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A black hole is supposed to suck in everything by nature. Micro black holes are theorized to "fizz out", so for example if one was on Earth it would not grow until Earth was consumed. It would seem then that there is a theoretical limit to the amount of matter that a black hole could consume.

Therefore, theoretically, you could have a black hole which was just big enough for your usage but not big enough to "eat" the whole facility or even the planet.

Of course, even the existence of black holes is still purely theoretical, but suppose you needed to experiment on one or use it as a disposal facility, could it be possible to control it or contain it?

Imagine the benefits of having a permanent waste disposal. Let physics itself condense waste into the smallest possible form through the utilization of a black hole. The only problem is: could it be contained?

A black hole would of course fundamentally require a controlled environment in order to have any practicality. However, being so strong that it even suck in light, I wonder if there is any possible way to even contain the black hole in order to utilize it. Of course, moving it is a completely different topic and I won't ask that here.

Can a black hole be contained within a facility in a controlled environment?

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    $\begingroup$ About how big is "big enough?" And are you measuring mass, or volume? $\endgroup$ – Kevin Jan 25 at 3:38
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    $\begingroup$ To be clearer, a micro black hole situated on Earth is limited by its own size (rather, mass)—it's very hard to get particles to follow just the right geodesic toward the singularity. The bigger the black hole, the greater the surface area of the event horizon and thus the easier it is to "feed" it. There would then come a threshold where a black hole situated on Earth (situated in a stew of particles with the average density of Earth?), with any greater quantity of mass, would allow for it to consume the Earth at a faster rate than its own evaporation. Is this right? $\endgroup$ – B.fox Jan 25 at 3:38
  • $\begingroup$ @B.fox: I don't think that's sufficient. You also have to keep it from falling through the floor of the facility (at which point it's rather useless even if it doesn't eat the Earth). $\endgroup$ – Kevin Jan 25 at 3:39
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    $\begingroup$ @Kevin Black holes can be contained positionally if they are charged, I think. So, Kerr-Newman black hole it would have to be (probably). Edit: micro black holes would also be very bright. Perhaps radiation pressure could do some work, though, I think I there might be flaws I'm not seeing in that. $\endgroup$ – B.fox Jan 25 at 3:41
  • $\begingroup$ I read that a planck length black hole have a mass of 10 to the power of 8 kilograms but would explode almost immediately. $\endgroup$ – user6760 Jan 26 at 6:03
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Probably not on Earth.

A black hole large enough to run macroscopic objects into is too massive to be kept from falling through the floor of a facility on Earth by any means other than magic (or handwave technology).

Black holes have three properties: Mass, angular momentum, and electric charge. If you manage to put a /lot/ of electric charge on your black hole, you can use magnetic containment to keep it from falling through the floor. But to keep that from happening will (dependent on mass) take a /lot/ of electric charge (with the attendant problems of preventing something with a ridiculous electric charge from discharging itself) and extremely powerful magnets.

A Black Hole with an event horizon a mere 1 micrometer in radius masses 6.733 * 10^20 kg. This is 71% of the mass of the Dwarf Planet Ceres.

Any black hole you could conceivably push a macroscopic object into would wreak havoc on your facility and on the surface of the planet.

Overall, your best bet is probably to have your facility in space, and use whatever technology you were planning to use on Earth to compress a few million tons of asteroid into a black hole out there instead. and build your facility around that. The biggest benefit there is that you don't have to support it against a planetary gravitational field, and can stationkeep your facility around it as they both orbit the earth/sun/whatever you left it in orbit around. It's still going to be way too small to run macroscopic objects into, but you could use it as an energy source (since it emits Hawking radiation), and you can perform whatever physics experiments you wanted to perform near it.

