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Home country: USA
Current location: Georgia
Member since: Tue Feb 10, 2004, 12:08 PM
Number of posts: 30,635
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Scientists on the CDF and DZero experiments at the U.S. Department of Energy’s Fermi National Accelerator Laboratory have announced that they have found the final predicted way of creating a top quark, completing a picture of this particle nearly 20 years in the making.
The two collaborations jointly announced on Friday, Feb. 21, that they had observed one of the rarest methods of producing the elementary particle – creating a single top quark through the weak nuclear force, in what is called the “s-channel.” For this analysis, scientists from the CDF and DZero collaborations sifted through data from more than 500 trillion proton-antiproton collisions produced by the Tevatron from 2001 to 2011. They identified about 40 particle collisions in which the weak nuclear force produced single top quarks in conjunction with single bottom quarks.
Top quarks are the heaviest and among the most puzzling elementary particles. They weigh even more than the Higgs boson – as much as an atom of gold – and only two machines have ever produced them: Fermilab’s Tevatron and the Large Hadron Collider at CERN. There are several ways to produce them, as predicted by the theoretical framework known as the Standard Model, and the most common one was the first one discovered: a collision in which the strong nuclear force creates a pair consisting of a top quark and its antimatter cousin, the anti-top quark.
Collisions that produce a single top quark through the weak nuclear force are rarer, and the process scientists on the Tevatron experiments have just announced is the most challenging of these to detect. This method of producing single top quarks is among the rarest interactions allowed by the laws of physics. The detection of this process was one of the ultimate goals of the Tevatron, which for 25 years was the most powerful particle collider in the world.
Posted by n2doc | Mon Feb 24, 2014, 09:41 PM (3 replies)
By Joel Achenbach
We live in Carl Sagan’s universe–awesomely vast, deeply humbling. It’s a universe that, as Sagan reminded us again and again, isn’t about us. We’re a granular element. Our presence may even be ephemeral—a flash of luminescence in a great dark ocean. Or perhaps we are here to stay, somehow finding a way to transcend our worst instincts and ancient hatreds, and eventually become a galactic species. We could even find others out there, the inhabitants of distant, highly advanced civilizations—the Old Ones, as Sagan might put it.
No one has ever explained space, in all its bewildering glory, as well as Sagan did. He’s been gone now for nearly two decades, but people old enough to remember him will easily be able to summon his voice, his fondness for the word “billions” and his boyish enthusiasm for understanding the universe we’re so lucky to live in.
He led a feverish existence, with multiple careers tumbling over one another, as if he knew he wouldn’t live to an old age. Among other things, he served as an astronomy professor at Cornell, wrote more than a dozen books, worked on NASA robotic missions, edited the scientific journal Icarus and somehow found time to park himself, repeatedly, arguably compulsively, in front of TV cameras. He was the house astronomer, basically, on Johnny Carson’s “Tonight Show.” Then, in an astonishing burst of energy in his mid-40s, he co-created and hosted a 13-part PBS television series, “Cosmos.” It aired in the fall of 1980 and ultimately reached hundreds of millions of people worldwide. Sagan was the most famous scientist in America—the face of science itself.
Now “Cosmos” is back, thanks largely to Seth MacFarlane, creator of TV’s “Family Guy” and a space buff since he was a kid, and Ann Druyan, Sagan’s widow. They’re collaborating on a new version premiering on the Fox Network on Sunday March 9. MacFarlane believes that much of what is on television, even on fact-based channels purporting to discuss science, is “fluff.” He says, “That is a symptom of the bizarre fear of science that’s taken hold.” The astronomer Neil deGrasse Tyson, of the American Museum of Natural History in New York City, serves as narrator this time, giving him a chance to make the case that he’s the Sagan of our generation. “‘Cosmos’ is more than Carl Sagan,” Tyson told me. “Our capacity to decode and interpret the cosmos is a gift of the method and tools of science. And that’s what’s being handed down from generation to generation. If I tried to fill his shoes I would just fail. But I can fill my own shoes really well.”
Read more: http://www.smithsonianmag.com/science-nature/why-carl-sagan-truly-irreplaceable-180949818/
Posted by n2doc | Mon Feb 24, 2014, 09:36 PM (9 replies)
Radiation from Japan's leaking Fukushima nuclear power plant has reached waters offshore Canada, researchers said today at the annual American Geophysical Union's Ocean Sciences Meeting in Honolulu.
