Civilizations at the End of Time: Black Hole Farming

Civilizations at the End of Time: Black Hole Farming


Today’s topic, Black hole Farming, is going
to be a difficult one because it’s a video I probably shouldn’t have made without covering
other topics first, and also because it draws heavily on quite a few other videos I did
make first. So it essentially amounts to three topics that we need to cover today and assumes
a knowledge of the most recent videos on the channel, which means that if this is your
first visit to this channel, while I normally try to make videos as standalone as possible
and you probably can watch this without watching the others first, it isn’t advised.
That said, it isn’t absolutely necessary and to help with that, whenever I bring up
topics we’ve covered in more detail in other videos you will usually see an in-video link
for that video pop up, and you can just click on it to pause this video and watch that one.
You can also turn on the closed caption subtitles if you are having problems understanding me.
So I said it was actually three topics, not just one, for today. What are those three
topics? Well let’s list them out. 1) Using Black Holes for Power Sources
We’ve talked about this before but mostly in the context of Hawking Radiation from small,
artificial black holes. Today’s video is focused on large, long-lived black holes,
where Hawking Radiation is incredibly tiny and other methods are needed. So we’ll be
discussing those other methods as well as what the implications of living on minimal
Hawking Radiation would be like 2) The Fate of the Universe
In this section we’ll go over the timeline of ages of the Universe fairly quickly, and
also quickly cover some of the other ideas for Civilizations far in the future, which
we may expand on in future videos. 3) Black Hole Farming
In the last section we’ll get into the meat of things, trying to contemplate what civilizations
would be like that essentially fed themselves off black holes. It’s the concept of using
black holes as the power source for your civilization, and actually creating or placing black holes
to make that work best, which is the origin of the title. I think it summons to mind the
image of farmer in coveralls with a pitchfork literally farming black holes but we’re
sticking with it anyway. So without further ado, let’s dig in.
Our first topic, using Black Holes as power sources is, as I mentioned, something we looked
at before in the twin videos discussing Hawking Radiation, Micro-Black Holes, and using them
to power starships. You may want to watch those, or re-watch those, before proceeding,
but the quick summary is that Black Holes are thought to emit Hawking Radiation loosely
in proportion to their size. Except backwards from what you’d expect, the giant monster
sized ones in the centers of galaxies emit so little of it you’d need a trillion, trillion
years to collect enough energy to turn on a little LED light for a fraction of a second.
Alternatively the small ones gush out power so fast they burn out their tiny mass in very
short times. There’s two upshots of this. First, that
the lifespan of black holes is proportional to the cube of the mass, one twice as massive
emits only a quarter of the power and lives eight times longer, one ten times as massive
emits a hundredth of the power and lives a thousand times as long, etc.
Second, if we can make artificial black holes, and especially if we can feed matter into
them to replace what they lose to Hawking Radiation, we have an excellent power source
for things. Black Holes are roughly on par with anti-matter, and vastly better than nuclear
fission or fusion, in terms of energy per unit-mass of fuel, and they don’t blow up
unless you starve them to death, a process that would take years or centuries normally,
making them a very attractive option for power generation and storage.
This is assuming we can figure out how to make small ones and feed them, both of which
are actually a lot harder than with their bigger, naturally occurring kindred. Which
again emit virtually no energy on timelines that can be measured without using scientific
notation. This doesn’t mean we can’t tap black holes
for power in other ways though. The preferred way to tap a black hole for
power quickly, which also works on neutron stars, is to suck out their rotational energy.
Stars spin, same as planets, they have a lot of angular momentum and that is one of those
conserved quantities in nature. When they die and collapse they start spinning much
faster for the same reason an ice skater twirling around with her arms out will spin much faster
by just bringing her arms in toward her body. Our sun rotates around once a month, neutrons
stars often rotate many times a second, that is why pulsars make such handy clocks. I was
going to say pulsars are a type of neutron star but all neutron stars begin as pulsars,
it’s just they have to be pointing in our direction for us to notice the pulsing and
that effect diminishes with time. This isn’t a video on pulsars so I’ll just simplify
it for the moment by saying they emit two narrow beams from opposite directions and
if you’re at the right angle each of those beams will pass over you every time it spins
around, which again is many times a second. They only do this for the first hundred or
so million years of their life, and only about a tenth happen to line up with Earth so it
is right to think of pulsars as a type of neutron star it’s just that the type is
A) Fairly young and B) coincidentally aimed our way. Every neutron star was a pulsar for
someone at some point. Science fiction loves to say you can use pulsars to get navigational
fixes off of, and that’s basically true, but you’d need a catalog of all the young
neutron stars to do that properly. And again it is only young neutrons stars you can use
for this as they slowly lose energy and cool with time, something we’ll discuss a bit
more in the second section of this video. Anyway needless to say black holes spin too,
and very quickly, and both them and neutron stars emit huge magnetic fields as a result,
same as Earth does from having a giant molten ball of spinning metal in the core. You can
tap that power, sucking energy from spinning magnets was how the first electric generator
worked, the Faraday Disc, which was the precursor of dynamos. The disc slowed down as it leaked
power as electricity. Stealing away that black holes rotational
energy, which is a large chunk of it’s total mass energy, is thus a pretty attractive option.
And there’s various proposed ways of doing that. The Penrose process is probably the
best known of them, and relies on being able to remove that energy because a black holes
rotational energy is thought to be stored just outside the event horizon in what’s
called the ergosphere. You obviously can’t dip under an event horizon and suck energy
out, but we can from the ergosphere. There’s also the Blandford–Znajek process
which is one of the lead candidates for explaining how quasars are powered. If you’re familiar
with Quasars, and how they are brighter than most galaxies, this gives you an idea how
much juice a black hole can provide. It also taps the Ergopshere for power and does it
by using an accretion disc, so you’d use this on a black hole that already had one
or that you were feeding, we’ll come back to that in a moment.
You can also just dump matter into a black hole, it gains kinetic energy as it falls
down, same as if we drop a rock off a tall building. If you tied a spool of thread to
that rock and ran an axle through the spool attached to an electric generator you’d
get electricity. And you could do the same with a black hole too.
Of course if you drop that rock off the building you’d get less power than you’d expect
because the rock is falling through air, slamming into air particles, and transferring much
of its momentum to them, actually heating the air up in the process. This is how parachutes
