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The mineral handwavium contains a naturally occurring, stable form of antimatter (i.e. prevented from coming in contact with regular matter) that can be mined. How is this even remotely plausible?

Ideally, this would be available via some planetary mining, but I'd settle for needing to go into space to get it.

Ideally, this would be stable on the scale of years (if left unperturbed), but I'd settle for it only being stable on the scale of days.

It seems to me like there need to be two mechanisms at play:

  1. Natural anti-matter generation. There is at least one mechanism by which this happens, namely positron emission. Are there others? Could any of them play well with theoretical forms of antimatter containment?

  2. Natural antimatter containment. This seems like the harder part. We can do this artifically. Is there any way this (or an alternate theorized containment mechanism) could happen naturally?

Alternatively, I'd take the pseudo-frame-challenge that is there some area of space that has antimatter left from the big bang, but in this case, how is it separated from the rest of the universe and how would we get into and out of it to mine said antimatter?

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    $\begingroup$ Anti-matter is exactly as stable as not-anti-matter. $\endgroup$
    – AlexP
    Jan 27 at 16:08
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    $\begingroup$ So what are you asking? How to explain that a nugget of anti-matter (whatever that may be) can be found inside of, for example, quartz? That might be a tall order since simplistically anti-protons cancel out protons (regardless of their configuration) and anti-electrons cancel out electrons (ditto). The two elements would need to not touch with a pure vacuum between them. Tough to claim nature can do that. Now, if we're talking about a chunk of the nefarious dark matter that happens to be anti-dark-matter and it's a nebula with the near-vacuum of space between it and all others... cool! $\endgroup$
    – Join JBH on Codidact
    Jan 27 at 16:15
  • $\begingroup$ @AlexP mostly. $\endgroup$
    – Starfish Prime
    Jan 27 at 16:38
  • $\begingroup$ The Earth's annual production is 2 nanograms... The energy of it is E=mc2, in case you'd burn 2 nanogram with normal matter, you'd get 360,000 Joules. With that, you could lighten your room with a 100W lamp, for about 1 hour. labroots.com/trending/chemistry-and-physics/16810/… quora.com/… $\endgroup$
    – Goodies
    Jan 27 at 18:20
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    $\begingroup$ @Goodies fusion dragons sound unsafe, somehow. Especially given the possibility of a stray cosmic ray causing one to "cook off". Still, I definitely think you should suggest that the next time a "how can my dragons work" question is raised ;-) $\endgroup$
    – Starfish Prime
    Jan 27 at 18:36

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I'd take the pseudo-frame-challenge that is there some area of space that has antimatter

I'm choosing to ignore the rest of that sentence, because there is antimatter available in space, just wafting around for the taking. It isn't leftover though, but naturally generated by the interaction of cosmic rays with regular matter. People have put some thought into harvesting it... there's a longer read at Extraction of antiparticles concentrated in planetary magnetic fields.

The supply is small (you only get nanograms from Earth's radiation belts) but it is naturally renewed over time. Collection is less expensive than manufacturing fresh antimatter ex nihilo (but then, so is almost everything!). Saturn's rings might be a much richer source, but even then getting micrograms of the stuff is an enormous haul.

Nanogram amounts of antimatter are useful for various things, including antimatter-initiated fission and fusion rockets that would be a plausible way to eg. fly manned missions to the outer solar system without needing a breakthrough in fusion technology first. The ICAN-II paper describes such a ship, and Project Rho has a summary, if you were interested.

If you needed much larger amounts of antimatter though, you're out of luck. Sorry.

Natural antimatter containment.

It may be possible to have antimatter confined for extended periods of time in regular matter, as opposed to a special antimatter trap built for the purpose by a a suitably technologically advanced society.

Earnshaw's theorem states that you can't have a nice static trap for ions using electrical or magnetic fields, but it doesn't take into account quantum-mechanical effects at suitably small scales. There's an interesting (but paywalled) paper, Alternative pathways to antimatter containment which suggests that it may be possible to trap antimatter ions in the voids of a material like a zeolite, or maybe in a cage formed by a fullerene molecule.

Now, the odds of an antiproton/regular matter trap forming spontaneously is pretty low... the sort of events that create antiprotons are also the sorts of things that tend to damage the regular matter the traps would be made of. Such materials are potentially at risk of all sorts of other destabilizing events such as background radiation damaging the cage, releasing an antiproton and starting a chain reaction whereby one leaked antiparticle breaks the cages of multiple others nearby and foom it all goes up. This suggests you're only likely to find it in a deep underground vault on a very old, very stable planet, left there by some other alien species (or your ancestors, if your setting's history stretches to that sort of thing).

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If you'd like something rather more speculative, consider the possibility of natural materials that can be used to change matter into antimatter without requiring the input of too much energy.

Powering Starships with Compact Condensed Quark Matter posits the existence of nuclear-density "quark nuggets"... stable leftovers from a very early stage of the universe's formation. Such nuggets might be just floating around, ready for the finding, possibly in the centre of small asteroids with suspiciously high densities.

If you found such a thing, you could bounce a beam of high energy (100MeV+) particles off its surface. The reflected particles become antiparticles, ready for harvesting and confinement by whatever means you have to hand. A single nugget might weigh 10 million tonnes, and be able to convert maybe a million tonnes of matter into antimatter.

