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Science News Reports

Quantum test strengthens support for EPR steering 19 October 2014, 22.25 Science
Quantum test strengthens support for EPR steering
Although the concept of "steering" in quantum mechanics was proposed back in 1935, it is still not completely understood today. Steering refers to the ability of one system to nonlocally affect, or steer, another system's
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Living cyberinfrastructure: Accelerating discovery
For scientists looking to complete large, complex, data-driven research projects quickly, living cyberinfrastructure can be a powerful solution. This is a different way of working for most scientists; applying for time on a
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Journeying from data to knowledge at ISC Big Data ‘14
Last week, decision makers and technical experts from the world of IT met in Heidelberg, Germany, for the second ISC Big Data conference. The event focused on a wide range of big data applications and featured discussion of
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The rain in Spain stays mainly in the ... hydrometeorological models
Last month, the Distributed Research Infrastructure for Hydro-Meteorology project (DRIHM) held its second summer school. The event brought together hydrometeorologists from 23 different countries, who learned about the latest
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‘Mars Rover Curiosity’ chronicles robot's journey
Mars Rover Curiosity Rob Manning and William L. Simon Smithsonian, $29.95  During its first two years on Mars, NASA’s Curiosity rover discovered that the Red Planet was once hospitable to life. For Manning, the rover’s
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'The Theory of Everything' reveals Stephen Hawking's personal side
LOVE AND SCIENCE  The challenging but rewarding relationship between Stephen (Eddie Redmayne) and Jane (Felicity Jones) Hawking plays a central role in The Theory of Everything. Liam Daniel/Focus Features When Stephen
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Tiny human intestine grown inside mouse 19 October 2014, 22.24 Science
Tiny human intestine grown inside mouse
LOOKS LIKE A GUT  Transplanted into mice, tiny specks of human intestinal tissue (stained pink) develop into working organs surrounded by a muscular sheath (stained green), just like real intestines. Slimy chunks of human
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Chemistry Nobel awarded for super-resolution microscopy
The 2014 Nobel Prize for Chemistry has gone to Eric Betzig, Stefan Hell and William Moerner for developing super-resolution microscopy techniques based on the fluorescence of molecules. The prize is worth SEK 8m (£690,000)
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Isamu Akasaki, Hiroshi Amano and Shuji Nakamura win 2014 Nobel Prize for Physics
The 2014 Nobel Prize for Physics has been awarded to Isamu Akasaki, Hiroshi Amano and Shuji Nakamura for their development of blue LEDs. The prize is worth SEK 8m (£690,000) and will be shared by the three winners who will
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Majorana quasiparticles glimpsed in magnetic chains
The strongest evidence yet that Majorana quasiparticles (MQPs) can be found lurking in some solids has been unveiled by physicists in the US. The team used a scanning tunnelling microscope (STM) to locate MQPs at the ends of
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Nobel laureate Martin Perl dies at 87 08 October 2014, 23.46 Science
Nobel laureate Martin Perl dies at 87
The US particle physicist Martin Perl has died at the age of 87. Perl was instrumental in discovering the tau lepton – an elementary particle similar to the electron but 3477 times heavier. The work led him to share the
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Megatelescope snaps up former fusion boss 08 October 2014, 23.46 Science
Megatelescope snaps up former fusion boss
Edward Moses joins the Giant Magellan Telescope Organization (GMTO) today as its first president, after stepping down as a scientific manager at the Lawrence Livermore National Laboratory. Moses had spent the past 15 years
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Are 'weak values' quantum after all? 08 October 2014, 23.46 Science
Are 'weak values' quantum after all?
A technique known as a "weak measurement", which allows physicists to measure certain properties of a quantum system without disturbing it, is being called into question by two physicists based in Canada and the US. The
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Dolphin-inspired sonar overcomes size-wavelength limitation
(Phys.org) —In a typical man-made sonar system, pulses of sound emitted by the projector bounce off hidden objects underwater. The echoes are then detected by the receiver to infer the location and size of the hidden
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Superposition revisited: Proposed resolution of double-slit experiment paradox using Feynman path integral formalism
(Phys.org) —The Schrödinger's Cat thought experiment, published in 1926 by Erwin Schrödinger, may be the most widely-known metaphorical explanation of quantum superposition and collapse. (Superposition is a
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Self-powered smart window also functions as a self-rechargeable transparent battery
(Phys.org) —Smart windows have the ability to become darker or lighter in response to the brightness and heat of sunlight, offering the potential to greatly reduce heating and cooling costs, among other benefits.
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Snake Robots! Slithering Machines Could Aid Search-and-Rescue Efforts
One snake's ability to shimmy up slippery sand dunes could inspire new technologies for robots that could perform search and rescue missions, carry out inspections of hazardous wastes and even explore ancient pyramids. A
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Sidewinder Rattlesnake's Sand Motion Studied For Robotics | Video
Rattlesnakes move across desert sand with ease. Researchers at Georgia Tech have been studying that movement to make robots that can move more efficiently across that type of terrain. Credit: Maxwell Guberman / Georgia
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NASA Crashes Helicopter Body For Impact Test | Video
NASA's Transport Rotorcraft Airframe Crash Testbed (TRACT 2) dropped a 45-foot-long fmr. Marine helicopter 30 feet to test. The test was done to improve helicopter systems and safety. Credit: NASA Langley Research
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Gassy Blob: Biggest US Methane Source Spotted from Space
A map of U.S. methane emissions that vary from background levels. Yellow and red are higher than average; purple and blue are below average. Credit: NASA/JPL-Caltech/University of Michigan A remote, coal-rich patch of
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Bionic Technology Offers Hope for Paralyzed  08 October 2014, 23.44 Science
Bionic Technology Offers Hope for Paralyzed 
An experimental spinal cord therapy allowed Rob Summers, 25, a paraplegic, to stand on his own for the first time in four years. CREDIT: Photo courtesy of Rob Summers. Technologies to help paralyzed people move again
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Where Is El Nino? And Why Do We Care? 08 October 2014, 23.44 Science
Where Is El Nino? And Why Do We Care?
The climate impacts typically associated with an El Niño during the months of December, January, and February. Credit: NOAA That El Niño we’ve been tracking for months on end — the one that is taking its sweet time
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Visionary Ideas From The South by Southwest Eco Awards
The annual South by Southwest Eco conference held its climactic event Tuesday night, announcing the winners of its Startup Showcase competition and Place by Design awards. Now in its fourth year, SXSW Eco has entered a sweet
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The Brilliant Ten: Michael Habib Uncovers The Secrets Of Pterosaurs
The fossil record on its own does little to explain how long-gone animals actually lived. For example, how could pterosaurs—some of which had a wingspan almost the length of a schoolbus—be so much bigger than modern-day
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Watch This Morning's Eclipse Happen In One Minute 08 October 2014, 23.44 Science
Watch This Morning's Eclipse Happen In One Minute
Early this morning, Americas time, the moon underwent a total eclipse. The Griffith Observatory in Los Angeles trained its telescope on the moon for the event, then made this wonderful one-minute video out of five and a half
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The Brilliant Ten: Katharina Ribbeck Makes Antibiotic Alternatives Out Of Mucus
The human body pumps out more than a gallon of mucus each day. People tend to dismiss this slippery stuff as waste, but Katharina Ribbeck, a biochemist at Massachusetts Institute of Technology, discovered that mucus is
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Giant Clams Are Greenhouses For Algae 08 October 2014, 23.44 Science
Giant Clams Are Greenhouses For Algae
Giant clams loom large on coral reefs, their gaping maws filled with bright lights. On other mollusks, this iridescence is a camouflage, guiding the eye away from the creature’s body. Recent research published in the Royal
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Throwback Thursday: Digital Dogs, The B-2 Stealth Bomber, And Innovations Against Climate Change
On this Throwback Thursday, we go back 25 years to the Popular Science of September 1989. In the waning months of the 80s, Popular Science asked what the most important concerns of Americans from that time were, and it
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Key brain cell linker region a potential target for neuromodulatory drugs
Parkinson's disease, Alzheimer's disease, and schizophrenia are all associated with malfunctions of a key brain cell receptor — NMDA. Read about a new, critically dependent linker region associated with NMDA and its
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Impotence drug boosts insulin in some with diabetes
A drug initially developed to treat erectile dysfunction helps a subset of people with type 2 diabetes. Called yohimbine, the drug is effective in people with a variant of a gene called ADRA2A, researchers report October 8 in
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Building bridges for research data sharing 08 October 2014, 23.44 Science
Building bridges for research data sharing
Last month, iSGTW attended the EUDAT Third Conference in Amsterdam, The Netherlands. EUDAT is facilitating efficient research by contributing towards a collaborative data infrastructure in Europe. This will enable researchers
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Big data informs conservation research and protects endangered species
With the aid of supercomputers and biotelemetry, researchers are creating detailed 3D models of land use and movement by endangered wildlife. Read about the California condor, giant panda, and dugong, and how big data and
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Yeast smell underpins partnership with fruit flies
YEASTY NOTES  Fluorescent yeast cells (green) cling to a fruit fly’s leg. Scientists have learned that yeast make fruity-smelling chemicals, which attract fruit flies. The flies eat some of the yeast, but give others a lift
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Celebrating CERN with the sounds of science 08 October 2014, 23.44 Science
Celebrating CERN with the sounds of science
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Rattlesnakes tutor robot on dune climbing 08 October 2014, 23.44 Science
Rattlesnakes tutor robot on dune climbing
