What do you think the Great Filter is?

The Great Filter is the idea that, in the development of life from the earliest stages of abiogenesis to reaching the highest levels of development on the Kardashev scale, there is a barrier to development that makes detectable extraterrestrial life exceedingly rare. The Great Filter is one possible resolution of the Fermi paradox.

https://en.wikipedia.org/wiki/Great_Filter

The Fermi paradox is the discrepancy between the lack of conclusive evidence of advanced extraterrestrial life and the apparently high likelihood of its existence. As a 2015 article put it, "If life is so easy, someone from somewhere must have come calling by now."

https://en.wikipedia.org/wiki/Fermi_paradox

Personally I think it's photosynthesis. Life itself developed and spread but photosynthesis started an inevitable chain of ever-greater and more-efficient life. I think a random chain of mutations that turns carbon-based proto-life into something that can harvest light energy is wildly unlikely, even after the wildly unlikely event of life beginning in the first place.

I have no data to back that up, just a guess.

randon31415 ,

Everyone is talking about society or physiology stuff. That is just things that might get humans.

Stars going super-nova is the real great filter. Our sun is 4.6 billion years old. Life started 4 billion years ago. In 4 billion years, the sun goes supernova. We are halfway to the end of the earth.

Smaller stars last longer, but have smaller ranges that life can exist in - and planets tend to move in or out in their orbits. Bigger stars have giant habitable zones - but some large stars born when humans took their first steps are in their last decades of life. You couldn't get from the pyramids to NASA in that time, never mind the 4 billion years it took to get to humans.

WhaleSnail ,

I think it's supposed to actually less than that, the sun's luminescence will increase over the next 1 billion years to the point that it will boil off the earth's oceans. No life will be able to exist past that, and earth will just be a barren rock in orbit for the next 3 billion years.

Aussiemandeus ,
@Aussiemandeus@aussie.zone avatar

Well I'm doing my part to make sure the oceans are full of Arctic ice for the great boil off

Subverb ,

When they do boil off they need to make sure to have a hell of a lot of cocktail sauce and melted butter on hand.

Pulptastic ,

That is an interesting idea that is not typically considered in the drake equation as far as I know. That could significantly reduce the chance of finding intelligent life elsewhere.

oo1 ,

I think it is in the drake equation effectively, it factors into the length of time that the civilization might send and receive detectable signals - It doesn't say why the Civilisation might collapse, but the planet becoming uninhabitable is surely one reason. On wikipedia for Drake Equation the Carl Sagan specification of L is in terms of the "fraction of planetary lifetime".

I think a missing factor might be how directional transmission and receiving is, if we can't broadcast to and listen to the whole sky equally then we might have a 1/r-cubed type issue with the chances of both listening and transmitting with enough strength/energy at the same time.

creditCrazy ,
@creditCrazy@lemmy.world avatar

While that is true I would counter point that humans have a bit of a handicap as earth got hit by a big astroid that killed just about everything on it making terran life have to start all over again but at the other hand I saw someone else on here mentioned that oil has given us a head start at space ferrang advancement and oil is made from dead life so granted I haven't done much reacerch on how oil forms naturally but I do wonder if we would have oil if earth never got blown up but on top of all that there are theorys that mars used to have life so if astroids haven't interfered with our solar system intelligent life may have formed faster and maybe twice also there used to be multiple species of humans in the past so maybe 4 or five times in the same solar system

vxx ,

If there really is a cosmic web and information flows through it, the other solar system will know that we're coming to destroy another world, but it will have developed defensive techniques against a known disease, humans. The same our immune systems does to known viruses.

I went a bit creative with this one.

CheeseNoodle ,

I'm starting to wonder if its LLMs. An AGI is something we would be incredibly cautious around and is really no more likely to be psychopathic than any other living thing, the vast majority of which are not. LLMs on the other hand are pushed into every role techbros can shove them into while having less understanding of what they do than a housefly, the potential for damage is immense if someone decides to put one in charge of something important like infastructure or weaponry.

rsuri ,

There's a lot of possibilities.