Two radioactive cesium isotopes, cesium-134 and cesium-137, have been detected offshore of Vancouver, British Columbia, researchers said at a news conference. The detected concentrations are much lower than the Canadian safety limit for cesium levels in drinking water, said John Smith, a research scientist at Canada's Bedford Institute of Oceanography in Dartmouth, Nova Scotia.
Tests conducted at U.S. beaches indicate that Fukushima radioactivity has not yet reached Washington, California or Hawaii, said Ken Buesseler, a senior scientist at the Woods Hole Oceanographic Institute in Woods Hole, Mass.
"We have results from eight locations, and they all have cesium-137, but no cesium-134 yet," Buesseler said. (Isotopes are atoms of the same element that have different numbers of neutrons in their nuclei. In this case, cesium-137 has more neutrons than cesium-134.)
Posted by n2doc | Mon Feb 24, 2014, 07:45 PM (2 replies)
ASBURY PARK, N.J. — Gov. Chris Christie is no longer on a pedestal.
With multiple scandals and probes swirling around his administration, the Republican governor's approval rating has dropped nine points in a month and 20 points from last year, according to a Monmouth University/Asbury Park Press poll released Monday.
While the still unexplained George Washington Bridge access lane closures in September 2013 and resulting traffic jams, traced back to his office, have taken their toll on the governor's popularity, one of his former strong points — the state's recovery from superstorm Sandy — has shown a serious erosion of support.
Fifty-seven percent of those polled gave Christie a mediocre to failing grade in the handling of the recovery. Only five months ago, 72 percent of those polled gave him an A or a B for his efforts.
"This hole is getting deeper," said Patrick Murray, director of the Monmouth University Polling Institute. "Christie's image as the hero of Sandy is now just a fading memory."
Posted by n2doc | Mon Feb 24, 2014, 02:17 PM (0 replies)
by Raul Reyes
Imagine if a major television network entered into a partnership with a presidential nominee, and promoted that candidate across their media platforms. Just think of the outrage and charges of bias that would ricochet through the press.
Or maybe not.
Univision, the country's top Spanish-language network, has entered into a multiyear deal with Hillary Clinton to promote the health, education and well-being of young children. As part of an early childhood development campaign that she began last year, Clinton has signed on with Univision to promote "Pequeños y Valiosos" (Young and Valuable), a program to encourage Hispanic parents to develop their children's language skills. Among other goals, the program wants to help close what is known as a "word gap," the vocabulary differential between low-income children and their classmates. Clinton and Univision officials kicked off the program at an event in at a Head Start program in East Harlem.
That's all good, right?
Not really. Although the program has worthy goals, the problem here is that a major broadcaster is getting awfully close to a presumptive nominee for president. A second problem is that many in the press are largely ignoring this relationship. Marc Caputo, a political reporter for the Miami Herald, wrote about the Univision/Clinton ties, and several conservative media outlets picked up his column. But other than that, this has been a non-story — which is a shame.
Posted by n2doc | Mon Feb 24, 2014, 02:14 PM (33 replies)
A better DU, perhaps?
Posted by n2doc | Mon Feb 24, 2014, 12:42 PM (2 replies)
An audacious plan to create a new energy source could save the planet from catastrophe. But time is running out.
BY RAFFI KHATCHADOURIAN
Years from now—maybe in a decade, maybe sooner—if all goes according to plan, the most complex machine ever built will be switched on in an Alpine forest in the South of France. The machine, called the International Thermonuclear Experimental Reactor, or iter, will stand a hundred feet tall, and it will weigh twenty-three thousand tons—more than twice the weight of the Eiffel Tower. At its core, densely packed high-precision equipment will encase a cavernous vacuum chamber, in which a super-hot cloud of heavy hydrogen will rotate faster than the speed of sound, twisting like a strand of DNA as it circulates. The cloud will be scorched by electric current (a surge so forceful that it will make lightning seem like a tiny arc of static electricity), and bombarded by concentrated waves of radiation. Beams of uncharged particles—the energy in them so great it could vaporize a car in seconds—will pour into the chamber, adding tremendous heat. In this way, the circulating hydrogen will become ionized, and achieve temperatures exceeding two hundred million degrees Celsius—more than ten times as hot as the sun at its blazing core.
