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Javier E

Finding the Higgs Leads to More Puzzles - NYTimes.com - 0 views

www.nytimes.com/...ggs-leads-to-more-puzzles.html

physics higgs boson science supersymmetry multiverse

shared by Javier E on 08 Nov 13 - No Cached
  • Taken at face value, the result implies that eventually (in 10^100 years or so) an unlucky quantum fluctuation will produce a bubble of a different vacuum, which will then expand at the speed of light, destroying everything.”
  • The idea is that the Higgs field could someday twitch and drop to a lower energy state, like water freezing into ice, thereby obliterating the workings of reality as we know it. Naturally, we would have no warning. Just blink and it’s over.
  • . You might think that finding the Higgs boson, after 50 years and $10 billion or so, would bring clarity to physics and to the cosmos. But just the opposite is true: they may have found the Higgs boson, but they don’t understand it.
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  • they don’t understand why it weighs what it does — it is about 125 times as massive as the protons that were collided to make it, not gazillions of times as heavy, as standard quantum mechanical calculations would suggest.
  • For years the preferred solution to this conundrum has been a theory called supersymmetry, which, among other things, predicted the existence of a whole new spectrum of particles, superpartners of the ones we already know, that would cancel out the quantum calculations and keep the Higgs light. One of these particles might also be the dark matter that makes up a quarter of the universe by weight.
  • experiments at CERN’s Large Hadron Collider have already eliminated the simplest versions of supersymmetry.
  • The most talked-about alternative to supersymmetry is the idea of the multiverse, an almost infinite ensemble of universes in which the value of the Higgs — as well as many other crucial parameters — is random. We just happen to live in the one in which the conditions and parameters are fit for us. This is a notion that flows naturally from string theory and modern theories of the Big Bang, but accepting multiple universes means giving up the Einsteinian dream of a single explanation for the cosmos, a painful concession.
  • “Physical science has historically progressed not only by finding precise explanations of natural phenomena, but also by discovering what sorts of things can be precisely explained. These may be fewer than we had thought.”
Javier E

All Signs Point to Higgs Boson, but Still Waiting for Scientific Certainty - NYTimes.com - 1 views

www.nytimes.com/...-for-scientific-certainty.html

higgs boson universe physics prediction

shared by Javier E on 10 Mar 13 - No Cached
  • physicists admit that it will take more work and analysis before they will have the cold numbers that clinch the case that the new particle announced on July 4 last year is in fact the exact boson first predicted by Peter Higgs and others in 1964 to be the arbiter of mass and cosmic diversity
  • What happened in the first instant of the Big Bang? What happens at the middle of a black hole where matter and time blink in or out of existence? What is the dark matter whose gravitational influence, astronomers say, shapes the structures of galaxies, or the dark energy that is forcing the universe apart? Why is the universe full of matter but not antimatter? And what, finally, is the fate of the universe? These are all questions that the Standard Model, the vanilla-sounding set of equations that ruled physics for the last half century, does not answer
  • Some of them could be answered by the unproven theory called supersymmetry, which among other things is needed to explain why whatever mass the Higgs has is low enough to be discovered in the first place and not almost infinite. It predicts a whole new population of elementary particles — called superpartners to the particles physicists already know about — one of which could be the dark matter that pervades the universe. If such particles exist, they would affect the rate at which Higgs bosons decay into other particles, but the CERN teams have yet to record what they consider a convincing deviation from the Standard Model predictions for those decays. Supersymmetry is still at best a beautiful idea.
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  • One thing that has hampered progress is that physicists still do not agree on how much the new particle weighs.
  • What does it matter how much a Higgs boson weighs? It could determine the fate of the universe.
  • his colleagues ran the numbers and concluded that the universe was in a precarious condition and could be prone to collapse in the far, far future. The reason lies in the Higgs field, the medium of which the Higgs boson is the messenger and which determines the structure of empty space, i.e., the vacuum.
  • It works like this. The Higgs field, like everything else in nature, is lazy, and, like water running downhill, always seeks to be in the state of lowest energy. Physicists assume that the Higgs field today is in the lowest state possible, but Dr. Giudice found that was not the case. What counts as rock bottom in today’s universe could turn out to be just a plateau. Our universe is like a rock perched precariously on a mountaintop, he explained, in what physicists call a metastable state. The Higgs field could drop to a lower value by a process known as quantum tunneling, although it is not imminent.
  • If that should happen — tomorrow or billions of years from now — a bubble would sweep out through the universe at the speed of light, obliterating the laws of nature as we know them.
  • The calculations assume that the Standard Model is the final word in physics, good for all times and places and energies — something that no physicist really believes. Theories like supersymmetry or string theory could intercede at higher energies and change the outcome.
  • The calculations also depend crucially on the mass of the top quark, the heaviest known elementary particle, as well as the Higgs, neither of which have been weighed precisely enough yet to determine the fate of the universe. If the top quark were just a little lighter or the Higgs a little heavier, 130 billion electron volts, Dr. Giudice said, the vacuum would in fact be stable.
  • , “Why do we happen to live at the edge of collapse?” He went on, “In my view, the message about near-criticality of the universe is the most important thing we have learned from the discovery of the Higgs boson so far.” Guido Tonelli of CERN and the University of Pisa, said, “If true, it is somehow magic.” We wouldn’t be having this discussion, he said, if there hadn’t been enough time already for this universe to produce galaxies, stars, planets and “human beings who are attempting to produce a vision of the world,” he said.
  • “So, in some sense, we are here, because we have been lucky, because for this particular universe the lottery produced a certain set of numbers, which allow the universe to have an evolution, which is very long.”
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