The Fermi Paradox Hidden Alien Civilizations

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This video is sponsored by CuriosityStream. Get  access to my streaming video service, Nebula,   when you sign up for CuriosityStream  using the link in the description.   We’ve examined before how a civilization  might build undetectable, stealthy spaceships.   But what if that entire civilization  wished to conceal itself?   So two episodes back, we were looking at  Stealth Spaceships and the problems with them.   We saw how nigh-impossible it is to hide a  spaceship from a civilization, so hiding an entire   civilization would presumably be much harder,  especially one with many planets. But today   we’re going to look at why a civilization might  try to hide itself and how this might be done—and   ultimately if this might be a valid solution  to the Fermi Paradox, the big question of why,   in a Universe so ancient and immense, we  don’t yet see any alien civilizations.  

Hiding a spaceship differs from hiding a planet  in much the same way hiding a person inside a city   varies from trying to hide an entire city. It’s  complicated in astronomical scales, and in part   because astronomy is history, and the Universe  is so old. A civilization hides but the light it   emitted a century ago just reached their nearest  neighbors, who may have been a mighty empire for   a million years and knew your planet was around  and peopled with clever apes for all that time.   So it's essentially hiding a city everyone already  knows exists, not building a new one in secret.   What would you do right now, to hide New York  City, so that people didn’t know it existed?   In addition to the ‘what’ and ‘how’,  now ask yourself why you would?   Normally when discussing not being able  to see aliens because they are hiding,   we tend to focus on how this is not really  a viable premise under known physics,   which is true enough. Hidden alien  civilizations are not a valid Fermi   Paradox solution, we often suggest, because  hiding seems impossible under known science.  

But I suspect this falls flat as a Fermi Paradox  solution for many for the simple reason that all   of us are raised on wondrous science fiction  with impossible technologies and grew up in   an era where the entire technological landscape  vastly shifts from generation to generation and   has done so for longer than anyone now  alive or anyone they knew was alive.   So “This is not physically possible under known  science” is just not a very compelling argument   to most folks. Fair enough, though I would note  that most of the core reasons we say stealth is   nigh-impossible under known science is based on  violations of scientific laws we’ve known for   many generations and that have not changed. By and large our knowledge of scientific laws   has expanded rather than altered, we don’t  learn the exceptions to the rules, we learn   the complete rule, which is very different and  usually a further restriction rather than some   expanded capability. Our better knowledge lets  us invent technologies that expand our abilities,   but I can’t think of any that let us push  at science’s legal boundaries, so to speak.   Of course this doesn’t mean that we might not  find some exceptions, or that aliens might not,   especially given that they are likely to be  throwing vast amounts of resources at expanding   their abilities or breaking those rules. And these  can be truly mind-bogglingly amounts of resources,  

even under known science. Indeed one  of the recurring themes of this show   is how massive civilizations can grow to be,  even compared to those juggernauts of size and   capability we see in science fiction, without  needing any of those made up special powers or   super-technologies we see in science fiction. Imagine a civilization that outnumbered us a   billion to one, and where their dumbest citizen  found our greatest geniuses rather slow,   and who had been hacking away at a problem for  a billion generations. Our generations anyway,   they might easily live billions of years with all  the accumulated knowledge of a billion, billion,   nigh-immortal super-geniuses. If there’s  a way to solve a problem, they found it.   So if there’s a way to hide, they can hide. Problem is, no matter how smart you are, 2+2 still   equals 4, and basic logical conclusions don’t  alter, and the follow up is that if you’ve got a   rival who can hide using some special method, you  are also devoting vast efforts to cracking that so   you can see them. This is the ‘selection’ part of  natural selection, nature’s arms race for better  

