Black Hole Dyson Sphere TIMELAPSE | Dyson Sphere Program
[Timelapse] Dyson Sphere around Black Hole (Dyson Sphere Program)
Dyson Sphere Program - FLYING INTO A BLACK HOLE!
In case you don't know what Dyson Sphere Program is -- think 3D Factorio in Space:
Dyson Sphere Program Trailer
Dyson Sphere Program Release Date Announcement Trailer
Katherine of Sky has some great DPS videos, and she also plays lots of Factorio and Satisfactory too:
Dyson Sphere Program Ep 1 - Factorio + Satisfactory + Astroneer = FUN? - Let's Play, Early Access
For a realistic visualization of what one would see when falling in a black hole see https://jila.colorado.edu/~ajsh/insidebh/schw.html
If anyone reading this loved building factories in factorio and building huge buildings in Minecraft, try Satisfactory now.
Satisfactory can be enjoyed by a wider audience, however. As can Factorio.
For some reason DSP is not hooking me as much as Factorio
If you haven't played DSP since they introduced blueprints, I'd encourage you to give it a revisit. Although ironically the mass deconstruction in Factorio is equally handy but is still missing in DSP, which can make any rework still be a grind
I bought it about a week after it became available on Steam and played it all the way through (Unlocked the last item in the tech tree) and wanted to try again with some different gameplay options, but not until blueprints were implemented. I must have missed the announcement.
DSP's is https://store.steampowered.com/news/app/1366540 and the update in question is https://store.steampowered.com/news/app/1366540/view/3008952...
They also added some kind of global scoreboard system (Milky Way) if one is into that kind of thing and want a bigger challenge that just "local universe automation nivrana": https://store.steampowered.com/news/app/1366540/view/3044975...
They alleged to have released some portion of the source code (https://store.steampowered.com/news/app/1366540/view/5694225...) in order to make mods easier, but there is some massive confusion about where, exactly, one can find such a thing and I'm evidently too old to find my way around Discord
It's for sure a game-changer(!) for "welcome to this new planet with some iron and copper next to each other: let me cook some interesting resource that I need (e-mag are my go-to because it seems one can never have enough of those)
As a QoL improvement, it's also handy for "oh, look: titanium -- let the drones lay out 15 smelters with their power poles to exfiltrate that resource"
Some of the screenshots folks have done about power production are insaneo -- to the point their GPU starts to drag from the game ticks :-)
I've poured about 60 hours into this game and I'm done. Back to Satisfactory for me.
There is no point to go and harness energy around a star or a black hole, when you can just produce it locally with a lot less resources/waste and materials. The sun itself is actually very inefficient in producing energy.
There is no need to harness the sun million of km away, when you can recreate it in your home planet. The only way to produce a dyson like of sphere, is to tame an over-heated sun, and reflect away un-needed energy. But there is no point to build one to just harness it.
It makes great sci-fi stories, but that's about it. Scientifically, it just doesn't make sense.
That is a lot of mass to extract and transport to the power stations (accelerate, decelerate). So it just makes sense to only needing to build the facilities to collect the power from existing sources (stars, black holes) without the logistics of transporting the fuel.
Moreover, the space around a star or black hole is real estate that would go unused otherwise, while asteroids, moons, ... are more likely usable by such an advanced civilization.
 https://www.quora.com/What-would-the-estimated-weight-of-Mou... (I took the highest estimate in the first answer)
With D + D fusion (easy to believe compared to CNO) an interstellar civilization could be essentially independent of stars.
I'm sure part of the resolution of the Fermi paradox is that dry inside-the-frost-line planets like Mercury, Venus, Earth and Mars are not the generic places you find life.
If things were a bit different I could see a would-be Galileo on an less cooked version of Io or a more cooked version of Europa who looks at the Earth with a spectroscope and sees oxygen and has a huge amount of trouble with his local "church" that thinks it is impossible to have life on a planet with less tidal activity, less radiation, inside-the-frost-line dryness, etc.
Even if creatures like us became interstellar we might have millions of kilometers of condominiums and shopping malls in the oort cloud and could care less about inner solar system planets.
> it just makes sense to only needing to build the facilities to collect the power from existing sources (stars, black holes) without the logistics of transporting the fuel.
Yeah OK, but then you have to transport your entire reactor to the fuel. For that matter, you also have to transport the energy where it's needed once you've harnessed it.
Seems like it would require, at minimum, several planets worth of raw material.
You could mine it from asteroids, which have plenty of base metals. There's already a speculative market for investors wishing to mine them. The only thing is; the technology for transporting it around doesn't exist yet. (We can land probes on them however for recon, but that's about it so far!).
