Black hole density Announcing the arrival of Valued Associate #679: Cesar Manara Planned maintenance scheduled April 17/18, 2019 at 00:00UTC (8:00pm US/Eastern) What stellar content do we want to share with Twitter?What is a singularity? What is at the center of a black hole? Specifically regarding space-timeIs there a maximum size for a black hole?How does gravity have an effect from the inside the event horizon of a black hole with the rest of the universe?What are the differences between a Black Hole and a Supermassive Black HoleBlack Hole, Object or Portal?Looking for help in understanding how black holes can moveStar versus Black HoleSuccinct explanation of black hole mass, diameter, shape?Complex life in binary black hole - Sun(s) systemEquating critical energy density to matter densityCan a black hole be torn apart by SMBHs?What can be learned from, or noted in this LIGO Orrery video?Black hole rotation and it's significance

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Black hole density



Announcing the arrival of Valued Associate #679: Cesar Manara
Planned maintenance scheduled April 17/18, 2019 at 00:00UTC (8:00pm US/Eastern)
What stellar content do we want to share with Twitter?What is a singularity? What is at the center of a black hole? Specifically regarding space-timeIs there a maximum size for a black hole?How does gravity have an effect from the inside the event horizon of a black hole with the rest of the universe?What are the differences between a Black Hole and a Supermassive Black HoleBlack Hole, Object or Portal?Looking for help in understanding how black holes can moveStar versus Black HoleSuccinct explanation of black hole mass, diameter, shape?Complex life in binary black hole - Sun(s) systemEquating critical energy density to matter densityCan a black hole be torn apart by SMBHs?What can be learned from, or noted in this LIGO Orrery video?Black hole rotation and it's significance










2












$begingroup$


How does more compression relate to a stronger gravitational pull. Like, when we say that a black hole is a tiny space that has 20-30 suns compressed in it, how does this increase its density and gravitational pulling power (I'm open to mathematical answers but I prefer a layman type answer for better understanding)






black-hole supermassive-black-hole density







share|improve this question









New contributor




noorav is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.







$endgroup$











  • $begingroup$
    @PM 2Ring, could you please link the questions? There are just too many on the Physics.SE site
    $endgroup$
    – noorav
    13 hours ago






  • 1




    $begingroup$
    From a distance, a BH of 20 solar masses has the same gravity as a normal star that size, from the same distance. It has no extra sucking power, although tidal effects get extreme when you get close, simply due to your distance from the centre. Any light or matter that falls into a BH quickly falls to the centre. Pure general relativity says it gets crushed out of existence, but we expect quantum effects to modify that, but the core of a BH will still be tiny, probably smaller than an atom under quantum gravity.
    $endgroup$
    – PM 2Ring
    13 hours ago






  • 1




    $begingroup$
    When stuff falls into a BH, it gets heavier, so its gravity gets stronger. There's no limit to how much a BF can consume, but if too much stuff tries to fall in at once you get a kind of traffic jam just outside the BH, and since that stuff collides at speeds approaching lightspeed, the collisions are extremely spectacular, emitting huge amounts of radiation across the spectrum, and spewing out collision debris, sometimes more than 1000 lightyears for a big active BH like M87*.
    $endgroup$
    – PM 2Ring
    13 hours ago






  • 1




    $begingroup$
    I've cut it down to one question, this isn't too broad.
    $endgroup$
    – James K
    12 hours ago






  • 1




    $begingroup$
    Similar question by the same user on Physics.
    $endgroup$
    – rob
    11 hours ago















2












$begingroup$


How does more compression relate to a stronger gravitational pull. Like, when we say that a black hole is a tiny space that has 20-30 suns compressed in it, how does this increase its density and gravitational pulling power (I'm open to mathematical answers but I prefer a layman type answer for better understanding)






black-hole supermassive-black-hole density







share|improve this question









New contributor




noorav is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.







$endgroup$











  • $begingroup$
    @PM 2Ring, could you please link the questions? There are just too many on the Physics.SE site
    $endgroup$
    – noorav
    13 hours ago






  • 1




    $begingroup$
    From a distance, a BH of 20 solar masses has the same gravity as a normal star that size, from the same distance. It has no extra sucking power, although tidal effects get extreme when you get close, simply due to your distance from the centre. Any light or matter that falls into a BH quickly falls to the centre. Pure general relativity says it gets crushed out of existence, but we expect quantum effects to modify that, but the core of a BH will still be tiny, probably smaller than an atom under quantum gravity.
    $endgroup$
    – PM 2Ring
    13 hours ago






