[HN Gopher] The Great Filter - Are We Almost Past It? (1998)
       ___________________________________________________________________
        
       The Great Filter - Are We Almost Past It? (1998)
        
       Author : DyslexicAtheist
       Score  : 89 points
       Date   : 2021-01-17 12:08 UTC (10 hours ago)
        
 (HTM) web link (mason.gmu.edu)
 (TXT) w3m dump (mason.gmu.edu)
        
       | tyfon wrote:
       | I think the "great filter" is evolution itself. Life formed
       | almost immediately that the conditions allowed for it.
       | 
       | But it took over three billion years of relative stable
       | conditions for it go go past the stage of single celled organisms
       | and even the cell itself took a long time to form. Higher forms
       | of life are only 500 million years old and the human line only
       | started taking shape the last few million years.
       | 
       | Personally I think the universe is teaming with life but
       | intelligent/sentient life is exceedingly rare.
        
         | [deleted]
        
         | bserge wrote:
         | Or we just can't detect any, and neither can they. Space is
         | incredibly vast, and interstellar travel and communication
         | might actually be insurmountable obstacles.
         | 
         | We're really optimistic about it, dreaming up FTL and stuff,
         | but it may turn out to be just... impossible.
        
           | dcolkitt wrote:
           | You don't need FTL or anything exotic. On the scale of O(100
           | million) years, expansion at 0.001c is enough to colonize the
           | galaxy.
           | 
           | A general purpose von Neumann probe is not that far off.
           | Self-replicating micro-machinery and reasonably intelligent
           | robots already seem on the horizon. Unless there's truly some
           | unforeseen roadblock, certainly within 1000 years of current
           | growth. A 1 KG probe at 0.001c takes about 90 gigajoules of
           | energy. On the order of what an Airbus A380 uses at cruising
           | speed.
           | 
           | Given lots of patience, and an only slightly higher level of
           | current technological development, interstellar colonization
           | does not seem like an insurmountable challenge.
        
             | bserge wrote:
             | Yes, I'm talking about "within a lifetime" and with
             | feedback/observable results. As it is, that kind of
             | colonization would mean nothing to Earthers.
             | 
             | 10-20 generations and it will most likely be all but
             | forgotten. Zero impact on our solar system. Might as well
             | be a story in a videogame.
             | 
             | Perhaps it would be worth it if we worked on extending our
             | lifespans first.
        
         | beamatronic wrote:
         | "Intelligent life" destroyed its own climate so a few could
         | profit. "Intelligent life" won't wear masks.
        
           | tlb wrote:
           | While those things are indeed dumb, all forms of human
           | stupidity including wars have killed at most a few percent of
           | any generation. At the Great Filter scale, those aren't a
           | significant evolutionary pressure.
        
         | jug wrote:
         | I sometimes think of how Earth is so OLD. It's a third of the
         | age of the Universe. That is just mind boggling. While I have
         | trouble mentally grasping ages on the magnitude "billions", I
         | do know what a third is. It's a very sizable chunk. And for
         | this very old thing with life as you say very early -- it's
         | crazy how we're here only now. The sample size is small though.
         | I have no idea if quirks on the path took evolution unusually
         | long or if we're early, or what. Still, yes, this is something
         | to consider.
        
           | tyfon wrote:
           | Even more mind boggling, in Canada you can find bedrock that
           | is 4.28 billion years old and have survived bombardments,
           | erosion and plate tectonics. I'd like to have one of those
           | rocks one day :)
           | 
           | In my country (Norway) the oldest rock is "only" 3 billion
           | years old, life was well underway at that time.
        
         | Balgair wrote:
         | Two things:
         | 
         | 1) Our knowledge of physics is still very small. ~20% of the
         | universe is 'dark matter'. All we really know about it is that
         | it falls down. It outweighs the stuff you, I, and the all the
         | stars in existence are made out of by ~4x. The other ~75% of
         | the universe is 'dark/negative energy'. We know even less about
         | it beside that it seems to fall ... up (?). And it's the super
         | majority of what we know it out there. Give it another 200
         | years, and even this understanding is going to be
         | embarrassingly outdated. Any other civ that is just 10k years
         | ahead of us is going to be working in physics that we can't
         | even imagine.
         | 
         | 2) That leads to the larger issue: Time. The difference in our
         | lives and the lives of the earliest humans is literally
         | astronomical, in that we have people living up in space now.
         | That same rate of difference separates us from any neighbors
         | out there. Their understanding of our universe is likely to be
         | so vast that we're essentially amoeba to them. Though
         | intelligent life may exist out there in bushels, we're still
         | infants in what 'intelligent' means. We may be surrounded by
         | olde gods rendering us effectively alone all the same, and
         | those gods themselves surrounded by yet grander deities
         | rendering them alone as well.
        
           | tyfon wrote:
           | Yeah, I'm not saying we are peak intelligence, but it took us
           | almost 4 billion years to reach the point where we even can
           | ask the question "Are we alone?". Much of the early universe
           | had conditions that were not as stable and favourable as the
           | last 4 billion years.
           | 
           | I also think distance and time is preventing us from
           | detecting any other like us, but I'm pretty sure some exists
           | somewhere out there. It's just that the reality of physics
           | (even with more knowledge) prevents easy travel and contacts.
           | 
           | Another thing is that we have barely looked at the sky. The
           | SETI project is very underfunded and most other projects have
           | just recently started looking for planets and signatures that
           | can indicate life (not intelligent life). Many think we have
           | surveyed all of space in as much detail as our current
           | technology allowed but we are _far_ from that.
        
       | throw0101a wrote:
       | Kurzgesagt has a ten minute video on the subject:
       | 
       | * https://www.youtube.com/watch?v=UjtOGPJ0URM
        
       | gizmodo59 wrote:
       | When you realize that even if by some miracle we find a way to
       | travel at really fast speeds we will never explore 99.99999% of
       | the universe is mind boggling.
       | 
       | This video by Kurzgesagt explains it well:
       | https://www.youtube.com/watch?v=ZL4yYHdDSWs
        
       | orbgirlgi98 wrote:
       | Humans are doomed to die at the Heat Death of the universe.
       | Science tells us our universe had a definite beginning, the Big
       | Bang, and that this event will not repeat: there will be no Big
       | Crunch, no reboot. SciFi authors prefer to ignore science so they
       | can imagine immortal humans who survive the cycle of infinitely
       | rebooting universes. If we colonize the stars and galaxies we can
       | postpone our death a few trillion trillion years, but eventually
       | the last star will snuff out, the last black hole will evaporate,
       | and there will be no energy left to power the phenomena of
       | intelligence and consciousness, and life shall be no more. The
       | last humans will have to bravely face certain and inevitable
       | death just as our prehistoric ancestors did, and just as you and
       | I must.
        
         | deanCommie wrote:
         | That's choosing an arbitrary finite point on an infinite
         | spectrum.
         | 
         | What is beyond the universe? What is beyond time? What IS the
         | universe?
         | 
         | We simply do not know the answers to these questions. Hell, we
         | barely understand what consciousness and sentience is.
         | 
         | Maybe by the time we make it to the heat death of the universe,
         | we will have answered these questions, and can reverse entropy.
         | Maybe not.
         | 
         | But the quest to get these answers and to overcome our elements
         | is what gives us purpose. Everything we do in our mortal lives
         | stuck on the rock of our birth, is in one way or another, in
         | the quest to achieve that.
         | 
         | Some people find that too overwhelming, and choose either
         | religion or nihilism. I think there is a middle ground.
        