work, transferring all that kinetic energy into a wide swath of air as heat. It’s not
a lot, but if the object is moving fast enough, like a spacecraft on re-entry, it’s a lot
more and can make the object and the air it’s hitting so hot it will glow.
You could gain some power with a solar panel that was nearby, drinking in that light. And
you can do the same with a black hole because as matter falls towards them and often ends
up in orbit around the black hole rather than directly entering, it forms what we call an
accretion disk. And those glow quite brightly, giving off a lot of photons you can collect
to use for power. If you dump matter into a black hole you can collect that power.
It should be noted that when things approach large masses they usually don’t curve and
slam down into them, and that’s as true for black holes as anything else. Their path
curves, depending on how close they get and how massive they are. If they are very close
to a very large mass they will hook right in, but normally they either fly off at a
different angle or enter an orbit. And if there’s other stuff hanging around there
for them to bump into their orbit will decay and they’ll eventually fall in. All that
bumping, again, generates heat and if there’s enough heat, lots of visible light too, same
as a red hot chunk of metal. That’s an accretion disc, for a black hole. And everything that
falls into a black hole will add to its rotational energy too, though if it goes in backwards
it will subtract from it. So if you’re dumping matter into black holes it pays to drop it
in the right direction. Now neither the rock on a string or the solar
panels collecting light off matter dumped into a black hole is terribly efficient as
these things go, but they are a lot conceptually easier for some then the other methods I mentioned.
Getting back to the Blandford–Znajek process, which I said was a prime candidate for how
Quasars work and another black hole power method, and for our purposes it’s pretty
similar to the penrose mechanism but happens to have an equation you can use to determine
how much power you get out of the thing. They aren’t the same thing, and if you want to
explore the difference I’ll attach a link in the video description to Serguei Komissarov’s
2008 paper that detailed the differences for those who are interested.
That equation shows us that the power output of a black hole via this process goes with
the square of the magnetic field strength of the accretion disc and the square of the
Schwarzchild radius of the black hole, both of which will rise if we increase the size
of that accretion disc or if we increase the mass of the black hole, and in nature bigger
black holes usually have much larger accretion discs. Particularly the big ones near the
center of galaxies, especially volatile young galaxies, as I mentioned this is usually considered
a prime candidate for how quasars are powered and quasars frequently give off a hundred
times the power of an entire regular galaxy. We would presumably want to tap that power
a lot slower, using much smaller black holes and matter flow rates.
Now any of the methods that involve extracting rotational energy will eventually cause that
black hole to slow and finally stop rotating. At that point while you can still dump matter
in, you won’t get nearly as a good a return, and the black holes mass will increase, making
it live longer and give off less power via Hawking Radiation, which is the only option
I’m familiar with that let’s you tap into the rest of that mass energy, as the black
hole slowly evaporates. And we do want that energy.
While lighter artificial black holes can emit useful sources of power via Hawking Radiation,
the big massive ones essentially aren’t. Not unless you can build ridiculously sturdy
equipment that can operate without wear or tear needing power or replacement matter to
fix over even more ridiculously long periods of time. But we will have at least a hundred
trillion years to get better at building sturdy material, and there aren’t many things around
to cause external wear and tear by then, and it is the only game in town after you suck
out the rotational energy and all the stars burn out, plus if you can do it there are
some big potential advantages to waiting that long to pull out your energy, as we’ll discuss
in part three. But first, let’s hit Part Two and review
the Fate and Chronology of the Universe. Or I should say the primary current theory for
a naturally aging and expanding universe. I mention that for two reasons. First that
theory could be wrong, it probably is at least in part, or incomplete, and second because
we don’t live in a universe that’s likely to continue along a natural path, because
we live in it. Intelligent critters can change their environment after all, and generally
tend to, and we’ve spent a lot of time on this channel talking about ways to tinker
with planets, stars, and whole galaxies so it would seem silly to ignore how that could
affect the progression of the Universe. So first we have the big bang, which doesn’t
terribly interest us today, other than it being worth keeping in mind that the Universe
began expanding then and continues to do so, and almost certainly has parts that are so
far away from us that we will never detect any light from them since new space emerges
between them and us faster than light can cover the distance. This effect will only
get worse with time and eventually only the galaxies in our local area close enough to
be bound to us by gravity will remain. As those galaxies get further away, and from
all that emerging extra space seem to get further away faster and faster, the light
from them red shifts and gets weaker and weaker. That’s not the only red-shifting light out
there though, and there’s one type that is of great interest to us today for our final
section. The Big Bang happened about 14 billion years ago, and just 400,000 years later an
event called the last scattering took place. Not a long time, an eyeblink compared to the
age of the Universe, but still a hundred times longer than recorded history and about the
duration of human existence. The last scattering was an important event,
and is aptly named. Up until then the universe was a much smaller and denser place. And small
and dense means hot. Very hot, up until then the universe would have glowed like a star
in every single direction you look, a big white haze. But the light emitted didn’t
go far because it was too hot for atoms to form yet and it that pre-atomic plasma soup
light scattered much easier. As the universe cooled down and suddenly atoms could form,
and were further apart from expansion, photons could suddenly travel long distance without
being likely to run into anything and that kept plummeting. Most photons will never run
into anything now. As a result there are always photons left over from then still flying through
space thus far uninterrupted in their journey. Now when they started off the spectrum was
pretty similar to what stars emit, visible light, but over time as they’ve traveled,
with new bits of space emerging along their path red-shifting them, they’ve lost power.
They went through infrared and finally entered the microwave range just recently, this left
over radiation that’s in the background of everything throughout the cosmos, is called
cosmic microwave background radiation. As more time passes it will grow weaker and
weaker and the universe will keep expanding and cooling. Eventually it will get so weak
and cold that those bigger naturally occurring black holes will finally start giving off
more Hawking Radiation then they absorb in background radiation and actually begin to
slowly age. Right now all naturally occurring black holes are actually growing in mass,
even if there’s no matter nearby to feed them.
That time, when things are that cold, is a long, long way off.
Before we get there we have our own sun slowly getting hotter until it eventually renders
Earth uninhabitable and goes Red giant, swallowing Earth, then leaves behind a earth-sized dense