My top contender would be a desire to explore, which probably requires consciousness. Given that we have pretty much no idea what leads to consciousness, it can be guessed (dubiously) that if it arose more easily then we'd have an explanation by now. It could be that it's an extremely rare phenomenon, and there may even be other planets with "intelligent" but mechanistic beings that act entirely for their own survival and don't build civilizations or explore much.

Second would be intergalactic and to a lesser degree interstellar travel. If we assume both 1) intelligent civilizations are extremely rare and 2) faster-than-light transportation is impossible, it could be that everyone is just too spread out to make contact.

Third, and the one I most feel is right but it requires pretending I understand quantum physics (which I don't) and probably offending many that do, is the notion that the concrete universe is not large but small and has no objective existence independent of our respective perceptions, and any part of the universe that's invisible is a mere wave function that will only have concrete reality upon our perceiving it. I make the further dubious assumption that conscious beings can't be part of the wave function. So there.

KevonLooney ,

conscious beings can't be part of the wave function

That's not how any of this works. Your brain is made out of regular matter, not special fancy matter.

rsuri ,

I don't know if the type of matter matters, rather I'm basing in on the idea that measurement collapses the wave function, and consciousness does measure things

KevonLooney ,

Your brain isn't what "collapses the wave function", it's the measuring device that you use. You can do a double slit experiment and watch it with your eyes the whole time. Light will still act as a wave until you interact with it experimentally.

You are reading too much Deepak Chopra. Your brain is just a computer made out of meat. It's not magic.

Cethin ,

For your final point, that's not what that means. It's not "observation" that collapses the wave function, at least as you're understanding the word. It's any interaction that requires the information to be known. That includes any particle interactions. It's not consciousness that matters. When we "make a measurement" it's only recording information of an interaction. It doesn't actually matter that we record it, only that there was an interaction. There is zero metaphysical consciousness mumbo-jumbo involved.

ammonium ,

That's what I thought too, but according to Sabine Hossenfelder there actually is, we just choose not to speak about it. I don't really know enough about quantum physics to make my own judgement.

Cethin ,

That video makes no argument for consciousness being required. Also, Sabine is not a reliable source of information. She is confident and convincing, but that doesn't make her accurate or correct.

For an example, not related to this topic: https://youtu.be/s7XAxiJGJdg?si=S0IkGdF_EV5If_wJ

Cryophilia OP ,

Second would be intergalactic and to a lesser degree interstellar travel. If we assume both 1) intelligent civilizations are extremely rare and 2) faster-than-light transportation is impossible, it could be that everyone is just too spread out to make contact.

Not just too spread out to make contact, too spread out to even detect each other's presence

HaleHirsute ,

I like the “Dark Forest” theory I learned from the Three Body Problem books. Basically it’s dumb for civilizations to make a big footprint and reveal themselves because other civilizations won’t know how powerful and dangerous you might become, and so out of precaution they might just zap you. Ironic and over dramatic, but just because that’s a possibility it might be wise to keep a low profile and not invite trouble.

Lmaydev ,

Tbf we are noises as fuck. We've been sending so much out for decades.

HaleHirsute ,

Sure, but it’s just small game chatter. We start building a Dyson sphere powered starkiller cannon or some such nonsense we might pop up on somebody’s radar.

FaceDeer ,
@FaceDeer@fedia.io avatar

The problem for the Fermi paradox is that there's no reason to do stuff like that before we start colonizing other solar systems.

Also, how do you destroy a civilization that has a Dyson swarm already? That's not exactly an easy task, and if you insist on remaining stealthy yourself it's nigh impossible.

FaceDeer ,
@FaceDeer@fedia.io avatar

The "Dark Forest" is fine for a scary sci-fi series, but it has many flaws that make it unrealistic as a real solution to the Fermi paradox.

  • Earth has been quite obviously life-bearing for at least 2 billion years. We should have been wiped out long ago.
  • The book series made up fantasy magic tech for how exactly a civilization can be destroyed by another without giving away their own location. I've yet to see an explanation for how that would be done in reality that doesn't give away the attacker's location.
  • It doesn't explain why nobody has colonized the galaxy.
HaleHirsute ,

I think others wouldn’t bother with us until we started demonstrating likelihood of using dangerous tech or crazy exponential expansion.