           | orbgirlgi98 wrote:
           | You don't need to fully understand something to know that it
           | will die. I don't need to know what the billions of
           | transistors in a MacBook CPU do in order to understand that
           | the CPU will cease to compute if placed in an incinerator and
           | burned to gas and ash. I don't need to understand how the
           | human brain works in order to understand that it will no
           | longer work when our star balloons to a red giant and
           | incinerates the brain to gas and ash. You don't need to
           | understand things in order to understand that they will end
           | when physically destroyed. Everything in our universe will be
           | physically destroyed at the Heat Death. Time, Space, Matter,
           | and Energy will all end. There is no "middle ground". It will
           | all end. If there is an eternal God who exists outside the
           | universe and who will sustain the immortality of souls, as
           | Plato thought 2400 years ago and all noteable Judeo-Christian
           | philosophers have held, then something of humans will exist
           | after the Heat Death. Otherwise, we know it will all die, and
           | we don't need to know how it works to know that it will die.
        
         | jmfldn wrote:
         | Science tells us no such thing, and when you're talking the
         | ultimate fate of the universe then there is no consensus, just
         | different theories. There's the big freeze, the big rip, the
         | big crunch... all manner of ideas. Then there is the universe
         | itself. Well what is that? What about multiverses etc?
         | 
         | Just to take one such theory emerging from heat death ideas.
         | Once the fundamental touchstones of mass and structure
         | disappear, scale also disappears. The infinitely large universe
         | becomes physically identical to an infinitesimal one, and is
         | reborn in a new Big Bang -- with all the mass and energy of the
         | previous universe once again jammed together into a tiny space.
         | 
         | These sort of cyclic cosmology ideas are held by prominent
         | physicists including the recent Nobel prize winner, Roger
         | Penrose.
         | 
         | Like all us, I have no idea what is true but its hardly a
         | closed subject.
        
           | orbgirlgi98 wrote:
           | Scientific observation has ruled out the Big Crunch. The Big
           | Rip happens in the remote future if the equation of state
           | parameter w is less than -1, where w is the ratio of dark
           | energy pressure to its energy density. If this is true it is
           | only a minor detail of the Heat Death as far as life within
           | this universe is concerned: all biological life and
           | biological consciousness will end whether the Big Rip happens
           | before the Heat Death or does not happen. (If there is non-
           | biological Life after Death as various religions maintain,
           | then consciousness will survive the Heat Death, but otherwise
           | it will not.) The Conformal Cyclic Cosmology (CCC) of Penrose
           | is speculative and has zero strong empirical evidence to
           | support it. They've studied the CMB but it has made no
           | testable and verifiable predictions. The astrophysics
           | community at large sees the observational inevitability of
           | the end of the universe as we know it: the universe is flying
           | apart and cooling, and nothing can change this.
        
             | jmfldn wrote:
             | The universe flying apart and cooling doesn't contradict
             | Penrose, it's part of the theory just to address that
             | point. An infinite structureless, massless universe is a
             | singularity, or so the theory goes.
             | 
             | Assuming this was "settled" (whatever that means in science
             | let alone theoretical physics), mavericks like Penrose are
             | frequently proven right. 'Kuhnian' paradigm shifts are the
             | norm in science, particularly in a field like this. Expect
             | many more...
        
               | orbgirlgi98 wrote:
               | Penrose's CCC predicts all biological life on our planet
               | and all biological life on all other worlds within our
               | universe will end, just like the conventional Heat Death.
               | To point out this fact - that all biological life is
               | doomed to die - was the purpose of my original post. We
               | can talk about nuclear war, climate change, hostile
               | aliens, and other short term threats to human survival.
               | We will survive these short term threats or we won't. But
               | in the long term it is 100% certain we don't survive. We
               | only survive the Heat Death if it turns out we are living
               | in a Matrix of sorts and the computers of the Matrix are
               | hosted in a datacenter universe that is truly eternal,
               | unlike our universe which will die the Heat Death. Or we
               | survive the Heat Death if there is an eternal God who
               | gives us a post-biological existence after the Death of
               | our universe. My point is that present humans and far-
               | future humans are in the same boat as prehistoric humans:
               | we all must learn to face death bravely. Future humans
               | will never have permanent biological immortality, because
               | our universe does not allow it. Neither does Penrose's
               | universe. Furthermore, Penrose's only testable prediction
               | (CMB concentric rings caused by past reboot of universe)
               | proved unable to be replicated by three independent
               | attempts. Einstein's theory in contrast said the orbit of
               | the planet Mercury should have an observable precession
               | if true: so we pointed our telescopes at Mercury and lo,
               | Mercury did indeed precess just as his set of equations
               | said it would.
        
               | jmfldn wrote:
               | Sure we will all die, assuming humanity was alive at the
               | end. To be specific about my objection, you said that
               | this event will not repeat and I'm saying, I'm not sure
               | and neither are certain others. An eternal recurrence is
               | not ruled out. Nothing would survive a reboot though,
               | sure.
               | 
               | To be clear, assuming there was an infinite reboot
               | sequence I'm not saying that there would be life again,
               | let alone intelligent life. I'm just making a statement
               | on the fate of the universe.
        
       | TheMechanist wrote:
       | It's low orbit pollution with high speed space junk by any
       | technological civilization,resulting in an inevitable self-
       | interdiction of space flight: https://www.economist.com/science-
       | and-technology/2000/03/23/...
        
         | ericbarrett wrote:
         | I find this improbable. Kessler syndrome could well make it
         | impossible to keep a satellite in orbit at certain altitudes.
         | However it is unlikely to create a "shell" that prevents space
         | flight entirely. Kessler in LEO would be cleared fairly quickly
         | (a generation or less) and at higher orbits the debris would be
         | less dense due to the volume of orbital space it covered, which
         | expands at the square of altitude. If we were really determined
         | to get off the planet, I don't think it would stop us.
        
       | m0llusk wrote:
       | Geoffrey West's work on the laws of life and metabolism might
       | provide some insight. He shows that adaptations tend toward
       | crashes so that survival requires constant ongoing adaptation to
       | avoid self disruption. This means it is highly likely that
       | advanced civilizations will tend to crash whether it is from
       | their own consumption of resources or catastrophic changes that
       | go beyond capacity for adaptation.
        
       | dang wrote:
       | If curious see also
       | 
       | 2015 https://news.ycombinator.com/item?id=9324566
       | 
       | 2009 https://news.ycombinator.com/item?id=597461
        
       | lumost wrote:
       | While it's difficult to imagine a scenario in which humanity
       | extinguishes itself, it's easy to imagine scenarios which make
       | civilized society difficult, and could preclude future advanced
       | civilizations from ever emerging on Earth, these may constitute a
       | variety of "hidden filters" which make exiting ones own solar
       | system or mustering the energy to make oneself known impractical.
       | 
       | The article makes reference to a million year time horizon,
       | however even earthly nuclear energy reserves may become strained
       | on a thousand year time horizon. As we're all acutely aware, the
       | great biochemical battery of fossil fuels is already operating on
       | diminished capacity. Planet's such as mars lack the hydro-cycle
       | to drive renewables, the organic legacy to support fossil fuels,
       | and potentially the tectonics to enable surface extraction of
       | nuclear fuels.
       | 
       | While a theoretical expansion outside of the confines of earths
       | gravity to acquire resources from asteroids, or produce high
       | concentrations of solar energy is currently achievable on a
       | 20-100 year time horizon, supporting the energy demands of the
       | aerospace supply chain or considering regular space launches may
       | be difficult in 2 centuries. On a thousand year time horizon it's
       | entirely plausible that maintaining a purely renewable economy
       | makes the production of certain materials impractically expensive
       | when considering the concentrated energy demands of blast
       | furnaces or industrial mining.
       | 
       | Similar collapse events have occurred historically due in part to
       | the exhaustion of limited resources such as forests have occurred
       | in the past in both Europe and polynesia. If a similar event
       | occurred in the future it's entirely plausible that a future
       | civilization would be unable to muster the resources to ever
       | "unlock" the next set of energy production capabilities.
        
