All by ourselves? The Great Filter and our attempts to find life.

The Universe should be full of alien civilizations. Why can’t we find any?

See full article...

 

[llanitedave]

Only “most” of the coal comes from the Carboniferous. Modern peat bogs build up similarly to those Carboniferous forests, for instance. It’s just that it takes a narrower range of conditions to do so.

Oil and natural gas, furthermore, do not take hundreds of millions of years to
Form. More like tens of millions. And they can form from ocean sediments (basically, layers and layers of plankton settling to the bottom) that haven’t been fully broken down.

Methane actually forms pretty quickly from decaying plant matter. The challenge is trapping it before it dissipates so that it can accumulate in reservoirs.

 

[Chuckstar]

It's such an amazing, fun topic. There's so much to factor in that one can get lost in the sheer minutiae of the Drake Equation alone.

Planets too small or with too little mass such as Mars just don't remain habitable long enough. Yet planets with merely 2x the mass of Earth aren't viable with rocketry, some argue even 1.5x wouldn't be economically feasible. Then the planet has to be in just the right goldilocks zone, at the right time in the star's life cycle, and intelligent life has to survive the random chance of asteroid impacts resetting the clock. Even that intelligent life would be cooperative, but also able to somehow refine, create, and utilize tools still makes assumptions, for example that their planet even has the correct & sufficient minerals that we are privileged to have on our ball of rock.

Even that becomes a nuanced topic. Our planet is enjoying additional metal and mass thanks to it being a second-generation planet that formed from the collision of two first-gen plantoids, by way of which formed the rock-heavy but mineral poor moon. Said moon played a key role in slowing the earth's rotation that calmed the weather while still accelerating geologic weathering. The additional metal & heat combined from that event may be why we still are able to enjoy a magnetic field, something it's worth pointing out that Mars and Venus both lack. Even radioactives are now said to account for a third (if not more) of the earth's internal heat, it wasn't 99% residual heat from accretion during formation as was taught when I was in school.

The more we refine our understanding of astronomy the more we are realizing the Sol System itself is a particularly rare set of circumstances in its development. Most systems are binaries, which greatly complicates the habitable zones & planet classes. Most systems get torn asunder by the early gas giants that always end up wrecking the place as they are guaranteed to swing inwards towards the sun, but that rampage was halted here.

Frankly if a civilization could develop FTL, they wouldn't have any need for trade. Anything we could mine or produce ourselves at our current technological level they could find elsewhere and mine more efficiently directly at their own technological level. We might be worth studying, but that would necessitate avoiding contact and keeping subject contamination to a minimum. Any sort of supercapacitor, quantum level technological aliens probably wouldn't even rely on radio signals anymore and likely wouldn't have for some time before even leaving their home system.

It’s not at all clear that the Moon formation event resulted in much different structure for an Earth-sized planet than Earth currently has. The Moon’s mass is very small compared to the Earth’s. That is, if the Earth had accreted to this size directly, it’s not clear its make-up would be all that different. We also can’t say for sure that Mars and Venus did not result from similar late-stage collisions. Only that if they did, the events didn’t result in spinning off 1% of their mass into a satellite. Mars and Venus lack magnetic fields because they lack convecting cores. Mars’ core cooled too much because Mars it’s small. Venus because plate tectonics shut downs and it spins so slowly.

There are lots of claims about the Moon’s contribution to the evolution of life on Earth. It’s not clear any of them make the Moon necessary. Maybe “helpful”, but we don’t even know that for sure.

 

[llanitedave]

Once you can sterilize an actual planet this changes the game. You're banking on science eventually delivering an absolute response to energy.
That's religious thinking, right there. Because from everything we know of physics?
We can, today, theoretically assemble planetbusters.
We can not, even in theory, assemble a defense or viable early warning system against such.

You assume this basic concept will fundamentally shift based on tech we don't even have a viable premise for.

Which is nice sci-fi but not a good argument because you might as well have said "God will save them" or "Gandalf will be around to fix it".



That's not a given.

From everything we currently can extrapolate, there are hard limits to physics. Break those and yes, you would effectively be a deity because concepts such as time, distance, entropy and thermodynamics are suddenly optional.

What you are currently doing is to argue that through means unknown any species a million years old is effectively a pantheon. Since we haven't observed any megastructures built of thousands of stars racked up to spell out words and images, or other massive-scale examples of stellar manipulation within the billions of lightyears we can observe, I posit there's no reason to believe that technogy ever violates those boundaries.

I get it, you want to believe. That's fine. So do I, because what reality offers us is evidence only of limits.
We can armchair our favorite fantasies in another thread.

