ريتشارد دوكنز's Blog, page 555
February 21, 2016
Incredible Time-Lapse Video Shows All Of 2015’s Wild Weather
Photo credit:
EUMETSAT/YouTube
Last year was a pretty busy year for weather presenters. Not only was it the hottest year on record, it also saw the likes of Hurricane Patricia and an exceptionally powerful El Niño.
5D Black Hole Could “Break Relativity”
Photo credit:
The ring black hole about to break apart. Pau Figueras, Markus Kunesch, and Saran Tunyasuvunakool
General relativity is one of the greatest ideas in human history. Relativity and quantum mechanics are the cornerstones of modern physics, and they are used from telecommunication to computers and smartphones.
Incredibly Well-Preserved Bronze Age Wheel Discovered At “Britain’s Pompeii”
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The wheel is the best-preserved example ever found in Britain. Joe Gidden/PA
Archaeologists have uncovered what is believed to be the largest and best-preserved Bronze Age wooden wheel ever found in the U.K., at a site that has been described as “Britain’s Pompeii." The astonishing new find has been revealed not long after the team excavating the site in the soggy fens of Cambridgeshire announced that they had found some of the most perfectly preserved Bronze Age houses, thought to date to
Awesome Power Of Nature Captured In Award-Winning Photography
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Volcanic thunderbolts: “The Power of Nature” by Sergio Tapiro, Mexico 2015
The winners of the 2015 World Press Photo contest have been chosen, and the images are nothing short of breathtaking. The devastation of the Syrian war, the refugee crisis in Europe, and clashes between police and protestors in the United States have all been beautifully and dramatically documented on camera.
But the natural world also provided photographers with a surreal source of inspiration. At times inspiring, and occasionally terrifying, here are some of the very best examples.
This Week in Science (Feb. 14 – 21)
Check out the “This Week in Science” profile on Wakelet and ‘follow’ for a weekly roundup.
February 20, 2016
Physicists discover easy way to measure entanglement—on a sphere
Quantum entanglement—which occurs when two or more particles are correlated in such a way that they can influence each other even across large distances—is not an all-or-nothing phenomenon, but occurs in various degrees. The more a quantum state is entangled with its partner, the better the states will perform in quantum information applications. Unfortunately, quantifying entanglement is a difficult process involving complex optimization problems that give even physicists headaches.
Now in a new paper to be published in Physical Review Letters, mathematical physicists Bartosz Regula and Gerardo Adesso at The University of Nottingham have greatly simplified the problem of measuring entanglement.
To do this, the scientists turned the difficult analytical problem into an easy geometrical one. They showed that, in many cases, the amount of entanglement between states corresponds to the distance between two points on a Bloch sphere, which is basically a normal 3D sphere that physicists use to model quantum states.
As the scientists explain, the traditionally difficult part of the math problem is that it requires finding the optimal decomposition of mixed states into pure states. The geometrical approach completely eliminates this requirement by reducing the many possible ways that states could decompose down to a single point on the sphere at which there is zero entanglement. The approach requires that there be only one such point, or “root,” of zero entanglement, prompting the physicists to describe the method as “one root to rule them all.”
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February 19, 2016
Male Sellers on eBay Have an Edge Over Women, Study Finds
Photo credit: Laura McDermott for The New York Times
By Pam Belluck
Successful sellers on eBay know certain things matter: item description, appealing photos, strong seller ratings and, of course, price.
Now, a study published Friday in the journal Science Advances suggested another factor might make a subtle difference: whether the seller is a man or woman. Using data supplied by the company, researchers analyzed some 630,000 auction transactions on eBay in the United States and reported that, on average, when men and women with equal selling reputations sold the same products, women received lower prices than men.
The difference was far less pronounced for used items: Women sellers received about 97 cents for every dollar men received. But with new items, where the authors say direct comparison is easier, women received about 80 cents on average for every dollar men sellers received.
“The basic point — that people have different expectations of women versus men and so we treat them very differently in the world — it’s fascinating and depressing,” said Linda Babcock, an economics professor at Carnegie Mellon University, who was not involved in the study.
