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!
After subscribing to Isaac Arthur's Youtube channel a while back I learned that when you see the little red science and futurism box on a video thumbnail you click that video thumbnail.
The content is amazing but on a purely superficial note, I love this guys accent and his name, Isaac Arthur, is perfect. Because Isaac Asimov and Arthur C. Clarke. It just fits
A brilliant video-series! I like how he doesn't dumb down any of the technical terms and the concepts he discusses is really fascinating. People who talk of the speech impediment, have you ever heard anyone with a thick accent speaking? Turn on the close captions and you'll get used to it super quickly
Nice to see some Isaac Arthur up in here.
It's Arthursday today! He comes out with a new video every Thursday and they're always good. Link
This guy is the shit...l have been following him for quite a while now and his biggest strength is he doesnt dum the topic down too much like most documentaries do...either you get it or you watch it again..and again....kkkk😂
I'm of the personal belief that we may never have to resort to farming black holes, because if we are still around at that stage of the universe we will have succeeded in traveling between dimensions or at the very least manipulating entropy by that point, therefore basically either having no need to stay in this one or choosing our own destiny.
Edit: I would totally agree that we should adhere to our current understanding of physical law and plan accordingly. This is simply a personal thought about a possible outcome a billion years from now, not something we as a species should hang our hat on.
Sub is r/IsaacArthur for those interested
this is youtube video, not a documentary.