Joined: 29 Aug 05
MEYRIN, Switzerland (AP) -- The most powerful atom-smasher ever built could make some bizarre discoveries, such as invisible matter or extra dimensions in space, after it is switched on in August.
But some critics fear the Large Hadron Collider could exceed physicists' wildest conjectures: Will it spawn a black hole that could swallow Earth?
Or spit out particles that could turn the planet into a hot dead clump?
Ridiculous, say scientists at the European Organization for Nuclear Research, known by its French initials CERN -- some of whom have been working for a generation on the $5.8 billion collider, or LHC.
"Obviously, the world will not end when the LHC switches on," said project leader Lyn Evans.
David Francis, a physicist on the collider's huge ATLAS particle detector, smiled when asked whether he worried about black holes and hypothetical killer particles known as strangelets.
"If I thought that this was going to happen, I would be well away from here," he said.
The collider basically consists of a ring of supercooled magnets 17 miles in circumference attached to huge barrel-shaped detectors. The ring, which straddles the French and Swiss border, is buried 330 feet underground.
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The machine, which has been called the largest scientific experiment in history, isn't expected to begin test runs until August, and ramping up to full power could take months. But once it is working, it is expected to produce some startling findings.
Scientists plan to hunt for signs of the invisible "dark matter" and "dark energy" that make up more than 96 percent of the universe, and hope to glimpse the elusive Higgs boson, a so-far undiscovered particle thought to give matter its mass.
The collider could find evidence of extra dimensions, a boon for superstring theory, which holds that quarks, the particles that make up atoms, are infinitesimal vibrating strings.
The theory could resolve many of physics' unanswered questions, but requires about 10 dimensions -- far more than the three spatial dimensions our senses experience.
The safety of the collider, which will generate energies seven times higher than its most powerful rival, at Fermilab near Chicago, has been debated for years. The physicist Martin Rees has estimated the chance of an accelerator producing a global catastrophe at one in 50 million -- long odds, to be sure, but about the same as winning some lotteries.
By contrast, a CERN team this month issued a report concluding that there is "no conceivable danger" of a cataclysmic event. The report essentially confirmed the findings of a 2003 CERN safety report, and a panel of five prominent scientists not affiliated with CERN, including one Nobel laureate, endorsed its conclusions.
Critics of the LHC filed a lawsuit in a Hawaiian court in March seeking to block its startup, alleging that there was "a significant risk that ... operation of the Collider may have unintended consequences which could ultimately result in the destruction of our planet."
One of the plaintiffs, Walter L. Wagner, a physicist and lawyer, said Wednesday CERN's safety report, released June 20, "has several major flaws," and his views on the risks of using the particle accelerator had not changed.
On Tuesday, U.S. Justice Department lawyers representing the Department of Energy and the National Science Foundation filed a motion to dismiss the case.
The two agencies have contributed $531 million to building the collider, and the NSF has agreed to pay $87 million of its annual operating costs. Hundreds of American scientists will participate in the research.
The lawyers called the plaintiffs' allegations "extraordinarily speculative," and said "there is no basis for any conceivable threat" from black holes or other objects the LHC might produce. A hearing on the motion is expected in late July or August.
In rebutting doomsday scenarios, CERN scientists point out that cosmic rays have been bombarding the earth, and triggering collisions similar to those planned for the collider, since the solar system formed 4.5 billion years ago.
And so far, Earth has survived.
"The LHC is only going to reproduce what nature does every second, what it has been doing for billions of years," said John Ellis, a British theoretical physicist at CERN.
Critics like Wagner have said the collisions caused by accelerators could be more hazardous than those of cosmic rays.
Both may produce micro black holes, subatomic versions of cosmic black holes -- collapsed stars whose gravity fields are so powerful that they can suck in planets and other stars.
But micro black holes produced by cosmic ray collisions would likely be traveling so fast they would pass harmlessly through the earth.
Micro black holes produced by a collider, the skeptics theorize, would move more slowly and might be trapped inside the earth's gravitational field -- and eventually threaten the planet.
