Extragalactic Sanctuaries Escaping to the Edge of Space and Time

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This episode is brought to you by Brilliant As we journey outward to the stars to claim   new worlds, many might make the trip fleeing  pursuit, and against a determined enough hunter,   even the vast voids of interstellar  space may not provide you sanctuary.  So, one day you or your civilization decide  your safety is imperiled and you wish to ensure   that safety by going to the most remote place  you can find, and today we will be discussing   why you might make this move and how you could go  about it. Our main focus will be living outside of   galaxies, not between them, but we will be  contemplating everything from hiding inside   more remote parts of interstellar space,  up to migrating to a cosmic void today.   This episode is a quasi-sequel to last week’s  episode on Deep Space Habitats and a quasi-prequel   to next month’s episode, Alien Refugees, and while  you don’t need to have seen Deep Space Habitats to   understand this episode, you might want to watch  that episode first, as its the basis for how you   could find the energy and resources to dwell  in what is essentially a barren nothingness. 

Now, to understand our concept, we need to set  the stage by repeating the point from last week   that interstellar space is a vast sea of near  nothing, even compared to the emptiness of   interplanetary space. Earth is one tiny pale blue  dot in the immensity of interplanetary space,   occupying less than a trillionth of what we might  consider the Habitable Zone of our Solar System,   which itself is perhaps a millionth  of what we might think of as the   interplanetary space in our Solar System,  out to Neptune, Pluto and the Kuiper Belt.  And yet this is a tiny fraction of the volume  of interstellar space itself, even in its vast   emptiness, it is but billionths of the volume  of our Oort Cloud and the vast gaps between even   our nearest neighboring stars, which, in turn,  are even more empty than interplanetary space.   As we saw last week, we don’t need that  much improvement in our technology in   order to be able to live and live well even  in the dark depths of interstellar space,   and in theory it should be a place that attracts  few competitors and in which hiding is easier.   Amusingly though, it’s also where you’d put your  best detection gear since noise is minimal. There   are also lots of actual stars in intergalactic  space too, it’s just much thinner than inside   the galactic disk; enough to build relay chains  to other galaxies. So in that regard there’s  

likely to be lots of old science stations and  even settled star systems in intergalactic space.  But stealth in space is no easy thing, for my  part I don’t think it’s truly possible to hide   from an enemy who wants you dead badly enough,  even in the dark void between stars. Nonetheless,   it would require a very determined foe  and not one that is acting out of fear.   If we control interplanetary space and a whole  star, some tiny refuge of a few thousand folks   buried into an icy cometary body a lightyear from  my star means so much less than nothing to me as a   threat. They’re not out producing us, and we are  getting way more research and development done   every day then they’d get done in a millennia.  Realistically, it’s not some tiny pacific island  

with a small tribe living on it versus a major  nation, it’s the entire human civilization   and infrastructure versus one lone flea sitting  on a plastic bottle floating in the ocean.   They just are not a plausible threat, so  if you’re hunting them, it’s because they   either specifically have someone or something you  want or they’re just obsessed with killing you.  As to what might be someone they want, that might  be a pirate crew or leader, or maybe a dangerous   political rival living in exile – and such a  civilization might have people living thousands   or millions of years. That’s a long time to build  a reputation or a grudge. As to precious things,   maybe a priceless relic, but I think we would  have to be talking something like the Shroud   of Turin or the Black Stone of Mecca, the  preserved body of some leader or prophet,   or hunting for Arthur’s Excalibur or the Holy  Grail, if they had confirmed magic powers. So too,   some hacker who had gotten the codes and  one-time pads for an interstellar empire’s   dirty secrets archive or Fort Knox equivalents  of wealth, or dangerous stowed-away technology   might invite such a hunt, but we also have to  keep in mind that trying to find some old hermit   guarding the Holy Grail in a tiny stealthy rock  need not even be in the same solar system. The   galaxy is huge after all and it’s hard to imagine  what might compel hunters to seek something out   through billions of star systems, let alone their  vastly larger empty interstellar regions. Plus  

often the best place to hide something is going  to be a safety deposit box in the capital city,   stealth and hiding come in many forms. Fundamentally, Interstellar space is so   empty and enormous that if someone is hiding a  small sanctuary, you have to be very motivated   to go find them, especially something  more covert like a post-biological one   run on ultracold computers. Indeed, there are  even emptier places inside our galactic disk   where the spacing of stars is much lower and  the galactic halo even more sparse. So going   extra-galactic would seem unnecessary.  Nonetheless, you might do this for   ultra-ultra-cold computing, as extragalactic space  is even colder though not by an immense amount,   there’s still the cosmic microwave  background radiation to contend with. 

