<p>Because you are somewhat larger than your <a href="https://en.wikipedia.org/wiki/Schwarzschild_radius" rel="noreferrer">Schwarzchild radius</a>.</p>
<p>In order to turn into a black hole and start experiencing exciting things like Hawking radiation, you'd need to be compressed down into a ball about <span class="math-container">$10^{-25}$</span> meters in diameter, about one ten-billionth the size of a single proton.  At that size, you'd have a hard time sucking anything in: your gravity falls off quickly with distance, and even most subatomic particles will just bend their paths slightly as they pass you by.</p>

CC BY-SA 4.0
2021-05-22T02:05:49.680Z
2021-05-22T02:05:49.680Z
Mark
<p>If you have a spherical ball of matter, then outside that ball of matter, the gravitational field is the same as if all them mass were concentrated at a point (as a black hole)</p>
<p>But inside the ball of matter, some of the mass of the ball is behind you and acts in the opposite direction.  This means that the gravitational field is at a maximum on the surface of the ball, and decreases to zero as you move towards the centre of mass.</p>
<p>You aren't a spherical ball, but the same principle applies: The gravitational field you produce becomes smaller inside you.  To get a black hole you need to have mass <em>inside</em> the Schwarzschild radius not outside it.  A black hole exists because you can get very close to the centre of mass, without having to go inside the object.</p>

CC BY-SA 4.0
2021-05-22T11:02:18.980Z
2021-05-22T11:02:18.980Z
James K
<p>I will try to generalize your question to 'why does any object not become a black hole?'. It is indeed true that the center of mass of an object pulls the mass around it, so why does it not collapse?</p>
<p>We need to see, what force is balancing the force of gravity. If you press an object (let's say: Iron), as hard as you can, why does it not get destroyed completely? There is certainly a force that is acting against or repelling your applied push force. This force is called the electromagnetic force. It is this force by which electron repels another electron and attract a proton. What is happening when you press on an Iron is that the electrons in Iron are repelling the electrons in your hand. Since, this is a very strong force and stronger than the force you can apply with your bare hand, you are unable to destroy iron. <strong>This is the reason why atoms do not collapse under their own gravity.</strong></p>
<p>In case, the gravitational pull becomes very strong, the electron repulsive force is unable to counter the gravity and the object starts to collapse. As a result, the electrons start getting nearer to each other. But this has its limit. When the object becomes too dense, the electrons become degenerate (meaning that they cannot get any closer). Now, the electron degeneracy pressure takes over to counter the gravity. This pressure is much stronger than earlier and is found in planets/white dwarfs. <strong>This is the reason white dwarfs or planets and moons do not collapse under their own gravity.</strong></p>
<p>But, if even electron degeneracy pressure is unable to hold gravity, the electrons all collapse into the nucleus of the star and this results <span class="math-container">$electron+proton \rightarrow neutron$</span>. Now, the neutron degeneracy pressure takes over and <strong>this is what is seen in Neutron stars.</strong></p>
<p>Finally, if none of this helps and the gravity is just way too strong, which happens if the radius of the object is smaller than the Schwarzchild radius, even these neutrons collapse and we get a black hole.</p>
<p><strong>So, now, getting back to your question, why do you not collapse under your own gravity, the answer is simply because you are not massive enough that your gravitational pull can overcome the electromagnetic (or electron repulsive) force.</strong></p>