SNAKES ON PLANES  A sidewinder rattlesnake’s unusual skill in climbing sandy slopes inspired tweaks to long, skinny robots. View the video Sidewinder rattlesnakes wriggling up sand dunes turn out to have a trick of
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Why thousands of bees are flying around with sensors 06 October 2014, 22.46 Administrator Science
Why thousands of bees are flying around with sensors
  Wireless data-collecting sensors are everywhere: contact lenses, parking spaces, phones, clothes, trash, stores. The list could go on. So it's not surprising that they're now on honeybees to help solve a major
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Earth's Water Is Older Than The Sun 29 September 2014, 19.17 Science
Earth's Water Is Older Than The Sun
Since water is one of the vital ingredients for life on Earth, scientists want to know how it got here. One theory is that the water in our solar system was created in the chemical afterbirth of the Sun. If that were the
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Climate Week 2014: The Wrap-Up 29 September 2014, 19.17 Science
Climate Week 2014: The Wrap-Up
As Climate Week NYC slips into the rearview mirror, what can we take away? Did anything, you know, happen? Yes ... sort of. From the sci-tech perspective, important energy and conservation agreements were announced. Now the
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How An Evangelical Christian Researcher Reconciles Science With Her Faith
Editor's note: Our profile of Bill Nye [September 2014] elicited an impassioned response from readers. We received more than 100 letters, many from readers grappling with how to reconcile scientific concepts like climate
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Science On Ice: 7 Antarctic Experiments To Keep An Eye On
Since the 1950s, a small but growing number of international scientists have spent months at a stretch on the world’s most remote continent: Antarctica. This year, 29 countries will host research programs there, meaning
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The Week In Numbers: Crabwalking Robots, Ferocious Fungi, And The Future Of Game Of Thrones
165: number of pounds Lonesome George weighed at the time of his death, before scientists stuffed and mounted him for display. 2: the number of rubber bands needed to build your own shoebox phone projector.  100,000,000:
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Enormous Butterfly Swarms, Saharan Duststorms, And Other Amazing Images Of The Week
Arthur E. Smith made took this microscopic photograph of a sheep tick 110 years ago to exhibit in London as part of a large collection. The pictures would have been the first many people of the time had ever seen.Arthur E.
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A Higgs-gravity connection may leave traces in white dwarfs
(Phys.org) —The discovery of the Higgs boson at the Large Hadron Collider (LHC) in 2012 marked an important step toward understanding the origin of the mass of fundamental particles. Since mass plays a major role in
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Scientists manipulate molecules inside living cells with temperature gradients
(Phys.org) —The ability to make measurements of the biomolecular interactions that occur inside living cells is essential for understanding complex biological processes. But probing the inside of living cells without
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Now hear this: Simple fluid waveguide performs spectral analysis in a manner similar to the cochlea
(Phys.org) —Within the mammalian inner ear, or cochlea, a remarkable but and long-debated phenomenon occurs: As they move from the base of the cochlea to its apex, traveling fluid waves – that is, surface waves, in
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The societal impacts of grid and cloud computing 29 September 2014, 19.15 Science
The societal impacts of grid and cloud computing
Monday 29 September marks the 60th anniversary of the founding of the European Organization for Nuclear Research, otherwise known as CERN, located near Geneva, Switzerland. A new book, entitled 'From Physics to Daily Life',
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Project will broaden access to geoscience data 29 September 2014, 19.15 Science
Project will broaden access to geoscience data
Civil and environmental engineering professor Praveen Kumar, from the University of Illinois at Urbana-Champaign, US, will lead a new project to develop a semantic framework to integrate long-tail data and models. The project
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Grid school empowers students in Africa's developing countries
The African Grid School provides science communities exceptional opportunities to learn new technolgies and improve research techniques. Read about Open Science Grid and the biennial
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Missing winds probably foiled 2014’s chance for El Niño
LUKEWARM  Warm water (red) in the Pacific Ocean sloshed eastward this spring, prompting many scientists to expect a strong 2014 El Niño.  The bottom of the image shows a vertical cross section of seawater temperatures in
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Blind cavefish got no (circadian) rhythm 29 September 2014, 19.15 Science
Blind cavefish got no (circadian) rhythm
Blind, cave-dwelling cavefish have an advantage over their sighted brethren in the form of a more efficient metabolism, a new study finds. Small, silver fish called Mexican tetra (Astyanax mexicanus) live in some Texas and
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Videos hint at why tree bats may die at wind turbines
 Your daily roundup of research news Ashley Yeager Science Ticker 7:30am, September 30, 2014 Heat-sensitive cameras give hints as to why tree bats fly so close to wind turbines. Image courtesy of Paul
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Physicists design zero-friction quantum engine 20 September 2014, 19.54 Science
Physicists design zero-friction quantum engine
(Phys.org) —In real physical processes, some energy is always lost any time work is produced. The lost energy almost always occurs due to friction, especially in processes that involve mechanical motion. But in a new
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Nanocontainers for nanocargo: Delivering genes and proteins for cellular imaging, genetic medicine and cancer therapy
(Phys.org) —By loading any specific protein and nucleic acid into an icosahedral phage T4 capsid-based nanoparticle, the resulting cell delivery vehicle's ligands can bind to the surface of specific target tissues to
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Tiny scaffolds toughen ceramics 20 September 2014, 19.54 Science
Tiny scaffolds toughen ceramics
A nanostructured ceramic material that does not break when deformed has been developed by researchers at the California Institute of Technology. The new material incorporates a scaffolding of nanotubes, which gives it
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Rosetta reveals its target landing site 20 September 2014, 19.54 Science
Rosetta reveals its target landing site
The European Space Agency's Rosetta mission has pinpointed the spot where its Philae landing module will touch down on the surface of a comet in November this year. The site, along with a second "back-up" location, has been
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Synchrotron X-rays track fluids in the lungs 20 September 2014, 19.54 Science
Synchrotron X-rays track fluids in the lungs
A new method of soft-tissue imaging could allow doctors to monitor respiratory treatments of cystic-fibrosis patients, reports an international research team. The technique – which measures the refraction of a grid pattern
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CERN celebrates 60 years of science 20 September 2014, 19.54 Science
CERN celebrates 60 years of science
The CERN particle-physics laboratory near Geneva is celebrating its 60th anniversary this month with a host of symposia, meetings, plays, films, concerts and other events being held at the lab and at member states across
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Gargantuan black hole found at the heart of dwarf galaxy
A supermassive black hole (SMBH) has been found lurking in an unexpected location – at the heart of an ultra-compact dwarf galaxy – according to new observations made by an international team of astronomers. Although
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New plasmonic nanolaser is cavity-free 20 September 2014, 19.54 Science
New plasmonic nanolaser is cavity-free
A new design for a cavity-free nanolaser has been proposed by physicists at Imperial College London. The design builds on a proposal from the same team earlier this year to reduce the group velocity of light of a particular
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Gallery: Snapshots from NYC's World Maker Faire 2014 20 September 2014, 19.53 Science
Gallery: Snapshots from NYC's World Maker Faire 2014
PREVIOUS | NEXT 1 of 20 Maker Faire Costumes Credit: Kelly Dickerson/Live Science World Maker Faire, a festival that celebrates science, technology and innovation, is being held on Sept. 20 and Sept. 21, 2014. The event
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Hello, Autumn! Why Fall Begins on Monday 20 September 2014, 19.53 Science
Hello, Autumn! Why Fall Begins on Monday
The autumnal equinox brings shorter, colder days and beautiful red, orange and yellow leaves to the Northern Hemisphere. Credit: Hernán Seoane On Monday (Sept. 22), the Earth will have nearly equal amounts of light and
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Actually, MSG Is Not Safe for Everyone (Op-Ed) 20 September 2014, 19.53 Science
Actually, MSG Is Not Safe for Everyone (Op-Ed)
Credit: Game day snacks photo via Shutterstock Kathleen Holton is a professor in the School of Education, Teaching and Health and the Center for Behavioral Neuroscience at American University in Washington, D.C. Her
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Well Water May Contain Earthquake Warning Signs 20 September 2014, 19.53 Science
Well Water May Contain Earthquake Warning Signs
The Húsavík-Flatey Fault in Iceland. Mineral levels in groundwater near the fault changed before two earthquakes. Credit: Alasdair Skelton Spikes in sodium and hydrogen in well water warned of mounting strain before
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The Week In Numbers: Origami Microscopes, Laser Turrets, And A Bit More Than One Texas
50: number of cameras researchers are using to study penguin populations in the Antarctic. You can help researchers identify penguins in adorable photographs, all while helping to train their artificial penguin-spotting
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How Gorilla Poop Could Help Stop Ebola 20 September 2014, 19.53 Science
How Gorilla Poop Could Help Stop Ebola
Police drove through Kroo Bay this morning, past the open sewers and snuffling pigs, yelling at people to go inside—largely to no avail. All the 14,000 residents of the shanty town in Freeport, Sierra Leone, had been
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Video: Peter Thiel On How We Can Make The Future Awesome
Peter Thiel has never shied from speculating on the future—and then pouring money into technologies that match that vision. As a cofounder of Paypal, he pioneered a new form of e-commerce. As an investor, he made an early
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Next Week Is Climate Week 20 September 2014, 19.53 Science
Next Week Is Climate Week
Next week is Climate Week in New York City. The happenings begin on Sunday with what promises to be a massive march demanding action to curb human-propelled global warming. On Tuesday, the United Nations will hold an all-day
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Earth News Reports

