The Large Hadron Collider at CERN, by William Haseltine The Large Hadron Collider at CERN, by William Haseltine Published: October 21st, 2013 My friend William Haseltine, one of the great innovators — early identifier of aspects of the AIDS virus, pioneer in researching the human genome, and now bringing low-cost health care to low-income communities globally — reports from his travels from time to time and here is a fascinating account of his visit to CERN — so rare and important to have scientists who can (and just as importantly, will) speak to non-scientists in ways we can understand and that can highlight for us what is important in what we are seeing! — Naomi The Large Hadron Collider at CERN, by William Haseltine While on a visit to Geneva to participate in a conference on Innovation and Science sponsored by the Aspen Institue of Italy, we had the wonderful opportunity to be taken on a guided tour of the large Hadron Collider at CERN. Our guide was the Director of Research Sergio Bertolucci. The Large Hadron collider made headlines last year with the discovery of the Higgs boson, for which the Nobel Prize in Physics was awarded this year. The Higgs boson is what imparts mass to matter. The existence of the particle was hypothesized by Peter Higgs almost 50 years ago. It remained hypothetical until the extremely high energies of made possible by this Collider made the discovery possible. The Large Hadron Collider is one of the great works of humankind. The accelerator itself is 27 kilometers in circumference and cost twelve billion dollars to build and operate over the last ten years. It employs almost three thousand physicists and technicians. The scientists come from more than 100 counties, the majority from the United Staes. Over two thousand PHD students train there at any one time. The Collider is a joint European project. Over twenty nations contribute to the budget. Based at CERN, the European center for high energy physics founded over 60 years ago, the Large Hadron Collider was conceived 30 years ago, approved twenty years ago and construction begun more than ten years ago. The goal of the work is to reveal the fundamental structure of the universe. To do so the instrument accelerates atom nuclei to 99.9999 percent the speed of light, focuses the beams of atoms as they speed around the 70 kilometer long tunnel to a beam less than the diameter of a single hair where there collide. The resultant energies approach those present with less than one millionth of a second after the Big Bang, the origin of the universe. The energies are so high the they create a quark-gluon soup from which the original hydrogen atoms of the universe emerged. Events that occur are recorded by sensitive instruments placed at the intersection of the beams. We visited one such detector called ALICE. ALICE detects events that occur when the nuclei of lead atoms smash into one another. To observe the instrument located in France, (the Collider spans the French Swiss boarder) we first descend 100 meters below ground, enter the 27 kilometer long tunnel and then ascend a platform above the detector. As we visited, the Collider is undergoing renovations that will double the energies achieved. The massive doors of ALICE were open allowing us to peer within and the enormous supercooled magnets surrounding the core. What next? The discovery of the Higgs boson capped almost 100 years of theoretical physics. Predictions about the fundamental nature of mass and energy made over fifty years ago are now confirmed. But much remains to be done. We know two great problems remain unsolved. One theory, Einstein’s general theory of relativity seems to explain all that we have observed about gravity. Another theory, the Standard Model seems to explain most of what we have observed about light and matter. However, they two theories cannot be reconciled. Thus, the most fundamental observable aspects of the universe remain unexplained by theory. One hope is that events that occur at even higher energies may reveal new forces and particles that help resolve this conundrum. However, not many believe that energies achieved with the Large Hadron Collider will be sufficient. Hence plans are afoot to build a much large machine one 100 kilometers in diameter. There are hopes that doubling the energies now underway will address at least on of the two other great mysteries of the universe. Observations based only on the visible matter in galaxies predict that the speed of their rotation will cause them to fly apart and disintegrate, yet obviously they do not. Therefore, physicists and cosmologists postulate the existence of what they call cold dark matter, matter that has enough additional mass to hold galaxies together. However, we cannot see or detect such dark matter, other than though its inferred gravitational effects. Cold dark matter must not interact with light or observable matter other than through the force of gravity. What is surprising is how much such cold dark matter there must be to account for what is observed. To make it all work out cold dark matter must account for twenty three percent of all the mass and energy in the entire universe! Many physicists believe that the particles the comprise cold dark matter will appear in the new set of of collisions made possible by the increased energies of the Large Hadron Collider when it begins operations a year or two from now. The other great problem is that of dark energy. Dark energy is postulated to exist to account for the observation that the universe appears to be expanding at an ever increasing rate. Given the total mass of the universe this is thought to be possible only if the universe is filled with far more energy than we can observe. Again, the total amount of such energy that must exist to account for observations is astounding, some sixty seven per cent of all mass and energy. This means that all we can observe, all that interacts with light (except for gravity) accounts for only about five percent of the mass/energy of our universe. Scientists seem more doubtful that energies achievable by the improved Collider will be sufficient to reveal the nature of dark energy. Again, bigger instruments or cosmological observations may be needed. A vist to the Large Hadron Collider is really a visit to the forefront of our knowledge of our universe. The Large Hadron Collider is a great achievement, a testament to our collective curiosity and an example of what we can achieve at our best when we work together to understand of universe and the fundamental questions of our existence. Please also see Clive Cookson’s recent articles on The Large Hadron Collider. Enjoy the photos. – Bill
Posted on: Mon, 21 Oct 2013 23:59:22 +0000
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