survival, and not something we would expect to be  an alien concept or concern to any alien race..   One thing I often raise in regard to civilizations  trying to hide themselves or keep quiet is that   they probably could do that from us, but why would  they need to hide from us? They could obliterate   us, they would want to hide from someone  older and tougher who could obliterate them,   and they have that same problem. We can’t really  hide from them because they are older than us,   and our planet was visible to them long before we  existed and the light of our modern civilization   will still be heading out into space if  we switched it off tomorrow, for all of   time. 1000 light years from here, a civilization  will just be hearing our radio signals from 1920   in the year 2920 AD. Even if we invent a  cloaking field tomorrow. And Biosignatures   of life in Earth's atmosphere existed long before  us and would have been visible even longer ago.   This takes us back to the comment from earlier:  “What would you do right now, to hide New York   City, so that people didn’t know it existed?” There are options, each for a given value of   hiding. We could suck New York City through a  wormhole into a pocket Universe and now it's  

hidden but people still remember it and will try  to hunt for it. So maybe we detonate a big nuke   at the same time so it looks like the city was  destroyed rather than vanished, and no one hunts.   Except they probably do, and more to the point,  the Fermi Paradox isn’t about why all the alien   civilizations have ceased to exist in some sort  of terrible calamity – albeit that’s one proposed   solution to it – it’s about why we don’t see any  of them at all, past or present, living or dead.  

Though mind you, if everyone got up to  about our level or a touch more advanced   and faked their planetary suicide, so to speak,  before becoming giant interstellar empires,   we would not know that at the moment. There’s also a big concern that if aliens   detect you they might want to go out of their way  to kill you, regardless of whether or not they   want to strip mine the whole galaxy for resources  they might just hate other lifeforms and wipe out   smart ones whenever they see them. We know little  of aliens beyond that they presumably share a   common evolutionary process as us, and nature is  not a friendly place. On first inspection at least   it should seem as likely that aliens would want to  wipe out competition as befriend it, and even if   only a small fraction were openly belligerent  and genocidal, that doesn’t help much.  

One psychopath with a machine gun might be  100 times rarer than pacifists who offer hugs   but if someone tells you they just  put that one psycho in a room with 99   pacifists, then asks you to go knock on  the door and see how everybody is doing,   since its gotten all quiet, you could be forgiven  for not wanting to announce your presence.   Of course you’d expect if the pacifists  also knew there was a psychopath in the room   they’d try to take care of them, depends on how  pacifistic they are and that’s not a trait nature   tends to encourage. At a galactic scale, you’d  think if a predator was wandering the galaxy   for eons while others remained, some of them  would at least try to deal with the matter.   And nature is definitely not producing pacifists  to violent killers at a rate of 100 to 1,   so we should not be surprised if  an emerging alien civilization   also came up with the idea of the Fermi Paradox  and worried if maybe the reason nobody had   dropped by to say hi yet was because they just  can’t be bothered to waste time speaking with   their victims before exterminating the pests. This is a common Fermi Paradox solution too,   that civilizations all hide assuming there  is a bigger and badder predator out there,   and it sounds good, except for a few problems. The first is that whole inability to hide under  

known science issue, followed by the whole past  presence issue of trying to hide your civilization   emerging from folks who had telescopes better than  Hubble before we were even playing with fire.   But even if you can get around those, it still  has some problems. Starting with this analogy.   I’m not afraid of being all alone in the forest  in the middle of the night and getting snuck up   on by some unknown bigger predator, because I’m  a human, and we’re the nastiest and most deadly   thing on this planet. This is not a coincidence.  There’s a number of preliminary steps to being  

able to confidently sit around, all alone in  the dark, and know that trouble is improbable,   especially when the very ground you’re  standing on is literally composed of   untold centuries of dead organisms, virtually  none of which got that way from dying of old age.   Humanity is free to lie in our backyards at night  contemplating the stars not because threats are   rare, but because we’re what’s left after all  those threats collided over and over again with   tooth and claw. We live as the victors on top of  a mountain of skulls, and that’s not a metaphor.   There’s the key notion, if there was a predator  out there that could rip out our throat,   it would have done so already and it wouldn’t  be hiding. It’s possible one just happens to   finally have gotten the opportunity right  now, same as it's possible a lone wolf   might have evaded notice and be getting ready  to jump on me next time I’m in my backyard,   but it’s unlikely. It doesn’t matter that we  didn’t share a world with some hostile alien   to evolve alongside each other, we share  a very old and large Universe with them.  

