Singularity Bombs?

[daniel l.]

According to Stephen Hawking, Black holes gradually lose mass over their lifetimes, And eventually explode. If you compressed a dime mass object into a black hole it would explode almost instantly with the force of a thermonuclear bomb, Is this feasible as a Sci-Fi weapon?

[magnemoe]

5 minutes ago, daniel l. said:

According to Stephen Hawking, Black holes gradually lose mass over their lifetimes, And eventually explode. If you compressed a dime mass object into a black hole it would explode almost instantly with the force of a thermonuclear bomb, Is this feasible as a Sci-Fi weapon?

Has an downside in that it would explode after an set time if you use it or not, you could feed it matter who would delay the explosion however.
Not very practical compared to anti matter or nukes. 
Using it as an energy source would be better, you could the use it as an bomb then its about to expire. 

[daniel l.]

Just now, magnemoe said:

Has an downside in that it would explode after an set time if you use it or not, you could feed it matter who would delay the explosion however.
Not very practical compared to anti matter or nukes. 
Using it as an energy source would be better, you could the use it as an bomb then its about to expire. 

Imagine though, If you were to have a machine capable of instantly collapsing any object within a certain size into a black hole, If you collapsed an asteroid just before it hit a planet then you could wipe that planet off the map.

[Gaarst]

It would make a pretty bad weapon, since you'd have to build a singularity factory where you want it to explode, since you can't just pack it into a shell and detonate it whenever you want.

That or you'd have to expend a tremendous amount of energy to keep it from evaporating (either by feeding it more energy than it releases, or by some sort of space-time distortion magic), which will probably end up being a lot larger than the energy released by the black hole evaporating.

Also good luck finding a way to actually make the thing.

In any case, you'd be better off spending energy destroying stuff (with lasers or antimatter annihilation) than trying to make a black hole to destroy stuff.

[daniel l.]

Just now, Gaarst said:

It would make a pretty bad weapon, since you'd have to build a singularity factory where you want it to explode, since you can't just pack it into a shell and detonate it whenever you want.

That or you'd have to expend a tremendous amount of energy to keep it from evaporating (either by feeding it more energy than it releases, or by some sort of space-time distortion magic), which will probably end up being a lot larger than the energy released by the black hole evaporating.

Also good luck finding a way to actually make the thing.

In any case, you'd be better off spending energy destroying stuff (with lasers or antimatter annihilation) than trying to make a black hole to destroy stuff.

I agree. Though it may be impractical for most tasks, I think it could be useful for destroying planets.

[Kryten]

Conservation of energy is a thing. If you have the energy required to compress matter that much, then you already have a powerful weapon.

[daniel l.]

1 minute ago, Kryten said:

Conservation of energy is a thing. If you have the energy required to compress matter that much, then you already have a powerful weapon.

And producing a black hole can be one way of releasing it

[Gaarst]

23 minutes ago, daniel l. said:

Imagine though, If you were to have a machine capable of instantly collapsing any object within a certain size into a black hole, If you collapsed an asteroid just before it hit a planet then you could wipe that planet off the map.

Did a bit of maths. Collapsing an asteroid to a black hole to destroy a planet would be a very very very bad way to destroy a planet.

Taking your average dinosaur killing asteroid weighing an average of 10¹⁶ kg according to a few estimates, turning it into a black hole and letting Hawking evaporation do its thing would output an energy of about 3e32 J, or about 10¹⁶ megatons of TNT, which turns to be of the same order of magnitude than the Earth's gravitational binding energy.

The problem is that it's going to take a little time for your asteroid black hole to disintegrate, since it's somewhat heavy. The numbers I've come up with show a lifetime of 10²⁴ years and a ludicrous power of 3 watts.

So yeah, no.

[daniel l.]

Just now, Gaarst said:

Did a bit of maths. Collapsing an asteroid to a black hole to destroy a planet would be a very very very bad way to destroy a planet.

Taking your average dinosaur killing asteroid weighing an average of 10¹⁶ kg according to a few estimates, turning it into a black hole and letting Hawking evaporation do its thing would output an energy of about 3e32 J, or about 10¹⁶ megatons of TNT, which turns to be of the same order of magnitude than the Earth's gravitational binding energy.

The problem is that it's going to take a little time for your asteroid black hole to disintegrate, since it's somewhat heavy. The numbers I've come up with show a lifetime of 10²⁴ years and a ludicrous power of 3 watts.

So yeah, no.

Okay then... So i know now to write that out of my story idea... 

[todofwar]

1 hour ago, Gaarst said:

Did a bit of maths. Collapsing an asteroid to a black hole to destroy a planet would be a very very very bad way to destroy a planet.

Taking your average dinosaur killing asteroid weighing an average of 10¹⁶ kg according to a few estimates, turning it into a black hole and letting Hawking evaporation do its thing would output an energy of about 3e32 J, or about 10¹⁶ megatons of TNT, which turns to be of the same order of magnitude than the Earth's gravitational binding energy.

The problem is that it's going to take a little time for your asteroid black hole to disintegrate, since it's somewhat heavy. The numbers I've come up with show a lifetime of 10²⁴ years and a ludicrous power of 3 watts.

So yeah, no.

If it's that stable though wouldn't it begin devouring the planet when it landed? Wouldn't vaporize the planet, but suck it up like a vacuum cleaner. It would be kind of slow though. In a nutshell talked about what a nickel sized blackhole would do to a planet, it ultimately destroyed it. 

[daniel l.]

7 minutes ago, todofwar said:

In a nutshell talked about what a nickel sized blackhole would do to a planet, it ultimately destroyed it. 

That was nickel size, Not mass, A Nickle mass black hole would only destroy a cities worth of area.

