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Force carrying particles in general don't have mass. Except that some of them seem to do, which was rather puzzling for some time, but was solved using the Higg

Force carrying particles in general don't have mass. Except that some of them seem to do, which was rather puzzling for some time, but was solved using the Higgs mechanism. I can't think of an obvious reason the Higgs mechanism wouldn't work for gravitons, but I could be mistaken, it's not exactly the most intuitive area of physics. Also, keep in mind that the strong force transmits the force between colour charges while also having a colour charge itself, so it isn't entirely inconceivable for the force transmitting the attraction between masses to have a mass. No clue if a massive graviton would allow for black holes, but it's not entirely sure what black holes even are (especially quantum mechanically). At the very least it's presumably possible for some particles to escape it (e.g. as Hawking radiation).

sandworm101 11y ago
If the massive gravitron was leaving a black hole it would be slowed by the black hole's gravity. (1) We should see this as some inconsistency in how gravity scales with the mass of a black hole. The larger ones would have proportionately greater 'drag' on leaving gravitrons, pulling more in. (2) If they are massive, and therefore subject to slowing, shouldn't gravity waves leaving a black hole be subject to some sort of doppler effect? Should we be looking for red/blueshifts in these waves? (3) If gravitrons have mass and are subject to gravity, what brings that gravity? What sub-gravitron particle regulates gravity going in/to/out of the gravitron? This would require a new set of particles be created by non-gravitron massive objects (ie black holes) alongside the gravitrons. Like I said, too strange to exist.
- contravariant 11y ago
  >(1) We should see this as some inconsistency in how gravity scales with the mass of a black hole. The larger ones would have proportionately greater 'drag' on leaving gravitrons. Perhaps, no clue how a quantum mechanical gravity would interact with a black hole. >(2) If they are massive, and therefore subject to slowing, shouldn't gravity waves leaving a black hole be subject to some sort of doppler effect? Should we be looking for red/blueshifts in these waves? The Doppler effect happens even for light, which isn't massive at all (that we know of). >(3) If gravitrons have mass and are subject to gravity, what brings that gravity? What sub-gravitron particle regulates gravity going in/to/out of the gravitron? There's no reason they couldn't interact with themselves, in fact I guess that's probably the most likely case.
  - sandworm101 11y ago
    If they interact with each other, then wouldn't any "wave" collapse? The particles leave the event in a smooth wave. Then they run into other waves, or each other, or just the background gravity fields. This perturbation should cause them to clump together. So in short order the smooth wave would become large blobs of gravitrons more akin to raindrops than waves. And without anything holding them apart, might not some of these clumps condense into some sort of ... I don't have the words for such an object. I wouldn't want to get in its way.
    - contravariant 11y ago
      I think what you're trying to describe is something like 'confinement'. I'm not confident that a massive graviton will necessarily lead to confinement, neither gravitons nor confinement are that well understood.
    - Manishearth 11y ago
      It's a converging series; instead of getting a clumping you may get a slight mass increase. These new gravitons that modulate gravity between existing gravitons are not 100% there, so they do not contribute that much.
- tfgg 11y ago
  (None of my points below say the graviton is massless, just that it's not crazy. As another post says, this new observation probably confines the graviton mass to be less than 10^-55 grams) > If the massive gravitron was leaving a black hole it would be slowed by the black hole's gravity. A graviton wouldn't be able to escape a black hole. A photon can't, and it's massless. The gravity of a black hole is actually a self-sustaining effect of the curvature of the spacetime around the black hole. > (1) We should see this as some inconsistency in how gravity scales with the mass of a black hole. The larger ones would have proportionately greater 'drag' on leaving gravitrons. We don't know details of the gravitational field around black holes and the mass that created it, because none have been observed close up. To an extent, the mass of a black hole is defined by its gravity. > (2) If they are massive, and therefore subject to slowing, shouldn't gravity waves leaving a black hole be subject to some sort of doppler effect? Should we be looking for red/blueshifts in these waves? Again, photons are massless and subject to the doppler effect. Gravitons, massless or not, will be too. > (3) If gravitrons have mass and are subject to gravity, what brings that gravity? What sub-gravitron particle regulates gravity going in/to/out of the gravitron? This would require a new set of particles be created by non-gravitron massive objects (ie black holes) alongside the gravitrons. Like I said, too strange to exist. Force carying particles can interact with themselves, c.f. gluons in QCD. In fact, GR is a non-linear theory so there will be non-linear interactions (as far as you can describe them in the weak limit).
  - guscost 11y ago