No natural phenomenon on Earth will be hotter. Like the sun, the cloud will go nuclear. The zooming hydrogen atoms, in a state of extreme kinetic excitement, will slam into one another, fusing to form a new element—helium—and with each atomic coupling explosive energy will be released: intense heat, gamma rays, X rays, a torrential flux of fast-moving neutrons propelled in every direction. There isn’t a physical substance that could contain such a thing. Metals, plastics, ceramics, concrete, even pure diamond—all would be obliterated on contact, and so the machine will hold the superheated cloud in a “magnetic bottle,” using the largest system of superconducting magnets in the world. Just feet from the reactor’s core, the magnets will be cooled to two hundred and sixty-nine degrees below zero, nearly the temperature of deep space. Caught in the grip of their titanic forces, the artificial earthbound sun will be suspended, under tremendous pressure, in the pristine nothingness of iter’s vacuum interior.
For the machine’s creators, this process—sparking and controlling a self-sustaining synthetic star—will be the culmination of decades of preparation, billions of dollars’ worth of investment, and immeasurable ingenuity, misdirection, recalibration, infighting, heartache, and ridicule. Few engineering feats can compare, in scale, in technical complexity, in ambition or hubris. Even the iter organization, a makeshift scientific United Nations, assembled eight years ago to construct the machine, is unprecedented. Thirty-five countries, representing more than half the world’s population, are invested in the project, which is so complex to finance that it requires its own currency: the iter Unit of Account.
No one knows iter’s true cost, which may be incalculable, but estimates have been rising steadily, and a conservative figure rests at twenty billion dollars—a sum that makes iter the most expensive scientific instrument on Earth. But if it is truly possible to bottle up a star, and to do so economically, the technology could solve the world’s energy problems for the next thirty million years, and help save the planet from environmental catastrophe. Hydrogen, a primordial element, is the most abundant atom in the universe, a potential fuel that poses little risk of scarcity. Eventually, physicists hope, commercial reactors modelled on iter will be built, too—generating terawatts of power with no carbon, virtually no pollution, and scant radioactive waste. The reactor would run on no more than seawater and lithium. It would never melt down. It would realize a yearning, as old as the story of Prometheus, to bring the light of the heavens to Earth, and bend it to humanity’s will. iter, in Latin, means “the way.”
Posted by n2doc | Mon Feb 24, 2014, 12:22 PM (4 replies)
The organization never had any.
I think it’s interesting that DeMint has pushed Heritage into an even more blatant political role; but the subtext of such stories often seems to be that until DeMint arrived Heritage was a center of honest, serious, if conservative-leaning research.
In their dreams — or maybe in the dreams of self-proclaimed centrists, who wanted to believe that such an organization existed.
The truth is that the pre-DeMint Heritage was Hack Central, producing garbage posing as research. It promoted the death tax scam; it proclaimed that the Ryan plan would push the unemployment rate down to 2.8 percent, then tried to send that “result” down the memory hole. Heritage economists have promoted the fallacy that government spending can’t increase demand. And so on.
So Heritage never was a “think tank” in the sense that actual thought or research took place there. It just played one on TV.
Posted by n2doc | Mon Feb 24, 2014, 10:49 AM (6 replies)
Remember the “death tax”? The estate tax is quite literally a millionaire’s tax — a tax that affects only a tiny minority of the population, and is mostly paid by a handful of very wealthy heirs. Nonetheless, right-wingers have successfully convinced many voters that the tax is a cruel burden on ordinary Americans — that all across the nation small businesses and family farms are being broken up to pay crushing estate tax liabilities.
You might think that such heart-wrenching cases are actually quite rare, but you’d be wrong: they aren’t rare; they’re nonexistent. In particular, nobody has ever come up with a real modern example of a family farm sold to meet estate taxes. The whole “death tax” campaign has rested on eliciting human sympathy for purely imaginary victims.
And now they’re trying a similar campaign against health reform.
I’m not sure whether conservatives realize yet that their Plan A on health reform — wait for Obamacare’s inevitable collapse, and reap the political rewards — isn’t working. But it isn’t. Enrollments have recovered strongly from the law’s disastrous start-up; in California, which had a working website from the beginning, enrollment has already exceeded first-year projections. The mix of people signed up so far is older than planners had hoped, but not enough so to cause big premium hikes, let alone the often-predicted “death spiral.”
And conservatives don’t really have a Plan B — in their world, nobody even dares mention the possibility that health reform might actually prove workable. Still, you can already see some on the right groping toward a new strategy, one that relies on highlighting examples of the terrible harm Obamacare does. There’s only one problem: they haven’t managed to come up with any real examples.
Posted by n2doc | Mon Feb 24, 2014, 10:25 AM (2 replies)
Posted by n2doc | Mon Feb 24, 2014, 09:15 AM (7 replies)