<p>"Really dense" is a bit of an understatement for small black holes.</p>

<p>A Black hole the mass of the Earth would have a diameter of about 18mm. </p>

<p>And it doesn't get any easier if you start smaller. The density of small black holes is bigger than large ones: </p>

<p>A black hole the mass of a human would have a diameter that is no only smaller than a proton, but a billion times smaller than a proton. Consider the difficulties in crushing something that small.</p>

<p>A black hole the mass of a proton...</p>

<p>The notion that you can make a black hole by "crushing matter very very hard" is many magnitudes beyond what is realistic.</p>

<p>It is, perhaps, possible that tiny black holes could be created in very high energy particle collisions.  We're fairly sure that no such black holes have been created at CERN.  Particle collions of much higher energies occur when cosmic particles hit the atmosphere, and again there is no evidence of black holes being created but we are looking: <a href="https://arxiv.org/abs/hep-ph/0112247" rel="nofollow noreferrer">https://arxiv.org/abs/hep-ph/0112247</a>  </p>

CC BY-SA 4.0
2020-04-06T17:53:40.673Z
Isn't it also true that without gravitational force, you simply can't keep particles close enough together to maintain a black hole?
Carl Witthoft
CC BY-SA 4.0
2020-04-06T19:03:06.237Z
Not sure what you mean by "maintain".  In practice the only force that is strong enough to create a black hole is gravitational collapse of a chunk of matter with more than 3 or so times the mass of the sun. But you don't need to maintain a black hole, If you created one, it would maintain itself (until evaporating through hawking radiation)
James K
CC BY-SA 4.0
2020-04-06T19:08:22.080Z
I plead some ignorance -- if your anvil made of unobtanium crushed a human down to that billionth of a proton diameter,  what force keeps the particles there, since there's no more self-gravity than when you began?  Or are we presuming the 'crushed' mass no longer has any of the particles we think of?
Carl Witthoft
CC BY-SA 4.0
2020-04-06T19:11:07.460Z
Gravity.  Humans have gravity, but at a distance measured in cm the gravity is very weak. But gravity scales as 1/r^2 If you get all the mass of a human into a very very small package, then there is lots of gravity. when you get close enough.  The key is very very small: far smaller than a proton.
James K
CC BY-SA 4.0
2020-04-06T19:13:02.313Z
Merci bien.   I should try actually doing some math before asking :-)
Carl Witthoft
CC BY-SA 4.0
2020-04-06T13:47:18.380Z
2020-04-06T13:47:18.380Z
James K
<p>Our most powerful accelerator has yet to make any quantum black holes; <a href="https://home.cern/resources/faqs/will-cern-generate-black-hole" rel="nofollow noreferrer">https://home.cern/resources/faqs/will-cern-generate-black-hole</a>
If it had, that would be big news.</p>

CC BY-SA 4.0
2020-04-06T14:51:20.147Z
From the page linked in that CERN article: "The creation of a black hole at the LHC would confirm theories that our universe is not 4 dimensional (3 space plus 1 time dimensions), but indeed hosts other dimensions." The LHC simply doesn't have enough energy otherwise.
PM 2Ring
CC BY-SA 4.0
2020-04-06T13:28:09.313Z
2020-04-06T13:28:09.313Z
Wayfaring Stranger
<p>To study the physics of black holes (What we presume as really dense matter) could we not simply simulate that here on earth? What if we took 1 hydrogen molecule and just crushed it with enough force that I'd fall apart and then crush it even more? I'm curious what would happen.</p>

CC BY-SA 4.0
2020-04-06T14:45:05.793Z
From [an answer I wrote on Physics.SE](https://physics.stackexchange.com/a/512644/123208): If you could turn all the energy of a dozen Earths colliding with a dozen antimatter Earths into kinetic energy, and used that energy to slam two billiard balls into each other, it could create a black hole, providing the collision fragments stay close enough to the collision point.
PM 2Ring
CC BY-SA 4.0
2020-04-06T17:51:29.653Z
I'm voting to close this question as off-topic because it's a Physics.SE topic
Carl Witthoft
<black-hole>
Could we make "tiny black holes"?
birbhouse
# Could we make "tiny black holes"?

(Asked by: username_0 on 2020-04-06)

To study the physics of black holes (What we presume as really dense matter) could we not simply simulate that here on earth? What if we took 1 hydrogen molecule and just crushed it with enough force that I'd fall apart and then crush it even more? I'm curious what would happen.

**Tags:** black-hole
> **Comments:**
> **username_1**: From [an answer I wrote on Physics.SE](https://physics.stackexchange.com/a/512644/123208): If you could turn all the energy of a dozen Earths colliding with a dozen antimatter Earths into kinetic energy, and used that energy to slam two billiard balls into each other, it could create a black hole, providing the collision fragments stay close enough to the collision point.  
> **username_2**: I'm voting to close this question as off-topic because it's a Physics.SE topic  

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## 2 answers

### Answer by username_3 on 2020-04-06. Score: 2 | Accepted answer

"Really dense" is a bit of an understatement for small black holes.

A Black hole the mass of the Earth would have a diameter of about 18mm.

And it doesn't get any easier if you start smaller. The density of small black holes is bigger than large ones:

A black hole the mass of a human would have a diameter that is no only smaller than a proton, but a billion times smaller than a proton. Consider the difficulties in crushing something that small.

A black hole the mass of a proton...

The notion that you can make a black hole by "crushing matter very very hard" is many magnitudes beyond what is realistic.

It is, perhaps, possible that tiny black holes could be created in very high energy particle collisions. We're fairly sure that no such black holes have been created at CERN. Particle collions of much higher energies occur when cosmic particles hit the atmosphere, and again there is no evidence of black holes being created but we are looking: <https://arxiv.org/abs/hep-ph/0112247>

> **Comments:**
> **username_2**: Isn't it also true that without gravitational force, you simply can't keep particles close enough together to maintain a black hole?  
> **username_3**: Not sure what you mean by "maintain".  In practice the only force that is strong enough to create a black hole is gravitational collapse of a chunk of matter with more than 3 or so times the mass of the sun. But you don't need to maintain a black hole, If you created one, it would maintain itself (until evaporating through hawking radiation)  
> **username_2**: I plead some ignorance -- if your anvil made of unobtanium crushed a human down to that billionth of a proton diameter,  what force keeps the particles there, since there's no more self-gravity than when you began?  Or are we presuming the 'crushed' mass no longer has any of the particles we think of?  
> **username_3**: Gravity.  Humans have gravity, but at a distance measured in cm the gravity is very weak. But gravity scales as 1/r^2 If you get all the mass of a human into a very very small package, then there is lots of gravity. when you get close enough.  The key is very very small: far smaller than a proton.  
> **username_2**: Merci bien.   I should try actually doing some math before asking :-)  

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### Answer by username_4 on 2020-04-06. Score: 0

Our most powerful accelerator has yet to make any quantum black holes; <https://home.cern/resources/faqs/will-cern-generate-black-hole>
If it had, that would be big news.

> **Comments:**
> **username_1**: From the page linked in that CERN article: "The creation of a black hole at the LHC would confirm theories that our universe is not 4 dimensional (3 space plus 1 time dimensions), but indeed hosts other dimensions." The LHC simply doesn't have enough energy otherwise.  

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