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

Why didn't this character "real die" when they blew their stack out in Altered Carbon?

In predicate logic, does existential quantification (∃) include universal quantification (∀), i.e. can 'some' imply 'all'?

What to do with chalk when deepwater soloing?

English words in a non-english sci-fi novel

What would be the ideal power source for a cybernetic eye?

How to Merge Multiple Columns in to Two Columns based on Column 1 Value?

At the end of Thor: Ragnarok why don't the Asgardians turn and head for the Bifrost as per their original plan?

What is the role of the transistor and diode in a soft start circuit?

Why is my conclusion inconsistent with the van't Hoff equation?

2001: A Space Odyssey's use of the song "Daisy Bell" (Bicycle Built for Two); life imitates art or vice-versa?

What LEGO pieces have "real-world" functionality?

Single word antonym of "flightless"

How do I keep my slimes from escaping their pens?

Short Story with Cinderella as a Voo-doo Witch

Why am I getting the error "non-boolean type specified in a context where a condition is expected" for this request?

Why are there no cargo aircraft with "flying wing" design?

Using audio cues to encourage good posture

If a contract sometimes uses the wrong name, is it still valid?

Coloring maths inside a tcolorbox

What is the meaning of the new sigil in Game of Thrones Season 8 intro?

How to tell that you are a giant?

Can a USB port passively 'listen only'?

Is it ethical to give a final exam after the professor has quit before teaching the remaining chapters of the course?

How widely used is the term Treppenwitz? Is it something that most Germans know?



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)






share|improve this answer









$endgroup$













    Your Answer








    StackExchange.ready(function()
    var channelOptions =
    tags: "".split(" "),
    id: "514"
    ;
    initTagRenderer("".split(" "), "".split(" "), channelOptions);

    StackExchange.using("externalEditor", function()
    // Have to fire editor after snippets, if snippets enabled
    if (StackExchange.settings.snippets.snippetsEnabled)
    StackExchange.using("snippets", function()
    createEditor();
    );

    else
    createEditor();

    );

    function createEditor()
    StackExchange.prepareEditor(
    heartbeatType: 'answer',
    autoActivateHeartbeat: false,
    convertImagesToLinks: false,
    noModals: true,
    showLowRepImageUploadWarning: true,
    reputationToPostImages: null,
    bindNavPrevention: true,
    postfix: "",
    imageUploader:
    brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
    contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
    allowUrls: true
    ,
    noCode: true, onDemand: true,
    discardSelector: ".discard-answer"
    ,immediatelyShowMarkdownHelp:true
    );



    );






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









    draft saved

    draft discarded


















    StackExchange.ready(
    function ()
    StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fastronomy.stackexchange.com%2fquestions%2f30499%2fblack-hole-density%23new-answer', 'question_page');

    );

    Post as a guest















    Required, but never shown

























    1 Answer
    1






    active

    oldest

    votes








    1 Answer
    1






    active

    oldest

    votes









    active

    oldest

    votes






    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)






    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.









            draft saved

            draft discarded


















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












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











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














            Thanks for contributing an answer to Astronomy Stack Exchange!


            • Please be sure to answer the question. Provide details and share your research!

            But avoid …


            • Asking for help, clarification, or responding to other answers.

            • Making statements based on opinion; back them up with references or personal experience.

            Use MathJax to format equations. MathJax reference.


            To learn more, see our tips on writing great answers.




            draft saved


            draft discarded














            StackExchange.ready(
            function ()
            StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fastronomy.stackexchange.com%2fquestions%2f30499%2fblack-hole-density%23new-answer', 'question_page');

            );