Michigan Poised to Start Banning Tesla Sales 19 October 2014, 22.26 Transportation
Michigan Poised to Start Banning Tesla Sales
Share on TumblrEmail Michigan just passed a bill in state legislature that essentially bans Tesla from selling cars within the state. HB 5606 prohibits vehicle manufacturers from selling cars directly to
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The Startram Maglev Train Could Make Space Travel Cheaper & More Efficient
Share on TumblrEmail Space travel is a costly and inefficient process. Not only does it take a large amount of fuel to send the lightest payload into orbit (the Space Shuttle used over one million pounds of
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Insane Russian Attack Bike is Powered by a Chainsaw 19 October 2014, 22.26 Transportation
Insane Russian Attack Bike is Powered by a Chainsaw
Share on TumblrEmail Other than the fact that it was constructed in Russia, we aren’t entirely sure who’s responsible for this mean-looking chainsaw bike. While it may look like it’s designed for the
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The Key Art Awards 2014: the best movie posters of the year 19 October 2014, 22.26 Green Architecture
The Key Art Awards 2014: the best movie posters of the year
The Key Art Awards are more famous for their focus on teasers and previews, but they also reward posters. On this post you can see a few of the print finalists, for the full list, just check this page on their website. The post
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Print love: new fine art prints published this week 19 October 2014, 22.26 Green Architecture
Print love: new fine art prints published this week
Poetic, funny, witty, or just beautiful, new art prints are published online every day. With this new weekly feature, I’ll try to share the best of new digital printmaking projects on a regular basis. The great escape by
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20 awesome typographic packaging designs 19 October 2014, 22.26 Green Architecture
20 awesome typographic packaging designs
In this competitive marketplace, if you want to survive with your products then packaging design plays a vital role. For a designer, when it’s the matter of packaging designs, typography is the first thing that hits his/her
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6 WordPress plugins to create cool image effects 19 October 2014, 22.26 Green Architecture
6 WordPress plugins to create cool image effects
As we all know “A picture speaks a thousand words,” it is very essential to pay close attention to images in websites. It has the power to attract your potential customers. That is why today we are here with 6 WordPress
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Illustrations by Jared Muralt 19 October 2014, 22.26 Green Architecture
Illustrations by Jared Muralt
Stunning illustrations by Jared Muralt, a talented illustrator from Bern, Switzerland. Make sure you don’t miss his shop. The post Illustrations by Jared Muralt appeared first on Design daily news. Download the free
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Amazing wooden tables by Lee Jae-Hyo 19 October 2014, 22.26 Green Architecture
Amazing wooden tables by Lee Jae-Hyo
Someone please explain me how these are made technically. Lee Jae-Hyo, a Korean artist, created a set of tables and furnitures made of pieces of wood attached together by some kind of magical technique. He also creates
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Historic photos where guns are replaced by flowers 19 October 2014, 22.26 Green Architecture
Historic photos where guns are replaced by flowers
Blick, a French creative artist, had fun with old war photos and made a pacific statement by exchanging guns in the pictures with flowers. Some powerful images. The post Historic photos where guns are replaced by flowers
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Future News Reports