Ellis said doomsayers assume that the collider will create micro black holes in the first place, which he called unlikely. And even if they appeared, he said, they would instantly evaporate, as predicted by the British physicist Stephen Hawking.
As for strangelets, CERN scientists point out that they have never been proven to exist. They said that even if these particles formed inside the Collider they would quickly break down.
When the LHC is finally at full power, two beams of protons will race around the huge ring 11,000 times a second in opposite directions. They will travel in two tubes about the width of fire hoses, speeding through a vacuum that is colder and emptier than outer space.
Their trajectory will be curved by supercooled magnets -- to guide the beams around the rings and prevent the packets of protons from cutting through the surrounding magnets like a blowtorch.
The paths of these beams will cross, and a few of the protons in them will collide, at a series of cylindrical detectors along the ring. The two largest detectors are essentially huge digital cameras, each weighing thousands of tons, capable of taking millions of snapshots a second.
Each year the detectors will generate 15 petabytes of data, the equivalent of a stack of CDs 12 miles tall. The data will require a high speed global network of computers for analysis.
Wagner and others filed a lawsuit to halt operation of the Relativistic Heavy Ion Collider, or RHIC, at the Brookhaven National Laboratory in New York state in 1999. The courts dismissed the suit.
The leafy campus of CERN, a short drive from the shores of Lake Geneva, hardly seems like ground zero for doomsday. And locals don't seem overly concerned. Thousands attended an open house here this spring.
"There is a huge army of scientists who know what they are talking about and are sleeping quite soundly as far as concerns the LHC," said project leader Evans.
Joined: 30 Aug 05
in case you missed this, some exciting science news from Large Hadron Collider (LHC)
get ready for september 10th 2008 - cern announces LHC switch on
It's official, the Large Hadron Collider (LHC) will begin operations in a little over a month. On September 10th, 2008 the most sophisticated particle accelerator will go online, injecting the first circulation of accelerated particles. Actual experiments involving collisions will occur once scientists are satisfied the LHC is fully optimized and calibration is complete. The LHC has been undergoing "cool-down" for some time, ensuring the LHC's eight sectors are approaching the 1.9K (-271°C) operational temperature (that is 1.9 degrees
above absolute zero). All going well, on September 10th, the first beam will be accelerated to an energy of 450 GeV (0.45 TeV), the preliminary step on the path to attaining particle energies of 5 TeV, a record breaking target… awesome.
Earlier today, CERN announced that the LHC will be ready by September 10th to attempt to circulate a beam of particles. This news comes as the "cool-down" phase of LHC commissioning reaches a successful conclusion, cooling all eight sectors to 1.9 degrees above absolute zero. To manage temperatures this extreme has been a long and painstaking task, referred to as a "marathon" by the project leader:
"We're finishing a marathon with a sprint. It's been a long haul, and we're all eager to get the LHC research programme underway." - LHC project leader Lyn Evans.
Now scientists and engineers must synchronize the LHC with the Super Proton Synchrotron (SPS) accelerator, which is the last component in the LHC's particle injector chain. For the system to work, the LHC and SPS must be synchronized to within a fraction of a nanosecond. This task is expected to begin on August 9th (Saturday). These calibration tasks are expected to continue through August and into the beginning of September, preparing the LHC for its first particle injection on the 10th.
The LHC will accelerate particles to relativistic velocities, accessing energies previously unimaginable. Once the LHC reaches its optimum design specification (possibly by 2010), it will generate beams seven-times more energetic and 30-times more intense than any other particle accelerator on the planet. The accelerator ring lies below the Swiss countryside with a circumference of 27 km (17 miles).
Joined: 3 Apr 07
My nodes is up and ready...lets do some science!
Joined: 29 Jun 08
My nodes is up and ready...lets do some science!
Once the Large Hadron Collider get running and [hopefully] LHC@Home starts to have work on a consistent basis, I believe that the whole BOINC enterprise will benefit from the interest in basic science that this project will gin up.
I have been collecting information on the LHC and the science involved:
The LHC: Mother of All Science Fair Projects
I hope that this thread will continue to be an interesting resource.
If everyone is thinking alike, someone isn't thinking. - General George Patton
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