116

What could be learned? There are so many things you could study by looking at a black hole. There are lots of open or partially unsolved problems that surround them: Does Hawking radiation exist? While it has been predicted theoretically, direct evidence is lacking - well, nonexistent. Stellar-mass black holes aren't the best targets - primordial black ...


56

You have bombs you can drop anywhere, there's no defense, and they're infinitely powerful. Not too different from reality. Just as in reality, you don't fight overwhelming military force with military force. You conduct asymmetric warfare. Hide. You can't hit what you can't see. Make the environmental cost too high (it eats planets). Make the collateral ...


53

I wasn’t sure how the weapon could be pulled back out, and I was thinking perhaps magnets? Nothing can get out of the event horizon of a black hole, not even light. And light is made of electromagnetic waves. The only thing you can get out of a black hole is Hawking radiation, but that's completely unrelated to what fell into the black hole.


52

You need to understand better how the event horizon works. It is a point of no return. Your implicit idea of it being a shell that destroys anything that passes is simply wrong. From physicist Matt Strassler’s blog: A horizon is not an object, but a place beyond which escape is impossible. A famous analogy is to a boat approaching a waterfall, in an ...


48

would it triggers extinction level event? Since they'd evaporate more or less instantaneously (known as Hawking radiation), releasing energy according to the famous equation beginning E=, the spaceship would last a few microseconds at best, Earth would be fine. Yes, the aliens in the ship would become extinct.


46

As mentioned, anti-gravity and or gravity generators will let you pull magic out of thin air, but let's try it without magic. I can't imagine why anyone would bother doing it, but I decided to see what happens and ended up with a totally insane project that uses a lot of carbon nanotube (CNT) and crazy amounts of energy. But, you don't need unproven ...


43

Welcome to How to destroy a black hole for dummies So, are you looking for a way to eliminate the right black hole, arent' you? Well, you're reading the right guide. But before beginning, it could be useful to make some clarifications on the nature of these galactic monsters. As Sun Tzu says, to defeat your enemy, you must first know him. Let's know what a ...


40

I'm surprised no one has mentioned this. Your ultra-black Dyson sphere is easily distinguishable from a quiescent black hole or unnaturally cold neutron star by one major thing, if you're close enough to tell those two objects apart: It blocks out too many background stars. That is, your Dyson sphere, to avoid having surface gravity too great to support ...


39

There is no point in sending a manned mission! As @HDE22686 noted, there are many interesting phenomena associated with black holes. Given the opportunity to study one up close, it is likely that missions will be sent. However, describing all the cool phenomena associated with black holes only means they will be studied - not that humans will be there to ...


37

Black holes are actually more like gravitational point-sources than anything. Unlike their depictions in movies, black holes emit only as much gravity as the object that they are made from. For example, if the sun were to suddenly turn into a black hole, the earth would keep orbiting it just like it normally would. That aside, the two major dangers of ...


37

This scenario is quite problematic for two main reasons: evaporation and peak wavelength. The black hole's lifetime is too short We can make a rough estimate of the properties of the Hawking radiation coming from the black hole. First, let's start with the luminosity. Since $L\propto M^{-2}$, where $L$ is luminosity and $M$ is the mass of the black hole, it ...


37

Dont do anything. 1: a BH of that size would evaporate in 129 years (which surprised me I thought it would be shorter). This makes my point of it evaporating in microseconds moot so ignore point 1. 2: a BH is tiny. At the mass of the empire state building it is smaller than atoms, and its questionable it will actually hit anything as it passes through the ...


36

When we “see” a black hole or neutron star, we don’t see the actual body itself — they’re much too small, as well as black holes being black. So there’s no point messing around with Dyson spheres and black paint, because none of that will change what we see. We detect both black holes and neutron stars from their effects on the nearby matter and light, and ...


36

We'd definitely notice. A 365000 tonne black hole has a luminosity of $2.6*10^{15}$ watts. On the K-scale of civilizations this is about 0.95. 1.0 is roughly consuming all of the energy the Sun deposits on the Earth. Even an advanced Earth-based civilization cannot pass, and practically cannot reach, 1.0 -- before 1.0, you literally cook the biosphere, as ...


35

Your planet needs to be about 722500 times more massive than Earth for its core to undergo collapse into a black hole. Leaving aside the small detail that at this point your "planet" would look and behave like a star larger than the Sun, because it would be a star larger than the Sun, what will happen shortly afterward is that the rest of it will ...


