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Topic: "God particle" close at hand?
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Boom Boom
rabble-rouser
Babbler # 7791
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posted 08 April 2008 12:43 PM
At 78, scientist hopes for proof soon that he was right about the Universeexcerpt: The Higgs boson was the professor’s elegant 1964 solution to one of the great problems with the standard model of physics – how matter has mass and thus exists in a form that allows it to make stars, planets and people. He proposed that the universe is pervaded by an invisible field of bosons that consist of mass but little else. As particles move through this field, bosons effectively stick to some of them, making them more massive, while leaving others to pass unhindered. Photons, light particles that have no mass, are not affected by the Higgs field at all. The mysterious boson postulated by Professor Higgs, of the University of Edinburgh, has become so fundamental to physics that it is often nicknamed the “God particle”. After more than 40 years of research, and billions of pounds, scientists have yet to prove that it is real. But Professor Higgs, 78, now believes the search is nearly over. A new atom-smasher that will be switched on near Geneva later this year is virtually guaranteed to find it, he said. It is even possible that the critical evidence already exists, in data from an American experiment in Illinois that has yet to be analysed fully.
From: Make the rich pay! | Registered: Dec 2004
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500_Apples
rabble-rouser
Babbler # 12684
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posted 08 April 2008 06:04 PM
quote: Originally posted by jrootham: No, I don't expect there to be a disaster. However, I don't think I'd be quite as sanguine about black holes as all that. The evaporation part is good, and a good thing too. The gravity gradient around a black hole would seem to make it very unlikely that it would be quite as non interacting as neutrinos.What happens if the black hole takes up an orbit that intersects the earth and gathers mass on its journey?
jrootham, First of all, "gravity gradients" don't matter, all that matters is gravity. The popular media teaches that black holes are vacuum cleaners, but that's false. If the sun collapsed into a black hole tomorrow, the Earth would keep rotating around the sun in exactly the same manner, however it would freeze due to lack of sunshine. A mini black hole would not weigh as much as the sun. It would not weight a gram. It would, due to the energies involved at the LHC, it would weigh around 0.00000000001 grams (that number of zeros). As gravity is the weakest force that would not matter. Does dust fall on you (70, 000 grams) because of your gravity? No. Molecules don't care about gravity, they only care about electricity and magnetism, gravity is so much weaker that theorists don't bother to include gravity in their calculations, and they still get the right answer to the limit of experimental precision (12 significant figures). Neutrinos actually don't interact with the Earth because of gravity, but because of the weak nuclear force, which is much stronger than gravity. A mini black hole would only interact due to the gravity of 0.00000000001 grams, and would as such be non-interacting. ETA: It can't take up an orbit and intersect the Earth. Everything produced at the LHC will be going at 99.99...% the speed of light. That's way beyond the Earth's and the Sun's escape velocity. [ 08 April 2008: Message edited by: 500_Apples ]
From: Montreal, Quebec | Registered: Jun 2006
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Agent 204
rabble-rouser
Babbler # 4668
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posted 08 April 2008 06:13 PM
That's the big question, isn't it? The main argument in favour of the safety of these experiments is that the energies produced is less than the amount of energy produced when certain cosmic rays strike the upper atmosphere, and these cosmic ray collisions happen all the time but the Earth is still here. For this to go wrong, three things would have to happen:1. A micro black hole (or something else equally dangerous- see below) would have to be produced by the collision. 2. The micro black hole produced would be moving much slower than the colliding particles (possible in a head on collision) so that its velocity is less than the escape velocity of the Earth, AND 3. Black hole evaporation, as predicted by Hawking, either does not happen or happens slower than he predicts- slowly enough that the black hole would acrete more mass than it loses through evaporation. Now 3 is perfectly plausible (the basis for Hawking radiation is entirely theoretical at this point, though the idea seems sound enough)... except that given the number of cosmic ray collisions with the upper atmosphere that have occurred it seems unlikely to me that the situation described in 2 would not have occurred at some point- unless the black holes never appeared in the first place. Another nasty scenario has been raised- the creation of a stable strangelet which could cause matter it contacts to also turn into strangelets. Again, the risk of this seems low, though a caveat exists in that most models for cosmic ray collisions producing strangelets involve positively charged ones which (it is hoped) would be prevented from colliding with nuclei by repulsion, but that some particle accelerator experiments might produce negatively charged strangelets, with drastically different results. In any case, apparently no evidence of strangelets has been found in either accelerators or cosmic ray collisions, so I'm not too worried about this.
From: home of the Guess Who | Registered: Nov 2003
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500_Apples
rabble-rouser
Babbler # 12684
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posted 08 April 2008 06:30 PM
quote: Originally posted by Proaxiom:
As a non-expert who reads some science blogs, I have been led to think that the hypothesis that a micro black hole could possibly be created by such an experiment is strongly linked to the hypothesis that Hawking radiation exists, and therefore we are likely to get both or neither, which makes us safe either way.
Hawking radiation is standard physics, quantum mechanics and stat mech and GR. Mini black holes are General Relativity... but not at these energies. There's an estimated 10% chance of seeing them if theories of extra dimensions are true. ETA: you can still get mini black holes from particles accelerators in known rather than speculative physics, but you'd need much, much, much higher energies than 7 Terra-ElectronVolts. [ 08 April 2008: Message edited by: 500_Apples ]
From: Montreal, Quebec | Registered: Jun 2006
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