CC BY-SA 4.0
2021-05-29T02:13:41.330Z
+1 I think you answered the question the OP was trying to ask.
franz_lyre
CC BY-SA 4.0
2021-05-28T18:38:49.017Z
2021-05-28T18:38:49.017Z
Aryan Bansal
<p>A black hole does not necessarily suck in everything around it. Something that is outside <span class="math-container">$r = 2GM/ c^2$</span> radial distance (Schwarzschild radius) from the black hole, behaves in a similar way as if the black hole were a normal gravitating object.</p>
<p><a href="https://www.omnicalculator.com/physics/schwarzschild-radius" rel="nofollow noreferrer">Here is a Schwarzschild radius calculator online</a></p>
<p>For a mass equal to that of the earth, the Schwarzschild radius is about 9 mm. The earth would become a black hole if its entire mass is compressed to less than this radius. Even in such a scenario,  outside this radius, objects would anyway behave in such a way as if there was a normal gravitational source.</p>
<p>For a 150 lb human being, the Schwarzschild radius would be practically zero.</p>
<p>Think about an alien object very very close to your centre of mass (inside your theoretical event horizon). Even though the net gravity of your body might be pulling the object towards your centre of mass, the effect would be very weak because there is mass of your body everywhere around the object, pulling it around in all directions. Therefore, your centre of mass does not behave like a micro blackhole (even in classical Physics reasoning).</p>

CC BY-SA 4.0
2021-05-30T10:29:37.733Z
2021-05-30T10:46:43.640Z
2021-05-30T10:46:43.640Z
user37778
<p>So, a black hole is very dense that you can get really close to its center of mass that it has a strong pull, well, if i have the mass of a black hole that has a really small event horizon, why doesnt my center of mass create an explosion from hawking radiation, or suck myself</p>

CC BY-SA 4.0
2021-05-21T17:44:06.820Z
Mass does not make a black hole. Mass density (mass per volume) does. You are MUCH less dense than any black hole, also in your centre, even when you just ate a big meal.
planetmaker
CC BY-SA 4.0
2021-05-21T19:38:07.653Z
Ok but that means that i am less dense, my body covers my center of mass, but when i become more dense, it exposes that event horizon, so why doesnt that event horizon suck me? I am still confused
Programmer
CC BY-SA 4.0
2021-05-21T20:50:08.573Z
As a human, you would need to compact yourself to smaller than the classical radius of an electron before you'd be dense enough to fit inside your own event horizon.
notovny
CC BY-SA 4.0
2021-05-21T20:58:51.517Z
Woops, made a mistake there. The classical electron radius is _ten orders of magnitude_ larger than the size of a human-mass event horizon (About $10^{-25}$ m)
notovny
CC BY-SA 4.0
2021-05-21T21:48:09.240Z
FWIW, a 135.725 million solar mass black hole (which has a Schwarzschild radius of 2.68 au) has an *effective* density equal to that of water, 1000 kg/m³ (i.e., roughly the same density as a human).
PM 2Ring
CC BY-SA 4.0
2021-05-21T22:33:29.537Z
"why doesnt my center of mass create an explosion from hawking radiation, or suck myself?" Why would it?
Daddy Kropotkin
CC BY-SA 4.0
2021-05-22T00:18:50.227Z
" if i have the mass of a black hole that has a really small event horizon, why doesnt my center of mass create an explosion from hawking radiation" If would, if the first statement was true. The statement is false, thus the conclusion is false. This is *very* elementary logic.
PcMan
CC BY-SA 4.0
2021-05-22T01:51:02.203Z
@PM2Ring that's... interesting, perplexing... now going to make another cup of coffee and pretend I didn't read it so I can get through my day without staring off into space :-)
uhoh
CC BY-SA 4.0
2021-05-22T03:37:00.147Z
@uhoh It's only an effective density, though: the value you get by dividing the mass of the BH by the volume of a (flat space) sphere with radius equal to the BH's Schwarzschild radius, $R_S$. It does *not* mean that a BH is literally a uniform sphere of that density! It's ok to think of $R_S$ in terms of the circumference or area of the event horizon, but it's geometrically dubious to think of it in terms of volume, or even the distance to the core of the BH. OTOH, if you *did* somehow manage to gather enough water to fill a sphere of that size, it would certainly collapse into a BH.
PM 2Ring
CC BY-SA 4.0
2021-05-22T07:48:33.653Z
@PM2Ring Ha that's something to imagine :-)  yep I understand that, but it still surprises me.
uhoh
CC BY-SA 4.0
2021-05-22T08:21:38.603Z
@uhoh It's a *lot* of water. :) You'd need to process about 11.6 billion $M_\odot$ of galactic matter to get the required oxygen. That's ~20% of the galaxy's non-dark matter.
PM 2Ring
CC BY-SA 4.0
2021-05-22T08:24:29.957Z
At the other end of the scale, here's a recent popular question from our sister site on extremely small black holes. https://physics.stackexchange.com/q/634080/123208
PM 2Ring
CC BY-SA 4.0
2021-05-23T02:30:09.573Z
maybe because black holes are unimaginably dense and humans are basically nothing to them.
Bruh Moments
<black-hole><gravity><mass><density>
If a black hole has the same mass as me, then why dont i suck everything at my center of mass?
Programmer
# If a black hole has the same mass as me, then why dont i suck everything at my center of mass?