  • 1




    $begingroup$
    When stuff falls into a BH, it gets heavier, so its gravity gets stronger. There's no limit to how much a BF can consume, but if too much stuff tries to fall in at once you get a kind of traffic jam just outside the BH, and since that stuff collides at speeds approaching lightspeed, the collisions are extremely spectacular, emitting huge amounts of radiation across the spectrum, and spewing out collision debris, sometimes more than 1000 lightyears for a big active BH like M87*.
    $endgroup$
    – PM 2Ring
    13 hours ago






  • 1




    $begingroup$
    I've cut it down to one question, this isn't too broad.
    $endgroup$
    – James K
    12 hours ago






  • 1




    $begingroup$
    Similar question by the same user on Physics.
    $endgroup$
    – rob
    11 hours ago













2












2








2





$begingroup$


How does more compression relate to a stronger gravitational pull. Like, when we say that a black hole is a tiny space that has 20-30 suns compressed in it, how does this increase its density and gravitational pulling power (I'm open to mathematical answers but I prefer a layman type answer for better understanding)






black-hole supermassive-black-hole density







share|improve this question









New contributor




noorav is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.







$endgroup$




How does more compression relate to a stronger gravitational pull. Like, when we say that a black hole is a tiny space that has 20-30 suns compressed in it, how does this increase its density and gravitational pulling power (I'm open to mathematical answers but I prefer a layman type answer for better understanding)






black-hole supermassive-black-hole density




black-hole supermassive-black-hole density






share|improve this question









New contributor




noorav is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.











share|improve this question









New contributor




noorav is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.









share|improve this question




share|improve this question








edited 12 hours ago









James K

35k257119




35k257119






New contributor




noorav is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.









asked 14 hours ago









nooravnoorav

111




111




New contributor




noorav is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.





New contributor





noorav is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.






noorav is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.











  • $begingroup$
    @PM 2Ring, could you please link the questions? There are just too many on the Physics.SE site
    $endgroup$
    – noorav
    13 hours ago






  • 1




    $begingroup$
    From a distance, a BH of 20 solar masses has the same gravity as a normal star that size, from the same distance. It has no extra sucking power, although tidal effects get extreme when you get close, simply due to your distance from the centre. Any light or matter that falls into a BH quickly falls to the centre. Pure general relativity says it gets crushed out of existence, but we expect quantum effects to modify that, but the core of a BH will still be tiny, probably smaller than an atom under quantum gravity.
    $endgroup$
    – PM 2Ring
    13 hours ago






  • 1




    $begingroup$
    When stuff falls into a BH, it gets heavier, so its gravity gets stronger. There's no limit to how much a BF can consume, but if too much stuff tries to fall in at once you get a kind of traffic jam just outside the BH, and since that stuff collides at speeds approaching lightspeed, the collisions are extremely spectacular, emitting huge amounts of radiation across the spectrum, and spewing out collision debris, sometimes more than 1000 lightyears for a big active BH like M87*.
    $endgroup$
    – PM 2Ring
    13 hours ago






  • 1




    $begingroup$
    I've cut it down to one question, this isn't too broad.
    $endgroup$
    – James K
    12 hours ago






  • 1




    $begingroup$
    Similar question by the same user on Physics.
    $endgroup$
    – rob
    11 hours ago
















  • $begingroup$
    @PM 2Ring, could you please link the questions? There are just too many on the Physics.SE site
    $endgroup$
    – noorav
    13 hours ago






  • 1




    $begingroup$
    From a distance, a BH of 20 solar masses has the same gravity as a normal star that size, from the same distance. It has no extra sucking power, although tidal effects get extreme when you get close, simply due to your distance from the centre. Any light or matter that falls into a BH quickly falls to the centre. Pure general relativity says it gets crushed out of existence, but we expect quantum effects to modify that, but the core of a BH will still be tiny, probably smaller than an atom under quantum gravity.
    $endgroup$
    – PM 2Ring
    13 hours ago






  • 1




    $begingroup$
    When stuff falls into a BH, it gets heavier, so its gravity gets stronger. There's no limit to how much a BF can consume, but if too much stuff tries to fall in at once you get a kind of traffic jam just outside the BH, and since that stuff collides at speeds approaching lightspeed, the collisions are extremely spectacular, emitting huge amounts of radiation across the spectrum, and spewing out collision debris, sometimes more than 1000 lightyears for a big active BH like M87*.
    $endgroup$
    – PM 2Ring
    13 hours ago






  • 1




    $begingroup$
    I've cut it down to one question, this isn't too broad.
    $endgroup$
    – James K
    12 hours ago