32

A black hole with a Schwarzschild radius of 4 feet would have a mass of 137.5 x Earth and the gravity to go along with it. Such a black hole would instantly liquefy the earth as it shreds it into an accretion disk and shoots gamma rays straight through the earth's poles. There would be approximately 0 seconds for a committee to consider the problem before ...


30

Not all that much Sagittarius A* is big, but not that big. Its mass is estimated to be around 4,200,000 (four million two hundred thousand) solar masses. That's a lot of gravity! But consider the Milky way is estimated to be around 1,000,000,000,000 solar masses! In all, the total gravitational effects would be minimal. The largest effect would be on ...


30

X-ray radiation at the orbit of HDE226868 Cygnus X-1 is famous as one of the most powerful X-ray sources in the sky. According to the US Naval Observatory, the max flux of Cygnus X-1 (near the bottom of the last page on the link) is 1.2672 Crabs in the 2-10 keV range. 1.2672 Crabs is equal to $3.04\times10^{-11} \text{ W/m}^2$. I have the distance to ...


30

Could this work in any scenario? Unfortunately not. If you are looking for a scientifically sound explanation, even in purely theoretical terms what you're asking just is not possible. As others have stated, nothing can escape black holes. And even if the black hole were to evaporate via Hawking radiation, there is no possible way to salvage anything that ...


30

Vantablack doesn't reflect light, but it'll still have black body radiation based on temperature. It may be far into the infrared, but the black body curve is a signature we can recognize from a distance.


28

I mean there’s a lot of ways to do this honestly. Humans are really good at destroying things. So there are a couple ways you can completely ”destroy” something. Let’s break it down. Physical: Technically your table would still be made of whatever wood it was made of before, but complete physical destruction would turn it into something more resembling ...


28

I am neglecting the effect of tidal forces on the integrity of any object Well, don't be doing that! Those forces can be used to answer your question. Given a couple of bars of known length and mass, and a black hole of known mass, you could measure the relative differences in length of a bar placed parallel to the local gravity vector and one placed ...


27

No A natural occurring black hole that comes into existence due to mass collapsing onto itself must have more mass than the Tolman–Oppenheimer–Volkoff limit, which has been estimated to be around 2.17 solar masses. There are no planets that are more massive than stars. At around 13 times the mass of Jupiter (in other words, at around 4,134 times the mass of ...


26

Time dilation comes from gravity and/or velocity. Since the planet is not orbiting a black hole it would either have to orbit another super heavy mass or fly through space with a lorentz factor of 0.5 (when seen from earth) as that would equal time dilation of a factor 2. $t_{planet} = \gamma * t_{earth};$ with $\gamma$ being the lorentz factor of $\...


26

Start with an 0.1% of Everest-mass black hole. Stuff it into a 0.001 meter radius (1 mm) containment device. At the edge of the containment device, gravity is 0.01 m/s^2 from the black hole. This is microgravity. It emits 1.358944e+10 watts, or 3 times that of a typical nuclear reactor, and it will last 10^10 years before evaporating (slowly increasing ...


26

Black holes evaporate by emitting Hawking radiation a 1-second-life black hole has a mass of $2.28 \cdot 10^5 \ \mathrm{kg}$ A grape has far less mass than that, thus the black hole would evaporate way faster than that. An intelligent life form dropping micro black holes on Earth would thus quickly annihilate its own bombing squad in a shower of gamma ...


26

I am NOT (not, not not) fluent in celestial mechanics, so if I'm wrong, let me know and I'll delete this answer. But... Our favorite supervillain, Gru, has asked his most trusted scientist, Dr. Nefario, to build him a black hole gun! From Wikipedia we find... $$t_{ev} \approx 2.1\times10^{67}\left(\frac{M}{M_{\odot}}\right)^3\;\text{years} = 6.623\times10^{...


25

That's some extreme time dilation. It is possible, but the black hole needs to be insanely massive for your ship to orbit it without falling into the event horizon and have the proper amount of time pass. Gravitational time dilation goes like this: $$t_0 = t_f \sqrt{1-{{r_0}\over{r}}}$$ Where, $t_0$ is the proper time between events A and B for a slow-...


25

You invented it, you decide Sorry for coming off as boring but this question is of the sort: I have invented Big Magic™ for my setting. Now please tell me how this little aspect of Big Magic™ works. Well... no-one knows that except you. Especially so since you have taken a figurative hole and somehow made usable energy come out of it, energy that you can ...


24

Yes. You can take binary or trinary star systems and swap one of the stars for a black hole and nothing changes in the orbital dynamics. Depending on the layout of the solar system planets can orbit the stars, the black hole, or some mixture of the above. Some of those planets could be in the habitable zone (liquid water). And some of those planets could ...


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