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Science Technology

RHIC Finds Symmetry Transformations In Quark Soup 140

eldavojohn writes "Today scientists at the Relativistic Heavy Ion Collider (RHIC) in Brookhaven National Laboratory revealed new observations after creating a 'quark soup' that revealed hints of profound symmetry transformations when collisions create conditions in which temperatures reach four trillion degrees Celsius. A researcher explains the implications, 'RHIC's collisions of heavy nuclei at nearly light speed are designed to re-create, on a tiny scale, the conditions of the early universe. These new results thus suggest that RHIC may have a unique opportunity to test in the laboratory some crucial features of symmetry-altering bubbles speculated to have played important roles in the evolution of the infant universe.' These new findings hint at violations of mirror symmetry or parity by witnessing asymmetric charge separation in these collisions."
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RHIC Finds Symmetry Transformations In Quark Soup

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  • by chrylis ( 262281 ) on Monday February 15, 2010 @03:04PM (#31147068)

    I'm not currently a research physicist, but I'm a (prior) collaborator on the experiment in question.

    No "strangelet" has ever been observed, and their behavior depends on certain parameters that are unknown... because they've never been observed. It's reasonable to guess at this point that the strangelet-eats-the-world scenario is probably bogus just due to the anthropic principle.

    The concern over the eating-the-world scenario was allayed to physicists' satisfaction based on calculations about cosmic rays. The kinds of collisions that would produce strangelets happen constantly to the moon because of the lack of an atmosphere or magnetic field to shield it, and the moon's still there. Statistics suggest, therefore, that these particular concerns are unlikely to be realized.

  • by mhajicek ( 1582795 ) on Monday February 15, 2010 @03:12PM (#31147160)

    And don't tell me that Nature regularly collides gold nuclei together in this fashion; they're not cosmic rays!

    Consider the particle collisions near the event horizon of a black hole; they're likely to occur at much higher energies.

    "Energies at the Large Hadron Collider are likely to peak at 14 teraelectronvolts. In contrast, the energies around a black hole would theoretically be limitless, says West. However, you needn't go beyond the so-called "Planck energy" - the point at which our mathematical understanding of particle interactions, in particular gravity, breaks down at the quantum level. This energy is in the order of 1018 gigaelectronvolts - 100 trillion times more energetic than the LHC." - []

  • Re:Relativism (Score:5, Informative)

    by mrsquid0 ( 1335303 ) on Monday February 15, 2010 @03:37PM (#31147508) Homepage

    The Planck temperature is the highest temperature that our current physics can work at. Temperatures higher than the Planck temperature require a theory of quantum gravity to understand. The Planck temperature is about 1.4e+32 kelvin. One day, when we have a working theory of quantum gravity, perhaps the maximum possible temperature will be higher, but until then this is the highest temperature that is possible assuming the laws of physics that we know about.

  • Re:Pedantic (Score:4, Informative)

    by Khashishi ( 775369 ) on Monday February 15, 2010 @03:44PM (#31147586) Journal

    Usually, in high energy physics, temperature is given in units of electron volts. One electron volt ~= 11600 Kelvin.
    So this would be written, 0.4 GeV. Which is still extremely hot.

  • Quark-gluon plasma (Score:4, Informative)

    by Rising Ape ( 1620461 ) on Monday February 15, 2010 @05:13PM (#31148656)

    The Higgs mechanism is often talked about as the source of mass, but what's less well publicised is that it's the dynamics of QCD (the strong interaction) that are responsible for the majority of the mass of ordinary matter, by a similar mechanism. Essentially, the vacuum isn't empty because the empty state isn't the lowest energy state - that requires a non-zero Higgs field and a non-zero quark condensate (from QCD).

    The consequences of this are that particles behave as though they have mass when fundamentally they don't - they just behave that way because of their interactions with the background fields. If you excite the system to a high enough temperature though, there's a phase transition to the "free" state in a manner crudely analogous to boiling of a liquid releasing the confinement of adjacent molecules so they behave freely. In the QCD case, this temperature is low enough to be probed by experiments (not so much the electroweak/Higgs case), so we get free, low-mass quarks.

  • Re:Well, duh (Score:3, Informative)

    by JoshuaZ ( 1134087 ) on Monday February 15, 2010 @07:28PM (#31150260) Homepage
    No multiple problems with that. For example, if the inflationary hypothesis is correct or some variant thereof then the universe is much larger than the observable universe so we might not just see the border areas. Also, matter is sufficiently spread out that this late in the universe serious collisions between the two would be rare, so as long as separate galaxies are either matter or anti-matter, we would see very little evidence of it. There are, as I understand it, more subtle ideas that suggest a true symmetry break, having to do with models of particle formation in the very early universe. Essentially, our universe looks a lot more like what one expects from a symmetry break than from a big chunk model. But I don't know enough to say anything in detail about what those differences are.
  • by Pictish Prince ( 988570 ) <> on Monday February 15, 2010 @10:01PM (#31151322) Journal

    How do we know other galaxies and stars are not anti-matter. It's not like we can touch them and find out. Would it not be likely that thermal explosions could have sorted the two into far flung clumps in the early days of the universe. Interactions might not be observed if all of the clumps are already flying away from each other.

    The only way to tell matter from anti-matter at a distance is to observe their neutrino emissions. Anti-matter objects will preferentially emit neutrinos in the direction of spin of the baryons (the majority of which spin in the same direction as the containing object assuming a magnetic field.) while matter objects will emit them preferentially in the opposite direction.

The only perfect science is hind-sight.