As time passes, that cooling makes computing more  efficient, as we looked at in our civilizations   at the end of time series, people might save their  fuel for the Dark Age 100 Trillion years from now   where they’ll get more efficiency from it.  We’re not contemplating Faster Than Light Travel   or Time Travel today, though odds are if you’ve  got one you’ve got the other, and hiding at the   Edge of the Universe in a Temporal Sense, at the  End of Time or back at the Big Bang is certainly   an option. The Period of 380,000 years after the  Big Bang until the Surface of Last Scattering,   when Cosmic Microwave Background Radiation  was originally emitted, is an even place   to hide than inside a Star, another concept we’ve  contemplated as an option for a sanctuary before.  Still, to return to why you need to hide, I can  see some astronomical bounties being offered if   someone stole the Shroud or the Black Rock, and  interstellar empires might consider offering   someone an entire planet of their own to be  a modest bounty compared to their economy.  Of course, someone choosing to hide need not  necessarily be making a realistic estimate of how   much people want them. It might be that they were  an infamous pirate with a big price on their head  

but nothing that motivated any real searches,  nonetheless, they think they need to flee to   the edge of reality itself to have any chance.  So too, while we might imagine a genocidal race   hunting down survivors, or alternatively a  war crimes tribunal hunting down the fleeing   leaders of a genocidal regime, it's even easier to  imagine that the folks being hunted are paranoid   and perhaps even grow more so as time rolls by. So, why extragalactic sanctuaries beyond just   extreme paranoia? Well, they do offer  the advantage of being even more remote,   while at the same time, the basic principles  of deep space habitats still apply.   Indeed the gas density in the intercluster medium  – the region of space between neighboring galaxies   as opposed to intergalactic medium in general –  isn’t that much lower than in more barren parts of   a galaxy, for those opting to use a power supply  that consists of sucking in ionized matter to run   fusion, or black hole power generation. We also  hypothesized using dark energy or vacuum energy to   power your deep space habitats last week and that  would be just as effective outside of galaxies.  Indeed, anything running on dark energy  or vacuum energy would work just as well   anywhere in the known universe, even cosmic voids,  but those are only about an order of magnitude   less dense in terms of matter than the mean  cosmic density anyway. With sufficient technology,  

and potentially even just controlled  fusion, any of these places can be home.  Now, a couple months back, in our episode:  Lost Space Colonies, I pointed out that a   great place to hide would be on the rimward side  of one of the stars at the edge of our galaxy   or in intergalactic space. You put a statite there  to keep your facility pinned behind that star   relative to the galaxy, rather than orbiting it,  and it’s going to be very hard to find you there,   hiding on the dark side of the Sun, so to speak.  You’re hanging as close to a star as you can – and   that might even be effectively in its upper  reaches – so folks only see you if they just   happen to be leaving the galaxy and decide to  turn their telescope backwards to stare at the   backside of that star and watch close enough to  see the tiny fleck of your space habitat there.  Which they might do. Unlike interstellar  space, anything near a star or big object,  