  • 1




    $begingroup$
    Similar question by the same user on Physics.
    $endgroup$
    – rob
    11 hours ago















$begingroup$
@PM 2Ring, could you please link the questions? There are just too many on the Physics.SE site
$endgroup$
– noorav
13 hours ago




$begingroup$
@PM 2Ring, could you please link the questions? There are just too many on the Physics.SE site
$endgroup$
– noorav
13 hours ago




1




1




$begingroup$
From a distance, a BH of 20 solar masses has the same gravity as a normal star that size, from the same distance. It has no extra sucking power, although tidal effects get extreme when you get close, simply due to your distance from the centre. Any light or matter that falls into a BH quickly falls to the centre. Pure general relativity says it gets crushed out of existence, but we expect quantum effects to modify that, but the core of a BH will still be tiny, probably smaller than an atom under quantum gravity.
$endgroup$
– PM 2Ring
13 hours ago




$begingroup$
From a distance, a BH of 20 solar masses has the same gravity as a normal star that size, from the same distance. It has no extra sucking power, although tidal effects get extreme when you get close, simply due to your distance from the centre. Any light or matter that falls into a BH quickly falls to the centre. Pure general relativity says it gets crushed out of existence, but we expect quantum effects to modify that, but the core of a BH will still be tiny, probably smaller than an atom under quantum gravity.
$endgroup$
– PM 2Ring
13 hours ago




1




1




$begingroup$
When stuff falls into a BH, it gets heavier, so its gravity gets stronger. There's no limit to how much a BF can consume, but if too much stuff tries to fall in at once you get a kind of traffic jam just outside the BH, and since that stuff collides at speeds approaching lightspeed, the collisions are extremely spectacular, emitting huge amounts of radiation across the spectrum, and spewing out collision debris, sometimes more than 1000 lightyears for a big active BH like M87*.
$endgroup$
– PM 2Ring
13 hours ago




$begingroup$
When stuff falls into a BH, it gets heavier, so its gravity gets stronger. There's no limit to how much a BF can consume, but if too much stuff tries to fall in at once you get a kind of traffic jam just outside the BH, and since that stuff collides at speeds approaching lightspeed, the collisions are extremely spectacular, emitting huge amounts of radiation across the spectrum, and spewing out collision debris, sometimes more than 1000 lightyears for a big active BH like M87*.
$endgroup$
– PM 2Ring
13 hours ago




1




1




$begingroup$
I've cut it down to one question, this isn't too broad.
$endgroup$
– James K
12 hours ago




$begingroup$
I've cut it down to one question, this isn't too broad.
$endgroup$
– James K
12 hours ago




1




1




$begingroup$
Similar question by the same user on Physics.
$endgroup$
– rob
11 hours ago




$begingroup$
Similar question by the same user on Physics.
$endgroup$
– rob
11 hours ago










1 Answer
1






active

oldest

votes


















4












$begingroup$

We can understand gravity as following a set of mathematical equations called "General Relativity" which were discovered by Einstein (and others) around the start of the 20th century. The same gravitational equations apply to black holes, stars, planets, people, apples etc. These equations are very hard to solve. Fortunately there is a very good approximation, that was discovered by Isacc Newton about 350 years ago.



It says that there is a force between any two objects that is proportional to the mass of the each object and inversely proportional to the square of the distance between the objects. The closer the objects are to each other, the stronger is the gravitational force. For normal objects (like you, and an apple) the size of this force is so small that it is almost undetectable. But if one of the objects is very big (like a planet) then it becomes a very strong force.



So if you get a couple of balls of styrofoam. They have some mass and so there is a force of gravity between them. But because they are not very dense they cannot come very close together. If you crush the styrofoam, you make it more dense. This would let you get the balls closer together, and so the force of gravity on the surface would be larger. If you don't push the balls closer together then the force between the balls would stay the same. It is the distance between the masses that is important.



A star is very massive, and its own gravity would be enough to crush it, if it didn't have a nuclear furnace inside which provides the energy to stop this. But when a star runs out of fuel, its own gravity is enough to crush the core of the star. Since you now have the same amount of mass in a smaller ball, the gravity on the surface is greater.



For a black hole this process runs away (in a way that can only be described accurately by General Relativity). The gravity gets so strong that nothing can prevent the star's complete collapse to a single point (it is a lot weirder than this, because space and time are bent by the mass). Around this is a region of space from which even light can't escape, which is why black holes look black. Furtherout from the black hole, gravity is normal. Black holes don't "suck" they just have strong gravity.



