificant little blue green planet whose ape-descended life forms are so amazingly primitive that they still think digital watches are a pretty neat idea.
posted by iotic at 3:47 AM on July 22, 2015 [9 favorites]


I could have sworn that Hawking was telling us that, if aliens exist, they would be the bad guys.

Oh yeah, that's right.
posted by Splunge at 4:06 AM on July 22, 2015 [1 favorite]


And what do we do if, after all these years of trying to make contact, they just finally send us back a restraining order?
posted by rongorongo at 4:11 AM on July 22, 2015 [2 favorites]


They've been here for some time.
posted by robocop is bleeding at 4:11 AM on July 22, 2015


Given the age of the galaxy, and the distances involved, a hypothetical interstellar community could have detected life on earth and send a probe by now.

The single biggest flaw in this and the Fermi paradox is that it's pure conjecture based on a sample size of 1. The only thing we know for sure about intelligent life in the universe is that it's taken 13 billion years for one to reach a point where it can start looking for other beings. And that particular life form still hasn't investigated much of its own solar system and shows little desire, overall, to do so.
posted by Brandon Blatcher at 4:38 AM on July 22, 2015 [2 favorites]


And Dr. Phil, only he's got a spiny carapace and breathes ammonia.

Ours doesn't?

The single biggest flaw in this and the Fermi paradox is that it's pure conjecture based on a sample size of 1.

Except that the evidence emerging from recent discoveries of exoplanets suggests that there are a fair few visible even with our incredibly crude and primitive methods of searching. The more we learn about our local stellar neighborhood, the more evidence emerges that the broad requirements for life, at least, are fairly well distributed.
posted by AdamCSnider at 5:08 AM on July 22, 2015


Except that the evidence emerging from recent discoveries of exoplanets suggests that there are a fair few visible even with our incredibly crude and primitive methods of searching.

It's still a sample size of one, with little interest in space travel. Which I'm not thrilled about either, but there it is. We just visited Pluto and that was a flyby that only managed to happen after being canceled twice due to funding and probably wouldn't have happened at all if its planetary status had been downgraded sooner. Then it took us 10 years to get there.

I'm not sure any advanced beings would have much need or will to travel beyond their own solar system.
posted by Brandon Blatcher at 5:43 AM on July 22, 2015


And Dr. Phil, only he's got a spiny carapace and breathes ammonia.

Ours doesn't?

The single biggest flaw in this and the Fermi paradox is that it's pure conjecture based on a sample size of 1.

Except that the evidence emerging from recent discoveries of exoplanets suggests that there are a fair few visible even with our incredibly crude and primitive methods of searching. The more we learn about our local stellar neighborhood, the more evidence emerges that the broad requirements for life, at least, are fairly well distributed.

Given the age of the galaxy, and the distances involved, a hypothetical interstellar community could have detected life on earth and send a probe by now.

Any number of probes could have passed through our system, photographed the locality, and moved on in the millions of years of human evolution (and billions of years of the biosphere generally). There would have been no reason to even attempt to do anything more than photograph and move on (maybe take biological samples?) until, what, the rise of civilizations with a footprint easily visible from space? So within the past twelve thousand years.

So presuming a probe was present and noticed the first moves of the Neolithic Revolution and immediately phoned home, it would have to be making contact with a civilization within six thousand light years. So the "hypothetical interstellar community" would, in that very best case scenario, have to be quite close indeed, considering the size of the galaxy (within the local 1/16th, basically, since our galaxy's diameter is 100k light years or so).

Worse case scenario, probe only notices us when we hit the electromagnetic spectrum. So, 1906 was the first radio broadcast, so let's say they notice that and spit off a message homeward. Then for word to get back and a reply to be sent that would have reached the local probe by now, They would need to be within 55 light years. The local 1/1,818 of the galaxy.