represents a tiny fraction of preferred  space or valuable real estate,   including stars and black holes, and barring  travel time, it’s almost easier to search all the   interplanetary regions of an entire galaxy than  the interstellar space of just a few star systems,   but you are now contemplating million-year  hunts, not just multi-generational ones.   The other problem is that such places  are valuable real estate, so, eventually,   someone is going to want to colonize it, but the  same is fundamentally true of interstellar space   if one waits long enough and civilization  can colonize it usefully, which is implied   by your being able to live there indefinitely  too. If you can live there, so can others. Timelines matter a lot, because, as we noted in  Deep Space Habitats, a small cylinder habitat   is quite capable of powering itself for  longer than Earth’s life around the Sun,   potentially far longer, just by having an  equal mass of fusion fuel as it has station,   and that fuel is vastly more abundant than the  raw materials for building habitats themselves.   Ironically, the kinetic energy the  ship, or habitat, or raw materials,   needed in order to get out of the galaxy, moving  at roughly .2% of light speed, represents fuel   needs greater than the habitat or ship would  need, to run life support for potentially   a million years or more, maybe a lot more. Now, it is important to understand that escaping  

the galaxy and escaping our gravitationally bound  cluster of galaxies isn’t quite the same thing,   and the appeal of the latter is that once you get  out into the true deep, the dark energy of the   Universe’s expansion is going to aid your escape,  and you don’t really need to bother slowing down,   once you feel confident you’ve reached the  point where your speed plus the Hubble Expansion   is going to carry you beyond search, you can  just spread some sails out to slowly gather   intergalactic gas and dust, very slowly  decelerating you while adding to your fuel   reserves. This is going to be a long process  at every level, billions of years perhaps or   even more, but it’s worth remembering that you’re  probably talking hundreds of thousands of years of   travel to get out of your galaxy and maybe a lot  longer if you’re trying to be stealthy about it,   not moving faster than other natural objects.  Though you might not be aiming for stealth.  To illustrate the options, let’s consider a  protracted flight scenario. We’ll begin sometime   in the 42nd Millenia, in a case where there are no  aliens, but where humanity has already colonized   and diverged so much that its various offspring  and creations might as well be alien. Indeed,   even in the Sol System, the trillion minor worlds  host millions of different sentient species.  

Humanity’s descendants and experiments, and the  descendant’s of those experiments. This includes   things so alien to humanity of the 21st century  that they would not even have appeared in fiction.   Some of those, like the giant technorganic ants  of the Derzhavin Hollows of Mercury are benign,   a quasi-hive mind that placidly  trades metal ores for supplies.  They have changed little since they were made  to help exploit Mercury’s resources in the late   3rd millennia, almost 400 centuries ago. Others,  like the vicious Returners from Barnard’s Star,  

having been more violent, as they have fought  a 400 year war down the spacetower arcology of   North Akna Montes, seek to purge all the inhumans  from the vast spacescraper, as defined by whether   or not they still have the genetically modified  wings their ancestors got during the early days of   Venus’s colonization, from where their colony ship  launched 38,000 years ago. In the 400 years since   they seized the spaceport, they’ve managed to  fight their way down to claim over 70,000 levels,   each level being a vicious battlefront akin  to the trench warfare of World War One.  This sort of thing has gotten a lot more common  in the last couple millenia, old factions that   left to colonize the stars coming home to try  to reclaim what they see as their birthright.  

It’s estimated that humanity, and its descendants,  have claimed over a million star systems   and sometime around the 30th millenia, those  settlers around other stars finally came   to outnumber those who dwelt around the  vast Dyson Swarm and Deep Space Habitats   of humanity’s original solar system, which  itself contains over a trillion sovereign   nations. It is estimated that at any given moment  in Humanity’s birth system, there are 200 million   wars going on, and that 3 million people die  every single second throughout those war fronts,   roughly 100 trillion people a year. For  a given definition of the word ‘people’,   a term whose definition is often being disputed  and frequently is the reason for a given war.  Those disputes and others, claim three  times as many people every single hour   as were alive on the day the first person  stepped on the Moon, and more every day   than had ever lived in all of Earth’s history  before the first person was born off Earth.  Those figures don’t include any conflicts out  in Sol’s own Oort Cloud or any of the other star   systems, nor any of the post-material entities  and people living entirely in virtual realities   in most cases. It also doesn’t include a  lot of sub-sapient machines and creatures.  Many will point out that such massive numbers  of conflicts and casualties are fundamentally   a relative thing, that just because more  people die every minute than died during   humanity’s wars of the ancient industrial  age, doesn’t mean things are more violent.  