I don’t remember well, but I think civilizations stationed their defensive or offensive tech away from their own civilizations, just dispersed around.

I think its explanation for why no one or anything has colonized the galaxy though is that if anyone shows signs of becoming that strong, they get zapped. Nobody wants to see a neighbor rise up into a behemoth, you get that bold you’re a threat.

My real preferred theory of why we don’t see other civilizations though is that I think they choose more inward, VR, computer-based evolution that doesn’t result in big mega structures.

FaceDeer ,
@FaceDeer@fedia.io avatar

I think others wouldn’t bother with us until we started demonstrating likelihood of using dangerous tech or crazy exponential expansion.

Why do you think that, though? It doesn't make sense, frankly - if you're worried about competition evolving you shouldn't wait until the last possible second to destroy it. That raises so many unnecessary risks of being slightly slow on the draw, and then it's too late. Why not do it at the earliest convenience, when it's super easy to do by comparison and there's an incredibly long margin of error if you somehow miss the first couple of tries?

I don’t remember well, but I think civilizations stationed their defensive or offensive tech away from their own civilizations, just dispersed around.

I think its explanation for why no one or anything has colonized the galaxy though is that if anyone shows signs of becoming that strong, they get zapped.

But they're already doing it, you just said they're putting outposts out there. If they can't do that secretly then the Dark Forest doesn't work in the first place. Placing a secret weapon base in another solar system is no different from placing a colony there.

My real preferred theory of why we don’t see other civilizations though is that I think they choose more inward, VR, computer-based evolution that doesn’t result in big mega structures.

As with many Fermi paradox solutions this one fails on account of requiring every single civilization (and every single subset of those civilizations) to all decide to do exactly the same thing, forever, with no exceptions. In a scenario like this what happens if a single subculture of a single advanced civilization decides for whatever reason that they prefer not to do that? They would be able to spread throughout the cosmos without opposition, everyone else is locked in their little dream boxes and therefore is basically irrelevant. It only needs to happen once, and the universe has been around for a very long time.

HaleHirsute ,

I agree, I don’t think they’d wait until the last possible moment when the civilization becomes super powerful or builds the mega weapon. I just mention it along the range of development to highlight the why.

I think they might let weaker civilizations keep going, though, just out of hope they wouldn’t be too mean. Also, zapping other civilizations when you don’t need to exposes yourself and your own aggression.

About the shift to VR /computer substrate worlds that wouldn’t have huge footprints, I agree that not all would do that, and it only takes one to go the big building and footprint route and it’s weird we don’t see it.

My guess then would be that maybe they do build big, but they just conceal well..? You get good enough tech at some point you can choose to be hard to see.

Cryophilia OP ,

I've never read the three body problem (started it but just couldn't finish...it was very slow paced and there were moments when the Chinese...I don't want to call it propaganda but more like promotion...took me out of it, like the supposedly international coalition of scientists where the non Chinese ones were just cardboard cutouts) but I can speak to this:

The book series made up fantasy magic tech for how exactly a civilization can be destroyed by another without giving away their own location. I’ve yet to see an explanation for how that would be done in reality that doesn’t give away the attacker’s location.

Relativistic missiles. Nothing moves faster than the speed of light. So if you can get a big rock to go 95% of the speed of light, we'd only be able to detect that it's coming right as it hits. Sure, you can calculate the origin of the missile after it obliterates its target, but it's almost impossible to form a counterattack especially if the attacker just yoinked an asteroid from a different star system than their own and strapped an engine on it. And ESPECIALLY if your civilization is still mostly planetbound.

And a rock moving at some appreciable fraction of the speed of light could obliterate the Earth.

FaceDeer ,
@FaceDeer@fedia.io avatar

Relativistic missiles. Nothing moves faster than the speed of light. So if you can get a big rock to go 95% of the speed of light, we'd only be able to detect that it's coming right as it hits.

This is a very common answer to "how", but it comes with lots of problems in the Dark Forest context.

