谢谢两位评论。作者: 晨思 时间: 2008-9-8 23:02 今天的新闻，晴山讲起过的。Glad to hear that we are not doomed from the experiment, phew!
CERN fires up new atom smasher to near Big Bang
GENEVA - It has been called an Alice in Wonderland investigation into the makeup of the universe — or dangerous tampering with nature that could spell doomsday.
Whatever the case, the most powerful atom-smasher ever built comes online Wednesday, eagerly anticipated by scientists worldwide who have awaited this moment for two decades.
The multibillion-dollar Large Hadron Collider will explore the tiniest particles and come ever closer to re-enacting the big bang, the theory that a colossal explosion created the universe.
The machine at CERN, the European Organization for Nuclear Research, promises scientists a closer look at the makeup of matter, filling in gaps in knowledge or possibly reshaping theories.
The first beams of protons will be fired around the 17-mile tunnel to test the controlling strength of the world's largest superconducting magnets. It will still be about a month before beams traveling in opposite directions are brought together in collisions that some skeptics fear could create micro "black holes" and endanger the planet.
The project has attracted researchers of 80 nationalities, some 1,200 of them from the United States, which contributed $531 million of the project's price tag of nearly $4 billion.
"This only happens once a generation," said Katie Yurkewicz, spokeswoman for the U.S. contingent at the CERN project. "People are certainly very excited."
The collider at Fermilab outside Chicago could beat CERN to some discoveries, but the Geneva equipment, generating seven times more energy than Fermilab, will give it big advantages.
The CERN collider is designed to push the proton beam close to the speed of light, whizzing 11,000 times a second around the tunnel 150 to 500 feet under the bucolic countryside on the French-Swiss border.
Once the beam is successfully fired counterclockwise, a clockwise test will follow. Then the scientists will aim the beams at each other so that protons collide, shattering into fragments and releasing energy under the gaze of detectors filling cathedral-sized caverns at points along the tunnel.
CERN dismisses the risk of micro black holes, subatomic versions of collapsed stars whose gravity is so strong they can suck in planets and other stars.
But the skeptics have filed suit in U.S. District Court in Hawaii and in the European Court of Human Rights to stop the project. They unsuccessfully mounted a similar action in 1999 to block the Relativistic Heavy Ion Collider at the Brookhaven National Laboratory in New York state.
CERN's collider has been under construction since 2003, financed mostly by its 20 European member states. The United States and Japan are major contributors with observer status in CERN.
Scientists started colliding subatomic particles decades ago. As the machines grew more powerful, the experiments revealed that protons and neutrons — previously thought to be the smallest components of an atom — were made of still smaller quarks and gluons.
CERN hopes to recreate conditions in the laboratory a split-second after the big bang, teaching them more about "dark matter," antimatter and possibly hidden dimensions of space and time.
Meanwhile, scientists have found innovative ways to explain the concept in layman's terms.
The team working on one of the four major installations in the tunnel — the ALICE, or "A Large Ion Collider Experiment" — produced a comic book featuring Carlo the physicist and a girl called Alice to explain the machine's investigation of matter a split second after the Big Bang.
"We create mini Big Bangs by bumping two nuclei into each other," Carlo explains to Alice, who has just followed a rabbit down one of the hole-like shafts at CERN.
"This releases an enormous amount of energy that liberates thousands of quarks and gluons normally imprisoned inside the nucleus. Quarks and gluons then form a kind of thick soup that we call the quark-gluon plasma."
The soup cools quickly and the quarks and gluons stick together to form protons and neutrons, the building blocks of matter.
That will enable scientists to look for still missing pieces to the puzzle — or lead to the formulation of a new theory on the makeup of matter.
Kate McAlpine, 23, a Michigan State University graduate at CERN, has produced the Large Hadron Rap, a video clip that has attracted more than a million views on YouTube.
"The things that it discovers will rock you in the head," McAlpine raps as she dances in the tunnel and caverns.
CERN spokesman James Gillies said the lyrics are "absolutely scientifically spot on."
"It's quite brilliant," Gillies said.
Apocalypse Not: Atom-smasher won't doom planet, says study
PARIS (AFP) - People who fear a powerful atom-smashing machine, due to start operations next Wednesday, will cause Earth to be gobbled up or reduced to grey goo can rest assured, according to a study released Friday.
The Large Hadron Collider (LHC) has been shadowed by Internet-fuelled concerns that it will release energies so powerful that it will create a runaway black hole that will engulf the planet, or a "strangelet" particle that would transform Earth into a lump of strange matter.
But the new report says these fears are unfounded.
It says the LHC will replicate collisions that already occur naturally when Earth runs into the path of high-energy cosmic rays.
"Nature has already conducted the equivalent of about a hundred thousand LHC experimental programmes on Earth -- and the planet still exists," it says.
The assessment is written by five physicists at LHC's operator, the European Organisation for Nuclear Research (CERN) in Geneva.
They had been asked by CERN to take a fresh look at a safety assessment written by CERN scientists in 2003 that also gave the project the green light.
The LHC, installed in a 27-kilometre (16.9-mile) tunnel on the French-Swiss border, is to start unleashing a beam of protons next Wednesday in the first stage of its commissioning process.
Two parallel beams of particles, one going clockwise and the other anti-clockwise, will blast around the underground ring.
At four locations on the ring, superconducting magnets will bend the beams so that groups of protons smash into each other in a giant chamber which is swathed with detectors to record the resulting sub-atomic debris.
This invisible rubble could help resolve some of the biggest questions in physics, such as the nature of mass, the weakness of gravity and whether, as some theoreticians suggest, there exist dimensions beyond our own.
The new Safety Assessment Report says that any black holes produced by the collider would be "microscopic" and decay almost immediately, as they would lack the energy to grow or even be sustained.
"Each collision of a pair of protons in the LHC will release an amount of energy comparable to that of two colliding mosquitoes, so any black hole produced would be much smaller than those known to astrophysicists," it says.
As for the hypothesised "strangelets," the report referred to data from the Relativistic Heavy-Ion Collider at the Brookhaven National Laboratory in New York to say that these would not be produced during collisions in the LHC.
The review is published in a journal of the Institute of Physics, London.
France has also asked a French watchdog agency, the Nuclear Safety Authority (ASN), to carry out a safety appraisal of the LHC.
On August 29, the European Court of Human Rights, based in Strasbourg, France, tossed out a last-ditch legal bid to stop the LHC's switch-on.
The suit had been filed by a group of European citizens, led by a German biochemist, Otto Roessler, of the University of Tuebingen.作者: 晴山 时间: 2008-9-9 07:49 呵呵，不就是明天？老天保佑，愿我们还有the day after tomorrow
写"达芬奇密码”的Dan Brown有另一部小说叫天使和魔鬼“Angels & Demons ” ，就是把欧洲粒子研究机构CERN拖进了一场决定天主教庭命运的生死斗，不光其反物质（antimatter）研究成果为阴谋所用，连CERN主任都成了阴谋中的重要角色，我觉得比达芬奇密码要有趣和可读得多了