Why do people keep insisting on the Dyson concept as though it was real, even though it's just the fanciest thing we can imagine with our current understanding of physics?
The same way in the 19th century nuclear power couldn't be envisioned, there's definitiely a bunch of technology we don't know about now that an alien civilization could be using; we could even be observing this right now and we would be none the wiser. Talking about Dyson shperes, or swarms, or rings, and then concluding that there's now alien civilzations because we can't see them is just anthropocentrism, failing to consider other possiblities
On Earth, none of those are available in the quantities needed to provide sufficient energy for us (close to a planetary civilisation in energy needs) on the scale of millions of years.
If you want your civilisation to not deplete available energy in the next million or so years and to allow for growth of energy demands in that time, you're going to have to make use of star power.
A planet only gets so much starlight that it becomes a limiting factor in energy budget. The easiest next step is to make more use of the abundant energy source next door: your star.
There are other options, e.g. using black holes. But those are orders of magnitude more challenging: black holes are extreme stars (extremely far from any developing civilisation).
On Earth, we've seen that every leap-frog in civilisation (fire, agriculture, industrialisation, ...) increased the available energy budget by orders of magnitude. There's not that many orders of magnitude left on this planet to grow further; if we want more, we'll need to get it from elsewhere.
Alien civilisations that remain bounds to their planet's energy budget similarly must remain stuck at a certain level of energy use. They can make advances in efficiency, but their total energy budget is capped.
When in the past, unanswered, mystery questions like these were finally answered (for example "how come light seems to appear in discrete packets?"), the answer ended up being a door to a completely new understanding of reality, and not a little footnote question at the End of Physics
So yeah, when there are no more unanswered physics questions, I will consider that the laws of physics have been exhausted. Right now that's not the case.
The additional benefit is the amount of power. With the power of a star at your disposal, beaming your energy using lasers and microwaves, even if only 1% efficient, would instantly solve the energy needs of any planet in a solar system. If we did it, we could instantly colonize all planets in our solar system because things like "running an AC on Mercury" or "Hovercraft in Jupiter Atmosphere" becomes trivial when you have limitless power.
Heck, you could start projects like moving planets in orbits or collecting astroids to built a planet if you wanted.
Black holes are the stage after that since you can use a spinning black hole to convert a given mass into energy at >10% efficiency (given E=MC^2). That would allow a civilization to power multiple solar systems at the cost of a few planets per year.
Granted, the sphere is difficult to build, but that is what you have dyson swarms for.
It's unstable without active stabilisation. The stabilisation has to be perfect because otherwise you get massive distorting spherequakes propagating through it, which will make it a very uncomfortable ride for a short time and will soon tear it apart.
A perfect spherical stabilising solution with components and sensors that are light minutes - or possibly light hours - from each other is impossible because of the signalling delays.
Ringworlds have the same problem. Even if the ring is made of infinitely strong unobtanium, it won't stay in a useful orbit for long enough to be built, never mind inhabited.
Swarms have more potential, because you can build them with sparse shells and move things around to handle instabilities. But you still need massive computational effort to keep swarm units from colliding with each other, possibly at very high speed.
None of this matters, because the limiting factor for civs is collective intelligence, not energy.
We already have access to far more energy than we could possibly use on earth for any technology that's actually buildable. But we're not using it because we don't have the species IQ to make the right choices.
Why couldn't a Dyson sphere have uncoordinated movement joints distributed all around to absorb those spherequakes? Or even active locally coordinated ones?
I'm sure a Dyson-sphere-building civilization would figure this out.
This is precisely the appeal of Larry Niven's Ringworld concept. You instead take a slice of that sphere and spin it around the star and generate gravity through centrifugal force. They can take a number of configurations but the default one would give you the equivalent of 2 million earth's worth of living space inside one continual surface. This is obviously hugely mass intensive and having a ring of that kind of radius spinning at the tangential velocities required for the equivalent of one g of simulated gravity (around 1200 km/s) requires materials so magically strong that they make graphene look like soggy tissues. The only material that could do this even in the theoretical realm is magmatter, which would be materials constructed out of magnetic monopoles, something that has been predicted to exist by some but has yet to be observed.
However, you could construct one using known materials by creating a superstructure around the ring that is much more massive and orbits the other direction at normal orbital speeds for a body about an AU out from the sun with the ringworld electromagnetically suspended from the superstructure, normalising their collective momentum to zero. That obviously greatly increase the mass requirements but this could mostly take the form of hydrogen and helium which is far more abundant than heavier elements and would be usable as fuel for fusion reactors. That superstructure can contain many smaller rotating habitats and the whole thing could be used as a vast habitat for microgravity living as well - something I envision as many humans doing as living on worlds with gravity by the time we would have constructed one of these.