         | throwaway189262 wrote:
         | > While it's difficult to imagine a scenario in which humanity
         | extinguishes itself
         | 
         | I used to believe this, until the pandemic. Now I think bio
         | weapons are infinitely more dangerous than nukes. Imagine if
         | COVID was a few times more contagious and as deadly as it's
         | close relatives SARS and MERS. Not a big stretch really.
         | 
         | We would be pondering extinction right now. If the power was
         | still working.
        
           | jononor wrote:
           | While the COVID-19 pandemic has struck hard in some
           | countries, it has not been on a scale which threatens
           | humanity in any form? Excess deaths for 2020 are in the
           | ranges 10-300 per 100k, meaning under 0.3% in the worst case.
           | https://www.economist.com/graphic-
           | detail/2020/07/15/tracking... Not that pandemics cannot be
           | properly devastating. During the bubonic plague up to 50% of
           | the population died in many areas across the world. It was
           | still no threat to humanity though.
        
             | sgt101 wrote:
             | A pathogen as deadly as the plague and as mysterious or
             | intractable to medicine as the plague was in the 1200's
             | released into a connected world such as ours would have an
             | astonishing impact.
        
             | TeMPOraL wrote:
             | The threshold that matters isn't extincting humanity, but
             | collapsing modern technological civilization. That's much
             | easier to do.
             | 
             | The current pandemic revealed how fragile our supply chains
             | are, and I still consider it a small miracle that the
             | impact so far was _so small_. Lots of people are in dire
             | straits, yes, but the world structurally didn 't change
             | much.
        
         | UweSchmidt wrote:
         | Scenarios where humanity extinguishes itself are easy to come
         | by: We are still living under the threat of accidental or
         | intentional launch of a great number of nuclear weapons. The
         | remaining civilizations might be unable to survive or thrive
         | with what's left.
         | 
         | On the other hand speculating about the technological limits of
         | humanity a million years in the future is difficult when we've
         | only come up with nuclear energy a few decades ago, and while
         | progress in some areas has been overdue, generally there seem
         | to be quite a few "research trees" with potential for scifi-
         | tech.
        
           | Retric wrote:
           | Industrialization would be slower without fossil fuels, but
           | that doesn't mean it can't happen. Small scale wood smelting
           | can eventually make way to hydro powered electric based
           | smelting.
           | 
           | We are used to a very energy extensive economy, but most of
           | the world would be habitual without any home heating or
           | cooling for example. Similarly, a network of street cars need
           | something like 1% of the energy as individual cars for
           | everyone in a city. Historically, rivers, streams, and canals
           | where similarly quite efficient long distance transportation
           | networks we have largely forgotten about.
        
             | henrikschroder wrote:
             | > We are used to a very energy extensive economy
             | 
             | Like you say, there are enormous amounts of low-hanging
             | fruit when it comes to energy efficiency across all of
             | society.
             | 
             | Take building insulation, for example. Where I'm from,
             | triple glaze windows were made mandatory 30 years ago,
             | every single existing apartment building was forced to
             | retro-fit. Yet when I moved to the US less than ten years
             | ago, apartment ads would regularly highlight "DOUBLE
             | GLAZING" as if that was some incredibly expensive and
             | luxurious feature.
             | 
             | Also where I'm from, I used to own an apartment in a
             | building from the 1940s. But a bit more than ten years ago,
             | new strict energy efficiency requirements went into effect,
             | so my building - and every building like it in the country
             | - had to fix it, often by adding a thick layer of
             | insulation on the outside.
             | 
             | I still own an apartment there, it's newer, but the outside
             | walls are 30cm thick and made of concrete for insulation
             | purposes. And yet, here in the US, I regularly see new
             | housing construction that's essentially just plywood for
             | every single wall, inside and outside.
             | 
             | The US is incredibly behind when it comes to insulation and
             | energy efficiency, because the economics of it doesn't make
             | sense. If energy were to become much more expensive, this
             | would change pretty damn fast.
        
               | count wrote:
               | There's also a US approach to 'grandfathering' in
               | existing structures as building codes are updated. The
               | only time I will ever 'have' to bring something in my
               | house up to date is if I voluntarily do something like
               | open a wall or install a new HVAC unit. And then the only
               | thing impacted is that item, nothing else even gets
               | inspected for safety/compliance.
               | 
               | I understand it to some extent: TONS of people can't
               | afford to just...replace all of their windows, for
               | example.
        
               | ghaff wrote:
               | I live in an early 1800s farmhouse which has had a lot of
               | work done on it over the years--to code--and has had new
               | top-of-the-line windows put in as well. But if the whole
               | house suddenly had to be fully compliant with modern
               | code? You'd probably just need to tear it down and start
               | from scratch.
        
           | lumost wrote:
           | It's really difficult to "extinguish" all human life. Even in
           | a full nuclear exchange between all major nuclear powers,
           | places such as patagonia, and new zealand will likely be
           | unscathed. Particulate matter does not generally cross the
           | border between the northern and southern hemisphere and the
           | vast majority of weapons will be detonated in the northern
           | hemisphere. This doesn't include the countless habitable
           | islands with the potential to sustain reasonably sized
           | villages.
           | 
           | A similar story exists for bio-weapons and other means. It's
           | definitely possible to end civilization today, but such
           | technologies are unlikely to end humanity - worst case,
           | rehabitation of the main continents takes 1-2 centuries for
           | the worst fallout to decay and enable farming.
           | 
           | While I don't subscribe to the view, there is modest evidence
           | that scientific progress behaves like any other process of
           | discovery - as a series of S curves where early progress is
           | slow but speeding up every year, followed by a spike of
           | progress and ultimately a steady period of diminishing
           | returns.
        
             | klyrs wrote:
             | The US has an interesting problem right now. Wild hogs are
             | wreaking utter havoc and we don't have effective means to
             | control their population. I'm fairly confident that humans
             | will win that battle. But what if we nuked population
             | centers? Most of the hogs would survive, but only a
             | fraction of the humans. Who would win out in the decades to
             | come? Hogs can eat all sorts of roughage, survive out in
             | the elements, etc., humans are much more dependant on their
             | technology. Want crops? Sorry, hogs ate 'em. Wanna eat
             | hogs? They're smart, and after your ammo stores are
             | depleted, you're back to the stone age.
             | 
             | But the question isn't mere survival -- can intelligent
             | life _thrive_ to the point where we can achieve
             | interstellar travel?
        
               | Retric wrote:
               | I think you're underestimating Stone Age humans, we used
               | to hunt freaking lions and other big cats with stone
               | tools. We started causing mass extinctions long before
               | industrialization.
        
               | klyrs wrote:
               | I'm not underestimating stone age humans -- I've spent
               | much of my life learning and using stone age skills. Not
               | enough that I can actually live as a stone age human,
               | mind, and there's the rub. In that learning, I've met a
               | very small number of folks (like [1]) who are actually
               | equipped to survive a stone age. Judging by my
               | experience, by watching other "good" students in those
               | classes... with good training by masters, we still fail
               | hard on our first few times out. And we're well-fed,
               | moderately well-equipped, and _not suffering from
               | radiation poisoning_.
               | 
               | The real question isn't "how badass were stone age
               | humans", it's "can the smartphone generation re-invent
               | stone age technology quickly enough to survive"?
               | 
               | https://www.outsideonline.com/2411125/lynx-vilden-stone-
               | age-...
        
         | tachyonbeam wrote:
         | You can very much use solar panels on Mars. There's also a
         | clear advantage that right now, there's nothing on Mars, lots
         | of land to place said solar panels, but IMO, that's not going
         | to be an issue. We will probably master nuclear fission within
         | the next few decades. Lots of progress has been made, and it
         | will solve our energy needs. What if we run out of deuterium or
         | tritium? Not a problem, by that time, in a few centuries, we'll
         | likely be able to build bigger, better reactors that can fuse
         | "normal" hydrogen and maybe even helium.
         | 
         | As for the great filter, I've always thought that the real
         | danger is something that would cause say, one person, to have
         | an outsized destructive power. Imagine if we successfully
         | invent nanobots that can self-replicate, for example, and
         | anyone with the right set of skills could program them. In that
         | scenario, it's within the capability of any individual to
         | create a deadly disease. You just need one unhinged person to
         | trigger a horrible disaster. Nanotech could be much more
         | dangerous than nukes, and if you combine strong AI and
         | nanotech, I could see that being an immense survival risk.
        