Quite to the contrary, we are vastly less  likely to die of war as an individual now.   Nonetheless, many folks point out that the numbers  of wars and deaths have risen proportionally   in the last few centuries, and talk about the  need to bring the solar system back under one   common banner. They say that if there’s going  to be wars, they should at least be for the   good purpose of bringing stability and peace  to the Solar System, a War of Unification.  And many of you think it might be wise to leave  the solar system before such a thing occurs,   especially as many of those trumpeting Unification  don’t seem to view that as including everyone,   and you’re not sure if you would be on that list  or want to be. What exactly we are doesn’t really  

matter, but we think of ourselves as human,  personally anyway. So, we and many others   decide to go build a deep space habitat, buying  the rights to an old rock in the Outer Oort Cloud   that a mercenary group recently purged of  pirates. They had to work pretty hard to get   the coordinates for that rock in the first place  so charged us a fair amount more to ‘lose them’.  The trick to stealth in the solar system in  the 42nd millenia is the same as it is on any   crowded shopping plaza or boulevard of any big  city throughout history: everyone sees us, and   nobody cares. Now, the thing about a sanctuary,  is that it isn’t a very good one unless people   know it exists and can flee to it, but since we  went and got a nice stealthy base off the radar   we would rather keep it as hidden as we can. So, we need a gateway facility and probably  

more than one. Then we have to decide if these  gateways are public or secret themselves with   a long road to reach, so to speak, and if we are  aiming for a stealth approach of actually hiding,   or hiding in plain sight, we also need to be  deciding how we can keep our reputation clean,   how we can avoid working with unsavory sorts  or them double-crossing us, and how we rule   our sanctuary. For instance, can people leave  if they want to? If so, are there conditions?   Can they communicate to the universe around  them freely and if not, how do we police that?   Are we willing to violate privacy, willing to  scan brains or give people psycho-indoctrination   to keep secrets? Are we willing to use  lethal force to prevent leaks or runaways?  It isn’t entirely lost on us that we could easily  end up every bit as ruthlessly authoritarian as   some of the factions and leaders who keep talking  about the need for peace and security at any   price. A lot of this is all hypothetical  and we’re mostly out in deep space now,   because things seem to be worsening and  we are maybe a little paranoid, but we’re   preparing for the worst and we want secure and  discreet ways to get information, supplies,   and those seeking sanctuary. We will take anyone  – almost - and so long as they agree to our rules.  Out in the broader galaxy, colonization continues  but there’s a lot more conflicts in more settled   regions than even back in the Sol System. By  and large, the galaxy is a pretty chaotic place,   though humanity has still only reached out to  a small pocket of it a few thousand light years   wide. A lot of Sol’s nearer neighbors seem to  be more aggressive to each other and internally.  

These are the older systems within a hundred  lightyears of Earth that have been settled for   tens of thousands of years now, and every  star near them is long since colonized and   developed and home to quadrillions. Many had  been shipping raw materials back to the Solar   System for millenia and funding colony missions  to deeper space and many feel both robbed by Sol,   deserted by their own colonies,  and crowded by their neighbors.  So, it seems like we’ve barely had a chance  to get our sanctuary prepared before we start   seeing border wars in the Oort Cloud between  various minor deep space kingdoms, many just   proxy wars between more powerful interplanetary  nations in neighboring solar systems. The notion   of Unification and Empire seems to be getting  more popular too, and by the 44th Millenia, one   confederation of factions controls over a fifth of  the Solar System’s people and resources and seems   to have made a lot of new allies among various  colonies in the light century wide inner sphere   of great old systems. We decide our deep space  habitat, which is increasingly not too secret,  

is not distant enough anymore and we decide it  will now be a gateway to a new sanctuary far   from the Inner Sphere and these Unification Wars. We figure we need to be leaving the local bubble   entirely, and we have a very loose coalition  of other secret and not so secret allies with   similar goals to ourselves, many are the exiles  of defeated states in these conflicts. Space is   three dimensional so it’s decided that we will set  off in different directions but keep in contact,   with various secure one-time pads and protocols  and a cell-based structure to help if anyone gets   captured or turns traitor, or traitor again,  many of our allies used to be enemies. This is   good because an awful lot of our allies go dark  during the bloody few centuries that see the rest   of the Solar System placed under one unified rule.  That ruler really isn’t anything anyone would call  