For this one, however, I posited that given what we can reasonably extrapolate, dark forest is plausible unless it turns out that interstellar travel is practically impossible.

Dark Forest Theory is based on a fallacy akin to an infant thinking its entire life must forever be bounded by its cradle. It sees another infant in another cradle across the room, and instantly jumps to the conclusion that the other infant is an existential threat and must be eliminated by any means necessary. It doesn't realize that the other cradle is irrelevant, and that it's future will expand into the rest of the house, later the wider community, and eventually the outer world itself.

In a practical sense, if one civilization in the galaxy becomes aware of another it will be because:

A. The first civilization has already expanded beyond its home planet and is at least capable, if it has not already, of becoming distributed across many bodies in addition to that planet. In this case, the civilization it has encountered cannot possibly be a threat to it.
B. Same situation but reversed, the newly discovered civilization is the widely distributed spacefaring one. In this case the first civilization cannot hope to destroy the other one.
C. Both civilizations are widely distributed spacefaring species. Neither can destroy the other without sustaining serious damage to itself. In this case, cooperation is the only practical existential choice.

Essentially, the starting assumption that any life form on or from another planet is a threat and must be eliminated is simply not a valid one. It's a paranoid delusion. Any culture or society that begins an expansion process with that paranoid delusion will inevitably come to look on other segments of its own civilization as that threat long before they find aliens. They'll then form their own Great Filter.

 

[llanitedave]

It’s not at all clear that the Moon formation event resulted in much different structure for an Earth-sized planet than Earth currently has. The Moon’s mass is very small compared to the Earth’s. That is, if the Earth had accreted to this size directly, it’s not clear its make-up would be all that different. We also can’t say for sure that Mars and Venus did not result from similar late-stage collisions. Only that if they did, the events didn’t result in spinning off 1% of their mass into a satellite. Mars and Venus lack magnetic fields because they lack convecting cores. Mars’ core cooled too much because Mars it’s small. Venus because plate tectonics shut downs and it spins so slowly.

There are lots of claims about the Moon’s contribution to the evolution of life on Earth. It’s not clear any of them make the Moon necessary. Maybe “helpful”, but we don’t even know that for sure.

There's abundant evidence that Mars at least suffered massive impact effects, considering its entire northern hemisphere is essentially one big impact crater.

One possible explanation for a lack of plate tectonics on Venus is due to its loss of water. Being closer to the Sun and further from the snow line, it may well have formed initially with much lower amounts of water, and its high temperatures have helped ensure the loss of what remained. Dry rocks aren't nearly as plastic, and are more difficult to melt, than hydrated rocks such as those within the Earth.

 

[EnPeaSea]

A beautifully phrased understatement, because overstatement using relatable human vocabulary is simply not possible.

One of my "local" favorites is that you can, depending on the time of year, fit every last planet in our solar system end-to-end between the Earth and the Moon. There's some drift back and forth, but on average the math works!! That's absolutely NUTS.

I just thought "surely the diameter of Jupiter is larger than the distance from Earth's surface to our moon's surface!" Nope, 88,695 miles vs 238,855 miles! ALMOST 3 JUPITERS FIT IN THERE! The distance from Earth to the Moon does not fit in Uranus!

Even "ankles" seems generous.

Standing on moist sand and we have thrown a message in a bottle into the ocean.

Not so. Defense radars make Earth brighter than the Sun at those wavelengths. We are relatively easy to detect up to 70 ly away.

Might as well be whispering and expecting to be heard by your neighbor in his house.

Don't Humpbacks communicate with their cousins out among the stars, using their songs?

Have you done a lot of LDS?

If you notice a species in the equivalent of our 21st century...

Hold it! Human civilization has existed much longer than 21 centuries, long before the arbitrary marker we placed as "common era" but still pinned to a mythological event.

 

[caseykoons]

Two points, one realistic the other artistic and dismal.
1) It's about the same to say, after analyzing a cup of water from the ocean, that whales do not exist, as it is to say, based on the space we've scanned for intelligent life, intelligent life does not exist. Space is BIG, we've barely started to look.
2) "Swarm" by Bruce Sterling and the Love Death and Robots episode based on it. Intelligence IS the great filter.

 

[llanitedave]

Have you done a lot of LDS?

What do mormons have to do with this?

 

[Surtrus]

Dark Forest is only nonsense if interstellar travel turns out to be impossible OR if no civilization out there has been shaped by evolutionary pressure.

It's rooted in cold war math. Deterrence only works if the other side can see the attack coming in time to launch the retaliatory response.
If you can only see the attack by the time it affects you the one to strike first always wins.
Dark Forest simply assumes that there will be no civilizations left who didn't keep quiet and who didn't strike first.