None of this answers the question "why does gravity get weaker as distance increases. Perhaps that is due to how gravity spreads out from a mass. It gets weaker in a way that is analogous to how light gets weaker as you get further from a lamp.



Nor does this explain why gravity is proportional to mass. There doesn't seem to be an answer to this (except that in a universe with no gravity, it seems likely that no structures with living creatures could form, so we wouldn't be here to ask the question)






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    1 Answer
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    1 Answer
    1






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    active

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    4












    $begingroup$

    We can understand gravity as following a set of mathematical equations called "General Relativity" which were discovered by Einstein (and others) around the start of the 20th century. The same gravitational equations apply to black holes, stars, planets, people, apples etc. These equations are very hard to solve. Fortunately there is a very good approximation, that was discovered by Isacc Newton about 350 years ago.



    It says that there is a force between any two objects that is proportional to the mass of the each object and inversely proportional to the square of the distance between the objects. The closer the objects are to each other, the stronger is the gravitational force. For normal objects (like you, and an apple) the size of this force is so small that it is almost undetectable. But if one of the objects is very big (like a planet) then it becomes a very strong force.



    So if you get a couple of balls of styrofoam. They have some mass and so there is a force of gravity between them. But because they are not very dense they cannot come very close together. If you crush the styrofoam, you make it more dense. This would let you get the balls closer together, and so the force of gravity on the surface would be larger. If you don't push the balls closer together then the force between the balls would stay the same. It is the distance between the masses that is important.



    A star is very massive, and its own gravity would be enough to crush it, if it didn't have a nuclear furnace inside which provides the energy to stop this. But when a star runs out of fuel, its own gravity is enough to crush the core of the star. Since you now have the same amount of mass in a smaller ball, the gravity on the surface is greater.



    For a black hole this process runs away (in a way that can only be described accurately by General Relativity). The gravity gets so strong that nothing can prevent the star's complete collapse to a single point (it is a lot weirder than this, because space and time are bent by the mass). Around this is a region of space from which even light can't escape, which is why black holes look black. Furtherout from the black hole, gravity is normal. Black holes don't "suck" they just have strong gravity.



    None of this answers the question "why does gravity get weaker as distance increases. Perhaps that is due to how gravity spreads out from a mass. It gets weaker in a way that is analogous to how light gets weaker as you get further from a lamp.



    Nor does this explain why gravity is proportional to mass. There doesn't seem to be an answer to this (except that in a universe with no gravity, it seems likely that no structures with living creatures could form, so we wouldn't be here to ask the question)






    share|improve this answer









    $endgroup$

















      4












      $begingroup$

      We can understand gravity as following a set of mathematical equations called "General Relativity" which were discovered by Einstein (and others) around the start of the 20th century. The same gravitational equations apply to black holes, stars, planets, people, apples etc. These equations are very hard to solve. Fortunately there is a very good approximation, that was discovered by Isacc Newton about 350 years ago.



      It says that there is a force between any two objects that is proportional to the mass of the each object and inversely proportional to the square of the distance between the objects. The closer the objects are to each other, the stronger is the gravitational force. For normal objects (like you, and an apple) the size of this force is so small that it is almost undetectable. But if one of the objects is very big (like a planet) then it becomes a very strong force.



      So if you get a couple of balls of styrofoam. They have some mass and so there is a force of gravity between them. But because they are not very dense they cannot come very close together. If you crush the styrofoam, you make it more dense. This would let you get the balls closer together, and so the force of gravity on the surface would be larger. If you don't push the balls closer together then the force between the balls would stay the same. It is the distance between the masses that is important.



      A star is very massive, and its own gravity would be enough to crush it, if it didn't have a nuclear furnace inside which provides the energy to stop this. But when a star runs out of fuel, its own gravity is enough to crush the core of the star. Since you now have the same amount of mass in a smaller ball, the gravity on the surface is greater.



      For a black hole this process runs away (in a way that can only be described accurately by General Relativity). The gravity gets so strong that nothing can prevent the star's complete collapse to a single point (it is a lot weirder than this, because space and time are bent by the mass). Around this is a region of space from which even light can't escape, which is why black holes look black. Furtherout from the black hole, gravity is normal. Black holes don't "suck" they just have strong gravity.



      None of this answers the question "why does gravity get weaker as distance increases. Perhaps that is due to how gravity spreads out from a mass. It gets weaker in a way that is analogous to how light gets weaker as you get further from a lamp.