human either, at least not back when we were  born, thousands of years back, but then again,   that might be the pot calling the kettle black,  in this case the kettle really hates us personally   after dozens of centuries of criticizing it, and  we’ll just call that ruler ‘Kettle’ henceforth.  Kettle seems to have gotten an empire together  at this point and is calling for a Great Crusade,   out to reclaim all of humanity’s lost worlds.  That seems to be Kettle’s priority, but we suspect   Kettle would cheerfully send an armada light years  out of its way to find us and put our metaphorical   head on a spike. So, we personally opt to hide  outside the main galactic disc and everyone   seeking to join us is routed on a very long path,  especially as it takes thousands of years just to   get a signal to where we are going, and where no  human has yet reached. We opt to build our first   quasi-extragalactic sanctuary on the south side of  a red giant in the lower depths of Omega Centauri,   an ancient Globular Cluster and the largest one  in our Galaxy, where roughly 10 million stars   are packed into a region only 150 light years  across. Omega Centauri is 17,000 light years from   Earth and contains more stars than humanity  had settled when the chaos back home started. 

It’s hard to coordinate a sanctuary over  tens of thousands of years, but we can move   a lot faster than empires can conquer, and  before long, our sanctuary at Omega Centauri   has instead turned into one of the largest  empires of the galaxy in the 2022nd century.   This or that armada or refugee fleet seems to  be constantly joining us in our dense cluster,   where stars are so tightly packed they are often  just light days, not light years apart. The last   one to join us fought a 150 century rearguard  defensive, chased by the True Empire, as it calls   itself these days, from world to world and system  to system, burning one after another to ash,   while entire colony fleets were sent to do nothing  but build fortress systems that could resist and   buy time and burn resources in a scorched galaxy  warfare approach. One refugee making it in,   has the somewhat singular claim of having their  parent, grandparent and great grandparent for 100   generations back, each die in a different star  system, defending the retreat of their nomadic   empire. An awful lot of our unintentional empire  is made up of defeated kings, disgraced admirals,   and other unsavory folks who were worse  than any distant tyrant on ancient Earth. 

What qualifies as a person is even vaguer  these days, many of the warships joining us,   fleeing the True Empire, don’t have any crew,  they are the person in question, a sentient ship,   and not many folks have classic meat brains these  days, at least in Omega Centauri. You can flee so   much faster by being a digital signal after all. We know it's just a matter of time before our   Sanctuary is attacked, a few thousand years at  most, so we plan a retreat. Some plan to flee to   other galaxies or less settled parts of our own.  Others plan to die fighting or to try to disappear   into the massive blackhole at the Center  of Omega Centauri, 40,000 solar masses,   an ancient remnant of when the cluster was a dwarf  galaxy, long before there was any Earth, let alone   an empire emerging from Earth gobbling up star  systems with greater rapidity than any black hole.   Some simply choose to build the fastest  and most well-stocked ship they can   and hurl themselves into space propelled by  enormous Stellasers and Nicoll-Dyson Beams,   heading out at nearly light speed and with no  hope of ever returning and a great likelihood   of finding themselves in galaxies that life  will have already developed and conquered in. 

Not us, we want to ensure that there will  always be a sanctuary, so our technique is   somewhat parallel. We aren’t leaving ourselves  just yet, not exactly. Our sanctuary will be   billions of years from now, and near no galaxy, so  nobody has a motive to come there for resources.   What we’re doing is hurling out a string of  massive artificial worlds, each with a black   hole at its center, and containing vast amounts  of supplies. Each will act as a relay to the  