Worst case scenario, probes fly through every few thousand years, the next one won't be through until the mid-3030s. By which time we'll have been through the jackpot and they'll be able to record the horror for future generations of alien xenohistorians and relay condolences to the survivors.
posted by AdamCSnider at 5:49 AM on July 22, 2015 [2 favorites]


Remember that there is absolutely no practical reason to visit Earth, much less settle here, for an alien species. It's bloody far away, anyone who's sufficiently advanced to get here will be able to find and harness sources of energy and material (asteroid belts, gas giants, stars for Chrissakes) that dwarf anything found on Earth. Likewise, there is no rational reason to fear our going to where they are to settle or conquer. No one is stopping by to steal our precious metals or our precious bodily fluids. No one with the ability to survive in space for decades or centuries of travel to get here is going to feel the need to settle at the bottom of a gravity well, much less one full of unfamiliar and potentially lethal microbes.

So, presuming that "humanitarian" feelings can't be generalized to non-human species, curiosity is about the only reason to wander by. Given the degree to which our own initiatives are driven by economic or military concerns, the absence of either threat or opportunity for exploitation suggests that whatever resources are devoted to checking out the back alleys of the galaxy for weird new life forms, intelligent or no, are probably a very small percentage of the collective resources of Whoever is out there. Which suggests whatever probes are flying around are probably fly-by or disposable. Not likely to hook into local orbit and stick around, although to be fair even if they did - considering the leaps and bounds we primitive monkeys have been making, what are the chances we would see anything that was stuck out in, say, Jupiter's shadow?

So yeah, I've never found the "they'd have gotten here already!" argument particularly salient. They've probably been and gone any number of times. Because they had no reason to stay. The key to the problem, in my view, is not weird and statistically unlikely absence of intelligent life throughout the rest of the universe, but the frank fact that we are of no particular importance, and no self-respecting alien civilization is going to spend stupid amount of resources just to contact the new kid on the block. If we're worth a candle, we'll find them eventually. Until then, they without a doubt have more significant things to think about.
posted by AdamCSnider at 6:01 AM on July 22, 2015 [8 favorites]


So yes, there is a preferred direction. We advance in areas we chose to research. One of those is space travel.

Though of course, that's utterly dwarfed by our millenia-spanning research into how kill each other more effectively.
posted by Greg Nog at 6:21 AM on July 22, 2015 [5 favorites]


The key to the problem, in my view, is not weird and statistically unlikely absence of intelligent life throughout the rest of the universe, but the frank fact that we are of no particular importance, and no self-respecting alien civilization is going to spend stupid amount of resources just to contact the new kid on the block. If we're worth a candle, we'll find them eventually. Until then, they without a doubt have more significant things to think about.

FWIW, I pretty much agree with you. We are a species driven to great heights because of hubris, so it's very hard for us to imagine not being interesting to an interplanetary species. We think we totally would be and they would want to let us know they think we're interesting. But if they have done drive-bys in the past, they would see a horrible little species intent on destroying their only habitat for very little worth in the long term. I'd understand how they would nope out of that contact for the time being.
posted by Kitteh at 6:26 AM on July 22, 2015 [1 favorite]


SETI is great. You can argue however you like, as there's no unambiguous evidence.

We don't even know how likely it is that proto-systems similar to our own Solar System's early state would develop in ways that would allow complex life to evolve. There's some speculation that for the Earth to end up as we se it today, bathed in liquid water and with the atmosphere it has, requires a particularly unlikely set of events in the planet's history. What happened to Venus and Mars? Why didn't it happen to us?

That's before you start wondering about how other, more different proto-systems may evolve, and what are the chances of self-replicating chemistry turning into beings that can play Angry Birds. Let alone double-guessing their capabilities, interests and detectability.

There's no alternative but to keep looking, as intelligently as possible.