This provides a possible means to provide very large amounts of antimatter, and do crazy things like fly ramscoop rockets to other stars. It also allows for the existence of a finite, valuable resource that can also be found in other star systems, with all the storybuilding that entails.

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  • $\begingroup$ "the sort of events that create antiprotons are also the sorts of things that tend to damage the regular matter the traps would be made of" what if the antiproton was created before it gets trapped in the crystal ? It gets decelerated and captured in some way.. $\endgroup$
    – Goodies
    Jan 27 at 19:13
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    $\begingroup$ @Goodies the problem is having enough energy to enter the trap but not so much energy that it shoots out again, and on its way it it mustn't hit any other nucleon. Maybe it'd happen once, but each successive capture event becomes increasingly unlikely, and each failed capture might cause a chain reaction to set you back to square one. $\endgroup$
    – Starfish Prime
    Jan 27 at 19:16
  • $\begingroup$ I am highly doubtful of zeolite even for a single antiproton. Quantum does stabilize matter, but not in this case. The potential function is still subject to Ernshaw's theorem. It is not a "bowl" in any region that is away from a nucleus. Thus, the anti-proton's wavefunction will pass-through the electron wavefunctions (no Pauli exclusion), find a nucleus, and then find a proton (even a neutron will do) inside said nucleus. (Neutral antihydrogen will electron-positron annihilate first). $\endgroup$
    – Kevin Kostlan
    Jan 28 at 1:45
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    $\begingroup$ @KevinKostlan you should probably read the paper. I regret that I don't have an unpaywalled source for it, but I can confirm that it is available on a somewhat controversial site that provides free access to otherwise non-free academic papers. $\endgroup$
    – Starfish Prime
    Jan 28 at 9:25
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It's not stable on planets

Antihydrogen happily wrecks every form of nuclei it meets, including random atoms like oxygen and nitrogen which are everywhere. It would explode on a planet.

It could be stable in an asteroid belt.

We generate antimatter with particle accelerators. Theoretically a gamma ray burst, or a supernova, could generate high energy particles which generated antimatter, with some weird magnetic effect separating away the matter. This could make an asteroid belt high in antimatter that you could mine, collecting the anti hydrogen from the dust.

This would be obviously visible from earth. If you want it to happen, have the asteroid belt be hit by the blast. The sun shielded the earth from the blast, and now the asteroid belts are full of antimatter that would be of immense value to the local civilization.

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  • $\begingroup$ Forget ye the solar wind? I'm accustomed to proposals such as matter and antimatter are segregated into different super-clusters. $\endgroup$
    – Joshua
    Jan 28 at 3:16
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    $\begingroup$ This only works if space is a pure vacuum. There’s actually lots of random particles of all kinds floating around! The densities are low enough to ignore in most cases, but they’re still high enough that we’d notice them constantly being annihilated by wandering into your antimatter asteroids. $\endgroup$
    – StephenS
    Jan 28 at 3:31
  • $\begingroup$ It works even if space is full of particles, so long as you don't mind your antimatter source slowly depleting. As I noted, this would be obvious from earth. That's because of the matter antimatter collisions that would happen. $\endgroup$
    – Nepene Nep
    Jan 28 at 18:02
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Any stable atom of antimatter, even if you put it into some container, sooner or later will get some elementary particle from a matter world. Let us say, you filter off all charged particles. Photons do not react with antimatter in any special way. But neutrino, neutron, several mesons/barions do. Sooner or later, some arrive, break some natural particle exchange in the atom and the reaction of annihilation will begin and you have the chained reaction of the great boom.

So, you can try that only far from any stars, out of planetary systems. And not near the center of the Galaxy, too.

If you need numbers, google the number of particles from the Sun, take into account the distance and the volume of your piece of antimatter. Notice, that while you are closer to the Sun than to the other stars, only the Sun is important. But a nearby superstar burst can change everything.

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Alternatively, I'd take the pseudo-frame-challenge that is there some area of space that has antimatter left from the big bang, but in this case, how is it separated from the rest of the universe and how would we get into and out of it to mine said antimatter?

(With apologies to the Cannonball Express and the ST∞.)

Captured wandering antimatter planetoid, perhaps? It's not inconceivable that there could be such things, although they would have to be rather rare as we haven't seen any evidence thereof.

Let's say that a wandering (anti)planetoid got captured by the local Jupiter-like. It'd likely be noticeable by astronomers, not just because it's warmer than it should be (if I did my math correctly, solar wind at Jupiter being converted to energy would be ~22W/m^2, compared to ~10W/m^2 of sunlight at Jupiter...), but also because of e.g. the presence of 511KeV spectral lines due to electron-positron annihilation.

The direct erosion rate wouldn't be terrible - only 1-2cm over the lifespan of the universe, assuming said planetoid was at Jupiter and made of anti-iron (which is a bad assumption - anti-iron would require antimatter stars, which we probably would have detected). I would be more concerned about vaporization and associated mass loss, especially from discrete impact events as opposed to just solar wind.

Actually collecting said antimatter could be an interesting challenge. Might be simplest to hit it with a pebble and collect ejecta...

Of course, this still has some major unsolved questions. How did said planetoid form? Where did it form? (If it formed relatively nearby, how did it survive dust clouds? If it formed further away, how did it get boosted to a high enough speed to show up here, and how did it slow to a slow enough speed to get captured?)

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