           | lumost wrote:
           | Martian solar energy production has a few "unique"
           | challenges. Including
           | 
           | - Dust - Supply chain - ~40% less watts/square meter
           | 
           | Of these the most unproven is the supply chain problem. The
           | link below summarizes why solar doesn't work in the short-
           | term for mars habitation missions - it's an open question as
           | to whether there are economically extractable deposits of
           | silicon, cadmium, and other materials to build out a solar
           | farm. Bear in mind, terrestrial resource extraction makes
           | extensive use of water.
           | 
           | https://medium.com/swlh/solar-power-is-never-going-to-
           | work-o...
        
             | Balgair wrote:
             | The comparison would be for locally produced solar. We know
             | that making solar panels on Earth is a net positive energy
             | expenditure, from raw materials to recycle/disposal, and
             | just barely so. But the cost of creation of solar panels on
             | Mars is unknown relative to net energy expenditure. I'm
             | fairly certain that it would be many decades, if not
             | centuries, before it became net positive. Sending solar
             | panels to Mars is obviously not a good use of Watts.
        
           | [deleted]
        
       | gmuslera wrote:
       | Reaching a conclusion with so many unknowns (specially unknown
       | unknowns) is risky.
       | 
       | That life must evolve in enough number of planets doesn't mean
       | that the next one is close. And that interplanetary travel is
       | practical doesn't mean that interstellar or intergalactic travel
       | must be. And considering the speed of our current technological
       | development, vs the time needed to get to the next stage in
       | colonization, something big may emerge in the middle. Or
       | something different and unexpected.
       | 
       | In some way, we are like churches deciding what and how a god may
       | think. We are not at the right stage to judge based on our lack
       | of knowledge or perspective. It may not be just one road forward,
       | and going galactic may be the wrong one.
       | 
       | I prefer to take one step at a time, and solve our current
       | roadblocks, if we can. Maybe we have the great filter in front of
       | us in plain view and we can't recognize it.
        
         | pashsdk27 wrote:
         | Yes, maybe civilizations of social biological species that have
         | a relativity low replication rate like us may find contentment
         | with colonizing only a few close star systems. Create a few
         | dense population clusters like our current cities on select
         | planets and space platforms and leave the rest to 'nature'. We
         | already have a declining population growth rate of 1.1 as more
         | people are opting out of starting a family and children due to
         | technological advances and better global socioeconomic
         | conditions. And maybe our current power fantasies of galactic
         | colonization may seem trivial and 'ignorant' to our future
         | generations. One could also call this a great filter. The
         | possibilities are endless and allows one to enjoy it as a bunch
         | of inconsequential thought experiments. Actual problems that
         | require solutions are usually not fun to think about.......
        
           | ALittleLight wrote:
           | Low fertility among women is not due to desire but to demands
           | of modern society [1]. Women typically desire 2-3 children
           | each. In modern society they can't have them because of low
           | marriage rates and increased employment among women.
           | 
           | 1 - https://ifstudies.org/blog/how-many-kids-do-women-want
        
             | sdenton4 wrote:
             | Interesting collection of stats, though I don't think the
             | author's conclusions are the only possible interpretation.
             | It's clear that the family size intentions really have been
             | falling since the 60s, and that actual fertility is a
             | fraction of that, which is unsurprising. The bigger sorry
             | here, I think, is that the intended family size drops from
             | 3.4 kids to 2.0. Possibly what's happening is that 'high
             | producers' now make four kids instead of ten, bringing down
             | the overall averages. Basically, it would be nice to see
             | how the distributions of kids per woman change over the
             | decades... I expect something at least bimodal, with a
             | shrinking tail.
             | 
             | (Ed: fixed a couple stats, removed a bad statement about
             | quotients. :P )
        
               | ALittleLight wrote:
               | One problem with the data is that it's hard to know to
               | what extent modern life changes how many kids you want.
               | Meaning: if a woman knows she has to have a full time
               | job, she may only want, or believe she can afford, two or
               | three children. Conversely, I suppose a woman in
               | agricultural setting might want 7-10 children knowing
               | they could help on the farm. It's probably impossible to
               | know what people would want "unconstrained" by reality,
               | and maybe not even meaningful.
               | 
               | Two things I think are true though. First, women have
               | fewer children than they want, even if what they want is
               | declining over time. Second, women who don't want
               | children, or who want children below replacement, won't
               | ever become the majority of the population - at least not
               | for any significant amount of time. Such women will be
               | replaced by women who, genetically or memetically, want
               | more children.
        
           | ethbr0 wrote:
           | How often has low fertily held true in virgin-frontier,
           | resource-rich scenarios though?
        
             | XorNot wrote:
             | We've never had one where reliable birth control was
             | available, so there is no data.
        
           | [deleted]
        
         | beamatronic wrote:
         | I agree and I've come to the conclusion that the highest moral
         | purpose any intelligent beings can aspire to is to broadcast
         | the information "You Are Not Alone!" by any means available.
        
           | pixl97 wrote:
           | Unless of course Dark Forest theory is correct.
        
             | shrimp_emoji wrote:
             | https://en.wikipedia.org/wiki/BLC1 "DO NOT RESPOND TO THIS
             | MESSAGE!" xD
        
             | ethbr0 wrote:
             | The noun you're looking for is "hypothesis," and that's if
             | we're being charitable.
        
           | gmuslera wrote:
           | At our current stage and philosophy, it may seem that way.
           | That is the point. It may not be valid for most or all of
           | civilizations (if they could be called that way) that are far
           | from us in those and more points.
           | 
           | The same goes for some assumptions behind the great filter
           | concept, like exponential growth and biological needs. Maybe
           | the ideal goal is just a silent self-suficient culture in an
           | small outpost far away from any galaxy.
        
         | walleeee wrote:
         | > Maybe we have the great filter in front of us in plain view
         | and we can't recognize it.
         | 
         | One candidate, if we take ourselves as the primary example, is
         | biogeochemical crisis following rapid discovery and
         | exploitation of environmental resources or energy reserves
         | without sufficient consideration of the consequences
        
           | ethbr0 wrote:
           | It seems a bit convenient that every species capable of
           | interplanetary colonization manages to (a) possess world-
           | climate-altering- industrial scale, (b) rest their industrial
           | needs on a resource that threatens their ecosystem, & (c)
           | remain ignorant of the threat until it's too late to do
           | anything about it.
           | 
           | Comparatively speaking, asteroids and/or ice ages being more
           | frequent than expected seems more plausible.
        
             | TheOtherHobbes wrote:
             | It doesn't have to be climate and it doesn't have to be
             | industrial.
             | 
             | Any process which requires scaling intelligence from
             | competitively local and tribal (or any equivalents) to
             | integrated and planetary will do.
             | 
             | You either pass that test or you fail it. If you fail it,
             | stagnation and eventually devolution beckon.
        
               | ethbr0 wrote:
               | > _stagnation and eventually devolution beckon_
               | 
               | What was critical in parent's comment was the
               | irrecoverability of the civilization, after such an
               | action. Scaling intelligence is more of a repeatable
               | "trial and error" step (as the article puts it, in a
               | biology context).
        