(Asked by: username_0 on 2021-05-21)

So, a black hole is very dense that you can get really close to its center of mass that it has a strong pull, well, if i have the mass of a black hole that has a really small event horizon, why doesnt my center of mass create an explosion from hawking radiation, or suck myself

**Tags:** black-hole, gravity, mass, density

> **Comments:**
> **username_1**: Mass does not make a black hole. Mass density (mass per volume) does. You are MUCH less dense than any black hole, also in your centre, even when you just ate a big meal.  
> **username_0**: Ok but that means that i am less dense, my body covers my center of mass, but when i become more dense, it exposes that event horizon, so why doesnt that event horizon suck me? I am still confused  
> **username_2**: As a human, you would need to compact yourself to smaller than the classical radius of an electron before you'd be dense enough to fit inside your own event horizon.  
> **username_2**: Woops, made a mistake there. The classical electron radius is _ten orders of magnitude_ larger than the size of a human-mass event horizon (About $10^{-25}$ m)  
> **username_3**: FWIW, a 135.725 million solar mass black hole (which has a Schwarzschild radius of 2.68 au) has an *effective* density equal to that of water, 1000 kg/m³ (i.e., roughly the same density as a human).  
> **username_4**: "why doesnt my center of mass create an explosion from hawking radiation, or suck myself?" Why would it?  
> **username_5**: " if i have the mass of a black hole that has a really small event horizon, why doesnt my center of mass create an explosion from hawking radiation" If would, if the first statement was true. The statement is false, thus the conclusion is false. This is *very* elementary logic.  
> **username_6**: @username_3 that's... interesting, perplexing... now going to make another cup of coffee and pretend I didn't read it so I can get through my day without staring off into space :-)  
> **username_3**: @username_6 It's only an effective density, though: the value you get by dividing the mass of the BH by the volume of a (flat space) sphere with radius equal to the BH's Schwarzschild radius, $R_S$. It does *not* mean that a BH is literally a uniform sphere of that density! It's ok to think of $R_S$ in terms of the circumference or area of the event horizon, but it's geometrically dubious to think of it in terms of volume, or even the distance to the core of the BH. OTOH, if you *did* somehow manage to gather enough water to fill a sphere of that size, it would certainly collapse into a BH.  
> **username_6**: @username_3 Ha that's something to imagine :-)  yep I understand that, but it still surprises me.  
> **username_3**: @username_6 It's a *lot* of water. :) You'd need to process about 11.6 billion $M_\odot$ of galactic matter to get the required oxygen. That's ~20% of the galaxy's non-dark matter.  
> **username_3**: At the other end of the scale, here's a recent popular question from our sister site on extremely small black holes. https://physics.stackexchange.com/q/634080/123208  
> **username_7**: maybe because black holes are unimaginably dense and humans are basically nothing to them.  

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## 4 answers

### Answer by username_8 on 2021-05-22. Score: 5

Because you are somewhat larger than your [Schwarzchild radius](https://en.wikipedia.org/wiki/Schwarzschild_radius).