I do rather like the idea we'll be able to analyse exoplanetary atmospheres, and the first real indication we'll have of intelligent life elsewhere is because they're shoving shit into their air, same as we do. Archaeologists love middens for a reason.
posted by Devonian at 6:44 AM on July 22, 2015 [1 favorite]


there is absolutely no practical reason to visit Earth

Excuse me, but have you heard the gospel of our lord and savior, Krthnx the Great?
posted by fings at 6:50 AM on July 22, 2015 [6 favorites]


Excuse me, but have you heard the gospel of our lord and savior, Krthnx the Great?

Still not answering the door.
posted by echocollate at 7:27 AM on July 22, 2015 [1 favorite]


Do you have an email address for our newsletter?
posted by Brandon Blatcher at 7:32 AM on July 22, 2015 [1 favorite]


There's some speculation that for the Earth to end up as we se it today, bathed in liquid water and with the atmosphere it has, requires a particularly unlikely set of events in the planet's history.

That may be, but current evidence points to most stars having planets, and there are a LOT of stars.
posted by wotsac at 7:51 AM on July 22, 2015


Make your computerator's idle cycles help SETI (since you probably dont have that kind of money to throw at them)
posted by Golem XIV at 7:51 AM on July 22, 2015


So when this news broke, I had some mixed feelings.

On the one hand, this money will be used to outright buy time on our radio telescopes, reducing the time radio astronomers have available for other projects chosen on the basis of scientific merit. That's a bit of a shame.

On the other hand, we astronomers have not been able to find enough public money to keep these telescopes operational. The Green Bank telescope has been on the National Science Foundation chopping block for a while, with a mandate to find at least 50% of operating expenses from "other sources". I blame ourselves as radio astronomers for not selling our science well enough, I blame other astronomers for being too easily distracted by other shiny toys, I blame the NSF for sheer political incompetence, I blame our Congresspeople who can fund F22 jets but not science, and I blame ourselves as taxpayers and voters for just not caring enough. (I'm an equal-opportunity blamer.) So at least this money will help keep the lights on at the GBT, for which I am grateful. (And the situation is very similar for the Parkes radio telescope, which has been on CSIRO's chopping block as part of the Australian conservative government budget cuts, but I no longer have first-hand knowledge of their situation.)

On the third hand, the science here is straight up close to my heart. I'm teaching The Search for Life in the Universe (on behalf of the Carl Sagan Institute, natch), and I work on pulsars and radio transients, and the data these guys acquire will be an incredible set to work with.

And yet, it's a pity that the science will get done due to the patronage of the modern-day nobility, rather than the democratic peer-reviewed process. We've gone backwards here - even though the science is close to my heart, and even though it hasn't fared so well with the taxpayers, I have some hesitation here.

And on the last hand - those press photos! Yuri Milner, with his sharp suit and bow tie - he is just one fluffy white cat short of having a secret lair under a volcanic island, isn't he? Even the amount - one hundred meeeeelion dollars! - is perfect.

Sigh.
posted by RedOrGreen at 7:58 AM on July 22, 2015 [11 favorites]


Stars are too far apart to travel between and there is zero reason to believe that 3.00 x 108 m/s isn't an insurmountable speed limit. We can't visit them and they can't visit us, and it would take centuries to carry on a conversation.

There's intelligent life here on earth that could make far better use of that $100M.

If you want to work on that speed of light problem then facilities like LHC are your best bet.
posted by rocket88 at 8:25 AM on July 22, 2015 [4 favorites]


Here's the thing that I wonder about: Dinosaurs existed for over a 100 million years. On the other hand, we as a species existed for only 200,000 years. So it's entirely possible that we're wholly late to the game. Also it might be entirely possible that we're also extra early.
posted by I-baLL at 8:26 AM on July 22, 2015


Given the fragility of most known biology the most likely contact would be with alien AI Robotics
posted by judson at 8:42 AM on July 22, 2015


And why would "we" care? What would humanity actually do with this information at the present time?