             | est31 wrote:
             | (d) their previous activities have rendered it way harder
             | to rebuild a technological society
             | 
             | There used to be iron deposits etc. on the surface. They
             | were recovered by pre-industrial societies. Now we are
             | digging deeper and deeper for resources, but once we lose
             | that ability, it's possible we won't be able to regain it.
             | 
             | What do you do once the nuclear power plant's core has
             | melted, the mine is full of water, and there is nobody
             | around who knows what these things are even there for
             | because all the people who did died years ago of old age.
             | You can't read it up either once we've moved our stored
             | knowledge from paper to machines in what the ancient texts
             | refer to as the mythical "US-EAST-2 region".
        
               | kryptiskt wrote:
               | Humans have deposited a lot of iron and other useful
               | elements on the surface for the next civilization to
               | start with though.
        
               | ethbr0 wrote:
               | It's less of an issue with recraftable materials (like
               | iron) and moreso with one-way ones (like petroleum,
               | fissionable uranium isotopes, helium, or some plastics).
               | 
               | Of those, it feels like the only irreconcilable one is
               | scale: e.g. something you need so much of, repeatedly,
               | that no less-efficient substitute is viable.
               | 
               | And of those, geologically-created, carbon-based energy
               | sources (coal, oil) are the primaries that come to mind.
               | 
               | (Also, nitrogen, but I imagine the Haber-Bosch process
               | would survive)
        
               | deathgrips wrote:
               | Where did all that iron that we mined run off to? Is it
               | not on the surface anymore?
        
               | est31 wrote:
               | 1. it might be covered in sediments requiring expensive
               | movement for little gain (and how do you know where the
               | iron was/is?) and 2. the structures that don't get
               | covered rust away and turn into dust that erosion
               | distributes over large areas. Post apocalyptic societies
               | will be able to salvage iron here and there for a long
               | time, but will it be enough to cover our planet with
               | railways and kick off a new industrial revolution?
               | 
               | Also, the iron was only an example. Coal and other fossil
               | fuels we can only burn once, then they are gone.
        
             | patentatt wrote:
             | We don't have any evidence that there are any species
             | capable of interplanetary travel. Maybe there are none.
        
               | bserge wrote:
               | Humans can do _interplanetary_ travel already.
               | 
               | A species at a similar development level in some other
               | solar system with slightly better societal goals or a
               | need for a specific resource could already be colonizing
               | other planets or asteroids.
        
             | sdenton4 wrote:
             | Curiously, the ability to alter biomes at a planetary scale
             | is also one of the prerequisites for colonization. The
             | trick then is having sufficient control of industrial
             | processes to 'get it right,' which requires better global
             | decision making than humans have thus far demonstrated.
             | 
             | (The alternative is extreme plasticity, allowing lifeforms
             | to adapt to otherwise hostile atmospheres...)
        
               | TeMPOraL wrote:
               | > _(The alternative is extreme plasticity, allowing
               | lifeforms to adapt to otherwise hostile atmospheres...)_
               | 
               | We meet that threshold, though. We are _extremely_
               | adaptive to otherwise hostile environments by virtue of
               | technology, particularly wearable one - from winter
               | jackets to SCUBA gear.
        
             | walleeee wrote:
             | Sure, I don't think there's necessarily a _single_ filter,
             | or that this is it. Just that it 's a candidate. Your
             | examples would presumably be much more common.
        
             | cortic wrote:
             | Could be intelligence in any form is brought about by some
             | kind of grand antagonistic pleiotropy. By this i mean the
             | genes that develop intelligence in any species infancy,
             | inevitably lead to the conditions for your (a)(b) and (c)
             | later on.
        
       | Giorgi wrote:
       | I think it's much simpler than that: if there is intelligent
       | life, it is at the same level of development that we are.
        
         | meowster wrote:
         | I believe that's unlikely given that the universe is billions
         | of years old, and many galaxies are older than ours.
        
           | pretendscholar wrote:
           | Life in other galaxies is unlikely to physically leave its
           | own galaxy just given the vast distances involved. Life in
           | our own galaxy takes a number of inputs that take billions of
           | years to produce.
        
           | pixl97 wrote:
           | Most theories show that galaxies all started pretty quickly
           | after the big bang. The number of mergers they have had are
           | what is significantly different. When the universe was
           | younger and things were closer mergers appear to have
           | occurred at a higher rate leading to higher rates of star
           | formation. This in turns floods a galaxy with powerful UV
           | light, which in large amounts doesn't seem conductive to
           | life.
        
           | f6v wrote:
           | The time between the emergence of procaryotes and the
           | eukaryotes is estimated to be about 1 billion years. Last
           | time I checked the Universe is thought to be 13.8 billion
           | years. That's just one order of magnitude between these two
           | numbers. I don't think it's inconceivable that we're the
           | first intelligent life form.
           | 
           | The life itself might be an extremely rare event.
           | Multicellular life might be where the first great filter is.
        
             | patentatt wrote:
             | People always say that if life is possible, then there must
             | be a bunch of aliens out in the universe. It may be
             | unlikely, but one has to be first, maybe it's us? It's a
             | somewhat comforting thought, I like it.
        
             | Izkata wrote:
             | Also how long dinosaurs were around before the world reset
             | and how quickly human civilization developed relative to
             | that.
        
       | imhoguy wrote:
       | What if there is unlimited number of The Great Filters. What if
       | we are already Nth contingency plan seeded on Earth by N-1th
       | parent life form(s) woring about the same problem - to survive,
       | replicate further onto closest places as N+1 backup.
        
       | shiftingleft wrote:
       | The Fermi Paradox has essentially been resolved:
       | https://arxiv.org/abs/1806.02404
       | 
       | This explanation is much more plausible than a Great Filter.
       | Here's a great comment summarizing the argument very intuitively:
       | 
       | https://news.ycombinator.com/item?id=17562439
       | 
       | I also found this one very helpful:
       | 
       | https://news.ycombinator.com/item?id=17564379
        
         | bobcostas55 wrote:
         | >This explanation is much more plausible than a Great Filter.
         | 
         | I don't see how it's any different from the great filter
         | explanation. It's just great filter with statistical
         | distributions.
        
           | shiftingleft wrote:
           | The Great Filter thesis is that there has to be one or more
           | _very_ low probability events in the Drake Equation.
           | 
           | However, as per my other comments, you can update the
           | distributions of your parameters in different ways, such that
           | none of the events in the Drake equation have a particularly
           | low probability.
           | 
           | Then the Great Filter disappears and there's no specific or
           | few set of events to point to - it's just that the
           | probability of all events succeeding in combination is
           | extremely low.
        
         | sanxiyn wrote:
         | Eh no? The paper basically IS a great filter argument. Life is
         | rare and we are alone. That means there is a great filter
         | behind us.
        
           | shiftingleft wrote:
           | From the website: "The Great Silence implies that one or more
           | of these steps are very improbable; there is a "Great
           | Filter""
           | 
           | The paper argues against this in that you don't need a few
           | _very_ improbable. In fact, there are many parameter choices
           | where none of the probabilities in the Drake equation are
           | particularly low, yet the resulting number of intelligences
           | is still staggeringly small.
           | 
           | tl;dr: All parameters can be a bit lower. Then you don't need
           | any events that are extremely improbable.
        
         | seppel wrote:
         | > However, the result is extremely different if, rather than
         | using point estimates, we take account of our uncertainty in
         | the parameters by treating each parameter as if it were
         | uniformly drawn from the interval [0, 0.2]. Monte Carlo
         | simulation shows that this actually produces an empty galaxy
         | 21.45 % of the time.
         | 
         | Isn't that just elaborated way of saying that some of the
         | parameters of the Drake equation have to be much smaller than
         | we think?
        