corpse called a white dwarf, which generates no new energy from fusion but still gives
off a lot of light compared to what our planet uses, and ought to still be warm enough to
light many earths for even longer than its current remaining lifetime before going red
giant. That’s our first example of a civilization
at the end of time, because normally we figure it’s the end of the road when our star goes
red giant, at least here on Earth, and sooner than that too because the Sun is heating up
and Earth will probably be uninhabitable inside a billion years.
Except it won’t be, because there are intelligent critters on it. We may come back and explore
this idea in more detail in the future but for now I want to use it as our first example
of how you can’t look at the timeline for the natural Universe as particularly likely.
Not because the science is wrong but because it doesn’t contemplate the impact of us
on that timeline. We’ve talked a lot about moving planets
or shielding them from light to cool them down. We looked at that in the terraforming
video and more recently in the Ecumenopolis video. So a billion years from now without
intelligence Earth might be rendered uninhabitable by a sun growing hotter, but that probably
won’t be how it goes down. We might sterilize our planet ourselves long before that, our
track record when it comes to screwing up our planet on accident or blowing up chunks
of it is not in my opinion quite as terrible as many naysayers think, but it certainly
isn’t anything we’d want to brag about either.
Or we might disassemble it for building material. In the megastructures series we’ve explored
the basic idea that a planet, in terms of living area, is basically as efficient as
mountain with a few caves on it is. You get a lot more space by disassembling that planet
to build megastructures, in the same way you would disassembling a mountain and its few
cramped caves to use the rock and metal to build skyscrapers. You could disassemble the
average mountain, and it’s cramped few caves able to hold maybe a few hundred people, and
build housing for the entire planet. Similarly you can disassemble a planet and reassemble
it as megastructures with thousands or millions of times the living area. So we might do that
and have no planet here in a billion years. Or we could shade the planet, putting a large
thin shade between us and the sun, decreasing the light we got, especially the infrared
range that’s pretty useless for plants, and keeping us from burning up. Or we could
just move the planet outwards. Moving planets is pretty time consuming as we discussed in
the Terraforming video but it is doable, requires no advanced technology, and we do have a billion
years. So in a billion years it would seem very unlikely
the world will die, because it either will have long before from us screwing up or using
it for building material, or because we valued it a lot and decided to preserve it. And you
can protect against red giant phase of a star and weather it and come back in to live around
that white dwarf remnant for many billions of more years.
Of course even thirty billion years from now when that white dwarf is too cold to be of
any further use to us, a black dwarf, the Universe will still be quite young and going
full tilt. Our galaxy will still be forming stars at the same rate as now, only a bit
faster since we will have merged with the Andromeda galaxy by then and some of our other
neighboring galaxies will have either merged in by then or be approaching.
It won’t be for 800 billion years, about 200 times the age of Earth and 60 times the
age of the Universe, and 200 million times the duration of recorded human history, before
that star formation starts dying off, and it will be an estimated 100 trillion years
before it ceases entirely. There are stars that live longer than a trillion years and
will still be around when star formation begins to ebb off, and they are more efficient at
burning their hydrogen into helium too, and we may look at some examples in the future
of how creating stars or intentionally storing hydrogen in artificial gas giant or brown
dwarfs might be used to similarly extend the lifespan of the star-forming age of the Universe.
Or to create essentially compact dyson spheres of high-efficiency, ultra long lived stars
in what’s been dubbed a ‘Red Globular Galaxy’, a sort of massive megastructure
light years across that hangs on the edge of being a black hole even though it’s not
very dense. To the best of my knowledge that’s the largest continuous megastructure you can
build, though I might be biased on it since it was my brainchild.
Still we get stars for 100 trillion years, and actually still some after that since even
though the universe will be composed of nothing but brown dwarves, white dwarves, black dwarves,
neutron stars, and black holes they will occasionally run into each other. And a white dwarf merging
with a brown dwarf could form a new star as hydrogen is added to that stellar remnant,
though if it is added to fast you get a Nova instead, a very common event in nature that
never seems to get any mention compared to its more spectacular big brother the supernova.
And the collision of dead stars is a common cause of supernovae. A whole lot of hydrogen
hitting a white dwarf or a neutron star or two of them slamming into each other, is quite
common, since many stars are binaries and the bigger of the pair will go red giant and
expand to include its neighbor and cause that star’s orbit to decay, just like an accretion
disc, until they run into each other. So it’s not just the explosion given off
when a big star dies. Kinda like the misimpression that pulsars are a particular type of neutron
star, I think popular science and science fiction has tended to make folks think supernova
is synonymous with big giant star dying and nothing else.
But that universe, at the 100 trillion year mark, will be pretty dark and cold, and just
keep getting more so. By then the other galaxies will all have either folded into our own or
fled over the cosmological event horizon never to be seen again long ago. We’ll still see
light coming from them forever, but it will keep red shifting to be weaker and weaker.
But we won’t be able to talk to them anymore or them talk to us, the signal lag will keep
getting longer and longer until it becomes infinite, and that will happen a lot sooner
than the stars burning out, indeed it’s pretty much constantly happening all the time.
The Universe keep expanding in size but the Observable Universe, which also keeps expanding
in size, is constantly hemorrhaging mass over the horizon.
Most of the galaxies that aren’t close enough to us to be gravitationally bound but close
enough to be reached without faster than light travel could conceivably be colonized over
the billions and trillions of years to come, by us, or might host alien life forms we might
exchange long, very delayed, cordial talk with. So I nickname this phase the ‘Long
Good Bye’, because all the civilizations around will presumably be emitting their history
and commentary on life constantly and one by one the furthest ones away will disappear,
and you from them, and you’d know when it was coming so you could send out one last
message to them. It probably would be cordial chat, and thus
probably a sad goodbye, since if you haven’t invented some form of faster than light travel
by then it’s not like you have anything to fight over since you can’t. I don’t
think even the most determined warmonger will spend a billion years flying off to do war
with someone. And it would seem if you haven’t figured out how to go faster than light by
then, or beat entropy, that you might as well settle in for the end. Though as we’ll see
it doesn’t have to be the end and the speed of light actually becomes an increasingly
smaller hindrance as time rolls on, even though the Universe keeps getting bigger.
So on to part three, black hole farming. The Universe is a hundred trillion years old,