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  • $\begingroup$ So it is theoretically possible then? $\endgroup$ – worldbuilder Jan 25 at 4:03
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    $\begingroup$ @worldbuilder Yes, I guess it would be. Doing it on a planet, however, results in a bunch of additional difficulties from the local gravity that probably make it extremely infeasible without magical technology, so I've modified the answer a bit to reflect that. $\endgroup$ – notovny Jan 25 at 4:18
  • $\begingroup$ Interesting thought about the facility in space. $\endgroup$ – worldbuilder Jan 25 at 4:27
  • $\begingroup$ Suggested reading - The Borderland of Sol by Larry Niven $\endgroup$ – KerrAvon2055 Jan 25 at 8:14
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    $\begingroup$ I would be concerned about your stationkeeping. You can move the facility around the black hole, but moving the black hole itself would be challenging. So I don't think you could put this contraption in LEO, because the orbit would be insufficiently stable. Ideally, you'd have it in a heliocentric orbit far away from the Earth/Moon system. Those will also decay, but they take forever to do so. The downside, of course, is increased launch and maintenance costs. But those could be defrayed by some combination of asteroid mining and in situ assembly. $\endgroup$ – Kevin Jan 26 at 4:29
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You can control a black hole using the magic power of Handwaving or even Plot Armor

Throw in some technical jargon, some Anti Gravity, Dark matter, Exotic matter, cutting edge technology, electromagnetic containment field and your ready to go.

The first issue is how you make sure the black hole stays stationary with you. We are spinning on the Earth, in orbit around the Sun, which is on its own trajectory through the Milky Way which has its own trajectory through the universe or whatever next is bigger. So just with us spinning once a day, your black hole also needs to spin with the earth, or its going to create a hole through everything that moved through it.

Secondly, its not a permanent waste disposal. I believe black holes emit radiation and you will then have to deal with this radiation which it outputs. You will also be spending a ton of energy in whatever containment field you setup to secure this black hole in the first place. You might as well burn everything and crush the leftovers into diamond.

The black hole may also grow in size as you dump too much stuff into it. More mass, larger event horizon to absorb stuff. It increases in 3 dimensions, and you need to make sure that it's stored in a vacuum and this containment needs to increase in size if you dump stuff in too fast.

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  • $\begingroup$ Interesting. However, a moving or even spinning Earth is not scientifically proven (still theory), so it would not be unreasonable to take the latitude of a fixed Earth world and not be fantasy. Alternatively, by the same overgeneralizations that assume a moving Earth yet stationary atmosphere, by the same unknown physics it could also be safely assumed that a black hole would neither move while on Earth by the unexplained phenomenon. $\endgroup$ – worldbuilder Jan 25 at 4:15
  • $\begingroup$ p.s. I do like your thoughts about plot devices, great thinking outside the box with that one :) $\endgroup$ – worldbuilder Jan 25 at 4:18
  • $\begingroup$ @worldbuilder Is your Earth the center of your galaxy and everything is orbiting earth? Or are you saying that in the real world, Earth moving and spinning is just a theory? $\endgroup$ – Shadowzee Jan 25 at 4:18
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    $\begingroup$ @worldbuilder I agree with Shadowzee. If your depiction of Earth has weight on an answer, I believe it should be stated in the question. So far, both answers utilize the current model of astrophysics and celestial mechanics which puts the Earth as a rotating ball of molten metal revolving about a star millions of times its mass. p.s., one experiment's results cannot falsify those of uncountable thousands of others which do conclude this nature of the Earth and other celestial bodies. $\endgroup$ – B.fox Jan 25 at 12:55
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    $\begingroup$ @worldbuilder - Maxwell's work predicting the speed of light as result of the interaction of electrical and magnetic waves, Special Relativity codifying the speed of light as being the same in all reference frames, Hughes-Drevers' experiments in the 60's all point to the same reality: no luminary Æther has been detected; further, this Victorian concept is not called for by any experimentally verifiable theories. Foucault's pendulum and the Coriolis effects are classical demonstrations of Earth's rotation; stellar aberration / parallax clearly demonstrate Earth's relative orbital motions. $\endgroup$ – GerardFalla Jan 25 at 18:52

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