    > A graviton wouldn't be able to escape a black hole ... the curvature of the spacetime around the black hole But isn't the curvature of spacetime around the black hole supposed to be the effect of its interaction with the graviton?? Is this where the translation from GR -> QM breaks down?
    - yk 11y ago
      > Is this where the translation from GR -> QM breaks down? Sort of, to get a graviton you introduce perturbations on a background metric. (Basically small wiggles of spacetime around an 'average.') You don't do anything like that when you solve the Einstein equations. Consequently, the background spacetime ( that is, the black hole) is not really made of gravitons. (At least in some sense.)
- Manishearth 11y ago
  > We should see this as some inconsistency in how gravity scales with the mass of a black hole. This inconsistency is a part of general relativity (even though gravitons themselves aren't). A black hole does not follow the GM/r^2 gravity law. > If they are massive, and therefore subject to slowing, shouldn't gravity waves leaving a black hole be subject to some sort of doppler effect? Should we be looking for red/blueshifts in these waves? Yes, there is a doppler effect. > If gravitrons have mass and are subject to gravity, what brings that gravity? What sub-gravitron particle regulates gravity going in/to/out of the gravitron? This would require a new set of particles be created by non-gravitron massive objects (ie black holes) alongside the gravitrons. Like I said, too strange to exist. Gravitons. Every now and then a pair of gravitons may exchange more gravitons (these are also virtual particles, so it's fine). This is why Feynman diagrams exist, so that you can not only calculate the interaction between two particles through a graviton, but also calculate the contribution of the lower-probability situations where more gravitons magically appear to transmit gravity between gravitons. This is nothing new. Gluons (the carrier for the color/strong force) do basically the same thing. They are also bound by the force they carry, and thus gluons can interact with each other with more gluons. Because these are virtual particles and only exist as a probability, this doesn't lead to infinite recursion. The secondary gravitons are improbable, and the tertiary gravitons more so, and so on, and the final series converges.
  - tbabb 11y ago
    > and the final series converges. Or not, and we yell "look behind you!" and then dump the infinities out the window. https://en.wikipedia.org/wiki/Renormalization https://en.wikipedia.org/wiki/Renormalization
    - Manishearth 11y ago
      Hah, that too :p When I first learned about renormalization formally (i.e., with equations) I realized it wasn't that bad. But still, pretty sneaky :P
kordless 11y ago
I'm going with the theory that black holes ARE gravitons themselves.
- egwor 11y ago
  There always seem to be pairs (as in yin and yang), so could something like anti-gravitons exist too?
  - kordless 11y ago
    I love groups who, while considering something as crazy as time turning into a physical direction as it does in a black hole, can still manage voting down someone down thinking outside the box. I like the idea of anti-gravitons being the inside of a graviton, or inside of a black hole. Given the inside of a black hole is essentially the end of time, coming out of a black hole or coming out of an anti-graviton, could equal going back to the beginning of time.
  - raattgift 11y ago
    Sure, and in several theories of gravitation where there are gravitons as an uncharged massless spin-2 gauge boson (General Relativity isn't one of these; it doesn't have any gravitons at all, although the non-quantized classical gravitational waves have spin-2 symmetry) then gravitons are their own anti-particles, just as photons (uncharged massless spin-1 gauge bosons) are their own anti-particles in the Standard Model. (i.e., anti-gravitons and gravitons are the same thing, just as anti-photons and photons are the same thing). There are a variety of other theories of gravitation with gravitons, but as far as I know, there are none in which gravitons are not their own antiparticles. (There may be such theories available in universes with a very different cosmological constant or with different numbers of dimensions than the one we are in).
purpled_haze 11y ago
> Force carrying particles in general don't have mass. Massless particles don't have energy. Massless and energyless particles have no speed. I have no interest in massless and energyless particles that stand still.
- cyphar 11y ago
  Photons are massless particles that have energy. All massless particles travel at the speed of light.
  - purpled_haze 11y ago
    Protons are said to be massless, but a proton may have mass that is so small that we cannot measure it easily. We can't currently say with 100% certainty that it is massless- only that it is at most very, very small: < 1×10−18 eV/c2
    - Jweb_Guru 11y ago
      What? Protons most definitely have mass.
      - dwaxe 11y ago
        They obviously meant photons
        purpled_haze 11y ago
        Yes, fingers kept typing wrong word.
    - deciplex 11y ago
      First, I'll assume you meant 'photon'. With that in mind, is it your assertion that if photons have no mass, they necessarily possess no energy? Because if so, and assuming you have some reason for believing this i.e. you can prove it, I would urge you to forward these findings to a physics journal of your choice posthaste, as this basically represents a total refutation of much of physics of the last century or so. You will easily win a Nobel Prize.