and now you are living on reserves of hydrogen you’ve collected to either run in artificial
fusion reactors or make new stars from. Or to feed into dead stars for a bit more power
as you collect their slowly decreasing heat and light. Or your artificial small black
holes are running out of fuel if you’ve got them.
Now you can tap all those black holes for their rotational energy and live on that for
a good long time. You can slam dead stars together to make more and live on those too.
But eventually they also run out of rotational energy. 100 Trillion years is usually the
timeframe given for the end of life, effectively the end of civilization. The point at which
the handful of folks still remaining show up around the last star and have a party at
the restaurant at the end of the Universe, but we could ration it out a lot longer using
those techniques we’ve discussed thus far. You can even stick black holes near each other
and suck power off their orbital decay and merger.
It does eventually run out though. Now all that’s left is Hawking Radiation.
And I’d have to conclude this pretty much has to be the end of biological life in favor
of minds that simply exist on computers running in virtual landscapes. From a practical perspective
this is probably irrelevant since you can still have all your planets and architecture
and art and fashion and so on inside those virtual landscapes. We talked about this sort
of concept in the Transhumanism and Immortality video and if the idea of living in a computer
feels off to you it might be better to watch that now or when you’re done with this video.
We used that to jump into the Doomsday Argument and Simulation Hypothesis videos too.
In the context of the Doomsday Argument and Simulation Hypothesis as we’ll see in a
bit when we examine the sheer immensity of these constructs in time, odds could be considered
pretty good you and I are actually in one of these setups, running on computers around
a black hole in a dark old universe and we just don’t know it because whoever put us
in there, which might have been ourselves, found it depressing to think about how they
were on a ticking clock edging toward infinity and it was evening not morning, so they erased
their memory of that. We will see shortly that these post-stellar
civilizations could actually be where the majority of living in this Universe occurs,
with the stellar phase just being a quick bright blip against the sea of eternity, but
even they run out of juice in the end and probably have to start sacking their stored
memories to keep going just a while longer and it’s not hard to imagine the ones near
the end might decide they’d be happier without being aware they were doing that and opt to
replicate those last eras of Old Earth long gone but not forgotten.
Anyway odds are good biological life is a long ago thing of the past, I mean it’s
been trillions of years and as we saw in the Matrioshka Brains video and Existential Crisis
Series, you can get a lot more thinking power out of digital people running on computers
than on food and air. But you can also do two other things with such digital people.
First you can slow down their sense of subjective time. We normally talk about speeding it up,
just taking a whole brain emulation of a person and running them faster than normal so they
might experience whole years in minutes, but when you’re low on power you can just slow
everyone’s subjective time down instead. And there’s not much point in hanging around
at real time to watch the Universe since its black and boring now.
But there’s two reasons you might want to start that rationing of time and energy a
lot sooner, that form the first upside of purely digital people. One is a touch mundane,
if you’ve got the remnants of our galaxies and its neighbors hanging out around a few
million black holes hundreds or thousands of light years apart from each other, messages
take hundreds or thousands of years to get back and forth. If you’re running at one
thousandth your normal speed, conserving power, those message takes only months or years to
arrive, and if you’re running at a billionth your normal speed you could have a phone conversation
with someone on the other side of the dead galaxy without noticing a time lag.
So the speed of light is finally beat by simple irrelevancy. You can’t exceed it but it’s
now so fast compared to your experience of time that it simply doesn’t matter.
The other upside I mentioned in the Matrioshka Brains video, and relates to the Universe
getting colder. Currently we use a lot of power to flip a bit, as it were, to perform
one single calculation, and there’s a little bit of heat generated, or a little power expended,
every time you do that. We try to get better and better at making that amount smaller and
smaller, and we may one day even figure out how to make it zero, through reversible computing,
though that would seem to violate thermodynamics at least if you were doing anything that might
qualify as thinking with it. It can’t be ruled out as an option but we are bypassing
reversible computing or any specific discussion of quantum computing today, too many topics,
too little time. The current theoretical limit is the Landauer
limit, and it is considered to be the absolute minimum energy needed to erase a bit of data,
essentially your minimum unit of thought. It happens to be linear to temperature, so
if you can get that to be the maximum on your computing you get more computing – more
thinking and more lifetime – out of every joule of energy you have. So as the universe
cools you still have the same energy or power available but you get more thinking for every
joule, and this setups a very different scenario and dynamic for the end of the Universe, if
this limit becomes the control factor on things. Right now you and I, as basically 100 watt
space heaters, get 1 second of thought for one hundred joules of energy, or 10 milliseconds
of thought per joule. In fact it’s a lot less than that since we basically use most
of our planet, and its nearly 200 billion megawatts of solar illumination to support
7 billion people and would have a rough time doing more than 20 billion off that without
using the methods we discussed in the Arcology and Ecumenpolis video. So in terms of sunlight
converted to food converted to thought we use around 10 megawatts of power to produce
a second of human thought and arguably a billion times more than that since Earth only absorbs
about a billionth of the sun’s light. But as we saw in Matrioshka Brains you could
run trillions of trillions of trillions of real time human brain emulations. We found
in the Transhumanism and Simulation Hypothesis videos that you could run a million people
real time off the same power needed to light a 100 watt light bulb, the same power as human
emits in heat, at room temperature if you could do your calculations at the Landauer
Limit. Pushing that down to the current temperature of the Cosmic Microwave Background radiation,
100 times cooler, would let you run 100 million people on that same power, or one million
people on a watt, and do that real time. But the Universe keeps getting colder, and
as I mentioned those naturally occurring black holes don’t stop gaining mass and emitting
real usable hawking radiation till the Universe gets colder than them. So what is the temperature
of a black hole? A naturally occurring one? Well we usually say you need to be about three
times more massive than our sun is for a neutron star to collapse into a black hole, or at
least most natural black holes will be that massive or more so. And those black holes
live more than 10^68 years, more than 10^54 times longer than the star-forming phase of
the Universe. A billion-billion-billion-billion-billion-billion times longer. And there temperature is not
much over a billionth of a kelvin, about 20 billionths. So when the Universe gets that
cold they start aging because they finally aren’t getting energy in faster than out