  • If you actually calculate how much energy is required to boost a big rock up to that speed you run into lots of difficulties. It takes a lot, a heck of a lot. How does a civilization that is "hiding" accumulate that energy? How does it store it long-term?
  • How is that energy actually put into the rock? This is basically a starship accelerating up to that speed and getting a starship up to that velocity is not easy even if you have the energy available. Does it have a rocket? The rocket equation for getting up to near-lightspeed requires ridiculous amounts of propellant. Is it beam-propelled? You're not being at all stealthy that way. How much acceleration can you get out of your system? It takes a full year at one Earth gravity of acceleration to get up near lightspeed, and that's a really high acceleration - you generally trade acceleration for efficiency so the faster you want to get up to speed the more energy you need and the noisier you'll be.
  • It actually is possible to counter an RKV. It's much easier to hit and destroy an RKV than it is to launch it, all you need to do is get a pebble in its path. The key is detection, and the above points give some pretty good options for detecting it before and during launch. That gives you time to fire your countermeasures.

And ESPECIALLY if your civilization is still mostly planetbound.

Absolutely not guaranteed to be the case. Earth's civilization could have easily had offworld colonies by now if circumstances had been slightly different, so a Fermi paradox solution that requires reliably blowing up Earthlike civilizations before they can get offworld doesn't work. They're already too late.

As I said previously, Earth has been quite obviously life-bearing for at least 2 billion years. Why wait until something like an RKV is needed, and even that is not guaranteed? They could have destroyed life on Earth far easier, and thus far more stealthily, if they'd done it a billion years ago.

Cryophilia OP ,

I agree, either we've escaped detection or the dark forest theory is wrong.

Couldn't antimatter bursts get an object to extremely high speeds relatively cheaply?

FaceDeer ,
@FaceDeer@fedia.io avatar

Well, "relatively cheaply" is a hard standard to nail down. I would say "no", though. Antimatter is very expensive to manufacture and store and you're going to need a lot of it. All of the energy that comes out of an RKV hitting its target has to be put into it in the first place, probably several times over given the inefficiencies likely inherent in the process.

Cryophilia OP ,

Fair enough, guess it depends on how many resources they're willing to sink into first strike capability. Maybe a strongly expansionist civilization would have such a more efficient use of resources it would quickly catch up to a dark forest predator trying to wipe them out. Like a swarm of piranha eating a shark.

papertowels ,

Earth has been quite obviously life-bearing for at least 2 billion years. We should have been wiped out long ago.

I believe the theory is that as civilizations broadcast a signal indicating life exists strong enough such that it is picked up by other civilizations, the dark forest theory applies. Essentially we haven't broadcasted a signal loud enough to be picked up

FaceDeer ,
@FaceDeer@fedia.io avatar

But that's not actually true. We've been "broadcasting" the fact that there's life on Earth in the form of the spectrographic signature of an oxygen-rich atmosphere, which is a clear sign that photosynthesis is going on. There's no geological process that could maintain that much oxygen in the atmosphere. The Great Oxidation Event is when that started.

We have the technology to detect this kind of thing already, at our current level. Any civilization that could reach out and attack another solar system would be able to very easily see it.

papertowels ,

This is quickly becoming beyond my knowledge pool, but does this assume that all life is intrinsically linked to oxygen?

FaceDeer ,
@FaceDeer@fedia.io avatar

It's not specifically oxygen that's linked to life, it's chemical disequilibrium. Oxygen is highly reactive, there are lots of minerals that will bind it up and there aren't any natural geological processes that unbind it again in significant quantities. If you put an oxygen atmosphere on a lifeless planet then pretty soon all of the oxygen will be bound up in other compounds - carbon dioxide, silicon oxides, ferric oxides, and so forth. There has to be some process that's constantly producing oxygen in vast quantities to keep Earth's atmosphere in the state that it's in.

There are other chemicals that could also be taken as signs of life, depending on the conditions on a planet. Methane, for example, also has a short lifespan under Earthlike conditions. You may have seen headlines a little while back about the detection of "life signs" on Venus, in that case it was phosphine gas (PH3) that they thought they'd spotted (turns out it may have been a false alarm). These sorts of gasses can be detected in planetary atmospheres at interstellar distances, especially in the case of something like Earth where it's quite flagrant.