[todofwar]

20 minutes ago, daniel l. said:

That was nickel size, Not mass, A Nickle mass black hole would only destroy a cities worth of area.

Yeah, but the idea was the blackhole was stable hence it devoured everything. So this asteroid mass blackhole would also start sucking  (auto correct keeps switching that to duckling) in the planet, albeit slowly. I'm guessing it would make its way to the core, no telling when the effects would be noticeable. 

[StrandedonEarth]

3 hours ago, magnemoe said:

Has an downside in that it would explode after an set time if you use it or not, you could feed it matter who would delay the explosion however.

Put it into a Niven-esque stasis field when it's just about to blow. When you want it to detonate, turn off the stasis field.

[magnemoe]

17 minutes ago, StrandedonEarth said:

Put it into a Niven-esque stasis field when it's just about to blow. When you want it to detonate, turn off the stasis field.

Niven stasis fields give so many cool options, my favorite was aerobraking from .9c in the suns atmosphere
Stasis structures would also be nice for building blocks for stuff like space elevators up to ringworlds. 

[Bill Phil]

You'd have to do a cost to benefit analysis. From where we are now, we need to develop the tech to even make a singularity at all. Then we'd have to somehow miniaturize the tech. That is extremely tough to do for most technology (nuclear bombs, being a good example). Antimatter weaponry is closer. Is it possible, though? I can't really tell.

[Jovus]

For SF? Sure.

Postulate that in this theoretical future where you want people to use singularity bombs some smart guy has found a way to collapse matter into a singularity with a much lower activation energy than the 'traditional' compress-it-really-hard trick. Maybe he strengthens and re-directs the strong force or whatever.

Then you get your black hole grenades on demand without having to use massively more energy to create them than they release.

[radonek]

9 hours ago, todofwar said:

Yeah, but the idea was the blackhole was stable hence it devoured everything. So this asteroid mass blackhole would also start sucking  (auto correct keeps switching that to duckling) in the planet, albeit slowly. I'm guessing it would make its way to the core, no telling when the effects would be noticeable.

If you used ordinary (ehm) asteroid on collision course, it will just fly through. You'd have to slow it down to be captured by planets gravity. Idea of using it as a planet killer does not make much sense to me, as other pointed out, if you have that kind of energy at your disposal, you have better options. If you drop the idea of planet-killer however… small singularities have pretty steep gravity gradient - you can use it to punch holes into anything. No bunker, no amount of armor can stop it. Neutronium would probably work even better, for lower cost.  Just putting few such objects at surface level polar orbit would be a great fun. From distance anyway.

[Gaarst]

11 hours ago, todofwar said:

If it's that stable though wouldn't it begin devouring the planet when it landed? Wouldn't vaporize the planet, but suck it up like a vacuum cleaner. It would be kind of slow though. In a nutshell talked about what a nickel sized blackhole would do to a planet, it ultimately destroyed it. 

A nickel sized (assuming you mean Schwarzschild radius since black holes have no size) would weigh about the mass of the Earth, so yeah it would mess things up.

But not as much as you'd think. At these scales, if you fired your Earth mass black hole, it wouldn't absorb Earth and make a bigger black hole. The reason is gravity is weak, very weak.
When you start compressing matter to stupid densities, particles (which are normally really far away from each other) get close, and some (fermions) don't like to get close; this is called the Pauli exclusion principle. And for an object lighter than about 1.4 solar masses the repulsion of electrons (called electron degeneracy pressure) is stronger than the gravitational pull; then you wouldn't end up with a black hole but a white dwarf.

Going back to our black hole, even if you found a way to make it stable, the absorbed Earth wouldn't become a black hole. It would become a white dwarf, everyone would still be dead and it would essentially be gone, but no black hole.

Then again, if you find a way crush one Earth mass of matter to a black hole, just crush the Earth itself and don't bother making a black hole to absorb it.

 

A nickel massed black hole would release about 2 Hiroshima A bombs worth of energy in a really small amount of time. It wouldn't have time to absorb anything really. It would blow up a city or two but "that's it".

[kerbiloid]

https://en.wikipedia.org/wiki/Kugelblitz_(astrophysics)

[todofwar]

3 hours ago, radonek said:

If you used ordinary (ehm) asteroid on collision course, it will just fly through. You'd have to slow it down to be captured by planets gravity. Idea of using it as a planet killer does not make much sense to me, as other pointed out, if you have that kind of energy at your disposal, you have better options. If you drop the idea of planet-killer however… small singularities have pretty steep gravity gradient - you can use it to punch holes into anything. No bunker, no amount of armor can stop it. Neutronium would probably work even better, for lower cost.  Just putting few such objects at surface level polar orbit would be a great fun. From distance anyway.

Why would it need to slow down? Do black holes pass through objects without hitting them?

[radonek]

1 hour ago, todofwar said:

Do black holes pass through objects without hitting them?

Do stones pass through fog?
 

[tg626]

I think this comes close to the planet destroying in Star Trek 2009.  And hence the whole (magical) red matter to do away with all the troublesome physics.

[Technical Ben]

If you can create/change gravity, then you could create a temporary black hole or gravity like field. Depends how you are breaking science, physics and logic as to how it would "work".

[todofwar]

42 minutes ago, radonek said:

Do stones pass through fog?
 

They certainly k ock water droplets they happen to hit. Also, not a very good analogy. Also, condescending. 

[andrewas]

3 hours ago, todofwar said:

Why would it need to slow down? Do black holes pass through objects without hitting them?

The black hole weighs billions of tons and has a cross section smaller than an atom. If it hits regular matter, the interaction is too small to transfer any significant momentum. If the black hole was on an orbital trajectory it would eventually slow down and settle at the core, though it its light enough it will evaporate long before that. But a black hole moving quickly enough to escape won't even notice the planet on its way through.