<p>Mini black holes are thought not to exist, so it's an unlikely idea anyway, and Hawking Radiation is largely accepted (but I think, not proven) . . . so maybe, "what if" concerns very unlikely but slightly valid, but there's also this: </p>

<p>We get particle collisions faster than Cern can produce in our upper atmosphere every day.    If there was any danger of high energy collisions, We'd have likely observed it already either in our atmosphere or by Hubble.    The fact that high energy collisions happen every day on every planet, every good sized moon and every star in the galaxy suggests that high energy collisions don't form into matter eating strangelets or tiny but hungry black holes.   If they did, we'd have seen some evidence of that.</p>

<p>So we have both very strong observational evidence as well as theoretical evidence.    CERN isn't playing with particle energy that doesn't happen - it happens all the time in space.</p>

<p>Just for fun - the Oh-my-god particle, way more energy energy than anything that happens in CERN:   <a href="http://en.wikipedia.org/wiki/Oh-My-God_particle" rel="nofollow">http://en.wikipedia.org/wiki/Oh-My-God_particle</a></p>

CC BY-SA 3.0
2015-05-14T01:23:27.547Z
2015-05-14T01:23:27.547Z
userLTK
<p>Small mass black holes are <strong>extremely</strong> small and, if Hawking Radiation is real, <strong>extremely</strong> short-lived. (I cannot over-emphasise how extremely!) Even a one hundred ton black hole would be smaller than an electron and evaporate in the blink of an eye (and in a multi-million megaton explosion).</p>

<p>According to <a href="http://en.wikipedia.org/wiki/Large_Hadron_Collider" rel="nofollow">http://en.wikipedia.org/wiki/Large_Hadron_Collider</a>, the LHC is achieving 328 TeV per ion in its heavy ion collisions. 328 TeV is about 5x10<sup>-24</sup>kg.</p>

<p>A black hole of that mass would be about 10<sup>-50</sup>m in diameter and would live for about 10<sup>-70</sup>s. <em>(Both of these are much less than planck length and planck time (10<sup>-35</sup>m and 10<sup>-44</sup>s) so such a small black hole is arguably impossible for that reason if not for others.)</em>
If it were possible it would be soo many orders of magnitude too small and too short-lived to be able to acquire any extra mass before it disappeared. </p>

<p>The process of evaporation (Hawking radiation) is virtual particle pairs forming on the event horizon and one falling in and one escaping. The one that escapes becomes a real particle with mass and that mass is taken from the black hole. (In effect the other virtual particle becomes a real negative mass falling into it). That's very simplistic and I don't understand enough myself to explain it in significantly greater detail. It is not proven to exist as UserLTK says and I doubt if it could happen at the lengths and timescales of this sub-planck-scale black hole if such a thing were possible anyway.</p>

CC BY-SA 3.0
2015-05-20T14:39:35.280Z
2015-05-20T14:39:35.280Z
Avon
<p>This result is due to <a href="http://en.wikipedia.org/wiki/Hawking_radiation" rel="noreferrer">Hawking radiation</a>.</p>

<p>Due to random quantum fluctuations, particles are radiated from a black hole.</p>

<p>When the black hole has a mass less than the Moon, it will <a href="http://en.wikipedia.org/wiki/Black_hole#Evaporation" rel="noreferrer">evaporate</a>.</p>

<p>EDIT</p>

<p>I should add that any black holes created can only have the mass of the particles involved in the collision - two protons. So it's not going to do any harm before it evaporates. However, we <em>would</em> learn a lot from the event.</p>

CC BY-SA 3.0
2015-11-02T19:58:00.947Z
The mass of the black hole would be the mass of the two protons *plus* the energy of their collision.
Keith Thompson
CC BY-SA 3.0
2015-11-02T20:44:57.373Z
@Keith Yes, that's correct. Of course, the black hole would still evaporate.
andy256
CC BY-SA 3.0
2015-05-13T04:58:02.813Z
2015-05-14T09:28:54.970Z
2015-05-14T09:28:54.970Z
andy256
<p>A scientist at CERN LHC (Large Hadron Collider) was asked during an interview about the possible results and consequences of operating the LHC at full power of collision in the near future, one of the results he literally said :</p>