            Post as a guest















            Required, but never shown





















































            Required, but never shown














            Required, but never shown












            Required, but never shown







            Required, but never shown

































            Required, but never shown














            Required, but never shown












            Required, but never shown







            Required, but never shown







            -black-hole, density, supermassive-black-hole
            -

            Popular posts from this blog

            Frič See also Navigation menuinternal link

            Image
            SurnamesCzech-language surnames ‹ The template Infobox surname is being considered for merging. › Frič Origin Language(s) Czechized German (eastern Middle German dialects and Alemannic German) - Thuringian, Upper Saxon, Low Lusatian, Silesian Meaning derived from German: Friedrich Other names Variant(s) Fritsch, Fritzsch, Frycz, Fricz, Fryczyński, Frietsch, Fritsche, Fritzsche; Fritschi (Alemannic), Fritz, Fritze, Fritzel, Fritzl, Fritzke, Fritzen Frič is a Czechized German surname. Notable people with the surname include: Alberto Vojtěch Frič, Czech botanist Antonín Jan Frič (Fritsch) , Czech paleontologist Jaroslav Erik Frič, Czech poet Martin Frič, Czech film director, screenwriter and actor See also Fričovce (Hungarian: Frics ) .mw-parser-output table.dmboxclear:both;margin:0.9em 1em;border-top:1px solid #ccc;border-bottom:1px solid #ccc;background-color:transparent Surname list This page lists people with the surname Frič . If an internal link intending to refer to a specifi
            Read more

            Identify plant with long narrow paired leaves and reddish stems Planned maintenance scheduled April 17/18, 2019 at 00:00UTC (8:00pm US/Eastern) Announcing the arrival of Valued Associate #679: Cesar Manara Unicorn Meta Zoo #1: Why another podcast?What is this plant with long sharp leaves? Is it a weed?What is this 3ft high, stalky plant, with mid sized narrow leaves?What is this young shrub with opposite ovate, crenate leaves and reddish stems?What is this plant with large broad serrated leaves?Identify this upright branching weed with long leaves and reddish stemsPlease help me identify this bulbous plant with long, broad leaves and white flowersWhat is this small annual with narrow gray/green leaves and rust colored daisy-type flowers?What is this chilli plant?Does anyone know what type of chilli plant this is?Help identify this plant

            Image
            Apollo command module space walk? prime numbers and expressing non-prime numbers Can a non-EU citizen traveling with me come with me through the EU passport line? Extract all GPU name, model and GPU ram How to deal with a team lead who never gives me credit? Why was the term "discrete" used in discrete logarithm? Why do we bend a book to keep it straight? When do you get frequent flier miles - when you buy, or when you fly? How come Sam didn't become Lord of Horn Hill? At the end of Thor: Ragnarok why don't the Asgardians turn and head for the Bifrost as per their original plan? Is it true that "carbohydrates are of no use for the basal metabolic need"? Using et al. for a last / senior author rather than for a first author How to tell that you are a giant? How to react to hostile behavior from a senior developer? String `!23` is replaced with `docker` in command line How to find out what spells would be useless to a blind NPC sp
            Read more

            fontconfig warning: “/etc/fonts/fonts.conf”, line 100: unknown “element blank” The 2019 Stack Overflow Developer Survey Results Are In“tar: unrecognized option --warning” during 'apt-get install'How to fix Fontconfig errorHow do I figure out which font file is chosen for a system generic font alias?Why are some apt-get-installed fonts being ignored by fc-list, xfontsel, etc?Reload settings in /etc/fonts/conf.dTaking 30 seconds longer to boot after upgrade from jessie to stretchHow to match multiple font names with a single <match> element?Adding a custom font to fontconfigRemoving fonts from fontconfig <match> resultsBroken fonts after upgrading Firefox ESR to latest Firefox

            Image
            How to type this arrow in math mode? Multiply Two Integer Polynomials What do hard-Brexiteers want with respect to the Irish border? Why isn't the circumferential light around the M87 black hole's event horizon symmetric? For what reasons would an animal species NOT cross a *horizontal* land bridge? Can one be advised by a professor who is very far away? Identify boardgame from Big movie slides for 30min~1hr skype tenure track application interview Why do we hear so much about the Trump administration deciding to impose and then remove tariffs? If I score a critical hit on an 18 or higher, what are my chances of getting a critical hit if I roll 3d20? Can we generate random numbers using irrational numbers like π and e? Worn-tile Scrabble Output the Arecibo Message What is the meaning of Triage in Cybersec world? How are circuits which use complex ICs normally simulated? Shouldn't "much" here be used instead of "more"? Dele
            Read more