A hyper-efficient power-source that you can’t meaningfully accelerate (small black holes) may make space-faring surprisingly difficult for advanced civilisations
I've always felt that solutions to the 'paradox' that amounted to 'home is nice and easy to take care of and upgrade and is radically co-evolved with yourself in a way that's hard to beat' have routinely gotten short shrift despite their obvious biological and historical analogues, even without a presumption of the plausibility/inevitability of building black hole power plants. Take most of the major speculative trajectories for big things happening in the future, and it's clear that most of them first and foremost make neighborhoods closer to home more habitable for longer more easily than they enable petri-dish-esque uniform expansion to the stars. Develop O'Neill-style closed-loop habitats? They work on Earth too, and no one dies on the days they don't. Get good at the whole terraforming gamut and can build planetary sunshades and concentrators and whip up custom atmospheres, and, at the far end, scoot planets around with complicated momentum transfer systems? All that lets you keep your home planet habitable through all the deep time hazards of brightening and dimming stars and thinning atmospheres, not to mention ordinary cruft like comet impacts. Even if you rock over hard into robot-and-singularity land, you're faced with the possibility of being able to extract astonishing amount of computation out of most of the grit around your home star on one hand and introducing an unfathomable amount of latency to some links in your suprastellar Dyson brain on the other, just to move next door.
I tend to suspect that life arises in places suitable for life, and that tautology actually has some force- that (even within the framework you're constructing with this project) astonishing fractions of the universe are unsuitable *even if we radically expand our conceptions of possible life*, and if that's the case that the Fermi paradox is like akin to asking why there aren't Bengal tigers in my bathroom.
Robert L. Forward's 1995 book "Indistinguishable From Magic" covers black hole technology and antimatter, among other (im)possible technologies. (available for borrowing from the Internet Archive).
Bob's 1965 PhD thesis may have introduced the first gravitational wave detector, he also invented several practical "magic" technologies such as the tidal compensator for nano-gee experiments in orbit, the "statite" for non-equatorial geostationary orbits, and the obital tether, which allows direct inter-conversion of orbital energy and electrical energy. Some of his ideas are far less doable, but will stretch one's mind.
A couple of subscribers have answered the email version of this post to share their thoughts, which is great. (Always feel free to just answer the email version, I read everything I get.) One asked a question which I thought was worth answering in the comments, because if he asked it, then others may well be thinking this too.
He wondered why, if you had abundant energy, would you care about the inefficiency of antimatter production? Just make it inefficiently! As he correctly points out, the potential gains would be enormous - reaching another star system could easily double your available energy resources. With such a tremendous return on investment, why not use a small amount of your total energy capacity inefficiently?
To which I replied.... Sure! I didn't say these problems would stop interstellar exploration, just that they put a lot more friction in the process than you would think.
Bear in mind the current cost of making a gram of antimatter is sixty two trillion dollars (more than twice as much as the price of all the real estate in the USA). Right now, we are only capable of making a few atoms of antimatter at a time, and it is UNBELIEVABLY wasteful of energy.
And you need hundreds of tons of antimatter to bring one spaceship the size of the space shuttle to the nearest star, Proxima Centauri, at 10% of the speed of light. (Thousands of tons of antimatter if you want to go at 80 or 90% of the speed of light.) At a million grams per ton.... And you haven't colonised anything yet, you've just sent one ship to a star system where there are no habitable planets. (Proxima Centauri is tiny, erratic, and flares regularly, scorching all the planets in the "habitable" zone.)
So you could send one small ship to the nearest shitty little dim star... or you could buy hundreds of millions of USAs.
What are you likely to do, if you have access to that much energy/wealth?
So... it can be done, but that's a lot of friction!
Thanks for your feedback, though, it's very useful. I probably didn't make clear just HOW high the friction would be.
I think if there is only one black hole per planet then it would certainly not be worthwhile to divert cosmological evolution towards the creation of intelligent life, particularly given how rare it seems to be with the Fermi Paradox.
It seems to me the that it would only be worthwhile if black holes are created all the time, as single-use devices. I think theoretically if you were able to create black holes of various sizes less than 100 million kilograms (which if I calculate correctly would last about one second), you could slingshot yourself forward at quite high speeds. Each trip would create two black holes of various sizes to control the duration, a (relatively) large one to accelerate and a smaller one to decelerate.
The problem with using Hawking radiation from a very small black hole to accelerate (or decelerate) is that the energy output is structured horribly for the job. At first, there is hardly any energy, and then there is, very, very briefly, a lot, and then it goes off like an atom bomb as the last of it evaporates at incredible speed. The acceleration would smudge you all over the floor. And the blast would evaporate your ship.
