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Light completely stopped for a record-breaking minute

25 July 2013 by Jacob Aron

The fastest thing in the universe has come to a complete stop for a record-breaking minute. At full pelt, light would travel about 18 million kilometres in that time – that's more than 20 round trips to the moon.

"One minute is extremely, extremely long," says Thomas Krauss at the University of St Andrews, UK. "This is indeed a major milestone."

The feat could allow secure quantum communications to work over long distances.

While light normally travels at just under 300 million metres per second in a vacuum, physicists managed to slow it down to just 17 metres per second in 1999 and then halt it completely two years later, though only for a fraction of a second. Earlier this year, researchers kept it still for 16 seconds using cold atoms.



MIT scientists implant a false memory into a mouse’s brain

By Meeri Kim

Sometime soon, a lab mouse could wake up thinking he had snuggled up to a girl mouse the night before. But he hadn’t. The memory would be fake.

Scientists have successfully implanted a false memory into a mouse’s brain — a seemingly far-fetched idea reminiscent of a science fiction film.

“If mice had Hollywood, this would be ‘Inception’ for them,” said one of the lead researchers, MIT neuroscientist Steve Ramirez, whose study was published online Thursday in the journal Science.

Ramirez and his colleagues tagged brain cells associated with a specific memory and then tweaked that memory to make the mouse believe something had happened when it didn’t.


A mysterious old spiral

This striking cosmic whirl is the centre of galaxy NGC 524, as seen with the NASA/ESA Hubble Space Telescope. This galaxy is located in the constellation of Pisces, some 90 million light-years from Earth.

NGC 524 is a lenticular galaxy. Lenticular galaxies are believed to be an intermediate state in galactic evolution — they are neither elliptical nor spiral. Spirals are middle-aged galaxies with vast, pinwheeling arms that contain millions of stars. Along with these stars are large clouds of gas and dust that, when dense enough, are the nurseries where new stars are born. When all the gas is either depleted or lost into space, the arms gradually fade away and the spiral shape begins to weaken. At the end of this process, what remains is a lenticular galaxy — a bright disc full of old, red stars surrounded by what little gas and dust the galaxy has managed to cling on to.

This image shows the shape of NGC 524 in detail, formed by the remaining gas surrounding the galaxy’s central bulge. Observations of this galaxy have revealed that it maintains some spiral-like motion, explaining its intricate structure.

A version of this image was entered into the Hubble’s Hidden Treasures image processing competition by contestant Judy Schmidt.


Scientists model 'extraordinary' performance of Bolt

As the world's best athletes descend on London today to take part in the Olympic Anniversary Games, a group of researchers from Mexico has provided an insight into the physics of one of the greatest athletic performances of all time.

In a new paper published today, 26 July, in IOP Publishing's European Journal of Physics, the researchers have put forward a mathematical model that accurately depicts the truly extraordinary feats of Usain Bolt during his 100 metre world record sprint at the 2009 World Championships in Berlin.

According to the researchers' model, Bolt's time of 9.58 seconds—which is still the world record—was achieved by reaching a terminal velocity of 12.2 metres per second and exerting an average force of 815.8 newtons.

What was truly amazing about his performance, however, was the amount of power and energy that Bolt had to exert to overcome the effects of drag caused by air resistance, which were exacerbated by Bolt's huge 6ft 5in frame.

By taking into account the altitude of the Berlin track, the temperature at the time of the race and the cross-section of Bolt himself, the researchers calculated that he had a drag coefficient of 1.2, which is less aerodynamic than the average human.



Blackbody radiation induces attractive force stronger than gravity

by Lisa Zyga

Perfectly non-reflective objects, called blackbodies, produce blackbody radiation when at a uniform temperature. Although the properties of blackbody radiation depend on the blackbody's temperature, this radiation has always been thought to have a net repulsive effect. Now in a new study, scientists have theoretically shown that blackbody radiation induces a second force on nearby atoms and molecules that is usually attractive and, quite surprisingly, even stronger than the repulsive radiation pressure. Consequently, the atoms and molecules are pulled toward the blackbody surface by a net attractive force that can be even stronger than gravity. The new attractive force—which the scientists call the "blackbody force"—suggests that a variety of astrophysical scenarios should be revisited.

The scientists, M. Sonnleitner at the University of Innsbruck and Innsbruck Medical University in Austria, M. Ritsch-Marte at Innsbruck Medical University, and H. Ritsch at the University of Innsbruck, have published their paper on the attractive blackbody force stemming from blackbody radiation in a recent issue of Physical Review Letters.

The underlying basis of the new force has actually been known for at least half a century: blackbody radiation shifts the atomic energy levels of nearby atoms and molecules. In these "Stark shifts," the ground state of the atom or molecule is shifted to a lower energy by an amount that is roughly proportional to the fourth power of the blackbody's temperature. That is, the hotter the blackbody, the larger the shift.