Us and any other species that might emerge and  contemplate a potentially hostile galaxy around   them, and contemplate hiding, just has to stop  and ask if keeping quiet and weak in the shadows   is really a policy worth pursuing, against the off  chance the galaxy has some horrid predator in it   who has luckily missed them prior to  now, when the odds are that’s not true   and that any future threat that might arise  would be easier to handle if instead of   keeping to the shadows you grow to an empire of  a billion worlds and a trillion battleships.   Then they just have to ask, “Hey, what would  our ancestors have done?” because the answer   is almost certainly not hide, but go grow  stronger, and then ask if that’s probably   the exact same reasoning any other alien  civilization might have gone through and   also likely concluded the same things. So it would seem weird they or anyone else   would choose to try to pursue a policy of  hiding. Especially since even if everyone  

else was doing it, it does not mean they are  not also trying to detect other civilizations,   have probably gotten good at it, and one  defense strategy is to expose other people   to the predator. As goes the story, two men are  running from the wolves, and one says to the other   “There’s no point, we can’t outrun the wolves”  and the other says “I’m not trying to outrun the   wolves, I’m just trying to outrun you.” With that in mind, there is no reason to   assume that if other aliens existed and were  hiding, that they wouldn’t still hunt for you,   probably have some good insight into finding  you, and cheerfully throw you to the wolves   to keep themselves safe a while longer. But that needs a caveat too. We always want   to be thinking from the position of the hunter  when trying to think of hiding a civilization.   They know there’s other life out there,  even if they were the firstborn civilization   in all the cosmos, there should have been  worlds with less sophisticated life on them   by the time they were exploring the cosmos. If  intelligent life is even a little bit common,   just occurring a few hundred times per galaxy  per billion years, where you still need to   search millions of likely planets to find a single  civilization or its remnant, then not only does   that probably mean there’s orders of magnitudes  more worlds that just developed simpler life,   but that the early civilizations on the galactic  scene would have encountered tons of planets that   would one day support intelligence, if left  alone, but at that point might have just had   dinosaurs or fish just crawling out of the sea. So they know how common life is and probably have  

a pretty good idea how often, and under  what conditions, it gets smart, and would   get suspicious if they enter a region of space  that didn’t have enough of them and nose around.   What’s more, for all that we often refer  to them as coming from the mindset of   exterminators crushing insect hives, these are  civilizations that are probably vast, ancient,   huge, and hyper-intelligent. Quite possibly  they have untold trillions of people smarter   than Einstein. They probably are not lobbing a  bomb at a place at first sign of intelligence  

then wandering off for a drink and a nap. They  will have tried to guess how the prey will behave   and the notion of hiding by occasionally exposing  a neighboring species will have occurred to them.   They may have armadas able to demolish a  planet without ever landing on it, instead   of risking their own necks. However,  they also probably have plenty of other   weapons that would leave a world intact  enough to go investigate and research   the civilization they are in the process of  wiping out or just finished obliterating.  

They might want to investigate since this helps  you better know what others would be thinking   and what they might try. And also if they got  any Hello messages and SETI signals from some   other unknown species who might have used them as  a distraction, scapegoat, or bait for a trap.   That latter might result in some big and hidden  empire hiding an armada near a primitive world,   signaling the predator species to the existence  of this new victim, then attacking when they   were busy attacking themselves, or even hiding  a few billion tons of antimatter in that planet   and blowing the whole thing when they arrived. Of  course they probably have a lot of extermination   fleets, the ability to make more of them, and  defenses on their own worlds so attacking their   forces arguably just alerts them to your  existence for minimal strategic gain.   In any event, investigating is likely to be  seen as the wise option. As a caveat to that,  