      Nor does this explain why gravity is proportional to mass. There doesn't seem to be an answer to this (except that in a universe with no gravity, it seems likely that no structures with living creatures could form, so we wouldn't be here to ask the question)






      share|improve this answer









      $endgroup$















        4












        4








        4





        $begingroup$

        We can understand gravity as following a set of mathematical equations called "General Relativity" which were discovered by Einstein (and others) around the start of the 20th century. The same gravitational equations apply to black holes, stars, planets, people, apples etc. These equations are very hard to solve. Fortunately there is a very good approximation, that was discovered by Isacc Newton about 350 years ago.



        It says that there is a force between any two objects that is proportional to the mass of the each object and inversely proportional to the square of the distance between the objects. The closer the objects are to each other, the stronger is the gravitational force. For normal objects (like you, and an apple) the size of this force is so small that it is almost undetectable. But if one of the objects is very big (like a planet) then it becomes a very strong force.



        So if you get a couple of balls of styrofoam. They have some mass and so there is a force of gravity between them. But because they are not very dense they cannot come very close together. If you crush the styrofoam, you make it more dense. This would let you get the balls closer together, and so the force of gravity on the surface would be larger. If you don't push the balls closer together then the force between the balls would stay the same. It is the distance between the masses that is important.



        A star is very massive, and its own gravity would be enough to crush it, if it didn't have a nuclear furnace inside which provides the energy to stop this. But when a star runs out of fuel, its own gravity is enough to crush the core of the star. Since you now have the same amount of mass in a smaller ball, the gravity on the surface is greater.



        For a black hole this process runs away (in a way that can only be described accurately by General Relativity). The gravity gets so strong that nothing can prevent the star's complete collapse to a single point (it is a lot weirder than this, because space and time are bent by the mass). Around this is a region of space from which even light can't escape, which is why black holes look black. Furtherout from the black hole, gravity is normal. Black holes don't "suck" they just have strong gravity.



        None of this answers the question "why does gravity get weaker as distance increases. Perhaps that is due to how gravity spreads out from a mass. It gets weaker in a way that is analogous to how light gets weaker as you get further from a lamp.



        Nor does this explain why gravity is proportional to mass. There doesn't seem to be an answer to this (except that in a universe with no gravity, it seems likely that no structures with living creatures could form, so we wouldn't be here to ask the question)






        share|improve this answer









        $endgroup$



        We can understand gravity as following a set of mathematical equations called "General Relativity" which were discovered by Einstein (and others) around the start of the 20th century. The same gravitational equations apply to black holes, stars, planets, people, apples etc. These equations are very hard to solve. Fortunately there is a very good approximation, that was discovered by Isacc Newton about 350 years ago.



        It says that there is a force between any two objects that is proportional to the mass of the each object and inversely proportional to the square of the distance between the objects. The closer the objects are to each other, the stronger is the gravitational force. For normal objects (like you, and an apple) the size of this force is so small that it is almost undetectable. But if one of the objects is very big (like a planet) then it becomes a very strong force.



        So if you get a couple of balls of styrofoam. They have some mass and so there is a force of gravity between them. But because they are not very dense they cannot come very close together. If you crush the styrofoam, you make it more dense. This would let you get the balls closer together, and so the force of gravity on the surface would be larger. If you don't push the balls closer together then the force between the balls would stay the same. It is the distance between the masses that is important.



        A star is very massive, and its own gravity would be enough to crush it, if it didn't have a nuclear furnace inside which provides the energy to stop this. But when a star runs out of fuel, its own gravity is enough to crush the core of the star. Since you now have the same amount of mass in a smaller ball, the gravity on the surface is greater.



        For a black hole this process runs away (in a way that can only be described accurately by General Relativity). The gravity gets so strong that nothing can prevent the star's complete collapse to a single point (it is a lot weirder than this, because space and time are bent by the mass). Around this is a region of space from which even light can't escape, which is why black holes look black. Furtherout from the black hole, gravity is normal. Black holes don't "suck" they just have strong gravity.



        None of this answers the question "why does gravity get weaker as distance increases. Perhaps that is due to how gravity spreads out from a mass. It gets weaker in a way that is analogous to how light gets weaker as you get further from a lamp.



        Nor does this explain why gravity is proportional to mass. There doesn't seem to be an answer to this (except that in a universe with no gravity, it seems likely that no structures with living creatures could form, so we wouldn't be here to ask the question)







        share|improve this answer












        share|improve this answer



        share|improve this answer










        answered 12 hours ago









        James KJames K

        35k257119




        35k257119




















            noorav is a new contributor. Be nice, and check out our Code of Conduct.









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