Even if these are sometimes false alarms, in a "Dark Forest" scenario it'd still be worth sending a probe to go and kill whatever planets exhibit signs like that. It's a lot cheaper and quieter than trying to fight an actual civilization. That's why I can't see why we wouldn't have already been wiped out aeons ago in this scenario.

papertowels ,

Thanks! That's a different way of looking at the problem that I hadn't considered.

intensely_human ,

The galaxy is a bowl of M&Ms. One
of every hundred M&Ms is poisoned and will
immediately kill you. It’s only a 1% chance you’ll die. Well maybe pike 5% if you eat a handful.

Most of the civilizations might even be moral enough not to destroy us, but all it takes is one.

HaleHirsute ,

Yep exactly. Who knows how murderous other civs might be, maybe they’re nice but maybe not.

FaceDeer ,
@FaceDeer@fedia.io avatar

How do they do it, though? It's not really a valid solution unless you can explain how it works, otherwise it's just "maybe some magic happens that kills civilizations."

Once a civilization has begun spreading to hundreds of other solar systems I have yet to hear of any plausible way to reliably "kill" it.

intensely_human ,

Guns? Bombs? Surely you can kill a civilization. Not sure why magic would be required.

FaceDeer ,
@FaceDeer@fedia.io avatar

I don't think you've thought through the logistics required for the sort of war where you'd just go around and shoot everyone who lives in hundreds of solar systems. Even assuming they do nothing at all to defend themselves, how do you even find them all?

littlecolt ,
@littlecolt@lemm.ee avatar

I would say it's the size of the universe and the fact that it is still expanding at an accelerated rate.

If the speed of light is really the "top speed" of the universe, it is inadequate for interstellar travel. It is barely good enough for timely communication, and not really even that.

Life can be as likely as it wants to be, but it seems to me that we're all quite divided, to the point of not being able to communicate at all with other potential intelligent species.

androogee ,

Isn't the fermi paradox specifically dealing with detection tho? Not just travel or communication.

littlecolt ,
@littlecolt@lemm.ee avatar

I suppose I was focusing on detecting some sort of communications. It still matters that when we see objects at great distance in space, it's the objects in the distant past

Tlaloc_Temporal ,

This universe being unfriendly to interstellar and especially intergalactic travel would seriously hamper a galactic civilization, and thus be less likely for us to notice them.

There might be hundreds of civilizations out there, each having only expanded to a few dozen stars, not caring to go further. Even the makeup of the interstellar medium might be incredibly dangerous, basically necessitating generation ships to cross. Large scale expansion might simply be too hard.

SLVRDRGN ,

That expansion at an accelerated rate - that's just so eerie when you think about it. The furthest objects we can see right now will slip away out of reach forever for the next generation, and so on. It's crazy to think that as time goes on, there will be less and less universe to observe.

littlecolt ,
@littlecolt@lemm.ee avatar

One of the weirdest facts. One that really makes you feel so small.

androogee ,

That's something really interesting, though. When we look at distant objects, we aren't limited by the distance they're at right now. We're limited by the distance they were at when they emitted the light.

So the observable universe is still growing because the edge of that bubble is such a long time ago that everything was still much closer together.

SLVRDRGN ,

But the light that reaches us is constantly getting stretched (red-shifted), so I'm not sure that our bubble is growing. Instead when they're stretched too thin, we won't be able to see it. I'm not 100% sure on the expansion rate of the universe and the pace of red shifting.
Also, eventually all the galaxies are expected to be pushed so far away from each other due to the pressures exerted by Dark Energy, that soon we'll only be able to see just the stars of our Milky Way.

sp3tr4l ,

Howabout a reasonably advanced civilization destroying itself and its homeworld after exploiting and then running out of petroleum?

Seasoned_Greetings ,

I think it's a fair thought that any form of life doesn't perfectly recycle their resources and all forms of life give off waste for other life to utilize. That said, a reasonably advanced civilization might just inevitably grow to the size where the waste they put off makes their planet unlivable for them before they can take action to control it.

For us, it's carbon dioxide.

Tlaloc_Temporal ,

Don't forget plastics and pesticides! Those get everywhere, and many are bioavailable by design.

Subverb ,

Oil has a bad reputation but how lucky we are to have it. How does a civilization on a planet without hydrocarbons make the leap to a technological species?