You also want to have a superstructure because at such a high tangential velocity, if a human being of 80 kg struck the ring from the outside, it would blow with the kinetic energy of a thermonuclear bomb. Point defence is absolutely necessary and the superstucture offers both an excellent shield covering the non sun lit side of the ring and a great platform for hosting those point defence systems. Ringworlds are also not in stable orbital configurations over astronomical timescales so you need to maintain their orbit through corrective thrust. This could be done through light sails which would also be appealing for it's mechanical simplicity.
Ringworlds are very mass intensive especially if your civilisation still has no access to unobtanium building materials and I don't think this would be something we would ever build a lot of in our particular solar system but even with that mass cost, you could easily gather enough rocky material from the sun to build a few and still have the vast majority of people living in other far smaller structures (but only relative to a star encompassing ring) in the swarm.
One solution is for the expansion joints to have infinite range— a disconnected swarm of platforms which is exactly what a Dyson swarm is.
I've heard Dyson spheres referred to as a K2 Civ's wonder or vanity project.
Eternal leader, those pesky Alpha Centaurans just completed work on a galactic wonder, the Dyson Sphere! [+1000 energy, +100 habitat]
Shall we redirect our own Dyson Sphere efforts to a new project?
Damnit! Yeah fine whatever, let's switch to building a Kemplerer Rosette.
Is this really the limiting factor? I've always assumed the limiting factor was distance. I can envision a species that is more intelligent or more altruistic. But what I can't envision is how collective action is coordinated over interstellar distances. It would seem to me that the extreme communication delay would cause any interstellar civilization to inevitably break apart into a bunch of separate "local" civilizations.
Repeat at 90 degrees, 45 degrees, etc until you have a sphere.
You're right that speed-of-light delays make negative feedback control difficult, but it might be possible to have rockets that sense local photon flux on the inner surface of the ring/sphere and fire autonomously when it increases.
That's an interesting take. It does seem that we're more limited by our poor choices than by underlying physical limits. We invest ridiculous amounts of money into weapons by comparison to things like nuclear and fusion power.
This. The entire “moving planets” and “powering asteroids” theme is just a projection of our historical aggressive reproduction, which is not even a requirement for an advanced civilization. Earth alone could serve us a few billions of happy years, if we didn’t have the happy urge to multiply until critical shortage. That’s far from intelligent, imo.
With that, being happy does not seem to be a universal quality of life; some would even posit that the opposite is true (ask Gautama B.)
I don't see humans completely overcome their biological nature any time soon, if ever.
That's just what species are selected for. If you have two competing populations and one multiplies and expands just slightly better than the other, everything else equal, then that one will eventually outcompete the slower one.
But it does not have to be that way. Humans are the top predator, so no competition here. We could make do with limiting expansion if we chose to. It's still life, but without this "quality" that you seem to consider a necessity.
We have no predators but we do have a lot of existential threats. The more we spread out the more chances we have of surviving. If we sit on our hands and stay put we’ll wind up like the dinosaurs one way or another.
Solving world hunger does not need expansion. Stopping climate change does not need expansion. Preventing the upcoming antibiotics crisis does not need expansion. To the contrary, expansion makes all those things worse or has even started them in the first place.
This problem is twofold. First is that much food is produced far from many poorly nourished people. This problem is totally solvable by modern transport. There are enough charity donations to prevent hunger everywhere.
Second, and most importantly, it's the social structure what prevents ending the hunger where the hunger still is. People prevent production and distribution of food in order to keep the social structures where they are on top, or are fighting to be on top. They themselves are not hungry, and don't care about the rest much.
Not intentionally, but we've managed to create societies where reproduction is extremely costly in every conceivable way and are even working to convince people that reproduction is outright tyrannical, sexist, and environmentally genocidal.
The instinct will certainly remain, but population decline seems inevitable the way things are going. Even a few decades from now, the human breadbaskets of the developing world adopt the anti-natalist systems we have in the developed world.
If the argument is that somehow the former is more environmentally friendly, then I don’t understand why we should accept dystopia for an uncaring god.
Humans are exceptional in this regard as that can expand beyond the limits, and at the expense of, all other known species. Humans are also exceptional in that they could extinguish themselves, either by choice on their own folly.
Of course. But they reach a limit. Only one species is able to exploit resources, and the biosphere, to its own ends. Agriculture, mining, and technological advancement are peculiar to humans. All of these permit us to live longer, with fewer setbacks, and in environments no other animals can survive (space, and soon other planets). Are these not exceptional traits?
