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Anyone of you guys read this month's Scientific American?

  1. Aug 17, 2005 #1
    Anyone of you guys read this month's Scientific American??
    The one on that our inflationary model of our Universe may have to be modified due to the unpredicted patterns of the mono-poles and dipoles and other multi-poles of the CMB. Certain harmonic Spheres were missing???

    then they talked about the constant Lambda being the Anti-gravitonal effects of the inflationary model of the expansion of the Universe.

    Does it suggest that Anti-gravitons exists?

    considering that Anti-neutrons may exist without any significant charges???

    Any suggestions? or am i just bladdering ? lol Sorry if i am
     
  2. jcsd
  3. Aug 17, 2005 #2
    like the photon the anti-graviton is the graviton it self. the photon is the same.
     
  4. Aug 17, 2005 #3
    Hmmm, but does the Anti-gravity Constant Lambda for the inflationary model suggest anything? Cause it has an anti-gravity property of which it is speculated that gravitons exist
     
  5. Aug 17, 2005 #4
    didnt u talk about anti gravitons? anti gravity and anti gravitons are 2 different things
     
    Last edited: Aug 17, 2005
  6. Aug 17, 2005 #5
    Oh, so Anti-gravity exist between Matter and anti-matter?
    Was wondering because it maybe that the anti-gravity property may come across as compared to an opposite charge between a positron and an electron...
     
  7. Aug 17, 2005 #6
    no, its between matter with posetive mass and negative mass. anti matter have a posetive mass. so it will fell and create normal gravity.
     
  8. Aug 17, 2005 #7
    Lots of confusion here, all due to the term "Anti Gravity".

    Gravitons which repel matter are not anti-gravitons, they are ordinary gravitons.
    They are gravitons produced not by anti-matter, but by matter or antimatter
    which has a negative energy density.
     
  9. Aug 17, 2005 #8
    Forewarning: I'm here to learn about this so excuse me if I sound very stupid.

    Zelos, how can you have negetive mass?

    ~Kitty
     
  10. Aug 17, 2005 #9
    We don't know how to manufacture it or if it even possible. It's
    just speculation.

    The only measureable instance I know of of negative energy density is
    the Casmir effect where the energy density of the zero-point fluctuations
    of empty space is decreased (below zero?) between the plates of a
    capacitor. But this is not matter, just energy.

    Matter and anti-matter both have positive energy, which means when
    they touch, there will be an "explosion" and the energy will fly away.

    When matter touches negative-energy-density matter, nothing should
    happen. If matter should touch negative-energy-density anti-matter,
    they should both disappear without an explosion.
     
  11. Aug 17, 2005 #10
    Huh. Who hypthesized that? I think its very interesting.

    ~Kitty
     
  12. Aug 17, 2005 #11

    EnumaElish

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    Shouldn't there be a discharge from + to - so both particles end up neutralized? (How is it different than short-circuiting a car battery?)
     
  13. Aug 17, 2005 #12
    It doesn't seem all that different in concept. If nothing happens as Antiphon said then they wouldn't cancel each other out, would they?

    ~Kitty
     
  14. Aug 17, 2005 #13

    EnumaElish

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    Yes, I did not meant to imply that matter will disappear; only energy will jump from the + particle to the - particle. There will be a spark, perhaps? :smile:
     
  15. Aug 17, 2005 #14
    Possibly. I'm not overly knowledgable about it.:blush: Thats why I was asking. However, common sense would lead one to think ther would be a spark causing a short circuit. :smile:

    ~Kitty
     
  16. Aug 17, 2005 #15

    EnumaElish

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    I am not a physicist, so just like you, I said "this is common sense." Unless a physicist explains that there won't be a spark, and why. (Sort of raining on the parade, I guess.)
     
  17. Aug 17, 2005 #16
    Where's Marlon when you need him? :smile:

    ~Kitty
     
  18. Aug 18, 2005 #17
    See the hypothesis of physicist Dr. Robert Forward that I posted on the PF thread called "negative mass" . From what I read Dr. Forward was well ahead of his time in thinking about "negative mass" as a real existent in the universe. See also the following paper: Hermann Bondi, "Negative Mass in General Relativity", Reviews of Modern Physics 29, 423 (1957). In this paper you will read how Einstein predicted that negative mass entities are linked with antigravity. The late nuclear physicist Ronald Brightsen (MIT) has taken this idea one step forward--that negative mass and antigravity can form stable union with positive mass and gravity to form 1-H-1, the neutron, and the deuteron. I would be happy to explain this Brightsen hypothesis if requested and such discussion is allowed by PF moderators.
     