and when it get hair colder you can start tapping that power and you’re now getting
a billion times more calculations out of every joule of energy you get then you did running
at the current theoretical maximum. And it will keep getting colder and the bigger black
holes won’t be available till then. But some weirder things probably happen at
below 10^-18 Kelvin, like macroscopic teleportation of matter, and it is also thought that you
can’t get colder than 10^-30 Kelvin, which is well below what even black holes consisting
of several entire galaxies, presumably the maximum sized naturally occurring black hole,
would need to reach before they started giving off more power than they received so for our
example I will stop at 10^-18 Kelvin, where you can get a billion, billion times more
calculations then you can squeeze out per joule now. It is more than enough to drive
home the sheer enormity of these sorts of civilizations anyway.
One person, digitized of course, could run on one millionth of a watt at the current
minimum temperature meaning they could run at one millionth of a billionth of a billionth
of a watt, or 10^-24 watts, at that 10^-18 Kelvin. Well time is an entirely subjective
and relative thing at this point, so those 3 solar mass black holes still lying around
are only giving you about 10^-29 Watts but that would let you run a person at 1/100,00th
of real time, and a message sent a hundred thousand light years would only take a year
to arrive form your perspective. Or let you run, say, a nice community of 10 million people
at a trillionth of natural time, where a phone call across a hundred thousand light years
would only take half a second to arrive and a full second for you to say something and
hear their reply to it. Them being some other community of ten million
living around another black hole. You could slow things down even more and have more people
active, if you wanted and if you could keep your equipment running and practically access
that ridiculously tiny power output in some fashion. I’ve no idea how you would do that
but it’s not actually barred by any laws of physics to the best of my knowledge.
Time might be running slow, but when your subjective time is all that matters who cares
what the real time is passing at? Normally, without contemplating the Landuaer Limit,
that perspective says you might as well run everybody really fast, because there’s only
so much available energy in your chunk of the Universe and a lot of it is being lost
to entropy every moment. So do your thinking now and get the most out of it, but in the
context where we get more thinking from the same energy by waiting till things cool down,
the dynamic changes completely. And even though you and your community of
10 million is only running at a trillionth of normal speed, or maybe a quadrillionth
if you want an Earth sized population of ten billion, that is a subjective eternity still.
Remember those 3 solar mass black holes lived more than 10^68 years. Scientific notation
not being great for giving scale, even at a quadrillionth of normal speed to support
10 billion people, that’s 10^53 subjective years or 10^39 times as long as the 100 trillion
year phase of the universe where there are stars, a thousand trillion-trillion-trillion
times as long. I said way back in the redo of the Dyson Dilemma
and Fermi Paradox Compendium, when I first decided to do this video, that we often see
that period after the stars die out as the end off everything, an eternity of darkness,
but in reality it would be pretty vibrant times. Most of the mass energy of the Universe
will still be around when the stars die off and we’ll be reaping it billions of billions
of times more efficiently, so you could have billions of billions times as many lifetimes
in that dark phase after the stars than during it.
And that’s what we’ve shown here. And if you have seen the Simulation Hypothesis
video, contemplate that, or keep it in mind should you go watch or re-watch it. Because
it not only adds massively to the sheer number of possible people involved it also adds us
another motivation for doing such things. Nothing lasts forever and running super-intelligences
is expensive, so near the end there could be a time where you’ve dumbed people back
down to modern levels and traded your history and the matter and energy used to store it
to buy more life and obscure that time is running down. I don’t want to focus on that
aspect because it should just be a final tiny and somewhat depressing snippet of that very
longed lived and enormous post-stellar civilization but I don’t want to bypass how that could
alter our view of some of our previous topics either.
Now it’s all very speculative, we may find better ways to power civilizations, that’s
a long time to learn to beat entropy somehow, and it may be impossible to tap these powers
sources practically to their full amount, but even the rotational energy methods we
discussed earlier, if held off until those cold phases for tapping, will do pretty good.
But the take away is that even as we’ve discussed before in the context of megastructures
and interstellar colonization, that we are probably only the tiniest earliest fraction
of humans around, the post-stellar civilizations at the end of time will overshadow even those
we’ve previously discussed in sheer size and duration.
They dwarf in every respect even the most extreme galaxy spanning Kardashev-3 civilizations
we’ve contemplated before. Even factoring in subjective time slowing things millions
or trillions of fold, the sheer number of people that can be supported this way, from
the cooling of the Universe lowering the cost of calculations, simply crushes the entire
stellar phase of the Universe into a tiny side note of civilization that is noteworthy
only because it was early, same as those early civilizations in the Fertile Crescent remain
important to us even though there are backwater towns by the tens of thousands that exceed
the mighty cities of that time in numbers and totally eclipse them in effective power.
These latter day civilizations in the cold universe, living off black holes and the other
seeming remnants of a dead universe, turn out to be so immense in scope that they can’t
be regarded as civilizations at the end of time, but rather the real civilization of
which everything that came before was simply a quick prologue.
And that’s Black Hole Farming, and they make for a pretty fertile farm after all.
We may revisit some of the earlier stages, life around dying stars or some options for
Galactic scale Megastructures in future videos. We might even take a peak at the idea of Boltzmann
Brains, which can conceivably exist in defiance of entropy, but that finishes our look for
today. In the meantime it’s back to the habitable
planets series next week for a look at Panthallassic Planets, Worlds entirely covered in water,
and what life might be like trying to evolve there or if we went to such a world to colonize
it. The week after that we finally return to the Faster Than Light series to look at
wormholes, where will discuss the theory, look at some of the problems with making them
and how they could result in time travel causality loops, and also explore a lot of the overlooked
uses of the things if they can be made to work like terraforming planets or serving
as power plants or even refueling dying stars. If you want alerts when those videos come
out, make sure to subscribe to the channel. If you enjoyed the video, please hit the like
button and share it with others. Question and comments are always welcome, and I encourage
you to read those left by others and talk to them because we get some very insightful
comments on these videos form the audience. If you want to help support the channel you
can find the patreon link in the video description, and in the meantime please try out some of
the other video series on this channel. As always, thanks for watching, we’ll see
you next time, and have a great day!