We can also engineer a virus, or deploy strategic weapons that could wipe out our entire species (and a bunch of others). Is that not exceptional?
But some animals have agriculture (ants?) and some plants exploit metals in the soil (phytomining)! Still, Sapiens are the champs.
And it's such a banal obvious claim I'm making, and yet it's being downvoted to oblivion. I can't imagine cane toads doing anything I mentioned.. or even ants having some sort of hegemonic control over the fate of all other species.
If tomorrow all ants disappear then most land-oriented ecosystems would just collapse.
We humans are having so egoistically anthropocentrical world views that it's not even funny anymore.
> Humans are also exceptional in that they could extinguish themselves, either by choice on their own folly.
Could you imagine ants finding a method to annihilate themselves? I don't claim that animals are unintelligent, but we are unique in our ability to create technology to achieve almost any goal, no matter goal's 'sapience'.
> If tomorrow all ants disappear then most land-oriented ecosystems would just collapse.
I don't dispute this, but it's completely orthogonal to my claim. Humans have disrupted the biosphere in a manner that is unprecedented since when meteor strikes and seismic events were still shaping earth
It's not very hard for ants to collectively commit suicide.
The age of star formation is mostly over yes, but not completely yet - and I believe it's figured that no red dwarf can have reached even a tiny fraction of its lifespan so far?
Yet there are actual dust rings and discs in the sky surrounding stars for long periods without falling into the star, being blown out of the gravitational influence of the star, or condensing into planets on life-evolving timescales.
Some of them are pretty occlusive and get hot (~ 1000 degC) and are consequentially observational targets for MATISSE at the European Southern Observatory. It's not at all my field, but I gather https://theskylive.com/sky/stars/kappa-tucanae-star is a principal hot dust belt target.
Retreating towards my islands of comfort, there are plenty of small rocky bodies ( flavour of "dust" in the sense of the previous paragraphs) in the solar system that are in no immediate danger of colliding, plunging inwards, or escaping to infinity in spite of ablation from solar radiation, differential radiation pressure and other effects that lead to the term "active asteroid". Most of them will be there, and have been there, for billions of years despite evil Jupiter trying to mess them up. Speculating a little away from my weak-gravity island, I would be surprised if there were no ongoing organic chemistry reactions in the more icy carbonaceous active asteroids in our solar system. It's not a huge leap from that to an asteroid-based power station that slowly produces some alcohol(s) at much denser concentrations than the wood alcohol molecular clouds like in W3(OH) astrophysical alcohol megamaser region. 
Icy-carbonaceous bodies in closer orbit and with sufficient spin angular momentum (perhaps supported by the Yarkovsky effect) for cheap thermal management could in principle host terrestrial photoautotrophs suitable for processing into biodiesel. Impractical at small scale, but maybe useful if one has many billions of such "power plants" around a single star. And of course, one could use the photoautotrophs to feed microbes more suitable for the production of more complicated molecules like, oh I dunno, oxycodone (for fun and profit).
(A sufficiently dense dust belt in the goldilocks zone could even make use of ideas from the panspermia hypothesis, so that one only has to populate an initial fraction of the bodies with economically useful microbes, and the little bugs will reproduce and spread throughout.)
One can easily imagine greater efficiencies from engineering non-organism power collectors and storage systems instead of adapting blue-green algae to output biological compounds, and one would probably want to do this for a dust that is in bulk much hotter than the vast majority of our solar system's asteroids tend to get, or if practically the entirety of the dust is manufactured rather than already in place ready for populating with mats or colonies of economically useful microbes.
Returning to the paper at the top, I think the only advantage a black hole gives is that a sufficiently large one might have a much larger localised "goldilocks" volume which one might seed with small icy-carbonaceous body light-powered power plants, compared to having many such belts around many many stars. However density of production could be an important advantage, even if one has to move a swarm of objects to it rather than adapt a swarm of substrate objects already in place.
Super-concisely: Earth has a lot of oil, inefficiently, seemingly by accident, after a long delay from initial "activation" of the biosphere, and with a fairly high collection cost because it below so much atmosphere (and water and rock) through which it would have to be lifted for off-world use. Sufficiently advanced aliens (and perhaps future humans), if they wanted oil, undoubtedly could do better than Earth.
 http://www.star.bris.ac.uk/mark/w3oh.html but don't inhale it, the W is for Wood alcohol (hydroxymethane).
After that your efficiency declines until... Well you end up with fusion reactors that look like the sun. You also end up fusing all the mass that we need to live our lives on and make stuff out of.