they might not like their civilizations getting  exposed to alien civilizations even posthumously   for fear of it building up empathy or deviancy.  Or even exposing them to some sort of infection,   biological or memetic, like the researcher  reads some ideological, philosophical,   or religious document that converts them and  that fleet. Which might curtail research a bit,   if you’re busy putting down a civil war. However   we always need to contemplate that they could  see that weakness too and have resources we   don’t. They can probably send in a trillion smart  and disposable robot soldiers down to a world   to hunt down every member of its population,  and choose to do so over planetary bombardment   because the cost of both is negligible to them and  they don’t care about the death of their robots.   Well they might take the same attitude toward  their forensic and archeology teams too,   simply deploy robot investigators or androids with  copied minds or clones to do their investigating   then kill them when it's done. Given that we  are contemplating a race of folks so passionate  

about genocide they’ve spent millions of years  practicing it, the odds aren’t good they are   terribly kind and lack a ruthless streak. I could  imagine some investigator who exited a cryochamber   on a new world investigating them and coming to  pity them while filing reports, only to realize   to his horror that his own people didn’t wake  him from a cryochamber, it’s a cloning vat that   keeps duplicating his mind from a saved state  of an original investigator who his employer has   been creating to investigate over and over again  and killing after each periodic report update.   That would probably be a good plot for a story,  with the investigator finding some way to rebel   or save the civilization from his kindred or  so on, but again we have to remember the key   point about the alien overlords not being stupid  and us needing to think from their perspective.  

There’s several ways that come to mind to  safeguard against that investigator going rogue,   like putting a camera in his eye, a position  tracker in his chest, and a bomb in his brain.   We also want to not just always be thinking  from the position of the hunter when trying   to think of hiding a civilization, but  from the position of a potential leader   of such a civilization who is as capable of  contemplating a hunter’s action as we are   when picking whether to try to hide from them. That decision to hide is essentially one   being made in absolute ignorance of the  state of affairs in the wider Universe   except by logical deduction from your own  world and basic physics and astronomy.   Odds are such civilizations are already aware  of the dangers of making decisions that way.   When making a decision you want to know as much  as possible but we have approaches for dealing   with various degrees of ignorance and uncertainty  when making decisions where we don’t anticipate   being able to get more useful information in  time for the decision. Bayesian Analysis would   be an example of that, but two others we discuss  a lot on the show are the Mediocrity Principle   and the Anthropic Principle. Both are  designed to help you draw a basic best  

conclusion when you know next to nothing. The Mediocrity Principle is the one we use in   science a lot to take a handful of samples  of something or even just a single one   and draw conclusions about that something. It’s  the thinking pattern that says if you meet ten   people and see brown, blonde, red, and black hair  on their heads, that they were probably fairly   normal and mediocre examples of the species and  that those are the hair colors most folks have. We   know that’s not universally true, meeting someone  with a very abnormal and artificial hair color,   or walking around with a wig or feather  headdress, is going to throw you off.   Even more so if you only get to meet one human.  But most of the time it will be mostly right.  

Again it’s not the best method if you have good  data, but it's one of the two best methods for   looking at things when you know very little  and don’t expect to get more information.   The Anthropic Principle is a very  different approach to the same thing,   acting in ignorance. It’s the one where you assume  you, the observer, are skewing the results of your   observations by existing. It’s the acknowledgement  that you are encountering intelligent folks with   various shades of hair because you are  an oxygen breathing lifeform who likes   to walk on sidewalks or inside climate controlled  buildings, so you see them more often than, say,   whales or dolphins or chimpanzees, who rarely have  blonde hair let alone artificially dyed hair.  