You can reasonably ask "why should we care?"--you can't reasonably ask "why would we care": it's a demonstrable fact that we do. One has only to point to the very large sums of money being spent on SETI and the self-evident fact that the discovery of intelligent life on another planet would set off one of the great media frenzies of all time.

(Sadly, one answer to "why should we care" is "what if they decide to preemptively kill us before we try to kill them?" Which will also lead to very serious discussion of the question of whether we shouldn't, in fact, try to kill them before they can kill us.)
posted by yoink at 9:19 AM on July 22, 2015


there is zero reason to believe that 3.00 x 108 m/s isn't an insurmountable speed limit.

And zero reason to believe it IS. The only thing missing is the what got us this far: motivation.
posted by blue_beetle at 9:25 AM on July 22, 2015


Here's the thing that I wonder about: Dinosaurs existed for over a 100 million years.

I see where you're going with this: When the aliens do visit, they're going to be carrying extremely large tranquilizer darts.
posted by mittens at 9:26 AM on July 22, 2015 [2 favorites]


jimmythefish: "it would be the equivalent of positing that someone in New York should head out to the Yukon to see a new bacterium under a rock that had once made it to the next rock over."

Dollars to donuts there is probably a scientist at Columbia University, New York that researches that, if not something pretty close.
posted by wcfields at 9:37 AM on July 22, 2015 [1 favorite]


And zero reason to believe it IS

"Zero"?
posted by yoink at 9:38 AM on July 22, 2015


And zero reason to believe it IS

Other than everything we know about physics.
posted by rocket88 at 9:40 AM on July 22, 2015 [5 favorites]


but Star Trek!
posted by entropicamericana at 9:43 AM on July 22, 2015


And why would "we" care?

Well for a start, to see if they're pointing a Nicoll-Dyson laser at us.
posted by happyroach at 10:12 AM on July 22, 2015 [2 favorites]


The thing is, there are some human beings who would be excited by the idea of a new fungus in the Yucatan and willing to go out and look at it. Assuming that an alien species had curiosity (which seems necessary for them to advance at all scientifically; how do you get to spaceships if you're not curious about things first?) then there's a possibility we would be interesting, if only because we were rare and/or very different from them. Not because we're awesome, but because we're something they haven't seen before. Like a new fungus.

If we were boring to another species, that would imply that life is so abundant wherever they come from (and so similar to us) that they didn't find studying us to be useful in any way. Which also seems unlikely. Even here on earth, we are capable of being astonished/intrigued by minor differences, hell, by whether people say "ya'll" or "you guys." Alien scientists would definitely be able to find something to write alien papers on by studying us. Hopefully they would also be nice about it.

The most likely reason that no one's said hello is that space is just so fucking big and there aren't that many spacegoing civilizations capable of finding us. Or possibly none.
posted by emjaybee at 10:42 AM on July 22, 2015


It would of course be very amazing and significant news, finding signs of other sentient life, but I have noticed a tendency among some futurists to think that it would completely transform consciousness and society and usher in a New Era of History, and I just don't think I buy it. People are going to mostly carry on the way they do now, I think. Of course that doesn't hold if someone enslaves or eats us or gives us FTL drive and the secret to immortality and full membership in their Federation.
posted by thelonius at 10:51 AM on July 22, 2015 [2 favorites]


but I have noticed a tendency among some futurists to think that it would completely transform consciousness and society and usher in a New Era of History, and I just don't think I buy it

Yes, I agree. I expect that the hopes and fears people place simply on the fact of knowing that "we're not alone" are wildly overblown. But that's a different issue from whether or not we would care. I find it hard to imagine any piece of information that has no practical impact on our day-to-day lives that people in general would care about more, off the top of my head.
posted by yoink at 11:21 AM on July 22, 2015 [2 favorites]


I don't know why you're all doubting the many charms of Earth when it comes to aliens visiting us. I know we're kind of in the ass end of nowhere, galactically/universally speaking, but we have many fine tourist attractions and natural wonders to recommend us! Surely some adventurous alien travelers would be up for some unique experiences on a primitive but charmingly enthusiastic planet with a wide variety of cultures, art forms, and modes of expression. Or maybe they'd want to visit our octopus friends.