If you don't think a civilisation could ever need the amount of energy that a Dyson sphere could provide, that's fine, we don't need one.
But if you imagine a civilisation that does need the energy a Dyson sphere can provide, then they make a lot of sense.
It's the inevitable end-result of Bitcoin.
The sun is about 2×10^30 kilograms. The rest of the solar system is about 3×10^27 kilograms and we kind of need it to live on and make things with. Put in other words, the entire solar system including the Sun is 1.0014 Solar masses. Why not go with the process we have rather than fusing everything we have to do the same thing?
If you're saying that we don't need that much energy then I think that's pretty meaningless since we have no idea what we could get up to or need in the far future.
Even without considering what to do with the resultant mass star lifting is just good stellar husbandry for a civilization looking to last.
If you really want to extract mass from a star, just wait long enough, or find one ready to release a suitable amount. There are plenty of options from CMAs to flares to UV Ceti style flare stars, to deflagrating white dwarfs, novas, and supernovas. Let the star's nuclear energy do the "heavy lifting", eliminating all the problems catalogued before the "... plasma jets hundreds or thousands of astronomical units long ... [t]he details of extracting useful materials from [that has] not been extensively explored".
(The linked article at the top discusses relativistic jets driven by million-solar-mass and larger black holes. The jets are likely to be more constant and/or more predictable than natural mass outflows from stars, but extracting and storing energy from that is even less "extensively explored". An option in between is to use the natural mass flow from a companion star onto a compact star (white dwarf, neutron star, black hole) by sticking the moral equivalent of a water wheel into the stream. It's just a (compared to water hot & sparse) fluid flowing downhill, and there are plenty of examples in our galaxy.)
So what if it's inefficient? It's happening anyway and it's not like you can siphon the hydrogen off and do anything else with it.
What kind of purism is it to not tap the largest energy sources in existence because you bristle at their inefficiency.
Actually this is another megastructure process known as Star Lifting. And it's not just hydrogen you can siphon off - the sun, by virtue of its immense size, contains the overwhelming majority of every element in the solar system.
Unfortunately because they burn up so quickly, the hydrogen isotopes we would use in fusion reactors are actually incredibly rare in the sun. The sun is estimated to have about the same amount of deuterium as Earth's oceans. On the other hand, Helium-3, another potential fusion fuel, is very abundant - about 10-20 Earth Masses are present. Still though, burning all this helium 3 at the same energy production rate of the Sun would only last us 870,000 years - a drop in the bucket compared to the lifetime of the sun.
Well, hydro energy is just there, requires comparatively little ongoing maintenance, and has less catastrophic failure modes.
I think the same caveats work for Dyson spheres.
Given incidence of dam bursts like the 1975 Banqiao dam failure, with an estimate death toll of 26,000 to 240,000 people and flooding of over 12,000 square kilometers, I'm inclined to disagree with this assessment.
Hypothetical scenarios can be constructed for both methods of power generation (What if Braidwood plant melts down, somehow killing the 5 million people living within a 50 mile radius? What if the Three Gorges Dam busts, inundating an area inhabited by 600 million people?) Either way, it is far from obvious to me that hydro has the superior safety profile, especially when their fatality rates are on the same order of magnitude even when the Banqiao incident is removed*.
* Sovacool et al. (2016), the source of the data in  includes a hydro fatality rate per tWh 2.4x larger than nuclear when Banqiao is included.
Lets say, you want to manufacture new planets/planetary sized spaceships. You would need very big fusion reactors and you probably want to save the special fusion fuel for those, when they are on their voyage to other worlds. Because then they need fusion.
But why build a fusion reactor, when you already have a big one avaiable?
Few planets are similarly sized as Earth already btw, although with varying densities.
And I just assume that a civilisation advanced enough to build a dyson sphere, can handle the non trivial orbital mechanics, too. But maybe still cannot travel FTL. So indeed rather choose to build planets, or planet sized space stations.
That would require lots of energy and maybe the need to harvest the sun directly and control the light going out towards the planets.
A.) Keep it in place and not hit the star/black hole.
B.) Avoid it being demolished by intercepting every piece of space trash, comet, asteroid in a solar system?
EDIT: Inb4 the downvotes.
I don't see any requirement why an intelligent civilisation would need to grow its population forever. It seems far more intelligent to attack the cause of the energy need instead of building crazy structures like Dyson spheres around black holes.
A Dyson sphere is foolish because one can simply build a small local fusion reactor instead of using the giant free one nearby?