  19. Aug 18, 2005 #18

    EnumaElish

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    I am not a moderator, but anything that is not explicitly forbidden by the rules and conventions of PF should be free. I for one am curious about Drs. Forward and Brightsen, and would appreciate your time if you post an explanation.
     
  20. Aug 20, 2005 #19
    I do not have access to the papers of Dr. Forward, but one of the posts above provides some information--apparently Dr. Forward has published equations to show how positive mass and negative mass can intermingle.

    Also, as seen from this discussion on Physlink.com, the concept of negative mass is not considered valid by modern day physicists:
    ====
    Question

    How can something have a negative mass, and what does that mean?

    Asked by: Jim Larkin

    Answer

    If a particle could have a negative mass it certainly would be hard to understand. That is why physicists define mass to be always positive. So by definition there is no such thing as 'negative' mass. This is not an arbitrary definition as there are very deep reasons as to why a negative mass could never be physical.

    Sometimes, in employing mathematical models to describe Nature, we come across solutions to equations that may allow for negative masses. For example, the formula for the energy of a relativistic particle is

    E2 = m2*c4 + p2*c2.

    So a particle with a certain positive energy but no momentum could presumably have a positive or negative mass. Dirac interpreted these negative mass states as anti-particles that he hid away in the 'Dirac Sea.' While this anachronistic interpretation still lives on in old-textbooks and new-Age books on quantum mechanics, we now know that this picture is wrong. Anti-particles have positive masses just as any other particle (see http://www.physlink.com/ae247.cfm). These 'negative' solutions are simply not physical and are dropped. Not everything that has mathematical meaning has physical meaning!

    Another place where people like to talk about negative masses is in reference to 'tachyons.' The tachyon (whose name comes from the Greek word tachys for swift) was originally any solution to Special Relativity that had a velocity greater than the speed of light. Such a state (like Dirac's 'negative energy' states) are non-physical. These particles would have imaginary masses (that is the mass-squared is negative) and this is just as unphysical as a negative mass or a negative energy. Thus such solutions are always discarded or removed from any theory that claims to describe Nature.

    Answered by: Brent Nelson, M.A. Physics, Ph.D. Student, UC Berkeley
    =====

    As for Mr. Brightsen, his papers are available at this link:
    http://www.brightsenmodel.phoenixrising-web.net. Mr. Brightsen passed away in 2001--he left much unanswered about the "dynamics" of this nucleon cluster model. I serve as webmaster for this site to allow for his model to be studied and debated.

    The Brightsen Model starts with a basic axiom that unbound protons [P] and neutrons [N] do not exist in beta-stable isotopes--this is what makes his cluster model unique. This is of course counter to the standard shell model which is widely held in nuclear physics. Because his model does not allow for unbound nucleons in isotopes, he has a problem with 1-H-1, the proton. He solves the problem by a hypothesis that the proton [P] is in fact a quantum superposition of different combinations of matter and antimatter nucleon clusters. For example, 1-H-1 can be formed by union of a matter [PNP] cluster + antimatter [N^P^] where ^ = antimatter. If one views each cluster as having a unique wavefunction, then the superposition principle of QM requires that when the two waves meet, their amplitudes add, but no mass is added or taken away. This is just the way QM works--when waves meet they always add because the waves are not "physical things".

    Next, applying complex number formalism z = x+yi the two clusters can form a stable superposition with a real part [P] within the same field as an imaginary part {[NP][N^P^]}. When we collapse the superposed wavefunction at low energy we "observe" what we call "the proton" [P]--when we use high energy in accelerators we observed the quark collapse of the imaginary {[NP][N^P^]}, which always appears as pions (matter quark+antimatter quark). The above is my understanding of how the Brightsen Model may work, it was not discussed by Mr. Brightsen in any of his papers. One will note that the above explains the so-called "missing mass" of the universe--it is not missing, it is found within 1-H-1, the neutron, and deuteron as "antimatter" according to the Brightsen Model.

    Another unique prediction of the Brightsen Model is that the stable union between matter and antimatter within 1-H-1 requires the ever presence of a new field force--gravity (from matter) linked with antigravity (from antimatter). When energy is applied to this "proton superposition", the QM superposition principle demands that the two initial wavefunction will separate entirely unchanged in terms of mass. Thus, the Brightsen Model predicts that the source of antimatter in proton interactions with heavy elements such as copper (a very common experiment) is the release of the antimatter [P^] and [N^] that exists within the element 1-H-1. Of great importance is that when the energy used is very low (i.e. cold) the imaginary [NP] and [N^P^] clusters emerge to allow for transmutation of heavy elements--that is, the Brightsen Model predicts one possible "dynamic" for what is called "cold fusion".