(Why yes, if the Earth Tourism Board was an actual thing, I would totally want to work for it. I want Earth to be the Milky Way equivalent of a quaint beachside party town, with a lot of great restaurants and art galleries and live performances.)
posted by yasaman at 11:27 AM on July 22, 2015 [4 favorites]


completely transform consciousness and society and usher in a New Era of History, and I just don't think I buy it

I thought this, but then it seems most folks around these parts believe climate change is a myth, the President is a Kenyan Muslim Lizard Person and that guns are the answer to every problem. If there's one thing that will definitely raise the collective consciousness of society, I don't see it being evidence.
posted by goHermGO at 11:42 AM on July 22, 2015


Surely some adventurous alien travelers would be up for some unique experiences on a primitive but charmingly enthusiastic planet with a wide variety of cultures, art forms, and modes of expression.

Alien: Hi! You must be one of the native life forms! This place is a paradise, huh?
Human: uh no. water falls from the sky onto me
Alien: You don't like that?
Human: makes me all wet. when water condenses in the sky it falls onto me. fuck that
Alien: But... you go swimming. And take showers. You... don't like water?
Human: sky water make me wet. fuck sky water
Alien: Well, I think your rain is kind of charming!
Human: buy something from me
posted by Greg Nog at 11:44 AM on July 22, 2015 [10 favorites]


A lot of folks here that I woild strenuously avoid at parties.
posted by Splunge at 11:49 AM on July 22, 2015 [1 favorite]


once i was a little too stoned and heard on the radio a theory about our universe meeting an anti-universe, and when the two met, both would wink out. Just everything, gone. Us, whatever other societies there were. In both universes.

i had to start watching funny animal videos to calm down
posted by angrycat at 11:53 AM on July 22, 2015 [1 favorite]


The most likely reason that no one's said hello is that space is just so fucking big and there aren't that many spacegoing civilizations capable of finding us. Or possibly none.

The possibility of none is troubling, because if we're the top of the food chain in the entire universe, that's freaking scary.

I do wonder if we can even detect signals from other beings or them detect us. Are we putting out signals that could last 10 light years? 30? 50? Is the other race? What if they're in the equivalent of the 15th century? What if they're in subsurface oceans? Too many what ifs!
posted by Brandon Blatcher at 11:54 AM on July 22, 2015


I think it's more likely that there's life out there, maybe lots of it. Technology may be really rare, though. Consciousness seems very rare among life forms, and the ability to invent new technologies would be vanishingly rare. I bet the universe is full of plants and animals but very few "people", much less technologically advanced "people".
posted by domo at 12:05 PM on July 22, 2015 [1 favorite]


But are humans flowers or "people"?!
posted by Brandon Blatcher at 1:04 PM on July 22, 2015


> Consciousness seems very rare among life forms

Yeah there's a kinda-sorta joking theory that holds that consciousness is entirely a byproduct of the stupid random design mistake where our trachea crosses through our esophagus (intelligent designer my ass). The only evolutionary "purpose" of consciousness in this theory is to make sure we don't choke on our food.

Lots of people in this thread are underestimating the magnitude of the Fermi paradox, though. Remember, you have to guarantee that *NO* civilization in the galaxy thinks that building a self-replicating exploring machine is a good idea. If even one does, where are they? The most obvious solution (and there are other more optimistic ones) is that a Great Filter lies in our future.

Say goodnight, Gracie.
posted by RedOrGreen at 6:05 PM on July 22, 2015


Lots of people in this thread are underestimating the magnitude of the Fermi paradox, though. Remember, you have to guarantee that *NO* civilization in the galaxy thinks that building a self-replicating exploring machine is a good idea. If even one does, where are they?