sandworm101 11y ago

If the massive gravitron was leaving a black hole it would be slowed by the black hole's gravity. (1) We should see this as some inconsistency in how gravity scales with the mass of a black hole. The larger ones would have proportionately greater 'drag' on leaving gravitrons, pulling more in. (2) If they are massive, and therefore subject to slowing, shouldn't gravity waves leaving a black hole be subject to some sort of doppler effect? Should we be looking for red/blueshifts in these waves? (3) If gravitrons have mass and are subject to gravity, what brings that gravity? What sub-gravitron particle regulates gravity going in/to/out of the gravitron? This would require a new set of particles be created by non-gravitron massive objects (ie black holes) alongside the gravitrons. Like I said, too strange to exist.

contravariant 11y ago
>(1) We should see this as some inconsistency in how gravity scales with the mass of a black hole. The larger ones would have proportionately greater 'drag' on leaving gravitrons. Perhaps, no clue how a quantum mechanical gravity would interact with a black hole. >(2) If they are massive, and therefore subject to slowing, shouldn't gravity waves leaving a black hole be subject to some sort of doppler effect? Should we be looking for red/blueshifts in these waves? The Doppler effect happens even for light, which isn't massive at all (that we know of). >(3) If gravitrons have mass and are subject to gravity, what brings that gravity? What sub-gravitron particle regulates gravity going in/to/out of the gravitron? There's no reason they couldn't interact with themselves, in fact I guess that's probably the most likely case.
- sandworm101 11y ago
  If they interact with each other, then wouldn't any "wave" collapse? The particles leave the event in a smooth wave. Then they run into other waves, or each other, or just the background gravity fields. This perturbation should cause them to clump together. So in short order the smooth wave would become large blobs of gravitrons more akin to raindrops than waves. And without anything holding them apart, might not some of these clumps condense into some sort of ... I don't have the words for such an object. I wouldn't want to get in its way.
  - contravariant 11y ago
    I think what you're trying to describe is something like 'confinement'. I'm not confident that a massive graviton will necessarily lead to confinement, neither gravitons nor confinement are that well understood.
  - Manishearth 11y ago
    It's a converging series; instead of getting a clumping you may get a slight mass increase. These new gravitons that modulate gravity between existing gravitons are not 100% there, so they do not contribute that much.
tfgg 11y ago
(None of my points below say the graviton is massless, just that it's not crazy. As another post says, this new observation probably confines the graviton mass to be less than 10^-55 grams) > If the massive gravitron was leaving a black hole it would be slowed by the black hole's gravity. A graviton wouldn't be able to escape a black hole. A photon can't, and it's massless. The gravity of a black hole is actually a self-sustaining effect of the curvature of the spacetime around the black hole. > (1) We should see this as some inconsistency in how gravity scales with the mass of a black hole. The larger ones would have proportionately greater 'drag' on leaving gravitrons. We don't know details of the gravitational field around black holes and the mass that created it, because none have been observed close up. To an extent, the mass of a black hole is defined by its gravity. > (2) If they are massive, and therefore subject to slowing, shouldn't gravity waves leaving a black hole be subject to some sort of doppler effect? Should we be looking for red/blueshifts in these waves? Again, photons are massless and subject to the doppler effect. Gravitons, massless or not, will be too. > (3) If gravitrons have mass and are subject to gravity, what brings that gravity? What sub-gravitron particle regulates gravity going in/to/out of the gravitron? This would require a new set of particles be created by non-gravitron massive objects (ie black holes) alongside the gravitrons. Like I said, too strange to exist. Force carying particles can interact with themselves, c.f. gluons in QCD. In fact, GR is a non-linear theory so there will be non-linear interactions (as far as you can describe them in the weak limit).
- guscost 11y ago
  > A graviton wouldn't be able to escape a black hole ... the curvature of the spacetime around the black hole But isn't the curvature of spacetime around the black hole supposed to be the effect of its interaction with the graviton?? Is this where the translation from GR -> QM breaks down?
  - yk 11y ago
    > Is this where the translation from GR -> QM breaks down? Sort of, to get a graviton you introduce perturbations on a background metric. (Basically small wiggles of spacetime around an 'average.') You don't do anything like that when you solve the Einstein equations. Consequently, the background spacetime ( that is, the black hole) is not really made of gravitons. (At least in some sense.)
Manishearth 11y ago
> We should see this as some inconsistency in how gravity scales with the mass of a black hole. This inconsistency is a part of general relativity (even though gravitons themselves aren't). A black hole does not follow the GM/r^2 gravity law. > If they are massive, and therefore subject to slowing, shouldn't gravity waves leaving a black hole be subject to some sort of doppler effect? Should we be looking for red/blueshifts in these waves? Yes, there is a doppler effect. > If gravitrons have mass and are subject to gravity, what brings that gravity? What sub-gravitron particle regulates gravity going in/to/out of the gravitron? This would require a new set of particles be created by non-gravitron massive objects (ie black holes) alongside the gravitrons. Like I said, too strange to exist. Gravitons. Every now and then a pair of gravitons may exchange more gravitons (these are also virtual particles, so it's fine). This is why Feynman diagrams exist, so that you can not only calculate the interaction between two particles through a graviton, but also calculate the contribution of the lower-probability situations where more gravitons magically appear to transmit gravity between gravitons. This is nothing new. Gluons (the carrier for the color/strong force) do basically the same thing. They are also bound by the force they carry, and thus gluons can interact with each other with more gluons. Because these are virtual particles and only exist as a probability, this doesn't lead to infinite recursion. The secondary gravitons are improbable, and the tertiary gravitons more so, and so on, and the final series converges.
- tbabb 11y ago
  > and the final series converges. Or not, and we yell "look behind you!" and then dump the infinities out the window. https://en.wikipedia.org/wiki/Renormalization https://en.wikipedia.org/wiki/Renormalization
  - Manishearth 11y ago
    Hah, that too :p When I first learned about renormalization formally (i.e., with equations) I realized it wasn't that bad. But still, pretty sneaky :P

