09-09-2008, 07:33 PM
- Join Date
- Aug 2005
-Five facts about CERN's Large Hadron Collider
- Following are five facts about the 10 billion Swiss franc ($9 billion) Large Hadron Collider (LHC), which will smash together particles at close to the speed of light after its start-up on Wednesday at the European Organisation for Nuclear Research (CERN):
* Though built to study the smallest known building blocks of all things -- known as particles -- the LHC is the largest and most complex machine ever made. It has a circumference of 27 km (17 miles) and lies 100 metres (330 feet) under the ground, straddling French and Swiss territory.
* At full power, trillions of protons will race around the LHC accelerator ring 11,245 times a second, travelling at 99.99 percent the speed of light. It is capable of engineering 600 million collisions every second.
* When two beams of protons collide, they will generate temperatures more than 100,000 times hotter than the heart of the sun, concentrated within a miniscule space. Meanwhile, the cooling system that circulates superfluid helium around the LHC's accelerator ring keeps the machine at minus 271.3 degrees Celsius (minus 456.34 degrees Fahrenheit).
* To collect data of up to 600 million proton collisions per second, physicists and scientists have built devices to measure the passage time of a particle to a few billionths of a second. The trigger system also registers the location of particles to millionths of a metre.
* The data recorded by the LHC's big experiments will fill around 100,000 dual-layer DVDs each year. Tens of thousands of computers around the world have been harnessed in a computing network called "The Grid" that will hold the information.
SonnabendGuest09-10-2008, 06:02 AM
We are still here.
The world did not come to an end.
The doomsayers and panic merchants are hereby invited to go play in the traffic.
09-10-2008, 11:34 AM
It was just a test.
We don't have to worry for a few more weeks until they start their Frankenstein like experiments.
If I die, I don't care. I'm sick as a dog all the time anyways (many health problems).
At Coretta Scott King's funeral in early 2006, Ethel Kennedy, the widow of Robert Kennedy, leaned over to him and whispered, "The torch is being passed to you." "A chill went up my spine," Obama told an aide. (Newsweek)
09-10-2008, 11:55 AM
Q&A: The Big Bang Machine
NPR.org, September 9, 2008 · Physicists threw the switch Wednesday on what is arguably the most powerful and most complex science experiment ever conducted.
It's an underground ring of superconducting magnets, reaching from Switzerland into France, that will smash together subatomic particles with terrifying force.
For the next month, scientists will be testing the ability to send beams of protons around the 17-mile tunnel at the international CERN laboratory. The Large Hadron Collider will push these proton beams close to the speed of light.
The first actual collisions may begin in about a month, when proton beams traveling in opposite directions are brought together.
When the experiment is fully operational, collisions will occur 600 million times every second, producing a spray of subatomic debris. Scientists hope this debris will resemble conditions close to those just after the big bang, the theorized colossal explosion that created the universe.
Somewhere in that subatomic smashup haystack, physicists may find the following needles:
The Hypothetical Higgs Particle
What do we think it does?
It gives things mass. The Higgs particle, named after physicist Peter Higgs, would be a companion to an (also hypothetical) Higgs "field." The field would pervade the universe and act like cosmic molasses, making everything hard to move. That's what we call mass.
Why do we need it?
Without the Higgs particle, electrons would have no mass and atoms wouldn't stick together. We would fall apart into piles of atomic nuclei.
How likely is it that it's real?
High. Physicists generally agree the Higgs or something like it must exist.
How hard would it be to find?
It depends on the Higgs particle's characteristics. Scientists think the Higgs doesn't live long and quickly decays into other particles. Depending on what those are, physicists might be able to pick out Higgs fingerprints quickly, or it could take years of sifting through data.
What is it?
Dark matter is the name given to the mysterious invisible material that seems to hang around galaxies. Estimates are that 20 percent of the stuff in the universe is dark matter. Astronomers call it dark because they can't see it.
If it's invisible, how do you find it?