No, just have to guarantee that their government doesn't see any point in such a huge expense for something that they won't see in their lifetime and which won't benefit their civilization at all.
posted by Brandon Blatcher at 6:26 PM on July 22, 2015 [1 favorite]


Besides we only have a sample size of 1 for intelligent life. We just don't know.
posted by Brandon Blatcher at 6:37 PM on July 22, 2015 [2 favorites]


Well, "government", "point", "expense", "lifetime", and "civilization" are all terribly parochial concepts...

> We just don't know.

Yep.
posted by RedOrGreen at 7:31 PM on July 22, 2015


A simpler assumption is that the sort of intelligence that leads to technological civilizations is a deleterious mutation. Species that go the "big brains and hands" route inevitably render themselves and most of their biospheres extinct.

Again, we have a sample size of one- but the evidence is not reassuring.
posted by happyroach at 7:37 PM on July 22, 2015 [1 favorite]


Brandon, the question is whether or not there is life out there that we recognize as "people" and that they in turn recognize us. We haven't had a great track record for our encounters with non-human intelligences.
posted by domo at 7:55 AM on July 23, 2015


We haven't had a great track record for our encounters with non-human intelligences.

That depends on the situation. Clearly humanity has done some awful shit in general, but we've also taken the time to try and communicate also. So we have the capability of reaching out peacefully and as long as we're not competing for the same resources, we generally do ok. There's hope for us.
posted by Brandon Blatcher at 9:04 AM on July 23, 2015


No, just have to guarantee that their government doesn't see any point in such a huge expense for something that they won't see in their lifetime and which won't benefit their civilization at all.

That would seem to be an instance of "*NO* civilization in the galaxy thinks that building a self-replicating exploring machine is a good idea," not a contrary example. That is, under the Fermi paradox you have to assume that every single alien race technologically capable of space travel or interstellar communication decides it's not a good idea: either because they think it's dangerous, or because they decide it's impossible or because, as in your instance, they think the cost/benefit analysis doesn't pencil out.

It is troubling. The more exoplanets we discover the more the sense that "something like what happened on earth" must have happened countless billions of times out there in the universe seems logical. But if you have billions of technologically capable alien lifeforms out there you also begin to think "then why haven't we detected any evidence of them?" It's not that you can't come up with answers, but they all tend to make us seem rather special in one way or another, and there are reasons to feel unhappy with a starting hypothesis which is "we're unique in the universe!"
posted by yoink at 10:30 AM on July 23, 2015 [1 favorite]


Everything else aside, I think this statement of yoink's gets at the real question: "But if you have billions of technologically capable alien lifeforms out there you also begin to think "then why haven't we detected any evidence of them?"

So are we capable of detecting them? Sure, we've found thousands of planets, but can we tell if they're inhabited or not? Do we have an idea what to look for? Are we scanning those regions for what we think might be an intelligent species versions of tv or radio? Is that even possible?
posted by Brandon Blatcher at 11:12 AM on July 23, 2015


This is giving me deja vu because I just got out of class, but:

So are we capable of detecting them?
Yes, absolutely, as long as we have enough money to spend.

Sure, we've found thousands of planets, but can we tell if they're inhabited or not?
Not yet. Maybe not even with the JWST, but maybe with the Terrestrial Planet Finder?

Do we have an idea what to look for?
If you're talking about biomarkers, yes, yes, yes. The oxygen (ozone) in Earth's atmosphere is a dead giveaway that something interesting is going on - neither Venus nor Mars has those very significant spectral features, for example. If you're asking about technomarkers, well...