           | shiftingleft wrote:
           | Yeah - but they don't have to be _much_ smaller.
           | 
           | Let's use the simple example you reference from the paper. If
           | we just use the mean as point estimates, then indeed we
           | obtain an extremely low probability that there's no other
           | intelligences:                 def
           | prob_of_no_intelligence_in_galaxy(p):
           | prob_of_intelligence = pow(p, 9)           planets = 100e9
           | return pow(1-prob_of_intelligence, planets)
           | prob_of_no_intelligence_in_galaxy(0.1) ->
           | 3.720086311124783e-44
           | 
           | However, there is already a 82% chance of an empty galaxy if
           | the parameter p is halved:
           | prob_of_no_intelligence_in_galaxy(0.05) -> 0.8225792614407508
           | 
           | Now of course halving every probability is a lot, however now
           | there's no single or few events that have a _very_ low
           | probability of happening. The Great Filter disappears.
           | 
           | See also my other comment here:
           | https://news.ycombinator.com/item?id=25811359
        
             | seppel wrote:
             | Why do you have 9 factors? The classical Drake equation has
             | 6 (and the L which is the avg. lifetime of the
             | civilization).
             | 
             | Also: The Drake equation has one factor which is the avg
             | number of planets per star, of which we are already quite
             | confident it is above 0.1.
        
       | dvh wrote:
       | Carbon is great filter
        
       | SkyMarshal wrote:
       | I don't think we're far enough along in tinkering with subatomic
       | physics or gravity to know whether we've passed the great filter
       | or not.
       | 
       | Hell, we haven't even managed to guarantee human rights to every
       | person on the planet yet. We've got a ways to go.
        
       | jl2718 wrote:
       | The thing I keep seeing people miss is the narrow slice of time
       | that we have existed in a technological state to be broadcasting
       | and/or looking. Assuming exponential distribution, this is most
       | likely to only last further as long as it has already. And with
       | us as the only example, it would most likely be the same for
       | others. So 50 years out of 5 billion on the planet and 3 billion
       | since life began. Are there 100M stars within radio range? Do we
       | even have time to point antennas at each one long enough to get a
       | signal? That's about 15 seconds each. How many bands do we need
       | to scan in that time?
       | 
       | Any hope of contact or expansion requires an extremely long
       | period of sustainable existence in a state of constant
       | technological development. Most of modern humanism is
       | antithetical to this. The entire world today seems focused on
       | expanding consumption. This is especially true of both
       | colonialism and immigration. Economist today judge an economy by
       | its internal consumption rather than older notions like export
       | productivity. Seems like we're going to have to reconsider
       | policies and priorities if we want to make it out of here.
        
       | carapace wrote:
       | Every time this sort of thing comes up (the Fermi Paradox, the
       | Great Silence) I like to point out that it says more about the
       | person than the real world. To wit: there is no time or culture
       | in the history of the world where humans have _not_ been in
       | contact with some kind of  "otherworldly" intelligence.
       | 
       | Personally, (not that anyone asked) I think we're in quarantine.
       | I think that most intelligent species rapidly reach a peaceful
       | "win-win" equilibrium, that we humans are rare or even unique in
       | our violence, that this is because of some specific but forgotten
       | event (maybe the Younger Dryas, I don't know) that traumatized us
       | and triggered the development of agriculture and cities, that
       | those are degenerate forms of civilization that perpetrate the
       | trauma that leads to our current malfunctions, and that we are
       | essentially in a hospice-type situation _vis-a-vis_ the little
       | green men.
       | 
       | So, um, there? Have a nice day y'all.
        
         | raldi wrote:
         | Could you explain your second sentence a bit further?
        
           | carapace wrote:
           | You mean this?
           | 
           | > there is no time or culture in the history of the world
           | where humans have not been in contact with some kind of
           | "otherworldly" intelligence.
           | 
           | If so, I'm just pointing out that communication with other
           | non-human beings is common to all human cultures. Every
           | culture has people who communicate with angels or spirits or
           | people from the sky or under the ground or some other realm,
           | sometimes those folks are central to the culture, other times
           | they are peripheral. I think our modern rational materialist
           | fundamentalists are the first to seriously posit the idea
           | that humans are strictly alone in the Universe.
        
             | cgrealy wrote:
             | > Every culture has people who _believe_ they communicate
             | with angels or spirits or people from the sky...
             | 
             | FTFY
             | 
             | There is zero actual evidence of anyone communicating with
             | any non-human intelligences.
        
               | carapace wrote:
               | > There is zero actual evidence of anyone communicating
               | with any non-human intelligences.
               | 
               | And that is _your belief._
               | 
               | Here's a whole documentary about interactions between
               | Brazilian military and something weird:
               | 
               | > In 1977, numerous UFOs were seen in the Brazilian city
               | of Colares, Para. The UFOs fired light beams at people,
               | causing injuries and sucking blood from 400 witnesses.
               | After a rise in local concern, the mayor of the city
               | requested help from the Air Force.
               | 
               | https://www.youtube.com/watch?v=ThkmRsEBOY0
        
         | oli5679 wrote:
         | I was more open-minded to this type of argument a few decades
         | ago.
         | 
         | The quality of our sensors - both smartphones held by everyone,
         | and telescopes, satellites and radar by governments has
         | improved exponentially, without a corresponding increase in
         | detection, so I think it's reasonably likely we are not
         | currently in contact with otherworldly intelligence.
         | 
         | Once I made this argument to a friend, and they sent me this
         | xkcd comic.
         | 
         | https://xkcd.com/1235/
        
           | shrimp_emoji wrote:
           | Unless the aliens stopped showing up _because_ we 've
           | developed smartphones, and they were showing up so often in
           | the 1900s because they knew it was their last shot of dorking
           | around with plausible deniability before camera and telecomm
           | tech became mainstream!
           | 
           | The tin foil always finds a way.
        
           | postalrat wrote:
           | > without a corresponding increase in detection
           | 
           | How many detections have we had? The camera argument to me is
           | ignorant of how hard it is to get a good picture of something
           | small in the sky. People are constantly taking videos of dots
           | they say was a UFO but it's impossible to identify what they
           | captured.
        
           | carapace wrote:
           | > without a corresponding increase in detection
           | 
           | With respect, have you gone and looked? To me it feels like
           | the folks who present that objection haven't actually gone
           | and checked, they're making an unfounded assumption.
           | 
           | About once or twice a year I lose a day to a youtube hole
           | wherein I go through all the recent videos of
           | {Bigfoot,UFOs,Cryptids,Ghosts} for fun. There's a lot of crap
           | out there, fake videos and hoaxes, but there are more and
           | more very good candidates for "real" videos.
           | 
           | The US Navy just released video of UFOs buzzing jets off the
           | coast, eh?
        
         | Izkata wrote:
         | > I think that most intelligent species rapidly reach a
         | peaceful "win-win" equilibrium, that we humans are rare or even
         | unique in our violence
         | 
         | This reminds me of a short story where Earth exists in a
         | Bermuda Triangle-like sector of space, known as the Veil of
         | Madness, that all other civilizations avoid:
         | https://creepypasta.fandom.com/wiki/Mankind
        
       | andi999 wrote:
       | I find the space colonization (outside own solar system) a bit
       | too optimistic, while it is 'only' a technical problem, it still
       | might be an impossible problem.
        
         | qayxc wrote:
         | Hm. I tend to think that it's not impossible, but simply very
         | impractical.
         | 
         | Outside of the very nearest neighbouring systems, any
         | interstellar colony would instantly become an isolated new
         | civilisation. There's simply no plausible way for interstellar
         | trade or even just meaningful communication.
         | 
         | All a colony at say, 82 Eridani - a sun-like star about 20 ly
         | from Earth, would have a two-way communication time of 40
         | years. Even digital "goods" aren't worth exchanging if it takes
         | 20 years to send them and another 20 years to receive any kind
         | of payment.
         | 
         | At a very optimistic 30% lightspeed, ships would take 67 years
         | to get there. This means no one can make the journey within a
         | single human lifetime, unless the lifespan is dramatically
         | increased or some form of hibernation technology is used.
         | 
         | In any case, colonists would be completely removed from Earth
         | and all that effort pretty much requires a suitable target
         | planet to be present. Without radical genetic changes, humans
         | wouldn't be able to thrive and survive on a Super Earth or in
         | poisonous atmospheres. So another factor would be spending tens
         | of thousands of years and unfathomable amounts of energy
         | terraforming planets or changing the human genome beyond
         | recognition.
         | 
         | The same issues would apply to extra-terrestrial intelligences
         | as well, which is why I don't think interstellar colonisation
         | would even be all that desirable in the first place.
         | 
         | First you have to find a suitable host star. Next you need to
         | find a matching planet. Then you need to scout potential
         | candidates (likely using automated probes), which would take
         | about a century even for just the nearest stars...
         | 
         | While all this is certainly doable, it's really not all that
         | attractive given that you instantly "lose" the colony anyway
         | simply due to the distances involved.
        