Obama's War Against US Energy Independence:  Give Away Oil Rich Alaskan Islands to Russia!
  By Joe Miller The Obama administration, despite the nation’s economic woes, effectively killed the job-producing Keystone Pipeline last month. The Arab Spring is turning the oil production of Libya and other Arab
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OSBIT Power's MaXccess system completes successful offshore trials 08 April 2012, 02.33 Administrator Energy
OSBIT Power's MaXccess system completes successful offshore trials
OSBIT Power's MaXccess system completes successful offshore trials Visit http://www.osbitpower.com for further information OSBIT Power (OP), Siemens Wind Power and Statoil have successfully completed offshore
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North America's EV charging infrastructure to get a boost 12 January 2012, 02.01 Administrator Energy
North America's EV charging infrastructure to get a boost
        North America’s EV charging infrastructure may soon see significant improvements, thanks to a recent agreement between Eaton Corporation and Coulomb Technologies. Under the deal, Eaton’s Level II and
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Could The Gravitomagnetic Field Be The Ultimate Energy Source? 28 May 2011, 01.34 Administrator Energy
Could The Gravitomagnetic Field Be The Ultimate Energy Source?
      Have scientists already unknowingly discovered the source for all atomic energy reactions, and could the discovery of the gravitomagnetic field be the ultimate energy source?  What if our understandings on how
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Physicists urge caution over apparent speed of light violation 25 September 2011, 16.27 Administrator Energy
Physicists urge caution over apparent speed of light violation
Physicists wary of junking light speed limit yet Physicist Antonio Ereditato poses before presenting the result of an experiment, which found a subatomic particle, the neutrino, seemed to move faster than the speed of
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STEORN ORBO  FREE ENERGY:  What's Next a Self Charging Unit for your Electric Car?
Steorn's Free Energy Orbo -- From Permanent Magnets to Solid State Systems   My associate, Hank Mills composed this for PESN, Saturday, February 12, 2011 6:17 Steorn is a small company based in Dublin, Ireland. For
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Cold Fusion, Releases Energy from Hydrogen's Gravitomagnetic Field 16 January 2011, 09.17 Administrator Energy
Cold Fusion, Releases Energy  from Hydrogen's Gravitomagnetic Field
Cold Fusion "In Bologna we did it" By Ilaria VENTURI, La Republica News, Bolona, Italy For the first time in Italy, in front of experts, the process was carried out using nickel and hydrogen. It 's the way to achieve
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Abu Dhabi Media Zone to generate renewable energy through its façade
Eco Factor: Sustainable development to generate renewable solar energy. Bernard Tschumi Architects have re-imagined their master plan for the new Abu Dhabi Media Zone, by incorporating several environmentally-friendly
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Quantum test strengthens support for EPR steering PDF Print E-mail

Although the concept of "steering" in quantum mechanics was proposed back in 1935, it is still not completely understood today. Steering refers to the ability of one system to nonlocally affect, or steer, another system's states through local measurements. The two systems are entangled, but it is an especially strong type of entanglement in which the systems are not just correlated, but correlated in a specific direction. Schrödinger originally proposed the concepts of entanglement and steering in response to a well-known Einstein-Podolsky-Rosen (EPR) paper that criticized quantum mechanics.

Since then, steering has only been experimentally demonstrated using inequalities, which involve testing whether or not systems obey the local hidden state model. Entangled systems that can steer each other violate the steering inequalities because they do not obey the local hidden state model. A disadvantage of these demonstrations is that they usually require many measurement settings, which weakens the tests.

In a new study published in Physical Review Letters, a team of physicists led by Professors Jin-Shi Xu and Chuan-Feng Li at the University of Science and Technology of China in Hefei; along with Jing-Ling Chen at Nankai University in Tianjin, China, and the National University of Singapore, have experimentally demonstrated EPR steering using a new method that requires fewer measurements and provides a stronger validation of steering.

The new technique is based on an "all-versus-nothing" (AVN) proof for EPR steering, which does not require inequalities. Using this criteria, the researchers could verify whether states are steerable or not.

"EPR steering exists between the concepts of entanglement and Bell non-locality; these steerable states are a subset of the entangled states and a superset of Bell nonlocal states," Xu told Phys.org. "Bell non-locality shows the conflict between the predictions of quantum mechanics and the local hidden variable theory. On the other hand, the AVN proof for EPR steering shows the conflict between the predictions of quantum mechanics and the local hidden state model.

"In our work, the AVN proof for EPR steering for two-qubit entangled states employs the different pure normalized conditional states (NCS) in one qubit along with a given projective measurement on the other as a criterion. According to quantum mechanics, two different pure NCS should be obtained, while the local hidden state model predicts that one cannot obtain two different pure NCS when the other qubit is performed by a projective measurement. The AVN proof provides a direct contradiction between and the local hidden state model, and it requires fewer measurement settings, which shows the advantage for demonstrating EPR steering."

In addition to providing a stronger test of steering, the AVN test also demonstrates an effect of steering that has never been demonstrated before: that it is possible to store a system's state information in the system that is being steered. This result has practical applications, for example in long-distance quantum information processing. The scientists plan to pursue these applications in the future.

"EPR steering could help us to understand the quantum non-locality comprehensively," Li said. "And it can be used to implement the long-distance quantum state preparation and quantum key distribution. What's more, EPR steering is an asymmetric process, which is different from the concepts of Bell non-locality and entanglement. This feature would find critical applications especially in the tasks where asymmetry plays an important role."

Explore further: Einstein vs quantum mechanics, and why he'd be a convert today

More information: Kai Sun, et al. "Experimental Demonstration of the Einstein-Podolsky-Rosen Steering Game Based on the All-Versus-Nothing Proof." Physical Review Letters 113, 140402 (2014). DOI: 10.1103/PhysRevLett.113.140402

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Living cyberinfrastructure: Accelerating discovery PDF Print E-mail

For scientists looking to complete large, complex, data-driven research projects quickly, living cyberinfrastructure can be a powerful solution. This is a different way of working for most scientists; applying for time on a machine does not guarantee their research proposals will be accepted. If they are, small sacrifices are often required to use shared equipment. The rewards, on the other hand, can be groundbreaking.