It's cold, simple logic.

Dark forest has a HUGE and UNREASONABLE assumption that strike first guarantees no retaliation. There's a reason that the cold war didn't turn hot, and it's that retaliation was inevitable. The idea that planet killing weapons are capable of wiping out a modestly advanced species is unreasonable. We will be beyond the reach of planet killers within 200 years, and likely beyond the reach of star killers within 1000. If you launch such a strike you need to be sure sure sure your opponent is not going to be able to retaliate.

 

[Aliester]

I think the better question is "when is everybody?".

How long do we expect other spacefaring civilizations to be leaving traces that we can detect at our current technology level? Human civilization has gotten from nothing to spaceflight in, what, under 10k years? Right now we're leaving a transient footprint in the form of radio emissions, but how long will humans be communicating by blasting out radio in all directions? A thousand years? More? Less? If intelligent life developed on another nearby planet and followed a similar trajectory, but achieved intelligence a few thousand years earlier - on a timescale of billions - we'd have just missed them.

The "great filter" doesn't need to be much more than "after 100k years, any intelligent species has developed to a point where we couldn't detect them and they wouldn't think to interact with us".

This is my feeling as well. Orcas, some octopus, crows, and ants arguable exhibit levels of intelligence. They build stuff, use tools, ..etc. But, we arent trying to open up diplomatic channels with them as the gap is wide between us.

A species which achieved our levels of intelligence thousands of years ago may see us the same way. Interesting but not reaching a level that they would consider intelligent. that is of course if they can even detect our existence.

Another piece of this is that we tend to be optimistic on what is possible technologically to the point of fantasy. But, our universe appears to have very real hard limits. If we can’t travel faster than the speed of light then the gulf between stars may just be too great to overcome. If fusion at scales smaller than a solar mass cant produce more energy than we put into it; then even generation ships may be impossible for us.

 

[dr_eeew]

I've given this some thought. I'm going to be using a lot of rounding of numbers here, so pedants can just chill.
Earth is about 4byo, life showed up about 3.5by ago, and the Cambrian Explosion was about 600my ago, but I'm going to round to 0.5by ago. In other words, if an alien probe were to check out Earth any time in that 4 billon years, 3 billion of them would have only had very simple, presumably, boring life. It's likely that simple life has evolved many, many, times, but maybe something like Eukaryotic life is 1 in a million, and complex (Cambrian Explosion stuff) is 1 in a billion. There is an estimated 100 billion star systems in the Milky way, so let's say 100 of them have complex life. That's not much. Millions with simple life, but few with complex life.

Tool making is maybe up to 2 million years old (1/2000th the history of Earth). Let's take an example of an alien probe, if they visit Earth, then only in .05% of the time will they find tool using beasties. If they visited 3 million years ago, would anything have looked interesting enough to them?

We've only been sending signals out to the universe for essentially 0 years, rounded off.

Let's be very, very, generous and say H Sapiens and our descendants are good for another whole million years, or 1/4000th of the history of the planet.

Let's have one of those 100 other solar systems with complex life develop enough to also be intelligent.

If they're only 2 million years offset from us, plus or minus, then essentially, we never existed at the same time as them.

That's with the assumption that intelligent life will be around for 1 million years. If we snuff ourselves out in 100,000 years, then the odds are microscopic that intelligent species would overlap. Even if all 100 of the systems that develop complex life also develop intelligent life, what are the odds they'd overlap?

Maybe there are hundreds of dead civilizations out there, and hundreds of potentially intelligent species out there, but most likely, none are where we are now at the same time.

Or we're just a computer simulation by some doped out alien teenager.

 

[postadelmaga]

I think earth like planet are kind of special on the galaxy scale:

- Water and Temperature are definitely a key factor.
If well balanced allows liquid water but also steam and ice and so mild enough weather pattern.
- Dimensions of the planet for light gravity

- Even Moon apparent size equal to sun is kind of unique ( and so full solar eclipse and huge tide as well)
Is there any other planet in the solar system with it ?
(Saturn and Jupiter have a huge amount of moons but I guess none has the above property)

 

[EnPeaSea]

What do mormons have to do with this?

In Star Trek 4, the same movie that introduced the idea that whales communicate into space to the lore*, Spock gives an odd response to a resident of 1980s Earth. Kirk says "I think he did a little too much LDS." (Intended LSD, but they don't have that drug nor the religion in the future.)

*The astronavigator whale in Lower Decks is a nod to ST4.