100 thoughts on “Civilizations at the End of Time: Black Hole Farming

  1. Objects entering the Earth's atmosphere (such as reentering spacecraft) are not heated mainly by friction but by adiabatic compression. This would not be significant for a rock falling from a building (or any reasonable object falling at terminal velocity), which does in fact get heated mostly by friction. Both effects are significant in accretion disks, but I don't know which one is larger.

  2. What the hell? This is Donnie Darko stuff. Very entertaining in the film aspect of things, but all the same, Jewish yadda-yadda.

  3. Your accent is very hard to follow. Content seems really good but would be easier to follow narrated buy a drunken Glaswegian.

  4. It seems that this video was you talking yourself into "ancestral" Simulation Theory. Personally, I prefer a "multidimensional ant farm" version of it, but either one works, given direct experience.

  5. You have waged an eternal war against pronouncing "r" in a word! So it becomes a WO, not WAR then.

  6. How could you get to 10^-18 Kelvin temperature when nothing can get below the absolute zero or – 273 degrees Celsius??

  7. These are amazing videos. I'm giving up reading hard sf just to watch these, Isaac, because these are better.

  8. So question. If you slow down a perspective time from a digitized being, allowing messages that would take exceedingly long to transmit and receive to become instantaneous from the perspective of the being, then what are the ramifications for other signals or waves? Particularly light? Being it is a particle, it is also still a wave and it is difficult to say that only a comunication wave is perceived quicker with time when in many theories, time seems to have a speed limit which itself matches light. I'm curious how light would be perceived in itself. Or if somehow the programs would maintain a constant light while allowing time to flow in with changeable means.

  9. I'm pretty sure reversible computing can theoretically emulate consciousness. There are reversible cellular automata that are Türing complete.
    The big caveat is that instead of being able to erase information as in classic computation, you tend to require an evergrowing space.

    But even if there are some things only classic computation can do efficiently, and assuming reversible or quantum computing are possible, a mix of the two should greatly increase the efficiency (reduce power consumption) of doing the same task with completely classic computation.

  10. Instead of simulating people and animals, it would be less consuming to simulate DNA's evolution and interaction with other DNA. Everything else is just a projection of DNA into a macroscopic world as a side effect.

  11. Can we start preparing for eventual end of the universe or does it make no difference what we do now? Seems to me like you can prepare and that is what any advanced civilization would be doing.

  12. There are some scientists who postulate a far future proton decay. How can a civilization exist without matter?

  13. I always enjoy your videos. You put so much work, thought and effort into each one. You should have your own cable network channel.

  14. I rarely follow people.
    I NEVER subscribe for notifications
    (because who wants to hear some random person rant for hours on end every day)
    Well Isaac, your my first
    'Subscribed for Notifications'
    Every single one of your videos is mind blowing.
    With a passion for astronomy, I normally would research topics of interest myself but your videos are so extremely-packed-full of amazing information, described in such ridiculously easy to understand & to visualize ways, I'll sit through 2-4 videos at a time.
    The amount of gratitude I have for people such as yourself & those who create these videos can't be described in words.
    Thank you, is the least I can say. Keep up the amazing work.