I was actually thinking about using the gravity well but after checking I see that doesn't actually provide any meaningful acceleration at all. Anyways, apparently the idea of using a quick burst of Hawking radiation for acceleration is common enough that there is a name for it: Kugelblitz drive. I just assume that a civilization capable of creating black holes is also capable of shielding against it (and probably isn't biological either).
Another possibility which occurs to me is that even if transportation is not feasible or cost-effective for people or materials, there is one thing which is still extremely important and valuable to transfer, which is information. Given the bandwidth limitations of radio or other wave transmission methods, shooting hard drives back and forth might actually be the most efficient form of information transfer.
Have you considered the possibility of utilizing a black hole energy generator to power an Alcubierre drive? If the black hole itself remains inside the warp bubble then you wouldn't actually need to accelerate it in the first place, nicely sidestepping the problem. Of course there is a lot of handwaving involved in how you would actually do this in practice, but the same can be said about turning an Everest-sized asteroid into a black hole.
I wonder if there would be a reason for a civilization to start moving slowly out of its initial solar system. For example, maybe in anticipation of the collapse of its star the civilization would move early enough that it would be out of the way when it happens.
I personally like the idea (read it in a Charles Stross novel) that advanced civilizations are some kind of ultradense supermind, and the low speed of light/low information bandwith prevents them to expand very far in space, since they would loose functionality and coherence.
In a nutshell: life as we know it evolved in the goldilocks zone of our star, right? Not too cold, not too hot. But since the universe started out extremely hot, and cooled down over time, that must mean that at some point in the past, the ENTIRE universe was a goldilocks zone. So maybe life didn't start on Earth - maybe it started everywhere all at once.
My favorite solution to the Fermi Paradox is that we're just the first ones. Well, one of many first ones - everyone's evolving at the same time, and even if there's another civilization with a headstart on us out there, it's not a HUGE headstart, it's not billions of years before us, so there hasn't been enough time for them to reach us yet. Or their probes to reach us yet or whatever.
Maybe there are alien spaceships flying around with cheap plentiful antimatter fuel all over the place, there just aren't enough of them to be enough of a signature we start seeing them or they start roaming around our neck of the woods.
A technology at this level could, I believe, make Von Neumann probes, and these, it has been calculated, could fill the galaxy in a relatively short time. We do not see them and the efficiency argument does not prevent them. Furthermore it is unsafe to stay at home; If there are hostile aliens (or badly aligned alien AIs) out there then it would seem safer to expand out to meet them rather than wait for them to come to us and history tells us that victory usually goes to the side with the bigger army.
If this is true, then the constraint on interstellar travel wouldn’t be _total energy available_, but the amount of potential energy in the form of “desire to explore the cosmos and willingness to endure privation to do so.” If the alternative is “a stately pleasure dome”, only the very much motivated to explore would ever leave. But that means any visitors are either angels or demons. They would have demonstrated immense willingness to sacrifice their own potential for comfort in exchange for … what, exactly? It can’t be experiences that could be faked or simulated or materialized. The only thing that fits the bill would be conscious beings. So maybe they’d travel the stars for the ability to explore with joyful curiosity to learn from and experience other life… or maybe the desire to experience new forms of suffering. Heck, maybe both could be true at once!
Ok so: manufacture a bunch of antimatter, but don’t use it to accelerate, only use it to decelerate. Use lasers to accelerate.
Of course this still leaves unanswered how to build new Everest-size black holes at the destination solar (or stanetary!) system. We have no idea what such a ship would need to carry along in order to re-bootstrap the civilization.
Have you read the Centauri Dreams blog at all? This seems like the exact kind of stuff one would find there. The maintainer might be willing to republish and get you great discussion from the interstellar-enthusiast folks who hang out there.
For interstellar travel one could perhaps use Quantised Inertia (theory developed by Mike McCulloch). It remains to be proven that this actually works as a space drive, but lab experiments done on Earth are promising.