 

[Chanur64]

It’s not at all clear that the Moon formation event resulted in much different structure for an Earth-sized planet than Earth currently has. The Moon’s mass is very small compared to the Earth’s. That is, if the Earth had accreted to this size directly, it’s not clear its make-up would be all that different. We also can’t say for sure that Mars and Venus did not result from similar late-stage collisions. Only that if they did, the events didn’t result in spinning off 1% of their mass into a satellite. Mars and Venus lack magnetic fields because they lack convecting cores. Mars’ core cooled too much because Mars it’s small. Venus because plate tectonics shut downs and it spins so slowly.

There are lots of claims about the Moon’s contribution to the evolution of life on Earth. It’s not clear any of them make the Moon necessary. Maybe “helpful”, but we don’t even know that for sure.

It's not? Scientists concluded we ended up with most of the core (hence minerals), and the moon ended up with most of the crust from that collision. The moon is nearly all crust with a very tiny core, around 20% of the diameter as compared to around a core diameter that's typically 50% of most planets. We know the impactor was another planetesimal of comparable size to Earth, some estimates of Theia think it was even close to Mars. But regardless even reducing Earth's size and mass by a conservative third would put us considerably closer to a planet like Mars, and as my original post and yourself both stated Mars was too small to retain its dynamo. Mars is not that much smaller than the Earth, even if it does have significantly less mass. Without Theia a smaller core would've meant less metals, a lower gravity, and almost certainly a weaker dynamo. And considerably less heat given the resulting collision reliquified the planet, and certainly remixed the distribution of metals through the crust.

As for Mars, they've been saying its age is around 100 million years older than Earth. Sure that's nothing on geologic timescales, yet on a human time scale that's everything. If the Earth had formed at the same time as Mars then humans would already be extinct... either because we killed ourselves off, or because whatever becomes of us would no longer fit the current definition of a human. 100 million years ago the dinosaurs still roamed the Earth, for that matter.

I never said the moon was necessary for life, but scientists agree it certainly helped and they have the evidence to back that up. We already have the math to calculate precisely what a 7 hour day's rotation would've done to the planet's wind speeds, storm strength, and weather patterns. Anyway my point was planet size matters quite a lot, even a 0.67x the size is too small and 1.5x the size is too big. That alone considerably narrows down the list of viable candidates out there to a more manageable number that is not infinite.

One possible explanation for a lack of plate tectonics on Venus is due to its loss of water. Being closer to the Sun and further from the snow line, it may well have formed initially with much lower amounts of water, and its high temperatures have helped ensure the loss of what remained. Dry rocks aren't nearly as plastic, and are more difficult to melt, than hydrated rocks such as those within the Earth.

Theory I heard was heat. Certainly the heat is why Venus has more than 50x the volcanoes found on Earth and considerably higher number of active ones at that. Forget which sciency astronomy show it was I last watched, but they indicated a current theory was simply that the heat was too high so there wasn't sufficient temperature differential for crust/plate tectonics to hang around after Venus heated up.

But who really knows, we don't yet even understand why Venus is rotating backwards. Any event strong enough to reverse the spin of a planet comparable to Earth would certainly shatter and reshape tectonics on a planetary scale, let alone be guaranteed to utterly mess up the planetary core & dynamo...

 

[Atterus]

What do mormons have to do with this?

I mean... honest answer? Hopefully not a lot...

Tbf, I'd think Scientology has more to say here.

 

[myk.dinis]

Through natural evolution probably not, but what if we could genetically engineer away the weaknesses? Or upload our contentiousness into less fragile bodies? While we are nowhere close to those things now, there is nothing saying that they are impossible. Although whether we would still be considered Homo Sapiens at that point is a matter of debate.

Warhammer?

 

[EnPeaSea]

I mean... honest answer? Hopefully not a lot...

Tbf, I'd think Scientology has more to say here.

Unless we find Kolob!

 

[LotusPoet]

One of the problems with a generational ship is that by necessity, every generation past the first one will be slave labor sentenced to a life locked in a metal can.

On earth if I don't like it where I live i can, with some difficulty, move elsewhere. Take up a different job. Reeducate myself and switch careers.

N31bzx, third generation crew on the "Hellbound" generational starship, named "Steve" by his genetic donors, will have to do his part to justify the strain he's putting on life support. The open slot which needs a worker to fill it is plumbing, so a plumber he will be. Or he'll have to be recycled for hydroponic biomass if he's unable to pull the weight to justify his existence as counted in matter and energy.