While this much has been known, however, the potential repercussions of these energy shifts have been overlooked until now. In the new study, the scientists have for the first time shown that the Stark shifts induced by blackbody radiation can combine to generate an attractive optical force that dominates the blackbody's own repulsive radiation pressure. This means that, despite its outgoing radiative energy flow, a hot finite-sized sphere actually attracts rather than repels neutral atoms and molecules, under most conditions.



Hypnotic Animated GIFs from Mat Lucas

UK-based artist Mat Lucas works by day as a graphic designer and by night runs a Tumblr of experimental art called 89—A. Lucas tells me that many of his GIFs begin as a problem he’s facing while learning various graphics and video applications like Cinema4D, After Effects, and Photoshop. The byproduct of his experimentation are often ethereal geometric forms that pulsate, rotate and contract in various hypnotic patterns.



The Expendables: How the Temps Who Power Corporate Giants Are Getting Crushed

July 25, 2013 • By Michael Grabell
It’s 4:18 a.m. and the strip mall is deserted. But tucked in back, next to a closed-down video store, an employment agency is already filling up. Rosa Ramirez walks in, as she has done nearly every morning for the past six months. She signs in and sits down in one of the 100 or so blue plastic chairs that fill the office. Over the next three hours, dispatchers will bark out the names of who will work today. Rosa waits, wondering if she will make her rent.

In cities all across the country, workers stand on street corners, line up in alleys, or wait in a neon-lit beauty salon for rickety vans to whisk them off to warehouses miles away. Some vans are so packed that to get to work, people must squat on milk crates, sit on the laps of passengers they do not know ,or sometimes lie on the floor, the other workers’ feet on top of them.

This is not Mexico. It is not Guatemala or Honduras. This is Chicago, New Jersey, Boston.

The people here are not day laborers looking for an odd job from a passing contractor. They are regular employees of temp agencies working in the supply chain of many of America’s largest companies—Walmart, Macy’s, Nike, Frito-Lay. They make our frozen pizzas, sort the recycling from our trash, cut our vegetables, and clean our imported fish. They unload clothing and toys made overseas and pack them to fill our store shelves. They are as important to the global economy as shipping containers and Asian garment workers.

Many get by on minimum wage, renting rooms in rundown houses, eating dinners of beans and potatoes, and surviving on food banks and taxpayer-funded health care. They almost never get benefits and have little opportunity for advancement.


The MOOC Racket

By Jonathan Rees|Posted Thursday, July 25, 2013, at 8:51 AM
The word mooc sounds a bit like slang from Goodfellas or the affectionate shortening of the already-affectionate name of a former outfielder for the New York Mets. In fact, a MOOC is a new kind of college-like experience that seems to possess the magical power to turn some of the smartest people in academia into followers of a faith-based cult because they want to become its idols.

MOOC stands for “massive open online course.” The term was coined by a group of Canadian academics in 2008 to represent a recently invented type of online class that depends upon small group interactions for most of the instruction. More recently, three instructors in the Stanford University computer science department appropriated that term to start two separate private education companies, Udacity and Coursera. Despite being free of charge, the MOOCs that these firms offer bear a more-than-passing resemblance to ordinary college classes—except they are delivered over the Internet to tens of thousands of people at once.

How do you teach tens of thousands of people anything at once? You don't. What you can do over the Internet this way is deliver information, but that's not education. Education, as any real teacher will tell you, involves more than just transmitting facts. It means teaching students what to do with those facts, as well as the skills they need to go out and learn new information themselves.

But the most common way to assess learning in the MOOCs offered by the largest providers is a single multiple-choice question after approximately five-minute chunks of pre-taped lectures. If I had told my tenure committee that I taught history this way, I'd be in another line of work right now. Anyone who has the slightest interest or expertise in education would never teach this way, even if they were paid to do so.


Rare 'Zonkey' Born in Italy Zoo; Zebra and Donkey Parents Weren't Meant to Breed

An unintended and unusual coupling between a zebra and a donkey has produced a rare hybrid specimen known as a zonkey.
Ippo, as the newborn creature is called, was born last week at a small zoo in Florence, Italy. The male zonkey has black and white banded legs like a zebra, but has the face, ears and fur of a donkey.

Ippo's father is a full-blooded zebra rescued from a failing zoo and his mother a breed of endangered donkey. The zoo where Ippo was born specializes in taking in neglected or unwanted animals.

Serena Aglietti, owner of the zoo where Ippo was conceived, never intended for the zebra and donkey to mate and there was a fence separating the two animals, the New York Daily News reported.

According to a translation from the Italian news website ANSA, Ippo is the only specimen of zonkey in Italy. Others zonkeys have been born in Germany, China and Georgia, the website reported.


Cross-posting for political junkies-Pete Souza's Instagram Account

Lots of good, up to the minute pics....


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