  15. So… imagine there's these super efficient slow-motion intergalactic civilizations running on peanut power that has been going on for a long time already, though for them it's been maybe a hundred years of percieved time. The power output is so low we don't recognize them and during our first stage of stellar colonization we accidentally bulldoze over all their stuff. For the intergalactic community, that whole galaxy worth of people cease existing suddenly and instantly, and about 5 minutes later, once humanity start doing the same thing, we appear. Then, 10 years in, we ourselves suddenly cease existing as the next heir to the milky way makes our same mistake. There's a lot of comedic potential to the idea that as soon as a civ slows down time perception enough to do cool long term things, they become unable to react to sudden changes in life… like a tree trying to react to a lumberjack. Until the last player enters the scene and starts the "real history" like you said, after the preamble ended.

  16. I'd just love to have your videos in just audio only format. Would be eating less battery from cell phone. Pretty please?

    Like your voice. And listening to these late at night helps me sleep.

  17. Any significantly advanced civilization could build a bunch of Dyson Rings ringworlds around a black hole, it doesn't have to be at the last stage of the universe's existence for the civilization to do it! Benefits of a significantly advanced civilization living close to a black hole include the time dilation, the black hole being the ultimate trash can, the energy the civilization could get from the black hole, and the ability to time travel! Who knows what scientific discoveries a civilization could make by living around a black hole, maybe they'd discover new physics that we don't know about yet, perhaps they could find out that wormholes are real and exploit them to travel to different places in the universe other universes or eras in time, or discover what dark energy is, etc!

  18. RE black hole era after all stars burn out – harvest tidal forces? Do these cause decay of orbits
    and eventual collisions? Supposedly stellar mass black holes and heavier
    can heat orbiting planets to habitability with
    tidal forces alone (given they emit so little radiation).

    I agree with you and not Kurzgesagt. We have at least 10,000 years to develop >0.5c
    travel before leaving for superclusters well beyond the local group.
    You really went to the long haul for this one, I hope I can experience this stuff…

  19. I set these videos going while I do the washing up because that is the only timw I have free.

    You are brilliant, I'm downloading you on Goole Podcasts to listen to you while driving.

  20. wait.. i might be missing something, but the more you slow down time for a given (simulated) individual, the faster external time passes for them.
    so while it might make sense to compensate for the communication delay in earlier times, at the end of everything the opposite is true: you would want to speed up the 'clock' for the individuals so they can cram more conscious existence into the limited time available at the end of the universe..

  21. Почему у меня название на русском? Охренеть, кто-то сделал субтитры! Спасибо, загадочный человек (олзоу они не то, чтобы мне нужны, но это всё равно великая работа!)

  22. Are you saying that if we become a capable of harnessing Black Holes, that we could use them to literally turn all of our waste products into energy?

    Well that's one way of burning garbage!

  23. if you apply the reasoning of the doomsday argument to a cosmic scale the n it'd make no sense for the number of observers past the stellar stage to far outnumber those of it, indeed you wouldn't even expect the star formation to go on much longer since we're only 14 billion years in and anything more than another 14 billion years starts becoming more and more unlikely unless star formation slows down dramatically. and for various reasons red dwarves aren't hospitable to life so beyond formation you only have the remaining g type stars to work with.

  24. I wonder, would it be possible in several trillion years time for a civilization that's ultra advanced enough to somehow extend the lifespan of the universe or move to another? It seems by that time, there would be a civilization that's sufficiently advanced to be able to travel between universes.

  25. jangkauan bintang galaksi nebula nebula .. dan habis. menghitung waktu dilangit berbeda dengan dibumi.. :d disini SolarSystem,LunarSystem, kemudian StarResolution, SVS,SVRS, SRVRS,.. sulit diceritakan. :/

  26. I(monery)=C(century) I(monery)=D(quingentury)
    I(Monery)=M(millenium)
    I(monery)=LM(Quinquantimillenium)
    I(monery)=CM(centummillenium)
    I(monery)=DM(quingentimillenium)
    terus terus dan terus..
    untuk skala waktu..
    dan itu belum masuk pengetahuan di bumi. informasi yang saya dapatkan. 😀

  27. While I love these videos I can't help but feel that you're overly optimistic Isaac. I think it's far more likely we'll be long extinct when it's time for the earth to become impossible for life in a billion years or so. So in conclusion I think it's more reasonable to assume our planet ends in a natural way than it is that we'll end it or save it. If we destroy ourselves I think we'll die long before all life on the planet dies and then the planet will simply heal itself. That said, there's more than enough time for other intelligent species to pop up on earth before our planet dies and I can't speak to their ability to stay alive.

  28. "You'd have to be a determined war-monger to fly a billion years to do war with someone."

    Imperium of Man dislikes this post! 😀

  29. One thing that puzzles me is what happens to any life in galaxies that vanish out over the "event horizon" out into the outreaches of the expanding universe? Do those galaxies fizzle and die out alone far from any other galaxies with which they could collide since they're occupying space that is expanding faster than the light from those galaxies can get to other places?

    Anyhow. Dunno that I'd want to last long enough that I'm forced to enter into a simulation running at very slow speeds just to extend my perceived runtime. Sure as fuck wouldn't want to erase my memories of having lived for aeons and having watched stars die of old age.

    I'm going to go out on a limb here and suppose that this hasn't already happened and we're still in the young star-forming period of the universe, and I'd be happy enough to become some sort of life-extended human or cyborg in order that I could live long enough that I can visit other planets, hang out in space habitats, watch as we move the Earth outwards to avoid a red giant and in again to harness the energy of a white dwarf – by which time there are probably lots more places to hang out and things to see.