1) Capitalism is never going to build a generation ship. I know you love your "everything will always be dystopian" bit, but if we're at the point we can make such a ship then we've pretty obviously moved past this bullshit capitalist belief of "everyone has to slave at menial jobs that are better done by machines just so the wealthy can have more"

2) Any "captain" can be stuffed in a recycling bin just as easy as anyone else, and they can't run away to a new country any more than you can. Also, our bodies getting recycled when we're done with them is such blatant common sense/practical need in that setting that, and I love jabbing you with the irony here: religious beliefs about the sanctity of dead bodies would be forbidden from the get-go because basic science is king in a fragile-ass tin can in space - and surely you wouldn't argue against a society where religion is subservient to science.

3) I worked as a plumber's gopher for 6 months. Fuck any job where you literally deal with other people's shit all day. Fuck "I finally got a real job besides flipping burgers!!" only to start building a goddamn Olive Garden. Fuck digging trenches in shitty mud while some suburban fucktard blathers on about stupid bullshit without even offering you a glass of water...

The people that do that job are God Damn Heroes of Society, but I fully agree that NO sane, rational person wants to do that job - so I'll agree on that point, but would note I may be slightly biased.

 

[Chuckstar]

It's not? Scientists concluded we ended up with most of the core (hence minerals), and the moon ended up with most of the crust from that collision. The moon is nearly all crust with a very tiny core, around 20% of the diameter as compared to around a core diameter that's typically 50% of most planets. We know the impactor was another planetesimal of comparable size to Earth, some estimates of Theia think it was even close to Mars. But regardless even reducing Earth's size and mass by a conservative third would put us considerably closer to a planet like Mars, and as my original post and yourself both stated Mars was too small to retain its dynamo. Mars is not that much smaller than the Earth, even if it does have significantly less mass. Without Theia a smaller core would've meant less metals, a lower gravity, and almost certainly a weaker dynamo. And considerably less heat given the resulting collision reliquified the planet, and certainly remixed the distribution of metals through the crust.

The Moon is 1% the mass of the Earth. What ended up in the moon doesn’t move the needle on what Earth ended up with. Earth got plenty of crustal material back. Unless one thinks that fractions of a percent differences in elemental composition would change the ability to host/evolve intelligent life, the missing mass of the Moon is irrelevant.

And of course the Earth would be smaller without the Theia impact, and I specifically addressed that I was saying that any other accretion to this size would have had a similar result, whether or not from such a big, late impact.

As for Mars, they've been saying its age is around 100 million years older than Earth. Sure that's nothing on geologic timescales, yet on a human time scale that's everything. If the Earth had formed at the same time as Mars then humans would already be extinct... either because we killed ourselves off, or because whatever becomes of us would no longer fit the current definition of a human. 100 million years ago the dinosaurs still roamed the Earth, for that matter.

Or we’d be having this same conversation 100 million years earlier.

I never said the moon was necessary for life, but scientists agree it certainly helped and they have the evidence to back that up.

No, there is not consensus on that point. Hence my comment in the first place. I’m not a lone voice.

We already have the math to calculate precisely what a 7 hour day's rotation would've done to the planet's wind speeds, storm strength, and weather patterns.

We wouldn’t necessarily have had a seven-hour day without the Moon. A slightly different impact from Theia and we might have had no Moon and any of a range of possible rotational periods. A planet’s rotation is a result of the the sum of all angular momentum during accretion. We’re not limited to imagining the necessity of a Theia-like impact and a big Moon to get to a reasonable day length. Not that I’d concede that bigger storms would necessarily do anything besides make life look different, and who knows what that means.

Anyway my point was planet size matters quite a lot, even a 0.67x the size is too small and 1.5x the size is too big. That alone considerably narrows down the list of viable candidates out there to a more manageable number that is not infinite.

One has to make an awful lot of assumptions to get there. Mars is stripped of atmosphere by a G-type star. What about a small planet at Goldilocks around a much cooler/dimmer star? What about a bigger planet where they don’t get to space until they invent nuclear rockets?

Theory I heard was heat. Certainly the heat is why Venus has more than 50x the volcanoes found on Earth and considerably higher number of active ones at that. Forget which sciency astronomy show it was I last watched, but they indicated a current theory was simply that the heat was too high so there wasn't sufficient temperature differential for crust/plate tectonics to hang around after Venus heated up.

The theory is that the heat drove out the water, and water is a both literal and figurative lubricant for plate tectonics.

But who really knows, we don't yet even understand why Venus is rotating backwards. Any event strong enough to reverse the spin of a planet comparable to Earth would certainly shatter and reshape tectonics on a planetary scale, let alone be guaranteed to utterly mess up the planetary core & dynamo...

All the more reason why Theia might not represent a special event that should be considered to make Earth more of a rarity. The three big inner planets all have some evidence of huge impact events late in formation.