    Now to question of negative mass. The Brightsen Model predicts that the "effective mass" for "antihydrogen" will always be "negative one". The term effective mass comes from a basic equation for all beta-stable isotopes derived from the Brightsen Model, (NP+NPN) + 2 (NP) = Z, where Z = number of "net positive charge" protons in a nuclei. Z takes the form of "net negative protons" where there are an excess of antimatter (negative) mass units. For example, antihydrogen can be formed by quantum superposition between [P^N^P^] antimatter cluster and [NP] matter cluster, and thus form the "effective negative mass" = (-1) for the antihydrogen.

    Finally, here are some comments provided by nuclear physicist Steve Nelson on the "anti-mass" (negative mass) predictions of the Brightsen Model for antihydrogen:

    ....The model you mention has a major problem with mass, and I note from one article relies on antimatter having an anti-mass. Anti-hydrogen is being created and trapped at CERN, and a hydrogen interferometer is being constructed by some groups I know. In a couple years, they'll have accurate measurements of the gravitational acceleration of antihydrogen and compare it with hydrogen. If antihydrogen turns out to have the same acceleration as normal hydrogen, there's no room for a model with extra mass. If it's exactly opposite in sign then there's room to return to this model to try and construct some predictive equations ....

    In summary, we will just have to wait for these experiments at CERN to see if the Brightsen Model negative mass predictions for antihydrogen hold.
     
  21. Mar 7, 2009 #20
    Re: Anti-gravitons?

    Sorry, like the original poster to this thread, I'm not a physicist. I came across this (old) thread from a google-search after thinking along similar lines to the original poster to this thread.

    Based on my popular science reading on physics, I've formed the quite possibly crack-pot idea that maybe:
    1. matter eminates gravitons, which act to attract other matter, but repulse anti-matter.
    2 anti-matter eminates anti-gravitons, which act to attract other anit-matter, but repulse matter.

    My logic for this conclusion is outlined in the points below. Please excuse me if any of this seems crackpot to those of you who are more knowledgable on physics than me.

    # Other forces such as electro-magnetism have the symmetry of acting to repel some things and attract others. Is the key difference between magnetism and gravity simply that it's a case of similars-attract rather than than opposites-attract? (in other words, is gravity the "gay force"!)

    # Similarly, it seems that in the particle-invention business, physicists are coming up with an anti-particle for every type of particle. Shouldn't this also apply to gravitons? And how would they differ from normal gravitons?

    # Could it explain why there is so much space between galaxies, with no outlying stars? If all galaxies were subject to the same type of gravity, wouldn't we expect to find some stars orbiting the galaxies on extremely large elliptical orbits? But if other anti-matter galaxies were pushing away the normal-matter stars, we should expect the galaxies to cluster more, the way they actually do.

    # Assuming (for the sake of symmetry) that the universe started off with equal quantities of matter and anti-matter in a small area, one would assume that if there was no repelling force between matter and anti-matter, the vast bulk of matter and anti-matter would have collided into each other and wiped each other out, and there'd be prety much nothing left. But if a repelling force was present, a lot less of the original mass would be eliminated.

    # Could the repulsion between matter and anti-matter help explain why the universe started expanding in the first place?

    The key reason for posting this is to find out whether there is any obvious reason why this idea must be wrong. I'd really appreciate it if anyone can explain in simple language why I must be wrong to speculate that matter might repel anti-matter through the exchange of gravitons (from matter) and anti-gravitons (from anti-matter).

    Some ideas I've had as to how this may be disproved are as follows:

    * I know that physicists have created anti-matter in particle-accelerators. Given the huge electrical forces that they've injecting into those underground doughnuts, is there any way that they can tell how the anti-particles are effected by gravity? Has this observation been made?

    * If some galaxies are composed of matter, and some are composed of anti-matter, then presumably (apart from the general expansion of the universe), there would be an effect whereby some galaxies (same type) are starting to slide towards or even orbit each other, whereas other galaxies would be trying to slide away from each other. Has anything like this been observed?

    * If an anti-matter galaxy was in the vicinity of a matter galaxy, might that affect the shape of the matter galaxy? i.e. Would the repelling force from one galaxy affect the orbits of stars around the other galaxy?

    I'd really appreciate it if anyone can tell me if I'm making some obvious mistake, in language that I, as a non-physicist, can understand.

    cheers

    Nicholas
     
    Last edited: Mar 7, 2009
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