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117 votes
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Is it worth sending a manned mission to a black hole?

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? ...
HDE 226868's user avatar
  • 102k
53 votes

Black hole as a storage device?

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 ...
L.Dutch's user avatar
  • 292k
52 votes
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Destroy a Planet inside a black hole?

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 ...
JDługosz's user avatar
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48 votes
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What would happen to a modern skyscraper if it rains micro blackholes?

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 ...
Escaped dental patient.'s user avatar
40 votes

How to tell a blackhole from a neutron star covered entirely by Dyson sphere painted in vantablack?

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 ...
Zeiss Ikon's user avatar
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39 votes

Is it worth sending a manned mission to a black hole?

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 ...
Zxyrra's user avatar
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39 votes
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The Moon turns into a black hole of the same mass -- what happens next?

what practical differences would arise when compared to a normal moon (such as it affecting the atmosphere) Almost none. There'd be no moonlight under normal circumstances, which means that no life ...
Starfish Prime's user avatar
37 votes
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A planet illuminated by a black hole?

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 ...
HDE 226868's user avatar
  • 102k
37 votes

How do you detect and defend against micro blackhole cannon?

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 ...
Yakk's user avatar
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36 votes
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How to tell a blackhole from a neutron star covered entirely by Dyson sphere painted in vantablack?

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 ...
Mike Scott's user avatar
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36 votes
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How do you detect and defend against micro blackhole cannon?

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: ...
Demigan's user avatar
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34 votes
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Black hole at the center of the planet

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 ...
Darth Biomech's user avatar
32 votes

How would someone destroy a black hole that’s at the centre of a planet?

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 ...
SurpriseDog's user avatar
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30 votes
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Is it safe to orbit HDE 226868?

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 ...
kingledion's user avatar
  • 85.6k
30 votes

Black hole as a storage device?

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 ...
overlord's user avatar
  • 6,312
30 votes

How to tell a blackhole from a neutron star covered entirely by Dyson sphere painted in vantablack?

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 ...
dspeyer's user avatar
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28 votes

How to annihilate an object completely?

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: ...
Nick's user avatar
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28 votes
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How would a space probe determine its distance from a black hole while orbiting around it?

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, ...
Starfish Prime's user avatar
27 votes

Black hole at the center of the planet

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 ...
The Square-Cube Law's user avatar
26 votes
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Reasons for time dilation to happen on a habitable planet with same g force and not orbiting a black hole

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....
ArtificialSoul's user avatar
26 votes

How to build a fail-safe system for an engine that can harness energy from a Black Hole?

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 ...
Yakk's user avatar
  • 15.9k
26 votes
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What happens if I shot a blackhole pellet point blank at someone?

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. ...
JBH's user avatar
  • 127k
25 votes

How to build a fail-safe system for an engine that can harness energy from a Black Hole?

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. ...
MichaelK's user avatar
  • 43.9k
25 votes

What would happen to a modern skyscraper if it rains micro blackholes?

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 ...
L.Dutch's user avatar
  • 292k
24 votes

Is a solar system around a black hole possible?

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 ...
Tim B's user avatar
  • 77.2k
22 votes

How do I feed my black hole?

In practice, you may not need to feed it at all - as long as you can deal with a sufficiently hefty mini black-hole. According to wiki a black hole with mass $M$ measured in kg will have: Power ...
Penguino's user avatar
  • 7,508
21 votes
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What exactly would happen if a black hole was introduced into the sun?

Using your black hole from the actual size would be much smaller than a proton so it would have difficulty accreting mass because its effective cross section is very small. It may even only be able to ...
Joe Kissling's user avatar
  • 6,706
21 votes

Black holes as heat sinks

Your issue is right here It seems pretty straightforward to just deposit the waste heat into the black hole Unfortunately this isn't true. The problem is that heat isn't something you can just ...
conman's user avatar
  • 3,422
20 votes

A planet illuminated by a black hole?

From Hawking radiation? No. The Hawking radiation emitted is inversely proportional to the black hole's size. To make the black hole glow with enough light to be as bright as a star from Hawking ...
stix's user avatar
  • 5,928
20 votes

Do (supermassive) black holes rotate?

Yes, supermassive black holes can spin, but your proposal for using their rotation as a timekeeping system isn't ideal. First, the rotation period is likely quite small. The angular speed of a ...
HDE 226868's user avatar
  • 102k

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