 

[Chuckstar]

Have you done a lot of LDS?

Isn’t that the Scientologists who believe in aliens, rather than the Mormons?

 

[VincentL]

how long will humans be communicating by blasting out radio in all directions? A thousand years? More? Less? developed to a point where we couldn't detect them and they wouldn't think to interact with us".

To a very large extent, we have already stopped blasting out high power radio waves. High power shortwave broadcasts are a thing of the past, television is largely digital now and would look like noise, and most other high power radio would be replaced by internet-based streaming.

 

[Chuckstar]

To a very large extent, we have already stopped blasting out high power radio waves. High power shortwave broadcasts are a thing of the past, television is largely digital now and would look like noise, and most other high power radio would be replaced by internet-based streaming.

Wouldn’t a high powered digital broadcast still show up as the carrier wave? Just that the data would be indecipherable?

 

[OptimusP83]

Maybe just like us, they're trying their hardest but they've also fallen victim of the wiles of greed, emotion, and power.

See: Dolphins and Orca whales.

 

[O/Siris]

The last few months have not been good for my environmental pessimism or my misanthropy, but do we have any real evidence that human-style technology-using, oil-drilling, spacefaring, atom-splitting intelligence is actually an adaptive trait that promotes survival of civilizations on a multi-millennium time scale? Because right now, it looks like we're bouncing on a diving board, eagerly preparing to triple-gainer ourselves into a fucking wood chipper. We have met the Great Filter, and he is half the electorate.

Maybe the most sustainable form of sentience is, I dunno, whales, or octopi. Sentient, smart as hell, but not actually technological and no real reason to be, and god help their asses if they learn how to build nukes and internal combustion.

It's possible for that to be both right AND wrong. Technology is not a given outcome to intelligence.

I'm reminded of a sci-fi story I read a long time ago whereby most intelligences were speculated to result in mind expansion and development, resulting, basically, in psychic powers and exploration. But the story speculated that such an evolution resulted in sterility. Humans "chose" technology.

It's always kinda tugged at my speculative mind. Intelligence doesn't have to mean toolmaking or machines. But tools, and machines, these are the evidence that we seek out in our efforts to find other intelligences. Maybe we've seen the trunk, the ears, the tail. Maybe we just haven't recognized the elephant. Not yet.

 

[passivesmoking]

If Earth is typical, then species probably all go extinct before they can reach the stage of space-faring civilisation because they're too busy voting for people who will ruin the environment for quatlus and persecute the subsection of their population that are black on the wrong side.

 

[akatsuki]

My pessimistic hypothetsis

Evolutionary pressure + intelligence creates naturally over-exploitative, aggressive characteristics leading to self-destruction. My n=1 at this point.

So maybe intelligence is just an evolutionary dead end and nothing very special at all.

 

[DeeplyUnconcerned]

That’s pretty misleading. What we decide to refer to as a theory is pretty loose, and lots of underlying principles have been understood for a long time.

Buoyancy has been well-understood since Archimedes, for instance. We tend not to refer to a theory of buoyancy, but not because that would violate the meaning of “theory”.

The Greeks also understood that eclipses were the shadows of the Moon on the Earth and Earth on the Moon, and understood how to predict them. One could certain refer to that as having been a correct theory of eclipses.

Purposeful breeding of plants and animals could be referred to as resulting from a correct theory of heritability.

Happy to be given a less misleading formulation; I'm trying to be precise there (although, OK, not trying that hard). It's also something that I heard like twenty years ago (albeit from someone who had the very specific credentials needed to be making that claim authoritatively), so I don't have a hard reference for it, unfortunately.

 

[Chanur64]

Maybe there are hundreds of dead civilizations out there, and hundreds of potentially intelligent species out there, but most likely, none are where we are now at the same time.

I couldn't agree more, I've made a similar argument to people.

You could take your calculations one step further. Quite literally, life as we know it (Jim) couldn't even have existed for who knows how long, because the universe required multiple millennia of star formation and explosions and reformations and still more explosions just to reach the point where the the current periodic table existed. Stars literally had to form, live out their entire lives, die, and start the process over again some number of times. Even short-lived hypergiants have rather long lifespans on human time scales, and we're talking about sufficient time to allow for generations of them to come and go before the elements we take for granted that allow us to evolve came into widespread existence. So unless the aliens are star trek style energy beings, then carbon based lifeforms would've only been able to evolve after a sufficient range & sufficient quantity of periodic elements had first been created.

 

[steelcobra]

Perhaps it is a combination of intelligent life being exceedingly rare combined with no possibility way to travel at a reasonable speed (no FTL travel possible, etc.)

