4 ms·

No. I imagine there is some context for this question, but I can not really give a better answer without knowing the question. My guess is that the question st

No. I imagine there is some context for this question, but I can not really give a better answer without knowing the question. My guess is that the question stems from a misunderstanding what a graviton is, so I will grossly simplify and say: graviton is to gravitational field what photon is to electrostatic field.

ianai 9y ago
True but the photon and graviton both transmit fields. For a black hole to pull matter in it must push out gravitons. Unless there really is no graviton particle and the Higgs tells space which way to curve. Ie gravity is an emergent property instead of a force.
- qubex 9y ago
  I’ve never heard of the Higgs being postulated as having a ’curving’ effect (it’s role is more akin to being a kind of molasses through which particles with weak hypercharge need to ’push’). Gravity at black holes’s event horizon is not quite coming from where you think it is: it isn’t ”emitted by” or ”emanating from” the singularity. Rather, as gravity is a form of energy, and mass-energy creates gravity, the gravitational field at the border, within our observable universe, is intense enough to whip itself up into a self-maintaining recursive but sustainable loop. No communication from what lies within the event horizon is neither possible nor required.
  - Santosh83 9y ago
    This is what I wanted to know too. Speaking as a non-physicist and a layman, that's almost the first conundrum that occurs to you when reading about black holes from popular science literature. How is it that gravitons can seemingly be exchanged by the pair of masses for any body to feel the pull of a black hole? I still don't quite get "the gravitational field at the border, within our observable universe, is intense enough to whip itself up into a self-maintaining recursive but sustainable loop" (especially the self-maintaining, recursive part. How?), but I guess one would need a good understanding of GR to go beyond this level?
    - rotorblade 9y ago
      Since black-holes interact gravitationally with other particles, there must be a mediation of a graviton between them (assuming quantum properties of gravity). However, force mediation is different from a physical particle escaping one object than interacting with another (e.g. physical graviton escaping a BH, interacting with an other particle). That is why we have the concept of virtual particles [0]: "[...] the electromagnetic repulsion or attraction between two charges—can be thought of as due to the exchange of many virtual photons between the charges." so when the electromagnetic force mediation takes place, it exchanges virtual photons, and this is different from an object exchanging physical photons with another (which we would more think of as one object shining (if the photon is in the visible spectrum) on another). How a virtual graviton would interact between BHs and other particles are up to any suggested theory for quantum gravity to explain. [0] https://en.wikipedia.org/wiki/Virtual_particle https://en.wikipedia.org/wiki/Virtual_particle
      - Santosh83 9y ago
        Thanks. That makes it somewhat clearer. Also including both links below as they are relevant to this misconception: http://math.ucr.edu/home/baez/physics/Relativity/BlackHoles/black_gravity.html http://math.ucr.edu/home/baez/physics/Relativity/BlackHoles/... https://www.quora.com/in/If-both-the-photon-and-the-graviton-are-massless-how-do-we-explain-that-the-photon-cannot-escape-a-black-hole-and-the-graviton https://www.quora.com/in/If-both-the-photon-and-the-graviton...
    - qubex 9y ago
      I’m not a physicist but I have a background in applied mathematics. What I am trying to describe is the inherent nonlinearity of general relativity, wherein compound solutions cannot be obtained simply summing up or overlaying simpler situations: the gravity filed itself generates more gravity, so it can recursively reach and sustain a critical value.
      - Simon_says 9y ago
        Black holes also evaporate. What’s happening here to make the field get smaller and ultimately disperse if the field is self-sustaining?
- rotorblade 9y ago
  > graviton particle and the Higgs tells space which way to curve The Higgs does not play that kind of role. It is a common misconception, since Higgs it often referred to as "giving mass to the other particles", which is true, and called the Higgs-mechanism, it does not influence the curvature of space-time that way. That is all due to the graviton (assuming, which it is also commonly believed, that gravity is quantised). Mass is one thing, interactions between masses another.
  - ianai 9y ago
    You took out part of my comment and only commented on the part you took out. In my original statement I made that statement as a hypothetical and in a context supposing there isn’t a graviton particle. My desire was to communicate that for gravitons to fill their hypothesized role for gravity they must somehow transmit the gravity from a BH.
- krastanov 9y ago
  > For a black hole to pull matter in it must push out gravitons. This is a non sequitur, presumably due to a misunderstanding caused from some pop sci article. You really do not need gravitons to describe any of the dynamics of "pulling matter in" (at least for "usual" black holes), and there is no "pushing out gravitons" involved.