Two key points on that, first a civilization  making decisions, be they hunter or hider,   is aware of both the concepts and their  limitations. So not only are they trying   to expand their data pool to be less ignorant, but  they also know that just because their sample size   of lifeforms encountered has risen to millions,  giving them a great statistical table for where   life is likely to form and how it grows or  behaves, that they still need to be contemplating   the Anthropic Principle and asking if their own  observational approaches are skewing the data,   letting some hide or leading to some other  bad conclusion. Like they only search   for life emerging on planets, and never  realized it could develop inside comets.   Or they never realized they might run into  rival civilizations immigrating from alternate   realities or parallels universes until one does. Second, those are approaches made in ignorance,   but folks often lock into the conclusions drawn  on them. We see that a lot with the Fermi Paradox,  

where folks get very certain  what the right answer probably is   even though we have little data and every theory  has holes in it. I’m pretty well known for being   of the opinion that the best solution is that  intelligent civilizations arise very rarely,   but I’m also pretty well known for saying I view  that as the least bad solution, not the best one,   because it's got holes in it too and I’ve yet to  hear a proposed solution that didn’t have some.   So to me there’s little cause for discussing  the Paradox with great confidence that your   preferred standpoint is clearly and obviously  right. No conclusion drawn from the Mediocrity   or Anthropic Principle, when you’ve only got one  or two samples, should ever inspire confidence.   But we see something similar in these  discussions with Game Theory too.   It comes up in these conversations and folks  present an example and are convinced that the   ironclad logic of the math makes that conclusion  right, because the math cannot be wrong.  

Game theory is a great tool too but its problem  is that it's rarely a good predictor of complex   decisions. Usually it involves a handful of  possible players each with a handful of possible   reactions and usually playing with the same  level of knowledge. It’s the sort of thing that   lets your predict a species evolved by Darwinian  survival imperatives is prone to trying to grow   their numbers and expand but won’t predict that  they had a Malthusian Catastrophe of overgrowth   and starvation centuries earlier that’s led to a  fanatical devotion to avoid those in the future   by slow growth and never fighting others for new  worlds, directly or just by stiff competition.  

It also wouldn’t predict that a millennia later,  after encountering species that didn’t believe   like them, a faction of their civilization  built and unleashed a self-replicating swarm   of exterminators. Some probes that went  to newly discovered intelligent species,   measured their growth rate, and if it was above  a certain percentage over a given period of time,   went all Thanos on them and wiped them out. When  building a game theory chart of possible logic   decisions the competitors can make, if you don’t  know them, you’re not going to be building that   on the assumption that one of those civilizations  was one that had that specific sequence of events.   That the culture descended from a minor  faction of a civilization that hid in mountain   caves to avoid being wiped out by a big faction,  which instead divided into two new factions that   wiped each other out, leaving the world to be  reconquered by the mountain cave survivors.  

Those folks are quite likely to have an irrational  trust in hiding and might think the best plan was   to hide and agitate the big players on the  galactic stage into killing each other and   just take for granted that this will eventually  work because it’s a key part of their cultural   mindset that it will and must. Same as we don’t  really sit around justifying or questioning if   personal freedom and liberty are good things.  They just are, the issue is so settled to us   we don’t really waste time asking how valid it  is. Which to be fair is because very detailed and   thorough discussions of it were done in the past,  but even if there’s a lot of solid logic for the   conclusion, there is still a large emotional,  cultural, and historical perspective on it.  

As a quick example, it's not too uncommon  for folks to suggest these days that maybe   we should drop the term ‘space colonization’  because colonization has some rather nasty   historical overtones and so other folks hear  us discuss that and assume that will replay.   Which it might, but obviously can’t happen that  way when colonizing a world that was lifeless   and needed terraforming first. A world that  had only one big supercontinent, Pangea style,   with no uncrossable boundaries, is  unlikely to have that specific worry.   They’d have their own historical baggage, their  great empires, mongol hordes, crusades, jihads,   and so on, but not that primitive and unaware  tribe first meeting people who were vastly   diverged from them in a vacuum, because no one  was isolated from their neighbors. Similarly, some   species that had evolved HAM radio transmitters in  their biology is likely to have had cross-cultural   exchanges all over their world before anyone ever  developed means of faster travel or travel across   rough oceans. This would be a culture with a  view of SETI and messaging interstellar space   very informed by their own history, with its  obvious parallel to interstellar space. These will  