It's not impossible, but it's got to be a lot harder.

Tlaloc_Temporal ,

Kelp farms? Domesticated bamboo? We need large areas of land to grow food anyway, we just skipped the charcoal agriculture step. Lathes and the three plate method are the real heroes of industry any way.

A slower ascension into the computing age could mean a more stable set of cultures and a more uniform global situation to avoid anthropogenic filters. Bright candles and all that.

nondescripthandle ,

I'm sure simply continuing to live will show me more about possible great filters than most teachers could unfortunately.

Hadriscus ,

It may very well be republicans

AA5B ,

Exponential functions. Seriously. You meet crisis after crisis, each having a risk of ending civilization, but that risk never goes away. It keeps multiplying and multiplying, until you realize the risk curve is approaching a vertical line

Cryophilia OP ,

Why would risk go up over time? For humanity, we're pretty much at the point that very little could end our species now.

Brickhead92 ,

Well except, obviously, for humanity. That's our greatest enemy, and it seems to be shown more frequently.

Cryophilia OP ,

We would be hard pressed to end our own species either. Even global thermonuclear war would end civilization but not our species.

DeanFogg , (edited )

Edit: This mf just jinxed humanity

Depends on the amount of nukes.

Acidifying oceans also dares a cascading effect that would wipe us out.

Disease.

Also, think about globale warming. The core of the sun is 27 million degrees. 130 degrees is enough to make the surface unbearable, higher than that is going to be>!!< uninhabitable.

Also let's not forget space is wild, meteors or GRBs can take us out instantly

Spacehooks ,

Universe 25 experiment.
My take away from it is when society gets bored and loses goals it's over. If the mice had some predators they probably wouldn't have collapsed.
Humans don't have predators but have dreams that we worked toward amd stimulate us. Once we lose that it's like what happened Walle. Stuck in a system slowly dying full of apathy.

squirrelwithnut ,

We're currently in it. Failing to create a clean, renewable, and scalable energy source powerful enough to run a society that is ever increasing in both population and technology without destroying their only inhabited planet has got to be the most common great filter.

Asteroids strikes, super volcanoes, solar CMEs, and other planetary or cosmetic phenomena that exactly line up in both severity and timing are too rare IMO.

Every society that attempts to progress from Type 1 to Type 2 has to deal with energy production. Most will fail and they will either regress/stagnate or destroy themselves. Very few will successfully solve the energy problem before it is too late.

Tudsamfa ,

A filter for sure, but not a great one. Call me optimistic, but I don't think that will set us back more than 10.000 years. If humanity can survive, society will re-emerge, and we are back here 2-3000 years into the future.

Is +5°C Earth a good place to be? No. Will the majority of humans die? Absolutely. Will the descendants get to try this society thing again? I believe so.

On a cosmic scale 10.000 years is just a setback, and cannot be considered a great filter.

Kyrgizion ,

Unfortunately we've pretty much used up all easily available resources. Anyone 'starting over' would have a much harder time getting the things they need to really get the ball rolling again.

When humans first discovered gold they practically only had to scoop it out of rivers. You'll be hard pressed to find any streams with such appreciable production anywhere in the world today.

Cryophilia OP ,

We've already discovered fission and photocells. We're past the point of needing fossil fuels for a new civilization (or existing civilization). Fossil fuels are only hanging around for economic reasons.

Spacehooks ,

Assuming that knowledge and resource locations are retained. Roman's had great concrete. Took a long time to reestablish what Humans already had and mixing raw materials is not complicated.

After the Roman Empire, the use of burned lime and pozzolana was greatly reduced. Low kiln temperatures in the burning of lime, lack of pozzolana, and poor mixing all contributed to a decline in the quality of concrete and mortar

We need a Foundation project to restart society If we want to avoid this. Worst case solar cells becomes myth like Greek fire.

Tudsamfa ,

I think that is thinking a bit too narrow. A lot of the stuff we use today might just be our bronze to our successors iron - you can build an unstable society on either. And what we do use up today could still work if used more efficiently - we might not have enough rare metals to give everyone a smartphone in the post-post-apocalypse, but I could see us still launching satellites if only big governments had computers - because they did.