ianai 9y ago

True but the photon and graviton both transmit fields. For a black hole to pull matter in it must push out gravitons. Unless there really is no graviton particle and the Higgs tells space which way to curve. Ie gravity is an emergent property instead of a force.

qubex 9y ago
I’ve never heard of the Higgs being postulated as having a ’curving’ effect (it’s role is more akin to being a kind of molasses through which particles with weak hypercharge need to ’push’). Gravity at black holes’s event horizon is not quite coming from where you think it is: it isn’t ”emitted by” or ”emanating from” the singularity. Rather, as gravity is a form of energy, and mass-energy creates gravity, the gravitational field at the border, within our observable universe, is intense enough to whip itself up into a self-maintaining recursive but sustainable loop. No communication from what lies within the event horizon is neither possible nor required.
- Santosh83 9y ago
  This is what I wanted to know too. Speaking as a non-physicist and a layman, that's almost the first conundrum that occurs to you when reading about black holes from popular science literature. How is it that gravitons can seemingly be exchanged by the pair of masses for any body to feel the pull of a black hole? I still don't quite get "the gravitational field at the border, within our observable universe, is intense enough to whip itself up into a self-maintaining recursive but sustainable loop" (especially the self-maintaining, recursive part. How?), but I guess one would need a good understanding of GR to go beyond this level?
  - rotorblade 9y ago
    Since black-holes interact gravitationally with other particles, there must be a mediation of a graviton between them (assuming quantum properties of gravity). However, force mediation is different from a physical particle escaping one object than interacting with another (e.g. physical graviton escaping a BH, interacting with an other particle). That is why we have the concept of virtual particles [0]: "[...] the electromagnetic repulsion or attraction between two charges—can be thought of as due to the exchange of many virtual photons between the charges." so when the electromagnetic force mediation takes place, it exchanges virtual photons, and this is different from an object exchanging physical photons with another (which we would more think of as one object shining (if the photon is in the visible spectrum) on another). How a virtual graviton would interact between BHs and other particles are up to any suggested theory for quantum gravity to explain. [0] https://en.wikipedia.org/wiki/Virtual_particle https://en.wikipedia.org/wiki/Virtual_particle
    - Santosh83 9y ago
      Thanks. That makes it somewhat clearer. Also including both links below as they are relevant to this misconception: http://math.ucr.edu/home/baez/physics/Relativity/BlackHoles/black_gravity.html http://math.ucr.edu/home/baez/physics/Relativity/BlackHoles/... https://www.quora.com/in/If-both-the-photon-and-the-graviton-are-massless-how-do-we-explain-that-the-photon-cannot-escape-a-black-hole-and-the-graviton https://www.quora.com/in/If-both-the-photon-and-the-graviton...
  - qubex 9y ago
    I’m not a physicist but I have a background in applied mathematics. What I am trying to describe is the inherent nonlinearity of general relativity, wherein compound solutions cannot be obtained simply summing up or overlaying simpler situations: the gravity filed itself generates more gravity, so it can recursively reach and sustain a critical value.
    - Simon_says 9y ago
      Black holes also evaporate. What’s happening here to make the field get smaller and ultimately disperse if the field is self-sustaining?
rotorblade 9y ago
> graviton particle and the Higgs tells space which way to curve The Higgs does not play that kind of role. It is a common misconception, since Higgs it often referred to as "giving mass to the other particles", which is true, and called the Higgs-mechanism, it does not influence the curvature of space-time that way. That is all due to the graviton (assuming, which it is also commonly believed, that gravity is quantised). Mass is one thing, interactions between masses another.
- ianai 9y ago
  You took out part of my comment and only commented on the part you took out. In my original statement I made that statement as a hypothetical and in a context supposing there isn’t a graviton particle. My desire was to communicate that for gravitons to fill their hypothesized role for gravity they must somehow transmit the gravity from a BH.
krastanov 9y ago
> For a black hole to pull matter in it must push out gravitons. This is a non sequitur, presumably due to a misunderstanding caused from some pop sci article. You really do not need gravitons to describe any of the dynamics of "pulling matter in" (at least for "usual" black holes), and there is no "pushing out gravitons" involved.