kordless 11y ago

I'm going with the theory that black holes ARE gravitons themselves.

egwor 11y ago
There always seem to be pairs (as in yin and yang), so could something like anti-gravitons exist too?
- kordless 11y ago
  I love groups who, while considering something as crazy as time turning into a physical direction as it does in a black hole, can still manage voting down someone down thinking outside the box. I like the idea of anti-gravitons being the inside of a graviton, or inside of a black hole. Given the inside of a black hole is essentially the end of time, coming out of a black hole or coming out of an anti-graviton, could equal going back to the beginning of time.
- raattgift 11y ago
  Sure, and in several theories of gravitation where there are gravitons as an uncharged massless spin-2 gauge boson (General Relativity isn't one of these; it doesn't have any gravitons at all, although the non-quantized classical gravitational waves have spin-2 symmetry) then gravitons are their own anti-particles, just as photons (uncharged massless spin-1 gauge bosons) are their own anti-particles in the Standard Model. (i.e., anti-gravitons and gravitons are the same thing, just as anti-photons and photons are the same thing). There are a variety of other theories of gravitation with gravitons, but as far as I know, there are none in which gravitons are not their own antiparticles. (There may be such theories available in universes with a very different cosmological constant or with different numbers of dimensions than the one we are in).

purpled_haze 11y ago

> Force carrying particles in general don't have mass. Massless particles don't have energy. Massless and energyless particles have no speed. I have no interest in massless and energyless particles that stand still.

cyphar 11y ago
Photons are massless particles that have energy. All massless particles travel at the speed of light.
- purpled_haze 11y ago
  Protons are said to be massless, but a proton may have mass that is so small that we cannot measure it easily. We can't currently say with 100% certainty that it is massless- only that it is at most very, very small: < 1×10−18 eV/c2
  - Jweb_Guru 11y ago
    What? Protons most definitely have mass.
    - dwaxe 11y ago
      They obviously meant photons
      - purpled_haze 11y ago
        Yes, fingers kept typing wrong word.
  - deciplex 11y ago
    First, I'll assume you meant 'photon'. With that in mind, is it your assertion that if photons have no mass, they necessarily possess no energy? Because if so, and assuming you have some reason for believing this i.e. you can prove it, I would urge you to forward these findings to a physics journal of your choice posthaste, as this basically represents a total refutation of much of physics of the last century or so. You will easily win a Nobel Prize.