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Journeying from data to knowledge at ISC Big Data ‘14 PDF Print E-mail

Last week, decision makers and technical experts from the world of IT met in Heidelberg, Germany, for the second ISC Big Data conference. The event focused on a wide range of big data applications and featured discussion of the latest developments in data-centric computing from both major industry players and academic researchers.

 

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Visualizing urban expansion, shaping urbanization PDF Print E-mail

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The rain in Spain stays mainly in the ... hydrometeorological models PDF Print E-mail

Last month, the Distributed Research Infrastructure for Hydro-Meteorology project (DRIHM) held its second summer school. The event brought together hydrometeorologists from 23 different countries, who learned about the latest computational approaches to critical hydrometeorological events, such as flash floods and thunderstorms.

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‘Mars Rover Curiosity’ chronicles robot's journey PDF Print E-mail

Mars Rover Curiosity
Rob Manning and William L. Simon
Smithsonian, $29.95 

During its first two years on Mars, NASA’s Curiosity rover discovered that the Red Planet was once hospitable to life. For Manning, the rover’s chief engineer, landing on Mars was the capstone of an adventure that started 10 years and $2 billion earlier.

In Mars Rover Curiosity, Manning and coauthor Simon offer a firsthand account of designing the most complex piece of machinery ever to land on another planet. Starting with a harebrained scheme and ending with a drive across the red dust of Gale Crater, the book deftly guides readers through the many setbacks, victories and difficult decisions that came with planning an interplanetary mission.

The book is a fun way to learn about the journey to Mars. The authors steer readers through the technical challenges without getting tangled in jargon. They explain engineering solutions with clear analogies, such as comparing lowering an 899-kilogram rover dangling from a hovering spacecraft equipped with an arsenal of thrusters to controlling a weight on a string with your fingertips while your eyes are closed.

Curiosity’s story is set within the context of previous Mars missions and the culture at NASA. The endless loop of budget pressures and redesigns haunts Manning’s team, eventually leading to a two-year launch delay and a temporarily shrink-wrapped spacecraft. But in the end, the team celebrated numerous successes, from convincing NASA to support a daring landing maneuver to the celebrated touchdown to the discovery of clays that formed when water once flowed across the Martian surface (SN Online: 3/12/13).

More than just a story about a nuclear-powered, laser-wielding robot, the book is about the people who brought Curiosity to life. Hundreds of engineers and scientists worked 70-hour weeks for years to make the impossible happen. And the effort took its toll: Manning lost (and regained) over 15 pounds and struggled with hypertension.

The book is a celebration of the ingenuity, the fears and the dedication of the people who were called to pull off one of NASA’s most daring missions to Mars. 

Buy the hardcover or Kindle edition of this book from Amazon.com. Sales generated through the links to Amazon.com contribute to Society for Science & the Public's programs.

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'The Theory of Everything' reveals Stephen Hawking's personal side PDF Print E-mail

LOVE AND SCIENCE  The challenging but rewarding relationship between Stephen (Eddie Redmayne) and Jane (Felicity Jones) Hawking plays a central role in The Theory of Everything.

Liam Daniel/Focus Features

When Stephen Hawking (played by Eddie Redmayne) first tries out his now-iconic computerized voice, his wife Jane (Felicity Jones) is aghast: “It’s American!” she says. That line draws a laugh, but it also highlights a pivotal draw of The Theory of Everything: That American-accented robotic voice is one of the few things most people know about this brilliant, complicated — and British — man.

“Very little is understood about [Hawking] in America or Canada,” says Anthony McCarten, the film’s screenwriter. “Nine of 10 people think he’s American. Most people think he was born disabled. They don’t know he was married and has three kids. There’s a lot of news to break with this film.”

The movie, based on the 2007 memoir by Jane Hawking, starts in 1963, when Hawking is an able-bodied, intelligent and exceedingly lazy physics graduate student at the University of Cambridge. Just as he appears to be hitting his stride — he falls in love and begins developing insights into black holes and the origin of the universe — he is diagnosed with motor neuron disease (the British term for amyotrophic lateral sclerosis, or ALS) and told he has two years to live. (Nearly 50 years after his predicted expiration date, Hawking is still going strong.)

The rest of the movie shows that as Hawking rose to fame, thanks largely to his book A Brief History of Time, he and Jane were battling through a tumultuous 25-year marriage. The film impressively avoids sensationalizing the deterioration of the Hawkings’ relationship, which ends with Stephen marrying the nurse Jane hired for him and Jane marrying a choir director who helped take care of Stephen.

McCarten and director James Marsh get creative trying to incorporate Hawking’s contributions to science: Cream swirling around a coffee cup illustrates the region around a black hole, while Jane Hawking uses a pea and a potato to explain the difference between quantum theory and general relativity. But for the most part, science takes a backseat to a story about love and, as Marsh puts it, “a battle against impossible odds to have a meaningful life.”

McCarten says Hawking was hesitant about the movie at first — “What man really wants his story told by his ex-wife?” McCarten asks — but warmed up to it after reading the script. He visited the set a few times and offered his robotic voice for use in the film.

A tear ran down Hawking’s face after he saw the completed film for the first time, McCarten says. Then, twitching his cheek to scroll through letters on his computer, Hawking composed two words: “Broadly true.”

“That’s a ringing endorsement,” McCarten says. “I’ll take that any day.”

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Tiny human intestine grown inside mouse PDF Print E-mail

LOOKS LIKE A GUT  Transplanted into mice, tiny specks of human intestinal tissue (stained pink) develop into working organs surrounded by a muscular sheath (stained green), just like real intestines.

Slimy chunks of human gut can now grow up and get to work inside of mice.

Transplanted into rodents, tiny balls of tissue balloon into thumb-sized nuggets that look and act like real human intestines, researchers report October 19 in Nature Medicine.

The work is the first time scientists have been able to transform adult cells into working bits of intestines in living animals. These bits could help scientists tailor treatments for patients with bowel diseases, such as Crohn’s disease or cancer, says study coauthor Michael Helmrath, a pediatric surgeon at Cincinnati Children’s Hospital. Doctors could test drugs on the gut nuggets and see how a patient’s tissues respond without having to subject the person to a slew of different treatments.

“If you give me a patient, I can grow their intestines,” Helmrath says.

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Chemistry Nobel awarded for super-resolution microscopy PDF Print E-mail

The 2014 Nobel Prize for Chemistry has gone to Eric Betzig, Stefan Hell and William Moerner for developing super-resolution microscopy techniques based on the fluorescence of molecules. The prize is worth SEK 8m (£690,000) and will be shared by the three winners, who will receive their medals at a ceremony in Stockholm on 10 December.

Betzig is a US citizen and works at the Howard Hughes Medical Institute, Hell is a German citizen and is at the Max Planck Institute for Biophysical Chemistry in Göttingen, and Moerner is a US citizen based at Stanford University.