That we know of. That's kind of the big issue, is that right now we're using two things, physical/chemical interactions, and electromagnetics, as the entirety of how we can study the universe. We don't know what gravity is, but we can detect its pull and use more and more precise sensors to measure that, but we can't directly measure the force itself. We can observe how it warps light itself. But we have no idea yet how to observe the actual force like we can a photon, much less manipulate it.

Hell, we have placeholders, dark matter and energy, to describe things that have to be there for the universe to work on the math that fits observations, but no clue on what it could be the way we can describe the discrete energy packets that make up normal matter.

 

[Chuckstar]

I couldn't agree more, I've made a similar argument to people.

You could take your calculations one step further. Quite literally, life as we know it (Jim) couldn't even have existed for who knows how long, because the universe required multiple millennia of star formation and explosions and reformations and still more explosions just to reach the point where the the current periodic table existed. Stars literally had to form, live out their entire lives, die, and start the process over again some number of times. Even short-lived hypergiants have rather long lifespans on human time scales, and we're talking about sufficient time to allow for generations of them to come and go before the elements we take for granted that allow us to evolve came into widespread existence. So unless the aliens are star trek style energy beings, then carbon based lifeforms would've only been able to evolve after a sufficient range & sufficient quantity of periodic elements had first been created.

To elaborate, our sun seems to be a third generation star, plus the nebula it coalesced from seems to have been seeded with heavy elements from a nearby neutron star merger. That is, binary neutron stars that spiraled into each other, and some of what was ejected from that ended up in the nebula from an earlier supernova that eventually collapsed into our solar system.

(Someone might ask if the those neutron stars might have also been the original source of the nebula, and I don’t know the answer.)

The first generation of stars might have formed within a hundred million years of the Big Bang, and burned out within a few million years after that. So it might have been one quick generation of stars and one relatively long-lived generation of stars (lifecycle on the order of a billion years) between the Big Bang and our Sun.

 

[steelcobra]

In Star Trek 4, the same movie that introduced the idea that whales communicate into space to the lore*, Spock gives an odd response to a resident of 1980s Earth. Kirk says "I think he did a little too much LDS." (Intended LSD, but they don't have that drug nor the religion in the future.)

*The astronavigator whale in Lower Decks is a nod to ST4.

There's actually at least a couple references to there being a Cetacean Ops sector on board the Enterprise-D hidden in TNG, too.

Prodigy also has a Cetacean Ops center on the Voyager-B.

 

[steelcobra]

Warhammer?

40K is actually really aggressive about the idea that the human form must be protected against unchecked mutation, and that even the useful mutations like Psykers (especially the really critical ones that hold the Imperium together, like Astropaths and Navigators) must be heavily controlled and regulated. Which is also why they restrict Stable Abhumans like Ogryn, Squats, Ratlings, and Felinids from mixing with baseline humans.

Random mutations are also usually a sign of chaos taint in the setting.

 

[domikai]

I think a problem with your argument is that it doesn't scale to galaxy sizes. (Or nearby-galaxy sizes.) 300 lightyears is not very far at all. Launch at a target that is 10000 light years away and you have absolutely no idea what it will encounter when (or if) it gets there.

The scales are too large for a reactive approach (i.e. observe and attack), and a preemptive approach (i.e. have agents watching and ready to act) would unfold over such large distances, times and numbers of star systems that it seems impossible to control.

I am left without a suggestion as to survival strategy for a nice decent civilization.

Make yourself a really comfy house boat or 10^n, and enjoy swanning around with your friends. Bring lots of media. Tune in regularly to the hit reality show "What will the sessile think of next !".

 

[passivesmoking]

There's actually at least a couple references to there being a Cetacean Ops sector on board the Enterprise-D hidden in TNG, too.

Prodigy also has a Cetacean Ops center on the Voyager-B.
View attachment 106164

Sorry to nitpick but it's Voyager-A.

But Prodigy is a damn fine addition to Trek, even for establishing that in the mirror universe even the whales are evil, and if it doesn't get a season 3 I'm going to riot.

 

[mmurray]

I thought the same. The Great Filter is the sheer size of the universe.

Maybe there are alien civilizations out there at roughly the same level of technological achievement. We have barely left the confines of our solar system via unmanned probes. Why assume there would be these mega-engineering feats to detect, even if we could detect them?

Remember too that because of the sheer vastness of space, any radio signals will take thousands to millions of years to reach us, if there is any radio signal left to detect. Maybe the intergalactic "Hello World" message is still on its way here. Maybe we lack the particular ability to detect or and missed the call.