Imagine a sphere of reflective particles around a star. Planets within would never experience nightfall. Free energy would be everywhere. Sounds useful.
Moreover, such a solar system would be difficult to detect. If it is mobile, and uses a low-signature form of propulsion such as UFOs exhibit, then it would be extremely elusive.
This solves the problem of someone launching stealth asteroids at one's base at relativistic speeds.
Moving a solar system presumably requires tremendous power. Using a star as the fusion reactor presumably helps.
The technology required to build a tier 1 swarm is not advanced. All you need is the ability to build a thin reflector (aluminium foil would work) with radio and a basic onboard computer. You do not even need onboard propellant because a reflector can generate the required thrust for minor corrections with solar pressure alone. These reflectors can then concentrate that light from close in to the star out to collectors further out in the system. This essentially makes your habitable zone as large as you want since you can also light entire planets this way and only utilize less than a percent of a percent of your total energy budget.
The real challenge is having good enough automation to construct and send these stations out without requiring too much oversight, and getting good enough at construction off earth (since you really don't want to deal with that gravity well). We're definitely close to having the required automation technology and we should be performing the first manufacturing off earth before the end of the next decade.
Artificial fusion can be made far more efficient than the fusion in the core of our sun, yes. However, the sun outputs enough energy to light 2 billion earths worth of surface. Moreover, it essentially contains all of both the hydrogen and rocky material in the solar system with the other bodies being essentially a rounding error in comparison, so even in a controlled fusion based economy, you would still create a Dyson sphere like construct since you would be using that star as your main fuel and mass source.
Black holes though? They make even aneutronic fusion look like a fire cracker in comparison. You're getting less than a percent mass energy conversion with even the best theoretical fusion models there are, whereas with black holes, you can get anywhere from 16% to 40% depending on the technique and mass range of the black hole. Stellar black holes have so much energy inside that they would dwarf even our star (consider that their progenitors were stars with far more mass than our own and with an even bigger disparity in power output). They also last for periods of time that make even red dwarfs look like still births. If you could make artificial ones in the gigaton and megaton ranges, then they can also make for amazing batteries. In this case, you are able to tap the hawking radiation emitted for power and this promises potentially even greater efficiencies than the stellar mass ones (albeit, you would not be gaining a net power gain here, this is strictly for power storage and potentially gravity generation purposes).
The results are fairly obvious: CMB and Hawking radiation provide almost zero power output, while an accretion disk and relativistic jets can provide a lot of power.
In theory you can get an arbitrary amount of power from Hawking radiation if you have a lot of very small black holes instead of just one big one. I feel like the stability of the negative-feedback control systems for their orbits might be important here, especially if they're orbiting something you care about like your home planet.
Energy is energy wouldn’t a matter black hole and an anti matter black hole just make a black twice the size, minus a bit for gravity waves.
I was thinking given a large enough gravity wave it might be able to stretch a black hole apart. How huge that could be, and how that could be generated is probably beyond the limits of reality.
Depending on what the cosmological constant is, massive black holes could be quite useful in the far future. 10^100 years from now, long after all the stars have gone out, it could be the case that the only life in the universe would be huddled up against the event horizon of supermassive black holes, exploiting the tiny temperature difference between the pseudosurface and the void to generate a trickle of power.
Splitting black holes would rob the far future of that power source to be used now. You could do it, but why shorten the useful life of the universe?
But on the off-chance you're not - and for everyone else who's intrigued by this comment's concepts - I can recommend watching it.
A black hole is generated when mass-energy density is above a certain threshold. You need to pack about a megatonne of mass-energy in a sphere 3 attometers in diameter to get a black hole approaching a useful lifespan. You could do it with bosonic matter, but photons are easier. Well, "easier":
>In Section V below, we discuss the plausibility of creating SBHs with a
very large spherically converging gamma ray laser. A radius of 1 attometer
corresponds to the wavelength of a gamma ray with an energy of about 1.24
TeV. Since the wavelength of the Hawking radiation is 8π^2
times the radius of the BH, the Hawking temperature of a BH with this radius is on the order of
16 GeV, within the limit of what we could hope to achieve technologically.
>In a previous paper by the first author , it was proposed that a SBH could
be artificially created by firing a huge number of gamma rays from a spherically
converging laser. The idea is to pack so much energy into such a small space
that a BH will form. An advantage of using photons is that, since they are
bosons, there is no Pauli exclusion principle to worry about. Although a laser
powered black hole generator presents huge engineering challenges, the concept
appears to be physically sound according to classical general relativity.