create attitudes that will subtly but decidedly  alter their worldview. And those alterations are   likely to present them counterarguments to logical  conclusions that are more ‘jingo’ than ‘ergo’.   Now you might be taking away from that the  conclusion that many might decide to hide,   but we are presented with a Universe of no alien  signals, or at least none loud enough or in the   right time and place to hear them. That would  require everyone to draw the same conclusion and   that would be dubious even if the logic for hiding  was flawless, down to 2+2=4 territory, which it   does not appear to be anywhere near. Civilizations  will be assuming that to maintain such quiet means   reliably, for millions of years, preventing  anyone by policy, accident, or insanity from   exposing them. They’d need to believe they could  do that and they would need to believe that was  

enough – which it isn’t, it doesn’t protect them  from someone just sending a mission or probe there   or having caught their first signals in their  equivalent to the early 1900s. They would also   need to believe that this was so clearly possible,  both things, that everyone else elected to do it,   even those cultures that might have evolved  from biology or early culture that encouraged   them to bellow out their presence not hide it. And keep in mind, nothing in nature does this.   Things hide their personal location at times,  indeed stealth is often vital to creatures,   particularly marine life. However, they  generally do not conceal their entire existence.  

Many critters mark their territory or call out to  potential mates and so on. Marking your territory   is a good idea, because while it forewarns  a potential invader that you exist, making   it harder to get the jump on them and giving them  the chance to scout you and get the jump on you,   often instead they will seek to avoid the conflict  and respect the territory because the best way not   to lose a territorial fight is not to get in one,  and there’s always a chance you will lose and if   you’re confronting them constantly, the coin  is going to come up tails sooner than later.   Indeed this is why bluffing and threatening and  posturing are handy in nature too, to avoid the   fight because not doing so runs a risk of death. It would seem likely this would be a common enough   behavioral pattern in evolution that many worlds  would want to take the territorial marking over   hiding approach, and so too, a civilization is  likely to be built on mutual cooperation a lot,   various folks specializing in skills or  working as teams, that we also shouldn’t be   surprised if many aliens thought friendly  but cautious was a good message. “Hello,   let's consider being friends, but  if you don’t want to be friends,   this is our turf, this place, right here, and we  will make you pay if you try to take it from us”   and that dynamic is a lot more likely  in a place populated by many factions.   And I say factions not species there  not just because some might team up,   but because even a species that evolved first and  had the galaxy to itself is likely to be divided   into a ton of different groups. Indeed such a  firstborn species is probably more likely to  

massively factionalize and diverge given they  have no external pressure keeping them unified   like an outside threat and no check on  their growth in an otherwise empty galaxy.   We see speciation like this in the natural world  quite often. In a many-faction environment trying   to wipe everyone else out is not likely to be a  winning strategy compared to cooperation. Be they   symbiote or parasite, working together is often  better, and it’s a failed virus or predator that   wipes out its host or prey. But if it does, it is  probably just a matter of time before that species  

begins to hunt its own members and divide into a  new pair of species with a predator-prey cycle.   So taken as a whole, none of this lends  itself to civilizations all deciding to hide,   because the ability isn’t there and neither is  the motivation. There’s just no compelling reason   to stare into the empty sky for millions of years  instead of saying hello, and once one group does,   the field changes. We’re not talking about a new  civilization like ours whose never put a person   on another planet yet either, for them caution  as a temporary plan is okay if mostly pointless,   we’re talking about them being willing  to maintain that policy for eons.  