The counter argument to that is if you can create aself-replicating probes that travel at about a tenth of the speed of light then calculations show they could reach all the stars in the galaxy in about 500,000 years. Of course I've made that "if" do a lot of work! Also the implication is we have looked for such artefacts and not found them but we haven't actually looked very hard in our own solar system yet.

 

[steelcobra]

Sorry to nitpick but it's Voyager-A.

But Prodigy is a damn fine addition to Trek, even for establishing that in the mirror universe even the whales are evil, and if it doesn't get a season 3 I'm going to riot.

It's in a weird place, where the showrunner basically has freedom to make more seasons, and Netflix is happy to host it, but they need someone to back its production because Paramount wont.

 

[steelcobra]

The counter argument to that is if you can create aself-replicating probes that travel at about a tenth of the speed of light then calculations show they could reach all the stars in the galaxy in about 500,000 years. Of course I've made that "if" do a lot of work! Also the implication is we have looked for such artefacts and not found them but we haven't actually looked very hard in our own solar system yet.

 

[orwelldesign]

The last few months have not been good for my environmental pessimism or my misanthropy, but do we have any real evidence that human-style technology-using, oil-drilling, spacefaring, atom-splitting intelligence is actually an adaptive trait that promotes survival of civilizations on a multi-millennium time scale? Because right now, it looks like we're bouncing on a diving board, eagerly preparing to triple-gainer ourselves into a fucking wood chipper. We have met the Great Filter, and he is half the electorate.

Maybe the most sustainable form of sentience is, I dunno, whales, or octopi. Sentient, smart as hell, but not actually technological and no real reason to be, and god help their asses if they learn how to build nukes and internal combustion.

In Bruce Sterling's Schismatrix the heroes encounters "the swarm" which is an interstellar species that doesn't think intelligence is a good adaptive trait. The Swarm makes an intelligence to interact with the heroes, having detected their experimental fuckery, then deleted it -- because intelligence is maladaptive. It doesn't work right and isn't helpful. An ant/queen model is much more likely to succeed -- because intelligent beings aren't often in the business of self-sacrifice, nor the business of the common good.

It's an interesting chapter in a very interesting book.

 

[OptimusP83]

Given I just dove into the Culture series of books, (midway through Matter right now) I find this article really interesting.

And also a bit depressing seeing our civilization's current development is roughly 200 years ahead of the Sarl and look where they are situated in the pantheon of galactic civilizations of that universe. The exact point in the book I am (Ferbin has just arrived at the Morthanveld Nestworld and is marveling at the unimaginable size and generally feeling quite small and insubstantial)really captures the existential crisis one might experience when confronted with the vastness of space.

Side note: The banter in the culture series is just so well written. I'm constantly guffaw-ing at Holse and Ferbin's interactions in the book and there are plenty of other examples in prior books as well, often ships/drones interacting with humans/organics, that are just so masterfully done and hilarious.

 

[brduffy]

Im not convinced that an earth like planet with a single moon as large as ours around a sun like star is "unremarkable". I'm guessing the stability of our planet's rotation is a big factor in providing the amount of time life needs to evolve intelligence. So maybe rare enough that we just don't see the other occurrences.

 

[fdhealy4]

1) This
2) The universe is unimaginably vast, and our intelligent friends could be billions of light-years away
3) We still have no clue how abiogenesis happened and we haven't been able to recreate it despite our best efforts. Life, even the most primitive one, is insanely inhumanly complex.
4) Evolution has created tens of millions of species, and in only one of them has it decided to grow the brain far enough to make us "intelligent". And it's taken us roughly 7 million years and a lot of luck to develop science and civilization.

Combine 2, 3, and 4, and the probability of intelligent spacefaring life is close to zero (1 divided by 10 to the power of 50), despite hundreds of billions of galaxies times hundreds of billions of planets.

5) The Earth itself is extremely unique:

• Just the right distance from the Sun
• Shielded by the five outer planets protecting us from meteorites
• Magnetic field
• The Moon (tides)
• "The gravity of Earth is strong enough to hold on to an atmosphere, but weak enough to allow chemical rockets to reach escape velocity" - germanofthebored

Paul you are my favorite astronomer but... Your premise that abundant planets capable of supporting life exist everywhere does not seem right to me. Most rocky planets in the habital zone seem to be around Red Dwarfs. Too unstable for me to seriously consider as candidates for life as we know it. Number 5 above seems to me to best describe our unique situation. Also, I don't think intelligent life is assured once life has started. Think of the extinctions that have happened in the history of our planet. If any of them hadn't happened, exactly the way they happened, we probably wouldn't be here.