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  1. Subscriber ogb
    19 Feb '18 14:26
    none have been detected because there aren't any.
  2. 19 Feb '18 16:20
    Originally posted by @ogb
    none have been detected because there aren't any.
    you cannot yet know that they don't exist. Too early to tell. They are implied by some albeit not necessarily all interpretations of quantum physics so the graviton hypothesis isn't an unreasonable hypothesis; just one that we have yet to find a practical way to test.
  3. Subscriber sonhouse
    Fast and Curious
    19 Feb '18 16:55
    Originally posted by @ogb
    none have been detected because there aren't any.
    Why are you so sure there are no gravitons? Are you an experimental physicist and have data from your experiments?
  4. 20 Feb '18 20:41
    Originally posted by @ogb
    none have been detected because there aren't any.
    My guess is that you are right.

    If space/time is discrete there might be no need for the graviton to explain gravity. My theory is that gravity is caused by the displacement of space/time by matter.
  5. 20 Feb '18 22:16 / 7 edits
    Originally posted by @metal-brain

    If space/time is discrete there might be no need for the graviton to explain gravity.
    Why "no need"?
    And it is NOT true that the theory of graviton is there to, as you said, "explain gravity", but rather to unite quantum theory with the theory of gravity.
    We already have general relativity to "explain gravity" so that is NOT the problem and thus NOT the reason for graviton theory.
    The problem is how to unify quantum theory with relativity; graviton may help with that.
    And it isn't "space/time", stupid. It is "spacetime"; you cannot even get that right.
    My theory is that gravity is caused by the displacement of space/time by matter.

    Your "theory" is based on what, exactly?
    Can you explain to us HOW is "gravity" "caused by the displacement of space/time by matter"? (And, again, it isn't "space/time", It is "spacetime" )
    What is your evidence?
    Are you a physicist?
    Do you understand the equations in quantum physics and relatively?
    Show us your maths to explain your "theory"...

    I don't have the delusional arrogance to assume I know better than the experts and you certainly shouldn't.
  6. Standard member lemon lime
    go phish
    21 Feb '18 05:39 / 1 edit
    Originally posted by @humy
    Why "no need"?
    And it is NOT true that the theory of graviton is there to, as you said, "explain gravity", but rather to unite quantum theory with the theory of gravity.
    We already have general relativity to "explain gravity" so that is NOT the problem and thus NOT the reason for graviton theory.
    The problem is how to unify quantum theory with relativity; g ...[text shortened]... e the delusional arrogance to assume I know better than the experts and you certainly shouldn't.
    How can we rely on "the experts" when it's apparent even they can't agree on what causes gravity?

    YouTube
  7. Standard member DeepThought
    Losing the Thread
    21 Feb '18 07:13
    Given that we can only just detect gravitational waves it's hardly a surprise that gravitons haven't been detected. The coupling strength of gravity in dimensionless units is roughly 42 orders of magnitude less than the coupling strength of the electromagnetic field. This means that it is far beyond our technological capability to detect a single graviton. So this is why they haven't been detected.

    It really isn't obvious whether these things exist. On the one hand there are families of particles associated with all the other forces, because quantum theories basically associate a particle with a field. Since gravitational waves exist we would expect the waves to be quantized. On the other hand naive approaches to quantization have failed to produce consistent theories. The best speculation we have is string theory and that predicts a spin 2 particle which is identified with the graviton and appears to be consistent. There are also technical difficulties with string theories which seem to have an immense number of possible vacuum states.