       | aptwebapps wrote:
       | Maybe by the time a civilization achieves the tech needed to
       | really expand, they no longer want to.
        
         | tlholaday wrote:
         | > Maybe by the time a civilization achieves the tech needed to
         | really expand, they no longer want to.
         | 
         | Is that your candidate for the Great Filter?
        
           | thow-01187 wrote:
           | Colonizing and terraforming every single rock in the solar
           | system increases the available land only by a factor of
           | three: https://xkcd.com/1389/
           | 
           | There's just no way every commoner gets their own Caribbean
           | cabin. Unless we find some unlikely physics hack in the last
           | few vestiges of scientific unknowns, any interstellar travel
           | seems impossibly difficult.
           | 
           | An alternative future: we live forever as brains in the vats,
           | plugged into infinite virtual worlds devoid of scarcity,
           | life-threatening danger or physical constraints. Most of the
           | human activity takes place there, with occasional
           | interactions between the virtual and the real. No new physics
           | required, just a series of incremental improvements in
           | biology and computing.
        
             | PeterisP wrote:
             | If we're being cynical, it's trivial to ensure that every
             | commoner gets their own Carribean cabin - just reduce the
             | number of commoners by a few orders of magnitude. After
             | all, with some technological advancements, you would not
             | need huge numbers of commoners just for their labor.
             | 
             | A stable future can plausibly take many forms, not all of
             | them are nice.
        
           | aptwebapps wrote:
           | That was what I meant, yes.
        
           | edgyquant wrote:
           | That's definitely what I believe
        
       | einpoklum wrote:
       | > among the billion trillion stars in our past universe, none has
       | reached the level of technology and growth that we may soon
       | reach.
       | 
       | May soon reach? I doubt it. I'd say there's a significant filter
       | between our technology level and large-scale inter-solar-system
       | colonization. It's not at all clear that there is a strong
       | motivation for that - except for a continuous-growth economy,
       | which is kind of unsustainable anyway. Once the population
       | stabilizes and human civilization is basically energy-neutral
       | (i.e. not taking more than the sun provides), where's the great
       | need to colonize someplace else (as opposed to communicating)?
       | And if we don't stabilize - civilization will burn itself out
       | soon enough, colonization or no.
       | 
       | > Even if life only evolves once per galaxy, that still leaves
       | the problem of explaining the rest of the filter
       | 
       | No it doesn't. It's extremely unlikely that one planet with life
       | will travel to a different galaxy. Even with intelligent life
       | it's extremely unlikely. Only if instantaneous travel were
       | possible would this be likely.
        
       | knome wrote:
       | I've wondered if the first of the great filters isn't simply
       | water.
       | 
       | Assuming something like octopuses evolved into a relatively long
       | lived tool-using species with complex communication, they would
       | be infinitely hampered by their environment. Even if they were
       | lucky, as we were, and their planet had available great reserves
       | of fossil fuels, they could not burn them. They cannot invent
       | fire. Without fire, they have no way to invent metallurgy. Or
       | glassworks. Or plastics.
       | 
       | What are the odds of having enough water for life to spark
       | without having so much of it that it blankets the surface?
       | Anything evolving on worlds with little land seem unlikely to
       | ever escape their world.
       | 
       | Life could be commonplace, but if most worlds it evolves on are
       | 99% water, we would never see it or hear it. The universe would
       | be silent.
       | 
       | It may be our luck in simply being terrestrial rather than
       | aquatic that separates us from our apparently absent galactic
       | cohabitants.
       | 
       | Being in a position to be capable of taking advantage of burnable
       | trees, and later coals and oils may be beyond rare in the
       | universe.
        
         | lisper wrote:
         | You don't need land to have fire. It's enough to have
         | photosynthesis producing free oxygen. That produces an energy
         | store at the water-air interface. That would lead to life forms
         | evolving to take advantage of the benefit of living at that
         | boundary and that would eventually lead to the formation of
         | biological rather than geological land masses.
         | 
         | Hm, sounds like a good premise for a SciFi novel. :-)
        
       | oli5679 wrote:
       | Recent data from New horisons mission is interesting, suggesting
       | there are an order of magnitude fewer galaxies (hundreds of
       | billions, rather than 2 trillion) which should be relevant update
       | to Fermi/great filter reasoning.
       | 
       | The probe is near Pluto, and so able to sky 10 times darker than
       | Hubble, but isn't observing the modelled galaxies extrapolated
       | from Hubble observations.
       | 
       | https://www.foxnews.com/science/nasa-finds-fewer-galaxies-th...
        
         | ben_w wrote:
         | The source material linked to from that article is better than
         | the article itself: https://hubblesite.org/contents/news-
         | releases/2021/news-2021...
         | 
         | For example, it explains why the sky would be darker from the
         | POV of Pluto than the POV of Earth orbit (Zodiacal dust is
         | relevant at this level).
         | 
         | That said, I'm still surprised that the estimate was ever as
         | high as 2 trillion; I thought the estimate had been the lower
         | 100 billion value for most of my life.
        
       | mellosouls wrote:
       | (1998)
        
         | Ariarule wrote:
         | For anyone noting the 1998 date and not already aware, Robin
         | Hason is still writing on the topic off and on at the
         | _Overcoming Bias_ blog, and has had a few posts on the topic
         | just this month: "Why We Can't See Grabby Aliens" -- more
         | generally about life in the universe at
         | https://www.overcomingbias.com/2021/01/why-we-cant-see-grabb...
         | and "Try-Menu-Combo Filter Steps" explicitly talking about the
         | Great Filter idea some more at
         | https://www.overcomingbias.com/2021/01/try-menu-combo-filter...
        
       | yboris wrote:
       | _Dissolving the Fermi Paradox_ by Anders Sandberg, Eric Drexler,
       | Toby Ord
       | 
       | > "This result dissolves the Fermi paradox, and in doing so
       | removes any need to invoke speculative mechanisms by which
       | civilizations would inevitably fail to have observable effects
       | upon the universe"
       | 
       | https://arxiv.org/abs/1806.02404
        
       | taylorius wrote:
       | I think technology acts as an amplifier to our impulses, both
       | good and bad. The more technology, the more sensitive the
       | balancing act, to stop civilisation going off the rails. We are
       | not sufficiently balanced. The sort of tech required to conquer
       | the stars, in human hands would probably lead us to wipe
       | ourselves out within an hour of getting hold of it.
        
       | stevehawk wrote:
       | I love the theory of Great Filters. I'm pretty sure that #9 on
       | the list should be "social media", though. Or in general, "self
       | destructing human behavior."
        
         | JohnJamesRambo wrote:
         | When I was a kid ignorant people kept their thoughts in their
         | heads safe and tucked away or maybe told a few people near them
         | that knew better. Now they let them out on social media where
         | they can find other ill-informed people and reinforce one
         | another. I don't know a way around this filter step. Maybe it
         | naturally will resolve. As Stewart Brand said, information
         | wants to be free. I will be optimistic enough to believe that
         | means correct information. The science and empathy just isn't
         | well distributed yet. "The future is already here -- it's just
         | not very evenly distributed." -William Gibson
        
           | im3w1l wrote:
           | Religion is on the decline.
        