You don't — or at least not directly. If the LHC makes dark matter particles, they will escape without leaving a trace. But physicists are prepared. They should be able to notice its absence.
What is the likelihood it will appear?
Unclear. Many physicists believe that dark matter particles are part of a whole family of new particles. This theory, known as Supersymmetry (SUSY), says that every known particle has a heavier sibling. The problem is, no one has ever observed one of these hefty partners.
Miniature Black Holes
What are they?
Teeny, tiny, superdense objects.
Should I be worried?
No, they wouldn't live long. Estimates are a thousandth of a trillionth of a trillionth of a second.
How do you detect one?
A miniature black hole would collapse and can create all particle types that exist.
What is the likelihood mini black holes really will appear?
Physicists agree they're a long shot. Miniature black holes appear in some theories that say there are extra, tiny dimensions to space-time. And while the idea of extra dimensions is popular — as part of something called string theory for instance — they don't necessarily allow for mini black holes.
http://www.npr.org/templates/story/s...oryId=94422852At Coretta Scott King's funeral in early 2006, Ethel Kennedy, the widow of Robert Kennedy, leaned over to him and whispered, "The torch is being passed to you." "A chill went up my spine," Obama told an aide. (Newsweek)
09-10-2008, 11:59 AM
- Join Date
- Aug 2005
Stephen Hawking: Large Hadron Collider vital for humanity
Prof Hawking said the £4.4bn machine, in which scientists are about to recreate conditions just after the Big Bang, is "vital if the human race is not to stultify and eventually die out."
And he sought to ease fears that the machine could have apocalyptic effects. "The world will not come to an end when the LHC turns on," Prof Hawking said, adding: "The LHC is absolutely safe."
Scientists at the CERN research centre in Switzerland are aiming to use the machine to gain a better understanding of the birth and structure of the universe, and to fill gaps in our knowledge of physics.
They hope that by recreating the moments after the Big Bang - the massive explosion thought to have created the universe - the experiment will make clearer what the universe is made of, what makes it expand and also to predict its future.
Prof Hawking, the Lucasian Professor of Mathematics at the University of Cambridge, said: "The LHC will increase the energy at which we can study particle interactions by a factor of four."
However, he doubts that the machine will have the power to unravel some of the universe's more elusive secrets such as the putative Higgs boson particle - thought to have given mass to all other particles.
Prof Hawking said he has placed a bet of $100 that the scientists won't find the Higgs boson - the so-called "God particle."
"Another discovery that we might make is superpartners, partners for all the particles we know ... they could make up the mysterious dark matter that holds galaxies together," he told BBC Radio 4.
"Whatever the LHC finds or fails to find, the results will tell us a lot about the structure of the universe," Prof Hawking added.
However he dismissed speculation that the world could be put in grave danger by the force of the experiment.
"The LHC is absolutely safe. If the collisions in the LHC produced a micro black hole - and this is unlikely - it would just evaporate away again, producing a correctoristic pattern of particles," he said.
"Collisions releasing greater energy occur millions of times a day in the earth's atmosphere and nothing terrible happens. The world will not come to an end when the LHC turns on."
However he pointed out that if the LHC were indeed to create minor black holes, his own work on the subject could be verified and he chould receive the highest acclaim in the field.
He said: "If the LHC were to produce little black holes, I don't think there is any doubt I would get a Nobel Prize, if they showed the properties I predict.
"However I think the the probability that the LHC has enough energy to produce little black holes is less than 1 per cent - so I'm not holding my breath."
Asked whether the results of the LHC experiment would offer immediate practical benefits for our day-to-day lives, Prof Hawking urged patience.
He said: "Throughout history, people have studied pure science from a desire to understand the universe, rather than practical applications for commercial gain. But their discoveries later turned out to have great practical benefits.
"It is difficult to see an economic return from research at the LHC, but that doesn't mean there wont be any."
Prof Hawking made clear that the LHC project is one of the most important in the history of scientific endeavour. Asked to choose between it and the space program, he said: "That is like asking which of my children I would choose to sacrifice.
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