In order to turn into a black hole and start experiencing exciting things like Hawking radiation, you'd need to be compressed down into a ball about $10^{-25}$ meters in diameter, about one ten-billionth the size of a single proton. At that size, you'd have a hard time sucking anything in: your gravity falls off quickly with distance, and even most subatomic particles will just bend their paths slightly as they pass you by.


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### Answer by username_9 on 2021-05-22. Score: 3

If you have a spherical ball of matter, then outside that ball of matter, the gravitational field is the same as if all them mass were concentrated at a point (as a black hole)

But inside the ball of matter, some of the mass of the ball is behind you and acts in the opposite direction. This means that the gravitational field is at a maximum on the surface of the ball, and decreases to zero as you move towards the centre of mass.

You aren't a spherical ball, but the same principle applies: The gravitational field you produce becomes smaller inside you. To get a black hole you need to have mass *inside* the Schwarzschild radius not outside it. A black hole exists because you can get very close to the centre of mass, without having to go inside the object.


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### Answer by username_10 on 2021-05-28. Score: 3

I will try to generalize your question to 'why does any object not become a black hole?'. It is indeed true that the center of mass of an object pulls the mass around it, so why does it not collapse?

We need to see, what force is balancing the force of gravity. If you press an object (let's say: Iron), as hard as you can, why does it not get destroyed completely? There is certainly a force that is acting against or repelling your applied push force. This force is called the electromagnetic force. It is this force by which electron repels another electron and attract a proton. What is happening when you press on an Iron is that the electrons in Iron are repelling the electrons in your hand. Since, this is a very strong force and stronger than the force you can apply with your bare hand, you are unable to destroy iron. **This is the reason why atoms do not collapse under their own gravity.**

In case, the gravitational pull becomes very strong, the electron repulsive force is unable to counter the gravity and the object starts to collapse. As a result, the electrons start getting nearer to each other. But this has its limit. When the object becomes too dense, the electrons become degenerate (meaning that they cannot get any closer). Now, the electron degeneracy pressure takes over to counter the gravity. This pressure is much stronger than earlier and is found in planets/white dwarfs. **This is the reason white dwarfs or planets and moons do not collapse under their own gravity.**

But, if even electron degeneracy pressure is unable to hold gravity, the electrons all collapse into the nucleus of the star and this results $electron+proton \rightarrow neutron$. Now, the neutron degeneracy pressure takes over and **this is what is seen in Neutron stars.**

Finally, if none of this helps and the gravity is just way too strong, which happens if the radius of the object is smaller than the Schwarzchild radius, even these neutrons collapse and we get a black hole.

**So, now, getting back to your question, why do you not collapse under your own gravity, the answer is simply because you are not massive enough that your gravitational pull can overcome the electromagnetic (or electron repulsive) force.**

> **Comments:**
> **username_11**: +1 I think you answered the question the OP was trying to ask.  

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### Answer by username_12 on 2021-05-30. Score: 1

A black hole does not necessarily suck in everything around it. Something that is outside $r = 2GM/ c^2$ radial distance (Schwarzschild radius) from the black hole, behaves in a similar way as if the black hole were a normal gravitating object.

[Here is a Schwarzschild radius calculator online](https://www.omnicalculator.com/physics/schwarzschild-radius)

For a mass equal to that of the earth, the Schwarzschild radius is about 9 mm. The earth would become a black hole if its entire mass is compressed to less than this radius. Even in such a scenario, outside this radius, objects would anyway behave in such a way as if there was a normal gravitational source.

For a 150 lb human being, the Schwarzschild radius would be practically zero.

Think about an alien object very very close to your centre of mass (inside your theoretical event horizon). Even though the net gravity of your body might be pulling the object towards your centre of mass, the effect would be very weak because there is mass of your body everywhere around the object, pulling it around in all directions. Therefore, your centre of mass does not behave like a micro blackhole (even in classical Physics reasoning).


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