The trio won the prize for overcoming what had seemed to be an insurmountable barrier to using microscopes to see features in biological cells that are smaller than a few hundred nanometres across – the so-called diffraction limit. Hell took one approach to solving the problem, while Betzig and Moerner took a somewhat different route. Both techniques, however, involve "tagging" a relatively large biological molecule of interest with much smaller fluorescent molecules that glow briefly (or "blink") after being illuminated with a pulse of laser light.

Suppressing fluorescence

Hell's method involves firing two lasers at the sample. One (the exciting laser) is tuned to cause the molecules to fluoresce and the other laser is tuned to suppress fluorescence. The clever trick is that the suppressing light has a dark region in the middle of its beam, the size of which is defined by the diffraction limit. The exciting light, on the other hand, illuminates a spot with a size defined by the diffraction limit. The effect of overlapping these two beams is the emission of fluorescent light from a central region that is smaller than the diffraction limit. Indeed, the size of the region can, in principle, be made arbitrarily small by adjusting the relative intensities of the two lasers. An image is acquired by scanning the location of the central region across the sample.

The technique developed by Betzig and Moerner involves illuminating the sample with a weak laser pulse to ensure that only a tiny fraction of the fluorescent molecules will blink at a given time. This tiny fraction means that it is extremely unlikely that any of these blinking molecules are separated by distances less than the diffraction limit. Each molecule will emit a number of photons during a blink and these are detected as an intensity peak that has a normal distribution with a width that is limited by the diffraction limit. However, because the light is known to come from a single molecule, the location of the molecule can be placed with high probability at the centre of the normal distribution. Furthermore, the uncertainty in the location of the molecule falls as one over the square root of the number of photons detected. While an individual image only shows the locations of a few molecules, repeating the process many times allows a composite image of all the molecules to be created.

Well deserved

Frank Jäckel of the University of Liverpool in the UK, who worked in Moerner's lab in the 2000s, described his former colleague as a "great researcher" and said that the prize is "well deserved". He points out that Moerner's discovery in 1989 that light from just one molecule can be detected was an important breakthrough that lead to the development of the super-resolution microscopy technique.

John Dudley, president of the European Physical Society, told Physics World that the work of Betzig, Hell and Moerner "has pushed back the accepted wisdom of the limits of optical resolution [and is] a timely reminder how we should constantly question received wisdom and pre-conceived ideas". He added that "Sometimes what we think is impossible is possible with new technology and imagination."

Eric Betzig was born in 1960 in Ann Arbor, Michigan. After obtaining a BS in physics from the California Institute of Technology in 1983, he received his PhD from Cornell University in 1988 for work on near-field scanning optical microscopy.

Betzig then moved to Bell Labs in New Jersey, where he continued to work on near-field optics for applications in biology and data storage. In 1994 he left Bell Labs to start a research and consulting firm called NSOM Enterprises, but two years later left to become vice-president of R&D in his father's machine-tool company, Ann Arbour Machine Company.

Return to academia

In 2002 commercial failure left Betzig unemployed, so he founded another R&D consulting firm, New Millennium Research. Three years later he went back to academia, joining the Howard Hughes Medical Institute (HHMI) in Ashburn, Virginia, where he is currently leader of the HHMI's Janelia Farm Research Campus.

Stefan Hell was born in 1962 in Arad, Romania. After receiving his BSc from the University of Heidelberg, Germany, in 1987, he was awarded a PhD from the same university in 1990 for work on the imaging of transparent microstructures. In 1991 Hell moved to the European Molecular Biology Laboratory, also in Heidelberg, and two years later became a senior researcher at the University of Turku in Finland. In 1997 Hell moved to the Max Planck Institute for Biophysical Chemistry in Göttingen, becoming a director in 2002. Hell is also currently a division head at the German Cancer Research Center in Heidelberg.

William Moerner was born in 1953 in Pleasanton, California. In 1975 he was awarded degrees in physics, mathematics and electrical engineering from Washington University in St Louis and in 1982 received his PhD in physics from Cornell University for work on the vibrational relaxation dynamics of alkali halide lattices. After his PhD, Moerner worked at the IBM Almaden Research Center in California as a researcher and then project leader, before joining the University of California, San Diego in 1995. He – along with his research group – then moved to Stanford University in 1998.

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Isamu Akasaki, Hiroshi Amano and Shuji Nakamura win 2014 Nobel Prize for Physics PDF Print E-mail

The 2014 Nobel Prize for Physics has been awarded to Isamu Akasaki, Hiroshi Amano and Shuji Nakamura for their development of blue LEDs. The prize is worth SEK 8m (£690,000) and will be shared by the three winners who will receive their medals at a ceremony in Stockholm on 10 December.

Akasaki is a Japanese citizen and works at Meijo University and Nagoya University. Amano is a Japanese citizen and works at Nagoya University. Nakamura is a US citizen and works at University of California, Santa Barbara.

The prize citation honours the trio for "the invention of efficient blue light-emitting diodes which has enabled bright and energy-saving white light sources". The now ubiquitous LEDs are used in a wide arrange of applications from televisions to sterilizers and do not contain toxic mercury that is found in fluorescent lamps.

Three-colour blues

A source of white light needs LEDs that deliver red, green and blue light. The first red LED was created in the 1950s and researchers then managed to create devices that emitted light at shorter wavelengths, reaching green by the 1960s. However, researchers struggled to create blue light.

In the 1980s Akasaki and Amano working at Nagoya University and Nakamura working at the Nichia Corporation focussed on the compound semiconductor gallium nitride (GaN), which could be ideal for creating blue LEDs because it had a large band-gap energy corresponding to ultraviolet light.

There were many challenges, however, in making useable LEDs based on GaN. One major problem was how to create high-quality crystals of GaN with good optical properties. This was solved independently in the late 1980s and early 1990s by Akasaki and Amano and also by Nakamura. Both teams used metalorganic vapour phase epitaxy (MOVPE) techniques to deposit thin films of high-quality GaN crystals onto substrates.

Doping discovery

Another seemingly insurmountable challenge facing the researchers was how to dope the GaN so it is a p-type semiconductor, which is crucial for creating an LED. Akasaki and Amano noticed that when GaN doped with zinc is placed in an electron microscope, it gives off much more light. This suggested that electron irradiation improved the p-doping – an effect that was later explained by Nakamura.

The next step for both teams was to use their high-quality, p-doped GaN along with other GaN-based semiconductors in multilayer "heterojunction" structures. Nakamura was then able to create the first high-brightness blue LED in 1993.

Praising the laureates, the chairman of the Nobel committee for physics Per Delsing said "A lot of big companies tried to [develop blue LEDs] and they failed, but these guys persisted and eventually they succeeded."

Today, GaN-based LEDs are used in back-illuminated liquid-crystal displays in devices ranging from mobile phones to TV screens. LEDs emitting blue and ultraviolet (UV) light have also been used in DVDs, where the shorter wavelength of the light allows higher data-storage densities. Looking into the future, UV-emitting LEDs could be used to create basic yet effective water-purification systems, because UV light can destroy micro-organisms.

