# Tag Info

Accepted

### 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? ...
• 98.4k
Accepted

### Protect a planet against a black hole attack

Physical Paradoxes we do have FTL travel and communication, but other laws of physics are the same They can't be the same, FTL breaks known physics. A lot. The speed of light isn't really the speed ...
• 30.1k

### 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 ...
• 262k
Accepted

### 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 ...
• 68.9k
Accepted

### 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 ...
• 23.7k
Accepted

### 1 Light Year Diameter Planet

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 ...
• 6,303
Accepted

### How would one destroy a black hole?

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 ...
• 1,280

### 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 ...
• 44.4k

### 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 ...
• 20.5k
Accepted

### 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 ...
• 67.3k
Accepted

### 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 ...
• 98.4k
Accepted

### 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: ...
• 43.1k

### 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 ...
• 13.9k
Accepted

### 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 ...
• 19.7k
Accepted

### 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 ...
• 8,497

### 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 ...
• 3,837
Accepted

### What would happen if the black hole at the center of a galaxy was removed?

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 ...
• 130k
Accepted

### 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 ...
• 84.9k

### 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 ...
• 6,212

### 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 ...
• 1,897

### 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: ...
• 5,273
Accepted

### 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, ...
• 67.3k

### 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 ...
Accepted

### 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....
• 6,829

### 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 ...
• 13.9k

### 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 ...
• 262k
Accepted

### 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. ...
• 107k
Accepted

### How big a black hole is needed for this story?

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 ...
• 48.3k