The process of aligning the laser array will be interesting, however. From Wikipedia:
>Unlike most objects, a black hole's temperature increases as it radiates away mass. The rate of temperature increase is exponential, with the most likely endpoint being the dissolution of the black hole in a violent burst of gamma rays. A complete description of this dissolution requires a model of quantum gravity, however, as it occurs when the black hole's mass approaches 1 Planck mass, when its radius will also approach two Planck lengths.
See table 2 from the paper. A 0.32 attometer wide black hole has a surface temperature of 98.1GeV and is losing 61.4 kilograms per second-- 5,519 petawatts of ultra-hard gamma radiation! Even at that diameter it has a sizable weight of 108,000 tonnes, but it doesn't have long to live-- a couple weeks. A poorly collimated laser array will produce undersize black holes which will rapidly evaporate. The paper suggests keeping them well away from Earth, on the other side of the Sun if possible. Not hard-- you'd want to put the array well within the orbit of Mercury for better solar power flux.
So the sub-attometer-sized black holes described here seem like they might be a lot more practical than what I was thinking of. But... what does it take to stop TeV gamma rays? (And I guess they might also spew out strange matter and naked truth and the like, but you could probably just toss it back in.)
The billion-tonne gamma-ray laser they're talking about here is absolutely tiny.
Nobody knows anything about quantum gravity, which is the problem ;)
>order of a nanometer
As db48x says, synthetic black holes aren't going to be much good as power plants, just because it's so darn hard to get them big enough that they can consume normal matter. Let's talk bare minimums. Say the nucleus of an hydrogen atom is about 2.4 femtometers wide. Plugging the numbers into https://www.vttoth.com/CMS/physics-notes/311-hawking-radiati... the mass of a black hole that size is 8.07991 * 10^8 metric tons. That is a lot of laser pulse power to get into a single point just to create the black hole. Wolfram alpha claims it's 2.01718 x 10^25 watthours. The sun radiates 3.828 x 10^26 watts, so we need about a tenth of total solar output for an hour-- assuming we can convert captured solar power into coherent gamma rays with no loss, which there is currently no plausible physical way to do, so we probably need 10 or 100 times as much power. We're beyond future ultratech, and getting into solar engineering.
Assuming the black hole is created, which is hard enough, we have further problems. A 2.4 femtometer black hole is still darn hot: it's radiating a total of 545.6 megawatts of light with a peak of 51.3 MeV-- still ultrahard gamma radiation. Our beam of hydrogen ions need to fight past this headwind and into the singularity-- quickly. It's losing 6.054 micrograms per second, which will be hard to deliver as a single row of hydrogen nuclei.
Making the black hole bigger in the first place will make it easier to feed... but if you can commandeer a tenth of the Sun's output at will, you don't exactly need domestic power from a black hole.
However, the trouble with larger black holes like the 2.4-femtometer example is not primarily that they require a lot of mass-energy to produce, but that they last a long time. According to the calculator linked above, it is indeed radiating 545.6 megawatts, which sounds like a lot. But compared to the 808 million tonnes you put into it, it's not very much; it will take you 4.2 trillion years to get back the energy you put in, about 250 times the current age of the universe. (The lifetime calculation on that page is shorter, only 777 billion years, because it's assuming you're allowing the black hole to evaporate rather than feeding it to keep it the same size.)
(BTW, actually that was all for a 2.4-femtometer-radius black hole, not a 2.4-femtometer-diameter one.)
This is really shitty energy-efficiency from a time-discounted perspective. If you use a conservative 3% yearly discount rate, the time-discounted earnings from your power plant over those 777 billion or 4.2 trillion years are equal to their non-time-discounted earnings over only the next 33.3 years. So from an economic point of view your efficiency is not 100%; it's 7.9e-10%, 0.000000000786% efficient. And that's not even taking into account the costs of building the giant gamma-ray laser.
So, for reasonable economic efficiency, you really need to build a black hole with a lifetime of 100 years or less. That means 400,000 tonnes or less, radius of 6.1e-10 nanometers (0.61 attometers) or less, 300 trillion kelvin or more, 102 GeV or more, 2.1 petawatts or more. In nuclear-bomb terms, that's 0.5 megatons per second (still very small compared to the sun's 390 yottawatts or 85 petatons per second), except that it's coming out in 102 GeV photons. That's about the mass of a silver atom, though still very small compared to the Oh-My-God Particle.
As skykooler points out, this could complicate the task of feeding the monster. Maybe you could set it to orbiting at a few kilometers per second inside a solid object such as Ceres, so that it occasionally gulps a proton on its way through the body, leaving a trail of rapidly cooling subterranean plasma in its wake.