Invention or discovery?

Over the past 10 years there have been three other physics Nobel prizes awarded for work with significant commercial potential: giant magnetoresistance in 2007; fibre optics and charged-coupled devices in 2009; and graphene in 2010. While most prizes are associated with more esoteric discoveries, like the Higgs boson, Alfred Nobel decreed in his will that the prize could also be given for an important invention in physics.

"Alfred Nobel would be very happy about this prize," says Delsing. "[The blue LED] is really something the will benefit most people."

David Gross from the Kavli Institute for Theoretical Physics at University of California, Santa Barbara, who shared the 2004 Nobel prize for his work on asymptotic freedom, is happy that in recent years both pure and applied research are being recognized. After addressing a meeting in Trieste to mark the 50th anniversary of the International Centre for Theoretical Physics, where he had stressed the importance of blue-sky research, Gross told Physics World that "Every five or six years the prize is awarded to an invention that has conferred a great benefit to humankind, such as the transistor, the laser and fibre optics. I think the existing ratio is just about right."

Akasaki was born in Chiran, Japan, in 1929. He graduated from Kyoto University in 1952 and received his PhD in 1964 from Nagoya University.

Amano was born in Hamamatsu, Japan, in 1960. He received his PhD in 1989 from Nagoya University.

Nakamura was born in Ikata, Japan, in 1954. He graduated from the University of Tokushima in 1977 with a degree in electronic engineering and obtained a Master's degree in the same subject two years later. He then joined the Nichia Corporation, a small company located in Tokushima on the island of Shikoku. Nakamura was awarded a PhD in 1994 from University of Tokushima.

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Majorana quasiparticles glimpsed in magnetic chains PDF Print E-mail

The strongest evidence yet that Majorana quasiparticles (MQPs) can be found lurking in some solids has been unveiled by physicists in the US. The team used a scanning tunnelling microscope (STM) to locate MQPs at the ends of atomic chains of magnetic iron lying on the surface of a lead superconductor. MQPs have special properties that could make them ideal for use in quantum computers, and this latest breakthrough could lead to practical devices that make use of the quasiparticles.

First predicted by the Italian physicist Ettore Majorana in 1937, the Majorana fermion has zero charge and is its own antiparticle. Unlike conventional fermions such as the electron – which obey Fermi–Dirac statistics – the Majorana fermion obeys "non-Abelian" statistics. This means that quantum information encoded in the particles would be highly resistant to decoherence. Decoherence is the bane of physicists who are trying to develop practical quantum computers, and therefore devices based on Majorana fermions could be used in future quantum-information systems.

Exciting excitations

Although Majorana fermions have never been spotted as free particles, there is growing evidence that collective excitations of electrons – called quasiparticles – in some solids can have the same properties as Majorana fermions. Evidence of such MQPs has already been seen at the interface between a superconductor and a non-superconductor in several different experiments – however none of these studies have been conclusive.

Now, Ali Yazdani and colleagues at Princeton University and the University of Texas at Austin have found further evidence of MQPs at the interface of a superconductor and a magnet. The team looked at magnetic chains of iron atoms on the surface of a superconducting lead crystal that is chilled to 1.4 K. Using a spin-polarized tip on their STM, the researchers were able to show that the iron chain is ferromagnetic. Then, using the STM to measure the energy spectrum of electrons in the chain, they showed that the iron was also behaving as a superconductor – a phenomenon known as the proximity effect.

Swirling electrons

The superconductivity in the iron chain involves paired electrons travelling in helical orbits. This rare type of pairing makes the chain a "topological superconductor", and MQPs are expected to occur at the end of the chains.

To locate MQPs, the team looked for something called a zero bias peak (ZBP) in the electron energy spectrum of the iron chain. The STM measures the ease with which an electron can be added or removed from the chain by applying a bias voltage between the tip and the chain. However, because the MQPs are a combination of a negative particle and a positive antiparticle, they can only move in and out of the chain when a zero applied voltage – or bias – is applied at the tip.

The team scanned the STM tip along a chain, and found the expected ZBPs at either end. But the ZBP could be due to an unrelated magnetic resonance that can occur in the chains. This was ruled out by repeating the measurement in a weak magnetic field, which stops lead from being a superconductor. The ZBP vanished as expected. If the ZBP was related to a magnetic resonance, it would have been enhanced by the magnetic field, not diminished.

Mobile Majoranas

While the physicists are not alone in seeing ZBPs at the ends of tiny wires, they are the first to be able to rule out the effect of magnetic resonances. Yazdani told physicsworld.com that the team is now studying edges of 2D islands of magnetic atoms on a superconductor for evidence of MQPs. Such MQPs should be able to move along the edge of an island, allowing physicists to further study their properties.

Joel Moore of the University of California Berkeley sees the work as a significant contribution to MQP research: "It goes beyond the previous efforts also seeing zero-bias tunnelling peaks in that it has excellent spatial resolution and a clearly defined system that can probably be reproduced by other groups."

However, Moore points out that for MQPs to be useful in quantum computers, their non-Abelian nature must be established – something Yazdani and colleagues are also working on at the moment.

The video below shows how the iron chains were made and studied using STM.

The research is described in Science.

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Nobel laureate Martin Perl dies at 87 PDF Print E-mail

The US particle physicist Martin Perl has died at the age of 87. Perl was instrumental in discovering the tau lepton – an elementary particle similar to the electron but 3477 times heavier. The work led him to share the 1995 Nobel Prize for Physics with Frederick Reines, who discovered the neutrino, for their "pioneering experimental contributions to lepton physics".

Born in New York City on 24 June 1927, Perl originally trained as a chemical engineer, obtaining a degree in the subject at the Brooklyn Polytechnic Institute in 1948. He then went on to work for General Electric, where he was involved in producing electron vacuum tubes. It was there that Perl's interests turned to physics, and he began to enrol in physics courses at Union College in New York.

In 1955 Perl was awarded a PhD in physics from Columbia University, which he did under the supervision of the 1944 physics Nobel laureate Israel Isaac Rabi. Perl's thesis applied Rabi's nuclear-magnetic-resonance technique to measure the nuclear quadrupole moment of sodium. After his PhD, Perl moved into particle physics, heading to the University of Michigan, where he used bubble chambers to study the scattering of pions with nucleons.

The third generation

In 1963 Perl joined the Stanford Linear Accelerator Center (SLAC), and it was there that he carried out his Nobel-prize-winning work in the 1970s. We now know that three generations of leptons and quarks make up the known fundamental matter states in the universe, but in the early 1970s only two generations of leptons were known to exist. The first consists of the electron and its associated neutrino – the electron neutrino (together with their antiparticles) – while the second generation includes the muon and the muon neutrino.

Perl's discovery opened up the third generation of elementary particles. In 1972 SLAC had just completed the SPEAR electron–positron collider, which could collide electrons and positrons at a then-record energy of 4.8 GeV (later reaching 8 GeV). In conjunction with the magnetic detector – developed at the Lawrence Berkeley National Laboratory – the facility could detect and distinguish between leptons, hadrons and photons.