Are we scanning those regions for what we think might be an intelligent species versions of tv or radio? Is that even possible?
This gets into the hairy stuff. Who's to say what another intelligent species would be doing? We put out a lot of TV signals into the ether, and then suddenly moved to cable TV. We did all those gloriously bright atmospheric nuclear tests (think of the gamma rays!) and then decided maybe that wasn't such a good idea after all. We're still radiating airport radar and planetary radar but not laser beacons or gravity waves. Maybe GalactoTwitter uses neutrino modulation and we're missing all the buzz about this shy hydrogen core intelligence that's come around and wants to play.

There's a fairly extensive serious literature on these topics now. For example:
Exoplanet Habitability, Seager 2013, Science.
The future of spectroscopic life detection on exoplanets, Seager 2014, PNAS.

But again, the Fermi paradox is a serious one, and the simplest solution is to posit a "Great Filter" that intelligent technological civilizations usually do not get past. There are, as I said, other more optimistic solutions, but the further we go with finding habitable planets and maybe life but not technology, the bleaker the future picture gets.
posted by RedOrGreen at 1:10 PM on July 23, 2015 [4 favorites]


RedOrGreen, do you have a newsletter? Because that answer was great, thanks!
posted by Brandon Blatcher at 5:58 PM on July 23, 2015 [1 favorite]


No one with the ability to survive in space for decades or centuries of travel to get here is going to feel the need to settle at the bottom of a gravity well, much less one full of unfamiliar and potentially lethal microbes.

Our overlords may be potentially lethal microbes; a little respect!
posted by rongorongo at 4:00 AM on July 24, 2015


Who's to say what another intelligent species would be doing? We put out a lot of TV signals into the ether, and then suddenly moved to cable TV. We did all those gloriously bright atmospheric nuclear tests (think of the gamma rays!) and then decided maybe that wasn't such a good idea after all. We're still radiating airport radar and planetary radar but not laser beacons or gravity waves. Maybe GalactoTwitter uses neutrino modulation and we're missing all the buzz about this shy hydrogen core intelligence that's come around and wants to play.

Right--those are perfectly reasonable hypotheses: but they do pose the problem that they rely on us being "special"--we were the specially stupid "smart" species that played around with nuclear fission, the specially stupid smart species that failed to figure out neutrino modulation and had an unusually long dalliance with radio waves etc.

I mean, it's all possible, of course--but any hypothesis that rests on "we were just the oddballs" (including the "we are just the first species to get this far")--should make us nervous: especially when we are always keen to employ arguments that suggest we're not oddballs (arguments of the "there are billions upon billions of habitable worlds out there with conditions roughly like earth's--something like what happened on earth must have happened elsewhere, and even if the odds are astronomically small, that still means that there are millions upon millions of complex, intelligent life forms out there").
posted by yoink at 9:58 AM on July 24, 2015


> Those are perfectly reasonable hypotheses: but they do pose the problem that they rely on us being "special".

Right, I didn't mean to imply that no other species (or every other species) would do what we did. My only point was that we - the one data point we do have - were detectable as bright gamma ray flashes, but only for a brief interval before we changed our mind. It is impossible to predict beforehand what an alien civilization will decide to do, or for how long. Those nuclear flashes might have been even brighter if they were signaling the end of our civilization, for example, and we came pretty close to that.

And so, of course, the correct response is to do SETI at every band. Hey, you never know.
posted by RedOrGreen at 10:20 AM on July 24, 2015


Right, I didn't mean to imply that no other species (or every other species) would do what we did.

It was really the opposite point I was musing on: that to assume no other alien species--or even very few--went our route (or something like it) is a problematic resolution to the Fermi Paradox. The more we make ourselves an exception to the rule, the less plausible the solution.
posted by yoink at 11:13 AM on July 24, 2015


Too late for this to be part of the conversation, but it seems almost certain to me that we'll either hit the great filter within a handful of centuries (5 at most, 1-2 seems likely) or understand which assumption of the Fermi paradox was erroneous. My money is on finding a flaw in the Fermi paradox, I think it's (slightly) more likely, and it's definitely more fun.
posted by wotsac at 9:21 PM on August 8, 2015


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