    30 billion years before the sun goes black dwarf on us and then over 99 trillion more years worth of stars we can visit before things start looking dark – that's a pretty respectable lifespan and I probably will have seen quite a few things by then (and probably be bitching that "the universe was better when we still had the Horse Head nebula – you don't get proper nebulae these days. You kids just don't know what a real nebula looks like…" and "the problem with the under-25-billion's these days is that they never had to push a planet away from a dying star, fucking kids don't know nuthin'…" and "there was this time – can't remember which star we had moved to by that point, but it was a nice star, very good neighbourhood – and I used to ride my motorbike on this nearby moon, y'don't get nice moons like that these days…")

    Close to 100 trillion years of life? Yeah, I figure that's enough for anyone – who wants to live forever, anyway (though I might not feel that when I'm pushing 99,999,999,999,955 and I may think "Hmm, maybe I'll just stick it out for another couple of trillion, just to see what happens…")

  30. Once entities exist purely as computer bits, they can travel around as info at light speed or faster, and clone themselves at will and merge with others.

  31. Will you make a video on Quasicrystals and Computing? For example Non-local Game of Life type computation? see: "Non-Local Game of Life in 2D Quasicrystals
    Fang Fang * , Sinziana Paduroiu , Dugan Hammock "

  32. If communication between simulated blackhole civilizations takes half a subjective second, how about actually travelling between them? Maybe an hour by simulated train? I guess a week-long cruise would be much less expensive… and a better metaphor, too. Outside the ship you'd see nothing but ocean.

  33. I’m really thinking about this rock tied to a rope…..
    Could you drop the rock into a black hole while holding the rope, and then pull it back out again …assuming you’re strong enough? Would it still be on the rope….? How about if you put a little camera probe on a rope…?

  34. The idea of the last goodbye to some far far far off civilization just as its galaxy disappears over the observable horizon…wow.
    I am SO looking forward to the party at the Restaurant at the End of the Universe!
    29:13 Or a trillion trillion people off a Watt which is considerably less power than whatever device you are watching this on. [is that understatement? <grin>]
    One of your best videos!

  35. Beautiful. Isaac consists of the same ingredients that they use for heroes and visionaries. I count myself lucky for seeing him.

  36. I just got a flash that we could be a simulation within a simulation ad infinitum, trying to hold on to that last shred of consciousness before it all goes black….
    …………………………………………………………………aaaaaand i think my head just fell out of my brain.

  37. ​Linky: @t What do you think about this Isaac? New study of the M87 black hole found that it is spinning at 90% the speed of light, 100 hour period, which generates around 10 trillion foes (1 foe = 10^44 joules). 1 foe is the average energy of a standard supernova. A civilization harvesting energy from this SINGLE black hole, would have as much energy at their disposal that the entire Milky Way galaxy produces during 10 billion years. Now that is just crazy. (edit: oh nice youtube refuses pdf links to scientific studies)

  38. Hi Isaac. About the several negative comments on your speech impediment: There are many parts to public speaking, cadence, stress on syllables and words, how fast you talk, emphasis on some points, pauses, etc. In all these areas, you excel, you're quite simply one of the finest public speakers I've ever heard, and I've heard a lot. It make the complicated material being presented much easier for me to digest. Your speech impediment is a very small thing, and doesn't bother me in the least.

    Though I realize you do these videos because you love doing them, I'd still like to thank you – for the work you put into them, and for the positive addition to my knowledge base, and more importantly, to my attitude and psyche. It's so easy to drown in the ridiculous stuff that's going on these days, but your presentations expand my horizons, and put things into a different perspective. They give me peace and hope as well as knowledge, and I'm in your debt for that.

    Okay – to my original reason for commenting: You touched on the big bang theory, as well as dark matter and energy. I have to say that I've long been bothered by these "theories" (hypotheses, actually). I believe in a perspective guided by Occam's razor, and when I think that all these theories are based on little photons that have traveled through almost unimaginable distances, through variations of space/time that we don't thoroughly understand yet, (if we ever do), I wonder if it may not be a bit presumptuous (if not downright arrogant 🙂 ) to put so much stock in them. Not being a physisist, I can only surmise that they help you in looking at other things. But they remind me of Eisenstein's fudge factor (Cos. Constant) and we know how that turned out 🙂

    It occurs to me that it's a much simpler explanation that travel through different space / time "areas" might distort our evaluation of the mass and trajectories existing out there, and our extrapolations from them might be wrong. Making up dark matter and energy, and especially the acceleration of the expansion of the Universe – man – mysterious, unseeable dark energy that is causing the acceleration? Dark matter that we can't see in any way other than that it weakly interacts with gravity? It all seems a bit far fetched. My intuition tells me that the universe is just out there, stationary, unending, always been there, and always will be there, and all these perturbations we manufactured are just a lack of understanding about how space/time works.

    Love your works, I eat them up, slowly, cherishing every bite, like a sublime cheesecake. 🙂 Keep up the good work!

  39. These videos are all good and interesting until you realize that what they are proposing is the equivalent of microbes building the Hoover dam, because why not.

  40. This makes me think that we are just a simulation or more precisely said an Ancestral Simulation, by a super intelligent AI that is harvesting the energy possibly from a black hole in the dark era of its current universe.

  41. Isaac Arthur should create new channel where he can reupload videos that are enchanced with deep fake AI to fix his speech impediment

  42. our Atlantia civ is making bLACK hole farming on this dyson sphere called Earth built around a tuny galactic black hole,also n Mars,Moon,Calispo,Calisto,Ganymede,Europa,Titan,Trton,Apollo and Luciferia -last 2 now destroyed

  43. "Znajek" would be pronounced somewhere in between "ZNAH-yek" and "ZNIGH-yek" if we're going to use English phonology. It's a Slavic name that, as far as I can tell, could be any of Polish, Bosni-Serbo-Croatian, or Bulgarian, and in any case would be derived from the respective word for "to know" or "to be familiar with" (making it an apt name for a published physicist). Name etymology notwithstanding, Roman Znajek appears to be a either a native Englishman or fully-assimilated immigrant of 40+ years, going so far as to serve on the Cambridge city council three times, so he may pronounce his name very differently than I have described here.

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