Though this does leave the door open to a  mix of hiding and late filter extinction,   which is where civilizations hide for a time  but also inevitably wipe themselves out,   so they never get big enough for long enough  to be seen by other civilizations like our own,   before they themselves wipe themselves out.   This still leaves us the option that some  might choose to hide though, like our Mountain   Cave survivors example from earlier. And just  because that decision isn’t maybe too logical,   that does not mean they are illogical on  everything else. They might be entirely aware how   seemingly futile hiding was when their footprint  is already there in the form of their world having   biosignatures for eons and them having sent  radio signals out before they knew better.   They still want to hide, so will seek to, and  that raises that question again from earlier:   What would you do right now, to hide New York  City, so that people didn’t know it existed?   Now you probably aren’t a big growth style of  civilization so hiding as uploaded minds running   on a few ultra-low-power generators buried in icy  Oort Cloud objects might be a viable approach,   we discussed the details and some ups and downs  of that case in our episode Hidden Aliens. You  

appear to wipe yourselves out on your native  world, and in the noise of the fiery apocalypse   have uploaded minds on harddrives carefully put  in a discrete icy comet far out in deep space.   But to hide yourself from the rest of the galaxy  it's probably easiest to get out of your own   galaxy. That’s a long trip, you probably need  to keep to under .1% light speed to have even   a chance of not looking artificial, and would  be pressing your luck hiding as a rogue ejected   planet or object in the top tier of fast naturally  moving objects since that would be exactly the   sort of thing a hunter would prioritize checking  out. That means your journey to the edge of the   galaxy and out is taking you at least 100 million  years. There’s also little out there to live   on which means bringing a lot of resources  and fuel with you. Dragging a larger body,   like a dwarf planet instead of a small asteroid  or comet, offers a bigger resource supply for when   you’re in the intergalactic void, but it is also  easier to spot and even if they think it's natural   it is more likely to draw unrelated efforts by  them at mining or harvesting it for themselves.  

That’s about it under known science, and black  holes are awful places to hide if you’re curious,   unless you know how to hide  inside one somehow without dying.   How about outside known science? We can talk  about blowing up a place right after evacuating   it to hide it in its apparent demise but once  we step into concepts like moving a whole city   or planet through wormholes, we probably  want to consider not just that the wormhole   might empty into a pocket universe instead  of our own, but that you might engage in   options like time travel to hide yourself. If you really want to hide your existence,   you need to contemplate sending covert agents  into alien civilizations to tamper with data and   archives, deleting your existence from them. But  maybe it is easier to delete your existence from   history, not just the records of it. These are scenarios I could imagine,   that technology might permit immigration of whole  civilizations into other realities or Universes   of their creation and that such a technology might  be something you stumbled into in your equivalent   to the 21st or 22nd century, before you could  really have gotten an interstellar empire going   and that this option was easier than travel to  other stars. So everybody leaves the Universe.  

That could leave a pretty barren looking  place, where civilizations all emerged   into a quiet Universe because nobody had time to  broadcast very long or loudly before leaving.   So too in the exodus to or creation of  Universes, we might remember the scenario   that one way to hide from your enemy or hunter  is to blind them instead, and species that don’t   want to murder other races nor fight them for  all time might decide to put them in a Zoo,   cordoning off a section off space for them to  live in that looked empty, even wrapping their   planet in a fake protective illusion, or outright  transporting them to pocket Universe or Virtual   Worlds their minds had been uploaded to. In such cases it probably behooves you to   make that reality or illusion look like  one where life emerging was improbable,   so as to discourage worries of the options,  but it does raise one last option for today.   If you’re making pocket Universes, either to hide  in yourself or to put new alien races inside,   and you can tailor those, it would tend to  make sense to aim for something where the   physical laws and layout made the emergence of  intelligent life very improbable, preventing   competitors or aggressors from arising or making  your transplants suspicious of their isolation.  