Of course, if all the energy that's coming out has to go in through a nuclear gamma-ray laser, it's not really a power source, just a battery that's conveniently portable and has a built-in rocket engine.
The thing with very small black holes is that they're virtually impossible to feed stuff into - not only are they an extremely small target, but the flood of energy escaping will push away any matter that comes nearby.
If you could make a fusion reactor almost infinitely better then it would produce a black hole which would immediately evaporate releasing more energy than you could ever imagine - but no way it can be done.
There are many awful engineering problems of a black hole drive, but they're not so bad as to dismiss out of hand. See https://arxiv.org/abs/0908.1803v1
By contrast, there's ample reason to believe that black-hole power plants are possible. In fact, the spatial precision required is actually the same order of magnitude as that of LIGO, about an attometer. So we might not even have to wait 350 years for it.
The central theoretical problem is that taking Hawking seriously, the stuff inside stays inside, but inside goes away. What happens to the stuff? There are more theoretical answers to that written down than there are actual theorists, and presently no astronomical or laboratory observations which let us throw practically any of them away.
(Also of course, inside might not go away after all -- not at all or not completely -- with large numbers of explanations of how that might work, and nothing concretely observed that lets us discount such possibilities in favour of total evaporation.)
Let's use your parenthetical as an excuse to keep charge vanishingly small, because we can avoid thinking "Which charge? Which charge carrier or carriers? What's the distribution of charges?", and largely ignore the electro- effects of electrovacuum (which answers these, but in surprising ways when you look deeply).
In a chargeless vacuum Schwarzschild or Kerr universe, we have total coordinate freedom because there is nothing there but the mass at an infintesimally small point, p. If one builds a system of coordinates with p always at a single spacelike point (say, the spacelike origin), then the symmetries of this vacuum system let one chop away spatial position (e.g. const.coord.x, const.coord.y, const.coord.z, t -> 0,0,0,t) and consequently the vector-quantity linear momenta of the black hole vanish. Moreover, these vacuum spacetimes are also eternal (the black holes do not grow or shrink), so we can do t = const. too. With suitable coordinates, gives us two free parameters: mass & spin (and in Schwarzschild, just one: mass).
These solutions do not superpose additively. By the Raychaudhuri focusing theorem, if we add a point mass to the Schwarzschild black hole universe, the two masses will eventually collide. We have broken the spherical symmetry of the Schwarzschild solution, and when we solve the geodesic equations, we find caustics, where our two infinitesimal masses can be in the same infinitesimal space. We have also broken time symmetry: at past time the two masses are spacelike separated. In the future they are not, as they will merge into one black hole. We also have the problem that the black holes move with respect to one another, so we either adapt or system of coordinates to be comoving with the black holes, or we have one or both of them move against the spatial-coordinate part of our system of coordinates.
When we take this further by breaking other symmetries than the time one, e.g. by adding angular momentum to the system, we have to consider the evolution of orbital angular momentum of the pair, and possibly the spin angular momentum of each. Either of our previous-paragraph choices with respect to encoding the coordinate evolution of the spatial distance between the pair of black holes complicates the calculation of the related vector quantities.
We're still in the land of a small number of parameters, but have gone from the three time-independent [mass, spin, charge] to eleven time-dependent [mass, spin, charge, 4-location, 4-linear momentum].
We can explode the number of parameters though by returning to "what is charge?", and equipping these universes with fields of matter. At this point one runs right into the question of: "does the no-hair conjecture hold in a physically plausible universe surrounding a theoretical black hole?" or almost equivalently "when do theoretical black holes fail to approximate astrophysical black holes?", and Ligo/Virgo are good laboratories for studying whether merging black holes go completely bald.
(The hair that is supposed to bald away may be soft and indirect: the circulation of gas and dust at a distance may reveal that a given black hole was previously more than one black hole. After merger, none of that should make a difference to anything (including a 3rd black hole) falling into the balded merged black hole that the merged black hole was previously two black holes. More critically, in the enormously distant future, the evaporation of the merged black hole should not reveal the number or types of objects that fell into it during its history, whether those are black holes or some neutral mix of standard model particles. The Hawking radiation spectrum at any moment should depend only on the eleven parameters in the previous paragraph. But maybe that still-outside dust and gas has memory that remains relevant arbitrarily far into the future. Or maybe classical general relativity is wrong and rather than being crushed into a memoryless ultramicroscopic point, the ingested gas, dust and other black holes retain or at least reveal their individual identities even during evaporation).
Questions like these make black holes extremely interesting, I think.
Termed the "halo drive", it's a very nice theoretical concept: https://www.youtube.com/watch?v=rFqL9CkNxXw