<blockquote>
  <p>One of the theories that predicts the consequences of operating the LHC at full power collision is that mini black holes might form, but do not be afraid of those black holes, they will not start expanding and destroy the earth, they will instantaneously disappear.</p>
</blockquote>

<p>I know that black holes create disturbance in space-time. And they actually appear when matter massively gets pressurized into a small size of volume in space which causes gravity to increase insanely which in turn initialize a black hole that even light its self can not escape away from.</p>

<p>So how can a mini black hole disappear anyway?
What in the world would cause a small size, a mini size, a tiny little black hole to vanish or disappear?</p>

CC BY-SA 3.0
2015-05-13T03:12:08.120Z
What would happen if the pressure in a system is more powerful than the attractive force of gravity on it?
Mitch Goshorn
CC BY-SA 3.0
2015-05-13T03:15:48.337Z
@MitchGoshorn Is this answering a question with a question? If so, I need more clarifications on your question.
Bilal Sulaiman
CC BY-SA 3.0
2015-05-13T04:31:56.573Z
Normally a planet or stellar body reaches the volume it does as the result of reaching equilibrium between internal pressure and gravity. If the force of gravity were greater, the body would compress until the pressure grew great enough that it stabilized. If the pressure were to increase, the body would expand, lowering pressure until the body stabilized. An ordinary black hole is the result of stellar amounts of matter compressing as internal pressure suddenly drops. But these micro blackholes are not the result of gravity, rather they result from a collision. So how will the body equalize?
Mitch Goshorn
CC BY-SA 3.0
2015-05-13T04:38:37.703Z
@MitchGoshorn  this specific question you asked, maybe the key for the answer. They are recreating the "Big Bang" circumstances in the LHC at CERN, as a result they put many theories of consequences of such an experiment and the mini black hole theory was one of them.
Bilal Sulaiman
CC BY-SA 3.0
2015-05-13T04:50:29.540Z
It's fascinating really. Sometimes the result of such systems can be counter-intuitive. In some circumstances, adding matter to a body will decrease its volume. Other times, removing matter could increase its volume. If you stuck the whole universe in a singularity and then found a way to give pressure the upper hand in the way gravity gets it during supernova events, the result might look a lot like the Big Bang. A MBH is certainly not a universe of matter, but it gives scientists a glimpse into what it might have been like.
Mitch Goshorn
CC BY-SA 3.0
2015-11-02T19:57:15.683Z
Isn't this more of a [physics](https://physics.stackexchange.com/) question than an astronomy question?
Keith Thompson
CC BY-SA 4.0
2020-02-10T19:22:50.213Z
I'm voting to close this question as off-topic because there is no astronomical question.  This might be on topic on physics.se
James K
CC BY-SA 4.0
2020-02-11T11:13:30.913Z
While your question is good, it would look much better on the https://physics.stackexchange.com .
peterh
<black-hole>
Mini black holes, a possible result of the LHC experiment at CERN
Bilal Sulaiman
# Mini black holes, a possible result of the LHC experiment at CERN

(Asked by: username_0 on 2015-05-13)

A scientist at CERN LHC (Large Hadron Collider) was asked during an interview about the possible results and consequences of operating the LHC at full power of collision in the near future, one of the results he literally said :

> One of the theories that predicts the consequences of operating the LHC at full power collision is that mini black holes might form, but do not be afraid of those black holes, they will not start expanding and destroy the earth, they will instantaneously disappear.

I know that black holes create disturbance in space-time. And they actually appear when matter massively gets pressurized into a small size of volume in space which causes gravity to increase insanely which in turn initialize a black hole that even light its self can not escape away from.

So how can a mini black hole disappear anyway?
What in the world would cause a small size, a mini size, a tiny little black hole to vanish or disappear?