             | Reedx wrote:
             | I think it's just changing form. Old religions being
             | replaced by new religions. Old priests with new priests.
             | Old gods with new gods.
        
             | dane-pgp wrote:
             | Perhaps that explains why people are increasingly adopting
             | dangerous secular myths, such as those about vaccines and
             | the Deep State.
        
               | Shaanie wrote:
               | Seems unlikely, if that was the case then wouldn't you
               | expect such things to be much more common in largely
               | secular countries than the US?
        
           | rootsudo wrote:
           | Before you were a kid, people talked and shared secrets and
           | inner desires with one another. What is ignorant, what isn't?
           | Discussion about a king? A president? What sort of people you
           | want to be around? What is dissident can become a movement
           | and become superior.
           | 
           | How do you decide which is which?
        
           | nullc wrote:
           | "Information wants to be free" is a physical law, not a moral
           | rallying cry.
           | 
           | In many cases the promiscuous nature of information works
           | heavily against human welfare. One aspect of that is that
           | incorrect information spreads as well -- sometimes better--
           | than correct information.
        
           | f6v wrote:
           | > Now they let them out on social media where they can find
           | other ill-informed people and reinforce one another.
           | 
           | People have been able to share incredibly stupid ideas with
           | high efficiency even before the social media.
        
         | rriepe wrote:
         | One that seems obvious to me (but others cheer for) is curing
         | aging.
        
         | dane-pgp wrote:
         | > Or in general, "self destructing human behavior."
         | 
         | That is definitely a credible theory, and it's currently
         | catalogued as number 2.2 on Wikipedia's list of hypothetical
         | explanations for the Fermi Paradox, where it is given the
         | haunting title: "It is the nature of intelligent life to
         | destroy itself".
         | 
         | https://en.wikipedia.org/wiki/Fermi_paradox#It_is_the_nature...
        
         | short_sells_poo wrote:
         | I have absolutely no education on the subject and have done
         | almost zero research, but I wonder if this "Self Destructive
         | Behavior of Humans" is merely the evolutionary local optimum of
         | tribal behavior.
         | 
         | Historically, it has been an advantage to have a strongly
         | tribal drive. Cohesive groups achieved much more than
         | individuals and yet were small enough that they could
         | effectively self-police and agree on common goals.
         | 
         | However, as the capabilities of each tribe increased and the
         | world became smaller through travel (and now the internet),
         | tribalism, us-versus-them still remain part of our basic
         | instincts and subconscious, however it is now the source of
         | international and high powered conflicts.
         | 
         | 10000 years ago, our tribal programming resulted in the
         | survival of a group of families and the development of
         | townships and emergence of societies. If a tribe got
         | particularly bloodthirsty, their impact was almost purely local
         | and perhaps eventually their notoriety resulted in a decline.
         | 
         | Now, sticks and stones have been replaced by nuclear weapons
         | and ICBMs. A first strike capability is no longer dangerous to
         | just one village, but entire continents.
         | 
         | Perhaps our technological evolution has outpaced our biological
         | and social evolution, and the behavior that was optimal even
         | 1000 years ago is now a grave danger?
        
           | hotstickyballs wrote:
           | This makes a lot of sense.
           | 
           | Any intelligent organism will have to overcome the biological
           | local optima that brought it to the intelligent state before
           | further developing as a species.
           | 
           | We already have explored a variety options, each with their
           | own advantages and downsides:
           | 
           | 1. Free individuals in a distributed system in a cottage
           | industry economy.
           | 
           | 2. Semi-free individuals who gather in tribes formed around
           | value-generation (i.e. corporations).
           | 
           | 3. Centralized system with individuals who are assigned
           | functions.
           | 
           | Future progress will have to be technological and will change
           | what it means to operate in the afore-mentioned scenarios
           | 1,2,3.
        
           | slfnflctd wrote:
           | This resonates with me. I've long said that if we are to
           | launch any kind of significant space-faring civilization, we
           | will need to some extent to become a different species,
           | through cybernetics & drugs or genetic engineering (probably
           | a mix).
           | 
           | Our current biggest challenge is to make ourselves 'smarter'
           | (i.e. less susceptible to the biases baked into our DNA).
           | Otherwise, it's likely only a matter of time before we
           | cripple ourselves into an extended Dark Age or worse.
           | Constant setbacks resulting from too many of us having
           | ignorant, emotional reactions to incomplete stories with
           | insufficient facts means we're all dancing on shifting sand.
           | It's not a good foundation upon which to build a durable
           | interstellar civilization.
        
       | h4kor wrote:
       | Climate Change will be the great filter for humanity.
        
         | cgrealy wrote:
         | Civilisation? Possibly.
         | 
         | Humanity? Unlikely.
         | 
         | Even in the absolute worst case scenarios, climate change
         | doesn't wipe out humanity. Life would be very different (and
         | would frankly suck), but some humans would still survive.
         | 
         | The question is how long it takes to get back to our current
         | level (hopefully with lessons learned!)
        
       | Animats wrote:
       | _" Life Will Colonize"_ _" So far, life on earth seems to have
       | adapted its technology to fill every ecological niche it could."_
       | 
       | Not any more. As technology has advanced, and agriculture has
       | become less labor intensive, there's been a sizable cutback in
       | populated area in the US and Japan, at least. Farms in less
       | productive areas are not competitive and those areas are emptying
       | out.[1] Towns which serviced the farms are dying off with
       | them.[2]
       | 
       | [1] https://www.visualcapitalist.com/u-s-population-change-by-
       | co...
       | 
       | [2]
       | https://en.wikipedia.org/wiki/List_of_ghost_towns_in_the_Uni...
        
         | edgyquant wrote:
         | Not to mention Antarctica is a whole continent that people do
         | not live on
        
       | api wrote:
       | I don't think there is a singular great filter. Instead I suspect
       | there is a relatively constant probability of a black swan event
       | across the entire existence of a biosphere.
       | 
       | It took over four billion years to get from simple replicators to
       | what exists here now. It is quite possible that most biospheres
       | simply don't make it that long without such an event.
       | 
       | We don't know the probabilities, but over billions of years the
       | continuous probability of biosphere extinction need not be very
       | high to filter out almost all biospheres before they develop
       | something capable of interstellar signaling or flight.
       | 
       | Keep in mind that another prior we don't know is the probability
       | of a diverse biosphere developing this type of intelligence. We
       | have no idea if that is likely or not even given sufficient time
       | and energy inputs.
       | 
       | Intergalactic flight is many orders of magnitude harder than
       | interstellar flight, which in turn is many orders of magnitude
       | harder than interplanetary flight. If the probability limits such
       | intelligences to no more than an average of 1-2 per galaxy then
       | there is your answer. We would be extremely unlikely to see
       | intelligent aliens any time soon, even if we do find a lot of
       | microbes.
       | 
       | Given where Earth is now I would be surprised if it does not
       | hatch an interstellar scale intelligence at some point in the
       | remainder of its habitable life. Will that be us? Hopefully so.
       | Given that we are already almost there (on evolutionary time
       | scales) it is reasonably likely it will be us or an AI we create.
        
       | blamestross wrote:
       | Life is a search algorithm for energy utilization. Arguably the
       | only evolutionary benefit of intelligence is the ability to
       | bridge troughs between local optima farther than genetics alone
       | can. It has limits as much as genetics does. We like to think of
       | intelligence as some boundless forever bootstrapping superpower
       | but all growth curves end up being sigmoid. The hard question is
       | are we close to topping out or are we just waiting on the next
       | punctuation in the equilibrium. I think future punctuations will
       | be found in "what comes after intelligence" in the search for
       | increasingly efficient energy utilization?
        
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       (page generated 2021-01-17 23:00 UTC)