SwingingTheLamp ,

Honesty, I don't think that there is a Great Filter. The Fermi Paradox strikes me as not very well-reasoned. A whole hell of a lot of things would have to go exactly right for civilizations to make contact, rather than it being the default assumption. There are lots of filters, not just one Great one.

But the closest to a Great Filter is that space is really, really. stupendously big. The chances of even detecting each other across such distances is vanishingly small, much less traversing them. Add in the difficulty of jumping the metabolic energy gap to become complex life, and that could reduce the density of civilizations down to a level that they're just not close enough to each other in spacetime to admit even the possibility of contact. And we're hanging our hat on some highly-speculative concepts like alien mega-structures harnessing whole solar systems to allow detection.

I think a lot of persnickety, smaller filters combine to make interstellar contact between civilizations against long odds. Perhaps the best we'll get is spectral signatures from distant planets that are almost-conclusive proof of some sort of life.

Cryophilia OP ,

I think at some point, almost certainly not in our lifetimes, we'll detect the spectroscopic signatures of a planet that has an atmospheric makeup that HAS to be from life, but with no detectable signs of any civilization. Just nonsentient life. And we may never be able to get there.

Gradually_Adjusting ,
@Gradually_Adjusting@lemmy.world avatar

I think you're probably closest. There aren't "filters" so much as we live in a universe that can only support life on a highly contingent basis, entirely by accident, at random intervals. It's filters all the way down, really. None of us are getting out alive, might as well enjoy it while it lasts.

Wahots ,
@Wahots@pawb.social avatar

I think there are many great filters, but I think one of those filters is fighting over limited resources and wars. Perhaps limited to humans/earth, but I doubt it. Nukes, dropping rocks from orbit, and theoretical (but possible) weapons like black hole bombs are all going to tempt irrational beings to take someone's stuff.

We have to be extremely careful that we don't accidentally trigger a weapon that is going to kill or dramatically cripple our civilization before we become a truly interstellar species. There is so much to learn out there, while so many people are currently focused on the wrong things such as minor conflicts or what children aren't allowed to learn.

Cryophilia OP ,

We have to be extremely careful that we don’t accidentally trigger a weapon that is going to kill or dramatically cripple our civilization before we become a truly interstellar species.

Great filter confirmed to be oopsie-daisies

Spacehooks ,

That's what everyone was thinking with the LHC. Really should put oopsie labs off world.

averagechemist ,

Space itself. I believe there are other intelligent life forms out there and some of those happen to be close enough to communicate to each other/discover each other. We just hit the unlucky(or lucky) spot that we are simply too far away.

Cryophilia OP ,

Man that would suck
https://lemmy.world/pictrs/image/76e8fa70-ed71-4284-87c7-ddfa95a56818.jpeg

Spacehooks ,

Kind of like we don't have hive minds so they just think we are regular animals.

Tramort ,

Your answer doesn't make sense.

"Photosynthesis" is a positive development for life. The great filter must be a negative development: it's a filter or a barrier that keeps life from achieving long term extra terrestrial survival.

So "climate change" would be an answer. Or "fuel depletion" (to which photosynthesis may be a solution). But the filter is the mechanism by which life forms are prevented from progressing.

Cryophilia OP ,

I was suggesting that photosynthesis is a very unlikely mutation to occur and thus its unlikeliness means most life, if it emerges, won't progress to that stage.

The filter doesn't have to be ahead of us, it could be some stage of development that we've already passed. Like photosynthesis, or the development of consciousness. If, out of all life that develops, only a tiny fraction ever develops photosynthesis, the universe would be largely devoid of any life that we can presently detect. Despite us being the lucky lifeform that did develop photosynthesis in our past.

Tramort ,

Regardless: photosynthesis is a possible solution to avoid the filter. Not the filter itself.

You can't filter something in

Cryophilia OP ,

The failure to develop photosynthesis is the filter. I don't know how you're not getting this. No photosynthesis, no complex life, no sentience, no interstellar civilization.

Tramort ,

You started here

Personally I think it's photosynthesis.

Now you're here

The failure to develop photosynthesis

I think you got it! Good job!

Cryophilia OP ,

I'm sorry to tell you this, but I think you might be stupid.

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