I've always felt that solutions to the 'paradox' that amounted to 'home is nice and easy to take care of and upgrade and is radically co-evolved with yourself in a way that's hard to beat' have routinely gotten short shrift despite their obvious biological and historical analogues, even without a presumption of the plausibility/inevitability of building black hole power plants. Take most of the major speculative trajectories for big things happening in the future, and it's clear that most of them first and foremost make neighborhoods closer to home more habitable for longer more easily than they enable petri-dish-esque uniform expansion to the stars. Develop O'Neill-style closed-loop habitats? They work on Earth too, and no one dies on the days they don't. Get good at the whole terraforming gamut and can build planetary sunshades and concentrators and whip up custom atmospheres, and, at the far end, scoot planets around with complicated momentum transfer systems? All that lets you keep your home planet habitable through all the deep time hazards of brightening and dimming stars and thinning atmospheres, not to mention ordinary cruft like comet impacts. Even if you rock over hard into robot-and-singularity land, you're faced with the possibility of being able to extract astonishing amount of computation out of most of the grit around your home star on one hand and introducing an unfathomable amount of latency to some links in your suprastellar Dyson brain on the other, just to move next door.
I tend to suspect that life arises in places suitable for life, and that tautology actually has some force- that (even within the framework you're constructing with this project) astonishing fractions of the universe are unsuitable *even if we radically expand our conceptions of possible life*, and if that's the case that the Fermi paradox is like akin to asking why there aren't Bengal tigers in my bathroom.
Robert L. Forward's 1995 book "Indistinguishable From Magic" covers black hole technology and antimatter, among other (im)possible technologies. (available for borrowing from the Internet Archive).
Bob's 1965 PhD thesis may have introduced the first gravitational wave detector, he also invented several practical "magic" technologies such as the tidal compensator for nano-gee experiments in orbit, the "statite" for non-equatorial geostationary orbits, and the obital tether, which allows direct inter-conversion of orbital energy and electrical energy. Some of his ideas are far less doable, but will stretch one's mind.
Oh, I love the sound of this book. Right up my Straẞe. Thank you for the tip!
A couple of subscribers have answered the email version of this post to share their thoughts, which is great. (Always feel free to just answer the email version, I read everything I get.) One asked a question which I thought was worth answering in the comments, because if he asked it, then others may well be thinking this too.
He wondered why, if you had abundant energy, would you care about the inefficiency of antimatter production? Just make it inefficiently! As he correctly points out, the potential gains would be enormous - reaching another star system could easily double your available energy resources. With such a tremendous return on investment, why not use a small amount of your total energy capacity inefficiently?
To which I replied.... Sure! I didn't say these problems would stop interstellar exploration, just that they put a lot more friction in the process than you would think.
Bear in mind the current cost of making a gram of antimatter is sixty two trillion dollars (more than twice as much as the price of all the real estate in the USA). Right now, we are only capable of making a few atoms of antimatter at a time, and it is UNBELIEVABLY wasteful of energy.
And you need hundreds of tons of antimatter to bring one spaceship the size of the space shuttle to the nearest star, Proxima Centauri, at 10% of the speed of light. (Thousands of tons of antimatter if you want to go at 80 or 90% of the speed of light.) At a million grams per ton.... And you haven't colonised anything yet, you've just sent one ship to a star system where there are no habitable planets. (Proxima Centauri is tiny, erratic, and flares regularly, scorching all the planets in the "habitable" zone.)
So you could send one small ship to the nearest shitty little dim star... or you could buy hundreds of millions of USAs.
What are you likely to do, if you have access to that much energy/wealth?
So... it can be done, but that's a lot of friction!
Thanks for your feedback, though, it's very useful. I probably didn't make clear just HOW high the friction would be.
I think if there is only one black hole per planet then it would certainly not be worthwhile to divert cosmological evolution towards the creation of intelligent life, particularly given how rare it seems to be with the Fermi Paradox.
It seems to me the that it would only be worthwhile if black holes are created all the time, as single-use devices. I think theoretically if you were able to create black holes of various sizes less than 100 million kilograms (which if I calculate correctly would last about one second), you could slingshot yourself forward at quite high speeds. Each trip would create two black holes of various sizes to control the duration, a (relatively) large one to accelerate and a smaller one to decelerate.
The problem with using Hawking radiation from a very small black hole to accelerate (or decelerate) is that the energy output is structured horribly for the job. At first, there is hardly any energy, and then there is, very, very briefly, a lot, and then it goes off like an atom bomb as the last of it evaporates at incredible speed. The acceleration would smudge you all over the floor. And the blast would evaporate your ship.
I was actually thinking about using the gravity well but after checking I see that doesn't actually provide any meaningful acceleration at all. Anyways, apparently the idea of using a quick burst of Hawking radiation for acceleration is common enough that there is a name for it: Kugelblitz drive. I just assume that a civilization capable of creating black holes is also capable of shielding against it (and probably isn't biological either).
Another possibility which occurs to me is that even if transportation is not feasible or cost-effective for people or materials, there is one thing which is still extremely important and valuable to transfer, which is information. Given the bandwidth limitations of radio or other wave transmission methods, shooting hard drives back and forth might actually be the most efficient form of information transfer.