next ones out, and each will follow a slightly  zig-zagging pathway, so that no one can target   them with light-speed quick superlasers. The  pattern of each zag is random but predetermined,   so that they alone know where they’re going  to be, except for those relays further out.  When Omega Centauri finally falls, we’re the  last to leave, one jump ahead of armadas of   ships that outnumber a locust swarm and each  with weapons capable of leveling worlds.   But we take no ship ourselves, first,  broadcasting a powerful signal out galaxy-wide,   listing a large number of space-time coordinates  folks can send a signal to that will be picked   up by one of our many disposable relays that  the various planet-ship gateways will string   out from themselves, so they can’t be targets  directly. Then we do what we advised others to,   and we transmit our mind digitally to the first  gateway, leaving the Milky Way more than a million   years after we left Earth the last time. When we awake, it is inside a space station  

of epic proportions, as big as a solar  system, and surrounded by utter darkness,   even to our post-human senses that  could see better than most telescopes.   Far, far away, we can see the vast darkening  globe that once was our galaxy and many others,   merged together to form some unknown megastructure  we recognize only by its red-shifted light,   it appears to be peaking at the source at about  double the temperature of the Cosmic Microwave   Background radiation, which itself is far cooler  than it used to be, and it is red-shifted as   appropriate for something that we keep a distance  and velocity of 99% of light speed away from,   accounting for Hubble Expansion. That’s because this station keeps itself   intentionally at just short of the cosmological  event horizon from what once was the Milky Way,   so that others may transmit themselves  down our relay gates to reach us,   here at the edge of space and so far forward in  time that there are no longer any natural stars,   only one vast hyper-efficient computer  simulating unimaginably huge virtual   worlds to serve as sanctuaries to  all. Last to leave but first to arrive   as we followed the most straight path,  we wait patiently for others to come,   knowing no war fleet can ever reach us, and that,  at last, we have reached our true sanctuary.

So I was intentionally a bit vague today about who  and what are protagonist and antagonist were but   the implication is that both are post-human and  change a lot over the course of the million-year   long timeline and the epilogue a quadrillion  years hence. Nonetheless they’re definitely   not running on classic brains anymore and yet  they probably are still using neural networks,   what are own brains use and what was often  predicted future supercomputers would use and now,   today, more and more of them use ever-better  neural networks to do ever more impressive work.  But it's still a mystery field to most  folks, like a lot of math and science,   and yet they don’t need to be. Our friends  over at Brilliant have created a number of  

interactive courses on Neural Networks that will  walk you through the topic of Neural Networks and   many other areas of Math, Science, and Computer  Science. These topics are often thought to be   hard to learn but they don’t have to be, they are  much easier to learn with interactive examples,   everything is. The best learning is hands-on  and interactive learning, hands down,   and Brilliant has worked tirelessly over the years  to offer more and ever better interactive learning   options for math, science, and computer science. These topics often seemed hard in the past   because there were so few interactive  options compared to other topics,   but now Brilliant makes it easier for anyone to  learn, be it the basics or advanced materials.  With Brilliant, you can learn at your own pace,  learn on the go, and learn something new. To get  

started for free, visit brilliant.org/IsaacArthur  or click on the link in the description,   and the first 200 people will get 20% off  Brilliant's annual premium subscription. So today’s topic was about escaping to a sanctuary  from the perspective of building it for others   far from home, and we’ll take a look at it from a  different perspective next mont on August 4th with   an episode Alien Refugees. As for next week, we’ll  return to the Fermi Paradox to ask where all these   enormous habitats and megastructures we discuss  on the show might be and what their apparent   absence indicates about the Universe. After that  we’ll look at two of the most mysterious things   in our Universe, Black Holes and Dark Matter,  and if dark matter might be black holes. Then  

we’ll close July out with our Monthly Livestream  Q&A on Sunday, July 31st, at 4 pm Eastern Time.  If you want alerts when those and other episodes  come out, don’t forget to subscribe to the channel   and hit the notifications bell. And if you  enjoyed today’s episode, and would like   help support future episodes, please visit our  website, Isaac Arthur.net, for ways to donate,   or become a show patron over at Patreon. Those  and other options, like our awesome social media   forums for discussing futuristic concepts,  can be found in the links in the description. 

Until next time, thanks for  watching, and have a great week!

2022-07-16

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