    On balance I'd say that gravitons exist and that space time is continuous, in the sense that it consists of a superposition of continuous manifolds, but I'm guessing.
  8. 21 Feb '18 08:59 / 1 edit
    Originally posted by @lemon-lime
    [b]How can we rely on "the experts" when it's apparent even they can't agree on what causes gravity?
    No no that isn't what I am saying to him at all.
    I am not saying we all should "rely" on the experts if they disagree (like they so often actually do).
    I am saying he shouldn't have have the delusional arrogance to assume he knows better than the experts when he obviously understands much less than them.
    I don't assume I know better than them about graviton theory and I at least have some basic physics credentials so why should he assume he knows better than them when he clearly has NO physics credentials?
  9. Standard member lemon lime
    go phish
    21 Feb '18 21:57 / 1 edit
    Originally posted by @humy
    No no that isn't what I am saying to him at all.
    I am not saying we all should "rely" on the experts if they disagree (like they so often actually do).
    I am saying he shouldn't have have the delusional arrogance to assume he knows better than the experts when he obviously understands much less than them.
    I don't assume I know better than them about graviton ...[text shortened]... ls so why should he assume he knows better than them when he clearly has NO physics credentials?
    I don't believe he thinks he knows better than the experts. If anything, I assume he has a pet theory that makes sense to him based on what he does know. I have my own pet theory as well... which just happens to agree with Einstein's belief that gravity is not a force, but rather is a property of spacetime.
    In any event, I've been looking for an excuse for some time now to post that particular youtube video... 😀
  10. Subscriber sonhouse
    Fast and Curious
    22 Feb '18 19:22
    Originally posted by @lemon-lime
    I don't believe he thinks he knows better than the experts. If anything, I assume he has a pet theory that makes sense to him based on what he does know. I have my own pet theory as well... which just happens to agree with Einstein's belief that gravity is not a force, but rather is a property of spacetime.
    In any event, I've been looking for an excuse for some time now to post that particular youtube video... 😀
    Spacetime warps due to mass is different from gravitational waves which we suppose has a graviton as the carrier, but like DT says, it lies at 420 DB lower than EM fields. Good luck detecting that. For instance, in audio recording, we are up to I think 32 bit recording, which is way overkill except for overhead, and at about 6 db per bit, that clocks in at 192 DB signal to noise ratio, with the caveat that nothing made by man can actually reach that level of noise so 420 DB would require 70 bit recording of whatever signal is being recorded, and good luck with that. Maybe by the 30th century......That is plucking at the Planck size, and we are not even CLOSE to that level of detection yet so any such detection would be totally indirect, like maybe long term effects of stars in orbit around black holes or some such. But like I said, not in century 21, or 22, or 23......
  11. 26 Feb '18 19:02
    Originally posted by @deepthought
    Given that we can only just detect gravitational waves it's hardly a surprise that gravitons haven't been detected. The coupling strength of gravity in dimensionless units is roughly 42 orders of magnitude less than the coupling strength of the electromagnetic field. This means that it is far beyond our technological capability to detect a single grav ...[text shortened]... ous, in the sense that it consists of a superposition of continuous manifolds, but I'm guessing.
    If gravitons exist wouldn't that mean spacetime is discrete instead of continuous? Please explain.
  12. Standard member wolfgang59
    Infidel
    27 Feb '18 10:16
    Originally posted by @ogb
    none have been detected because there aren't any.
    Like gods you mean?
    ... except there are good theoretical reasons to suppose gravitons do exist.
  13. Standard member wolfgang59
    Infidel
    27 Feb '18 10:17
    Originally posted by @lemon-lime
    How can we rely on "the experts" when it's apparent even they can't agree on what causes gravity?

    Yeah ... those idiots can't even do that!
  14. Standard member wolfgang59
    Infidel
    27 Feb '18 10:28
    Originally posted by @ogb
    none have been detected because there aren't any.
    I suppose you would have said that about atoms?
    ... and electrons (1897)
    ... the atomic nucleus (1911)
    ... protons (1920)
    ... neutrons (1932)
    ... neutrinos (1959)
    ... Higgs bosun (2012)

    ... but I admire the magnificence of your ignorance.
  15. 27 Feb '18 12:25
    Originally posted by @metal-brain
    If gravitons exist wouldn't that mean spacetime is discrete instead of continuous? Please explain.
    In the same that the existence of white holes would prove the universe is cyclic.