However it would probably be hard to make one  where life could not arise where you could   actually live, let alone have a species that  thought it was natural and merely improbable,   not statistically impossible. Such being  the case, in a very large Universe,   many times the size and volume that a given  sub-light traveling species could have colonized,   like our Universe, it's entirely possible  a handful of species would arise anyway.   Particularly as there is no need to make life any  more improbable than evolving to intelligence once   per supercluster to avoid bad neighbor relations. Such being the case, a civilization, like ours,   might emerge in such a created universe blissfully  unaware that far from our galaxy’s creators,   or original transplanted civilization, exists an  empire of a trillion suns a billion years old,   and we are just the fluke civilization  that arose far in the outskirts. Unseen   because the light of our planet’s first forming  hasn’t even reached them yet, and unaware that   we are just a weed that grew as the accidental  byproduct of them farming whole Universes.   So as I mentioned, our scifi sunday episode  earlier this month, Stealth Spaceships,   was written as an unofficial companion video to  today’s episode and I do recommend giving that a   watch if you haven’t already, but one thing  I didn’t look at today was the concept of a   civilization living on stealthed spaceships,  and it’s a bit embarrassing as an oversight   since our episode on Nomadic Space-Fleet Based  Civilizations that came out just over a year   ago also skipped that option, but today’s episode  is already long even for normal shows standards.  

So we’ll have an extended edition looking  at civilizations on stealthed spaceships   today over on Nebula, and hopefully develop  that into an episode sometime this winter   or spring on civilizations on the run, such as  we see on Battlestar Galactica. If anyone has   any good suggestions for an episode name for  that, please drop it in the comments below.   As a sidenote, while we often tend to think of  stealth spaceships and compare to them to stealthy   aircraft we have now, in many ways the better  comparison is going to be stealth submarines,   and there’s some great videos on  submarines on Curiositystream,   like the Disappearance of the PX-15, a small  sub that got lost right around the time Apollo   11 was happening and the story of the crew’s  survival is just as exciting as Apollo 13’s.   Again today we have an extended edition over on  Nebula, our streaming service, which is full of   awesome content from STEM creators like Real  Engineering, Mustard, Answers with Joe, MKBHD,   Rene Ritchie, and a bunch of others. It’s  designed to give creators more freedom than  

other platforms, like letting me run long even  for an SFIA episode, or do trial balloons for   sequels and full-length episodes, as we’ll do  today. Also, our episodes of this show appear   early and ad free on Nebula, and we have a  growing catalogue of extended editions too,   as well as some Nebula Exclusives like  our Coexistence with Aliens Series.   Now you can subscribe to Nebula all by itself but  we have also partnered up with CuriosityStream,   the home of thousands of great educational videos,  to offer Nebula for free as a bonus if you sign   up for CuriosityStream using the link in our  episode description. That lets you see content   like “The Disappearance of the PX-15”, and watch  all the other amazing content on Curiositystream,   and also all the great content over  on Nebula from myself and many others.   And you can get all that for less than $15 by  using the link in the episode’s description.  

So we’re almost done with September but first  we’ll have our Monthly Livestream Q&A on Sunday,   September 26th at 4pm Eastern Time before closing  the month out by asking if it’s possible for   future civilizations to exist without money, on  Sept 30th. Then we’ll open October up by asking   how in vast space empire of countless trillions  someone could stand out, then on October 14th   we’ll ask how we might feed all those folks, as  we look at the future of farming in the next few   decades and beyond. Then We’ll have our October  Sci-Fi Sunday Episode, Sentient Planets & World   Consciousnesses, on October 17th to discuss the  popular scifi idea of living and thinking worlds,   and if they might occur naturally or  be created by high-tech civilizations.   Now if you want to make sure you get notified when  those episodes come out, make sure subscribe to   the channel, and if you enjoyed the episode,  don’t forget to hit the like button and share   it with others. If you’d like to help support  future episodes, you can donate to us on Patreon,   or our website, IsaacArthur.net, and patreon and  our website are linked in the episode description   below, along with all of our various social  media forums where you can get updates and   chat with others about the concepts in the  episodes and many other futuristic ideas.  

Until next time, thanks for watching,  assuming we weren’t too hidden to see us,   and have a great week!

2021-09-24

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