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Space Science

X Particle Might Explain Dark Matter & Antimatter 285

cold fjord writes "Wired Science has a story on a new theory that tries to explain dark matter, and the balance of regular matter with antimatter. This theory may even be testable. From the article: 'A new hypothetical particle could solve two cosmic mysteries at once: what dark matter is made of, and why there's enough matter for us to exist at all."
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X Particle Might Explain Dark Matter & Antimatter

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  • Who cares (Score:0, Interesting)

    by Anonymous Coward on Wednesday December 08, 2010 @11:08PM (#34496578)

    Scientists haven't grasped anything new in physics since Einstein. They still think the speed of light is the fastest speed in the Universe. And the wave-particle is the only force in the Universe.

    I'm getting tired of them naming things after their ignorance. "Dark Matter". "Black Hole". "X Particle". Maybe they can call the next theory "WTF" to top it all off.

  • Kindof Summary (Score:4, Interesting)

    by cosm ( 1072588 ) <thecosm3NO@SPAMgmail.com> on Wednesday December 08, 2010 @11:36PM (#34496738)
    Alright, so IANAPP, but, FTA:

    Equal amounts of X and anti-X were created in the Big Bang, and then decayed to lighter particles. Each X decayed into either a neutron or two dark-matter particles, called Y and . Every anti-X converted to an anti-neutron or some anti-dark matter.

    But the hypothetical X particle would rather decay into ordinary matter than dark matter, so it produced more neutrons than dark matter. Anti-X preferred decaying into anti-dark matter, and so produced more of it.

    Bold emphasis added is mine. Does this theory explain why "particle X" would rather decay into ordinary matter? Isn't that begging the question? How is that any different than moving to the larger set of all mass, and just saying "Hypothetical universe X would rather form more ordinary matter than dark matter". I understand they may be foregoing the DiffyQ's that perhaps stand behind their assertions for the word "rather" to provide for the layman, but this premise kills the theory for me unless there exist math/science/evidence/a reason besides the word "rather for this article.

  • by hedwards ( 940851 ) on Wednesday December 08, 2010 @11:51PM (#34496812)
    Which ones specifically? In fact, I challenge you to name even one theory that isn't testable. And String theory doesn't count. It's about as scientific as Astrology.
  • Re:Who cares (Score:5, Interesting)

    by Chris Burke ( 6130 ) on Thursday December 09, 2010 @02:49PM (#34504618) Homepage

    In relativity nothing can travel beyond light speed because that would imply an infinite energy,

    Not exactly. In Relativity nothing with rest mass can travel at the speed of light because that would imply infinite energy.

    Nothing at all, not even information, can travel faster than light because that implies that you could create scenarios where from certain reference frames, effects appear to happen before causes. As in time travel, or causality violation, and both Relativity theories (and the rest of physics) assumes causality to hold.

    Ten years after Einstein's death we discovered a universal velocity reference in the microwave background dipole, so one of the main tenets of special relativity is not true anymore.

    Not true. All Special Relativity says is that there is no preferred reference frame, as in the laws of physics must appear to hold true according to every observer. There is not one "special" reference frame where causality only needs to hold for it.

    There was never anything in Relativity saying that there couldn't be some convenient reference against which to measure your velocity. Which is all the CMB dipole really is, and in the sense of what it implies for Relativity is no different than arbitrarily deciding the Andromeda Galaxy is our reference.

    I believe the future lies in information theory.

    The present and recent past lies is information theory. Information theory, which arose from QM, is fundamental to explaining many situations encountered today, like limits on the efficiency of irreversible calculations or the decay rate of black holes. However there is nothing in Information Theory that suggests information can travel faster than light. Indeed, quite the opposite, and this limit is key to understanding things like quantum entanglement and why it cannot be used for information transfer.

    Assuming observable events happen in the universe, and assuming that causality exists, i.e. that if some event causes another that relation will exist under all circumstances, then we can think on how information about different events is transported through the universe. Again, this would be a truly absolute limit, not one imposed by our limitations in measuring and calculation.

    That's pretty much how it's already done -- assume causality holds for all reference frames, and you can see that information cannot travel faster than light.

    However at the end of the day no matter how elegant a mathematical model you have constructed, there are going to be variables whose values in our universe must be determined experimentally. Like c. You can get c via direct measurement, you can calculate it based on other constants which must themselves be measured. Either way.

    Yet as our measurements get more precise, the values for these constants becomes more precise, and doesn't suddenly change values to something outside the error bars on previous less precise measurements. We're still depending on measurement, but we aren't going to up-end physical theories at some point when we hit the 32nd digit of c and suddenly nothing works.

    This only seems like a problem if it bothers you for some reason that you can't derive all physical constants from a mathematical model, and instead the only way to know what values to place in that model of the universe is by actually looking at the universe.

If a thing's worth having, it's worth cheating for. -- W.C. Fields