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Storm Water, Long a Nuisance, May Be a Parched California’s Salvation
Photo credit: Monica Almeida/The New York Times
By Adam Nagourney
The winter rains finally arrived in Southern California, bringing drenching relief this week to a part of the nation suffering one of the worst droughts in history. But the El Niño storms brought something else as well: a reminder of lost opportunity, on display in this coastal city, as millions of gallons of storm water slipped down the usually dry Los Angeles River and out into San Pedro Bay.
After a year in which Californians cut water use by 25 percent, storm water has become the next front in what amounts to a fundamental restructuring of Southern California’s relationship with its intricate water network. More than 200 billion gallons of storm water, enough to supply 1.4 million households for a year, could be captured statewide — but instead end up spilling down sewers and drains and into the ocean, as was on display Thursday, in the hours after the rainfall ended, at the spot where the Los Angeles River ends here.
Nowhere is the disparity felt more than in parched Los Angeles, with its short winters and its overwhelming reliance on water imported from Northern California and the Colorado River. For nearly a century, since deadly floods in 1938 killed 97 people, engineers have focused on ways to flush storm water safely out of Los Angeles as quickly as possible. Now, officials want to capture that water.
“Something that was once viewed as a nuisance is now seen as a necessity,” said Eric M. Garcetti, the mayor of Los Angeles. “We haven’t done enough.”
Mr. Garcetti invoked the legacy of William Mulholland, the city engineer who oversaw the construction of the Los Angeles Aqueduct, as he outlined policy intended to press Los Angeles to increase the amount of storm water captured, to 50 billion gallons by 2035 from 8.8 billion gallons now. “This is a Mulholland moment,” he said in an interview. “I intend to re-engineer the water system again to keep water here.”
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Francis and Trump: Populist Leaders Preaching Divergent Messages
Photo credit: David Wallace/The Arizona Republic, via Associated Press
By Jim Yardley
In the cage fight of American presidential politics, the matchup is irresistible: Pope Francis, leader of the world’s 1.2 billion Roman Catholics, the pope of the poor who has knelt to wash the feet of prisoners and Muslims, versus Donald J. Trump, billionaire Republican who disparages Muslims and kneels to no one.
When Francis suggested that Mr. Trump “is not Christian” in answering a reporter’s question during his return flight from Mexico, the Latin American pope not only served up red meat for global headline writers (“Francis Excommunicates Trump,” declared La Stampa in Italy), but again demonstrated his knack for sticking his nose into putatively secular affairs. His flap with Mr. Trump is about immigration, and to Francis the issue transcends any campaign cycle.
From the first days of his papacy, when he insisted on paying his hotel bill himself, Francis has understood the power of a gesture, and of a global spotlight available to any pope capable of using it. The pontiff who made a politically charged visit to the United States-Mexico border on Wednesday is the same one who in 2014 stopped in Bethlehem to pray at the graffiti-covered wall dividing the Palestinian city from Israeli-controlled Jerusalem.
His critics in the United States, many of them conservative Catholics, argue that Francis is a “political pope” pursuing a leftist agenda that castigates capitalism and environmental degradation. Even before Francis’s remarks about him, Mr. Trump had criticized the pope as “a political person” and accused him of visiting the border as a favor to the Mexican government.
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New Delhi Car Ban Yields Trove of Pollution Data
Photo credit: iStock.com
By Scientific American
New Delhi may be the world’s most polluted city, but it’s making an effort to relinquish that title. With pollution from particulate matter at potentially lethal levels early last December, city officials took a drastic step: they announced that they would temporarily restrict the use of private vehicles by allowing owners to drive only on alternate days, based on the sequence of their number plates.
The initial results of that 15-day trial, which began on January 1, are now in. Although traffic actually increased in the first week of the ban, the levels of PM2.5 — particulate matter measuring less than 2.5 micrometres across—fell by roughly 10%. That is a victory not just for New Delhi officials, but also for the scientists who sprang into action to collect the data necessary to determine whether the test had achieved its goal.
“This experiment with ‘live research’ has been really quite exciting,” says Santosh Harish, assistant director of the India centre of the Energy Policy Institute at the University of Chicago (EPIC-India). EPIC-India and the New Delhi-based Council on Energy, Environment and Water (CEEW), an independent think tank, used video monitors around the city to document the types and numbers of vehicles on the roads. The groups had less than a month to collect baseline data before the driving restrictions began.
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