**Tags:** black-hole
> **Comments:**
> **username_1**: What would happen if the pressure in a system is more powerful than the attractive force of gravity on it?  
> **username_0**: @MitchGoshorn Is this answering a question with a question? If so, I need more clarifications on your question.  
> **username_1**: Normally a planet or stellar body reaches the volume it does as the result of reaching equilibrium between internal pressure and gravity. If the force of gravity were greater, the body would compress until the pressure grew great enough that it stabilized. If the pressure were to increase, the body would expand, lowering pressure until the body stabilized. An ordinary black hole is the result of stellar amounts of matter compressing as internal pressure suddenly drops. But these micro blackholes are not the result of gravity, rather they result from a collision. So how will the body equalize?  
> **username_0**: @MitchGoshorn  this specific question you asked, maybe the key for the answer. They are recreating the "Big Bang" circumstances in the LHC at CERN, as a result they put many theories of consequences of such an experiment and the mini black hole theory was one of them.  
> **username_1**: It's fascinating really. Sometimes the result of such systems can be counter-intuitive. In some circumstances, adding matter to a body will decrease its volume. Other times, removing matter could increase its volume. If you stuck the whole universe in a singularity and then found a way to give pressure the upper hand in the way gravity gets it during supernova events, the result might look a lot like the Big Bang. A MBH is certainly not a universe of matter, but it gives scientists a glimpse into what it might have been like.  
> **username_2**: Isn't this more of a [physics](https://physics.stackexchange.com/) question than an astronomy question?  
> **username_3**: I'm voting to close this question as off-topic because there is no astronomical question.  This might be on topic on physics.se  
> **username_4**: While your question is good, it would look much better on the https://physics.stackexchange.com .  

---

## 3 answers

### Answer by username_7 on 2015-05-13. Score: 7 | Accepted answer

This result is due to [Hawking radiation](http://en.wikipedia.org/wiki/Hawking_radiation).

Due to random quantum fluctuations, particles are radiated from a black hole.

When the black hole has a mass less than the Moon, it will [evaporate](http://en.wikipedia.org/wiki/Black_hole#Evaporation).

EDIT

I should add that any black holes created can only have the mass of the particles involved in the collision - two protons. So it's not going to do any harm before it evaporates. However, we *would* learn a lot from the event.

> **Comments:**
> **username_2**: The mass of the black hole would be the mass of the two protons *plus* the energy of their collision.  
> **username_7**: @Keith Yes, that's correct. Of course, the black hole would still evaporate.  

---

### Answer by username_5 on 2015-05-14. Score: 2

Mini black holes are thought not to exist, so it's an unlikely idea anyway, and Hawking Radiation is largely accepted (but I think, not proven) . . . so maybe, "what if" concerns very unlikely but slightly valid, but there's also this:

We get particle collisions faster than Cern can produce in our upper atmosphere every day. If there was any danger of high energy collisions, We'd have likely observed it already either in our atmosphere or by Hubble. The fact that high energy collisions happen every day on every planet, every good sized moon and every star in the galaxy suggests that high energy collisions don't form into matter eating strangelets or tiny but hungry black holes. If they did, we'd have seen some evidence of that.

So we have both very strong observational evidence as well as theoretical evidence. CERN isn't playing with particle energy that doesn't happen - it happens all the time in space.

Just for fun - the Oh-my-god particle, way more energy energy than anything that happens in CERN: <http://en.wikipedia.org/wiki/Oh-My-God_particle>


---

### Answer by username_6 on 2015-05-20. Score: 1

Small mass black holes are **extremely** small and, if Hawking Radiation is real, **extremely** short-lived. (I cannot over-emphasise how extremely!) Even a one hundred ton black hole would be smaller than an electron and evaporate in the blink of an eye (and in a multi-million megaton explosion).

According to <http://en.wikipedia.org/wiki/Large_Hadron_Collider>, the LHC is achieving 328 TeV per ion in its heavy ion collisions. 328 TeV is about 5x10-24kg.

A black hole of that mass would be about 10-50m in diameter and would live for about 10-70s. *(Both of these are much less than planck length and planck time (10-35m and 10-44s) so such a small black hole is arguably impossible for that reason if not for others.)*
If it were possible it would be soo many orders of magnitude too small and too short-lived to be able to acquire any extra mass before it disappeared.

The process of evaporation (Hawking radiation) is virtual particle pairs forming on the event horizon and one falling in and one escaping. The one that escapes becomes a real particle with mass and that mass is taken from the black hole. (In effect the other virtual particle becomes a real negative mass falling into it). That's very simplistic and I don't understand enough myself to explain it in significantly greater detail. It is not proven to exist as UserLTK says and I doubt if it could happen at the lengths and timescales of this sub-planck-scale black hole if such a thing were possible anyway.


---