Have you considered the possibility of utilizing a black hole energy generator to power an Alcubierre drive? If the black hole itself remains inside the warp bubble then you wouldn't actually need to accelerate it in the first place, nicely sidestepping the problem. Of course there is a lot of handwaving involved in how you would actually do this in practice, but the same can be said about turning an Everest-sized asteroid into a black hole.
I wonder if there would be a reason for a civilization to start moving slowly out of its initial solar system. For example, maybe in anticipation of the collapse of its star the civilization would move early enough that it would be out of the way when it happens.
I personally like the idea (read it in a Charles Stross novel) that advanced civilizations are some kind of ultradense supermind, and the low speed of light/low information bandwith prevents them to expand very far in space, since they would loose functionality and coherence.
You ever see this Kurzgesagt video?
https://www.youtube.com/watch?v=JOiGEI9pQBs
In a nutshell: life as we know it evolved in the goldilocks zone of our star, right? Not too cold, not too hot. But since the universe started out extremely hot, and cooled down over time, that must mean that at some point in the past, the ENTIRE universe was a goldilocks zone. So maybe life didn't start on Earth - maybe it started everywhere all at once.
My favorite solution to the Fermi Paradox is that we're just the first ones. Well, one of many first ones - everyone's evolving at the same time, and even if there's another civilization with a headstart on us out there, it's not a HUGE headstart, it's not billions of years before us, so there hasn't been enough time for them to reach us yet. Or their probes to reach us yet or whatever.
Maybe there are alien spaceships flying around with cheap plentiful antimatter fuel all over the place, there just aren't enough of them to be enough of a signature we start seeing them or they start roaming around our neck of the woods.
A technology at this level could, I believe, make Von Neumann probes, and these, it has been calculated, could fill the galaxy in a relatively short time. We do not see them and the efficiency argument does not prevent them. Furthermore it is unsafe to stay at home; If there are hostile aliens (or badly aligned alien AIs) out there then it would seem safer to expand out to meet them rather than wait for them to come to us and history tells us that victory usually goes to the side with the bigger army.
If this is true, then the constraint on interstellar travel wouldn’t be _total energy available_, but the amount of potential energy in the form of “desire to explore the cosmos and willingness to endure privation to do so.” If the alternative is “a stately pleasure dome”, only the very much motivated to explore would ever leave. But that means any visitors are either angels or demons. They would have demonstrated immense willingness to sacrifice their own potential for comfort in exchange for … what, exactly? It can’t be experiences that could be faked or simulated or materialized. The only thing that fits the bill would be conscious beings. So maybe they’d travel the stars for the ability to explore with joyful curiosity to learn from and experience other life… or maybe the desire to experience new forms of suffering. Heck, maybe both could be true at once!
Ok so: manufacture a bunch of antimatter, but don’t use it to accelerate, only use it to decelerate. Use lasers to accelerate.
Of course this still leaves unanswered how to build new Everest-size black holes at the destination solar (or stanetary!) system. We have no idea what such a ship would need to carry along in order to re-bootstrap the civilization.
Have you read the Centauri Dreams blog at all? This seems like the exact kind of stuff one would find there. The maintainer might be willing to republish and get you great discussion from the interstellar-enthusiast folks who hang out there.
This would probably be solved via von Neumann probes.
1. Use lasers to accelerate a small probe
2. Probe slows down with classic anti-matter/ ram scoop
3. Probe breaks down raw materials (extracted from asteroids, moons, gas giants, etc.) to create replicas of itself
4. Robot swarm builds receiving laser + terraforming local planets + building a new black hole generator
5. Even before the first colonists arrive, the next wave of probes is lasered to neighboring star systems
I plugged this into DeepThink and his timeline is the following:
Total Timeline for Proxima Centauri Mission
Acceleration + Travel: ~21–30 years.
Deceleration: ~30–50 years.
Self-Replication: ~50–100 years.
Infrastructure Build: ~100–200 years.
Next-Wave Launch: ~0 years (after Step 4).
Total (Earth to Next-Wave Probes): ~200–400 years (optimistically).
Pretty fast! Only a few generations for current humans.
For interstellar travel one could perhaps use Quantised Inertia (theory developed by Mike McCulloch). It remains to be proven that this actually works as a space drive, but lab experiments done on Earth are promising.
https://foresight.org/summary/mike-mcculloch-how-quantised-inertia-can-revolutionise-space-travel-space-workshop-23/