So, let me get this straight right here.

According to Wikipedia:

"The KBC Void (or Local Hole) is an immense, comparatively empty region of space,...... The underdensity is proposed to be roughly spherical, approximately 2 billion light-years (600 megaparsecs, Mpc) in diameter. As with other voids, it is not completely empty but contains the Milky Way, the Local Group, and the larger part of the Laniakea Supercluster. The Milky Way is within a few hundred million light-years of the void's center."

So basically, the KBC void is basically the largest supervoid in the Observable Universe, and our Milky Way galaxy is inside this Supervoid. So basically, we live in the Universe's largest supervoid. This Supervoid isn't like other supervoid, which tend to contain only a handful of galaxies, like Bootes, but it contains the Laniakea Supercluster, the Local Group, including the Milky Way, which is just within a few hundred million light-years of its center. Basically, a "dense" supervoid that contains nearly 100,000 galaxies.

And here is the next part, this time, it is more about the question: Our universe is not really empty. No matter how much you try to bring the pressure to zero, you will never achieve a pure, perfect vacuum, because of one reason- Quantum Fluctuations.

Even in a vacuum, particles keep on appearing and disappearing out of existence. This is the same force that drives Hawking radiation (RIP Black hole), and maybe the same force that caused the Big Bang(Very theoretical). But that is not the question, we are now moving on to the actual question. enter image description here

"Vacuum" Hydrogen Mines

So, according to this article, it is possible to rip particle-antiparticle pairs out of the vacuum, just by inducing an extremely strong electromagnetic field.

In this story, Humans, who have already became a Type III+ civilisation, are now moving out of the galaxy, and are now using FTL warp drives, which are based on Casimir-Alcubierre Drives, and FTL communication, made by wrapping radio-wave photons in a Warped-spacetime packet, which will assist them at much higher speeds to their destination. Their empire is called the Laniakea Empire.

Now they are planning on colonizing the entire Laniakea Supercluster, and in doing so, they discover the KBC void. They have a plan to make basically free fuel from "nothing".

First of all, they get a bunch of Supermassive black holes and magnetar and scatter them throughout the supervoid. Next, the trick is to feed them something, a starter, which could be anything. Then, the next trick is to produce a strong electromagnetic current.

As the magnetars and SMBHs' accretion disks produce an immense amount of electric charges and powerful magnetic field, the result is that the strong electromagnetic fields rip away particles from the quantum vacuum, and turn them into Actual particles, like quarks and gluons, which will be further used to make protons and electrons. These protons and electrons will then be used to make hydrogen. Part of the hydrogen will go into further feeding the SMBHs and magnetars, while the rest is dispersed into the void/used in fusion reactors for power-generation/ further fused to make heavier elements like iron, silicon, carbon, oxygen etc. This essentially makes it a sort of "Hydrogen-breeder reactor", as though the "reactor" consumes matter for producing the powerful electromagnetic field, it in return produces much more matter (Hydrogen).

One of the problems is that, the reactor produces both Hydrogen and Anti-hydrogen. The big problem is that I don't want them both to contact each other and annihilate. One of the easiest ways to do this is to dump the antimatter into a black hole. However, this would be a massive waste of resources, as nearly half of the output is thrown away.

Instead, I want to convert the anti-hydrogen, into normal hydrogen. This way, I can ensure that none of the products are wasted.

How can I convert the Anti-Hydrogen into Normal hydrogen from my "Vacuum Hydrogen" reactors?

Reasons why the humans are building this:

  • This takes place maybe about 20 million years in the future. Humans are now aware that hydrogen is rapidly dwindling in the observable universe, and in just a few trillion years, hydrogen is going to get polluted with heavy elements, which will render star formation almost impossible. Any star formed would be incapable of sustaining life. The civilisation strives to live much longer than just a few trillion years.
  • Another reason, is to make sure that the hydrogen produced will make more stars and planets. The humans are aiming at "creating" life. The aliens will be used as labor force for their empire.
  • The fusion of hydrogen to create heavier elements like iron, silicon, uranium, gold is also very important for the economy of the Laniakean Empire.
  • $\begingroup$ Seems like an awful lot of trouble for very little gain for a civilisation that can just pull supermassive black holes hither and tither at will. $\endgroup$
    – biziclop
    Apr 19, 2023 at 14:17
  • 3
    $\begingroup$ All this work just to create hydrogen? It's literally the most common material in the universe! And, it comes bundled in very convenient, almost totally pure blobs for you to take, if your civilization is even a fraction this advanced. $\endgroup$
    – Cadence
    Apr 19, 2023 at 14:32
  • 1
    $\begingroup$ "Type III+ civilisation" if you mean 3 on the Kardashev scale, then you haven't really thought this through. They aren't humans at that point... they can't be. Honestly, nothing that might be reasonably described as human is ever going to reach type 2. Type 3 can only be unimaginable star gods. $\endgroup$ Apr 19, 2023 at 15:44
  • 1
    $\begingroup$ annihilating hydrogen and anti-hydrogen is how you burn the fuel. Energy conservation aside, you'd want to store both parts so you can burn them with each other! $\endgroup$
    – user253751
    Apr 20, 2023 at 12:01
  • $\begingroup$ The premise makes no sense. You are expending hydrogen to produce, if the system operates at 100% efficiency with zero losses, at best an equal total mass of hydrogen and antihydrogen, the latter of which is considered a waste product?!? $\endgroup$ Apr 22, 2023 at 11:47

3 Answers 3


One of the problems is that, the reactor produces both Hydrogen and Anti-hydrogen.

There is a more fundamental problem as well: you cannot gain energy by extracting it from vacuum. You can only increase the concentration of energy in one place by lowering the concentration of energy somewhere else. But vacuum by definition has the lowest concentration of energy possible, and therefore cannot serve as a source of energy. Your Type III+ civilisation will be better served by making their fuel elsewhere, and in other ways.


We can pull particle antiparticle pairs out of the vacuum yes. The EM field will have to do an enormous amount of work to separate them, and so require this energy to maintain itself, the oppositely charged proton / antiproton will attract. so all particle pairs self annihilate instantly, except under extreme conditions. The energy obtained from fusion is utterly negligible (>>100x less) compared to the energy needed to pull a particle pair from the vacuum. You can not turn Antimatter into matter. Annihilating matter with antimatter is the most efficient way of turning mass into energy there is.


Setting aside the issue of whether things capable of calmly seeding a multi-billion-lightyear wide region of space with supermassive black holes could a) reasonably be considered humans or b) worry very much about creating fresh hydrogen (and they'd know full well that TANSTAAFL and you can't create energy like this)...

One of the easiest ways to do this is to dump the antimatter into a black hole. However, this would be a massive waste of resources, as nearly half of the output is thrown away.

Black holes release Hawking Radiation and shrink over time. A suitably small black hole will radiate quite energetically, and represent a handy way of converting mass into energy without faffing about with annihilation. As the hole shrinks smaller still it'll start releasing particles... this would be a mixture of particles and antiparticles, so you can construct a black hole from pure antimatter and recover half of it in the form of regular matter. Bit of a roundabout way of doing things, though.

Given that your peeps are clearly improbably advanced and powerful star gods who can do silly things like this on a whim, a better way of handling this might be to construct non-orientable wormholes. Throw antimatter into one end of such a wormhole and you'll get regular matter out of the other (and vice versa, of course, but you're not so interested in that). If you can make warp drives and happily move multiple-stellar-mass objects millions of lightyears, conjuring up a wormhole is presumably child's play.

Again, though... you aren't going to get more energy out of this system than you put in. This is just changing the form it takes.


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