Using SPEAR between 1974 and 1977, Perl and colleagues observed events in which the electron–positron annihilation produced electron–antimuon or positron–muon pairs with an energy less than the initial energy and with no other particles visible. Perl's interpretation was that the initial electron–positron pair had annihilated to produce a new lepton–antilepton pair, which Perl dubbed the tau–lepton pair. The tau then decayed into an electron (or muon) plus two undetected neutrinos, while the antitau decayed into an antimuon (or positron) and two neutrinos.

Given that the signal could be explained by other events, some particle physicists were initially sceptical about the discovery. What finally convinced the community that the tau lepton had been discovered was when Perl's results were later confirmed by the DESY particle-physics lab in Hamburg, Germany, as well as by further experiments at SPEAR.

Perl was active in physics until the end of his life. Indeed, recently he had turned his sights on experiments to understand the nature of dark energy. One such proposal, in 2011, involved dropping caesium atoms through two 1.5 m-long atom interferometers in the hope of detecting any hitherto unknown "dark content of the vacuum".

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Megatelescope snaps up former fusion boss PDF Print E-mail

Edward Moses joins the Giant Magellan Telescope Organization (GMTO) today as its first president, after stepping down as a scientific manager at the Lawrence Livermore National Laboratory. Moses had spent the past 15 years overseeing the effort to develop laser-based fusion at Livermore's National Ignition Facility (NIF), but will now focus on managing the construction of the massive 25.4 m optical telescope on northern Chile's Las Campanas Peak.

When it comes online about a decade from now, the $880m GMT will have almost 10 times as much light-gathering capacity as any existing instrument. Astronomers will use the telescope for everything from spotting exoplanets and examining the formation of stars and galaxies shortly after the Big Bang to measuring the masses of black holes and exploring dark matter and dark energy. Moses' appointment comes as the project moves from design to construction, with the first of the instrument's seven primary 8.4 m mirrors having been completed, and two others being ground and polished. Workers have also cleared more than 40,000 m3 of rock from the Chilean site to make way for construction.

Eye on the sky

Moses takes up his new position 16 months after he left the directorship of NIF to concentrate on Livermore's photon science directorate. At the time, critics accused him of mismanaging NIF and speculated that he had paid the price for NIF's failure to hit its target of achieving a self-sustaining fusion reaction by 2012. But those murmurings have seemingly not affected his ability to land new roles. "We looked into how people related to him as staff and many at NIF came close to worshipping [Moses] and would have followed him off the cliff," says Rocky Kolb – dean of physical sciences at the University of Chicago – who is a member of the GMTO board that recruited Moses. "There's simply no substitute for experience with large technical projects and we're convinced that he's the person to get the telescope into operation."

Moses intends to draw on his 30-year experience in big-science facilities and other ground-breaking projects, which included having to develop new systems and technologies at NIF that did not exist before the facility started. "To manage that, do the R&D, and integrate it together was the big issue," says Moses, who promises to take the GMT "from a giant telescope to a great laboratory". GMTO director Patrick McCarthy adds that Moses brings "an order of magnitude attitude, skill and vision" to the project. "We think this is a transformative moment," he says.

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Are 'weak values' quantum after all? PDF Print E-mail

A technique known as a "weak measurement", which allows physicists to measure certain properties of a quantum system without disturbing it, is being called into question by two physicists based in Canada and the US. The researchers argue that such measurements, and their counterparts known as "weak values", might not be inherently quantum mechanical and do not provide any original insights into the quantum world. Indeed, they say that the results from such measurements can be replicated classically and are therefore not properties of a quantum system.

More than 25 years ago, Yakir Aharonov, Lev Vaidman and colleagues at Tel Aviv University in Israel came up with a unique way of measuring a quantum system without disturbing it to the point where decoherence occurs and some information is lost. This is unlike conventional "strong measurements" in quantum mechanics, in which the system "collapses" into a definite value of the property being measured – its position, for example. Instead, the researchers suggested that it is possible to gently or "weakly" measure a quantum system, and to gain some information about one property (such as its position) without disturbing a complementary property (momentum) and therefore the future evolution of the system. Although each measurement only provides a tiny amount of information, by carrying out multiple measurements and then looking at the average, one can accurately measure the intended property without distorting its final value.

Screening unwanted measurements

The process involves making a "pre-selection" by preparing a group of particles in some initial state, followed by weakly measuring each of the particles at some point in time. Then, a "post-selection" second set of measurements is made at a slightly later time. The results of the weak measurements will, on average, imply certain results for the post-selection measurements, but they do not determine them. Ultimately, by screening unwanted measurements, one is left with a "weak value".

In the original theoretical paper published in 1988, Aharonov and colleagues consider measuring the spin of a spin-½ particle. First, an ensemble of particles of only a particular state, say spin up, is created – this is the pre-selection. Next, one would make weak measurements of the spin of the particles many times, but as "gently" as possible. A final measurement would be made, and particles that are not in the desired state are discarded in the post-selection process. Then, by combining all three measurements, one would be able to measure the state of the system, according to Aharonov and colleagues.

The paper, however, identifies a very strange property of weak values. If the weak measurement is done in a certain way, it is possible for the weak value of the spin to be 100 rather than one-half, which would be the outcome of a strong measurement. Aharonov and colleagues call this an "anomalous weak value" and the paper remains controversial.

In 2011 Aephraim Steinberg and colleagues at the University of Toronto demonstrated the technique by tracking the average paths of single photons passing through a Young's double-slit experiment. In recent years, this method of weak measurement has gained momentum and has been used in some quantum-information technologies, including quantum feedback control and quantum communications.

Weak understanding

Now, Christopher Ferrie of the University of New Mexico along with Joshua Combes of the Perimeter Institute for Theoretical Physics in Waterloo, Canada, are questioning the concept of weak measurement. Indeed, they are highly sceptical of the whole field, saying that, at the very least, what information is gleaned from a weak measurement is currently not understood.

There might be something genuinely quantum about weak values, but to my eye that's not clear yet
Joshua Combes, Perimeter Institute for Theoretical Physics

"Weak values do not seem to be a property of the system in any way," says Ferrie. He and Combes claim that while the idea of weakly measuring a system is fine, making pre- and post-selections is akin to having a set of data and just favouring a subset of it – meaning that any measurement made is a consequence of classical statistics, rather than a physical property of the system. "So long as there is some co-relation between the second [weak measurement] and third [post-selection] steps, you will have an anomalous weak value," says Ferrie. But such a correlation would mean that the original quantum system being measured is no longer sound.

To illustrate their point, the researchers have come up with a classical analogue of a weak value presented in the Aharonov paper by adopting the world's simplest random system: a coin flip.

It can be imagined as a coin-flipping game in which one player, called Alice, flips a coin and only passes the coin on to the other player, Bob, if it is "heads", which is pre-selection. Bob has no prior knowledge of the state of the coin and can only glance at it quickly to try to determine its state, which is the weak measurement. Bob then fumbles the coin so there is a small chance that it flips, which is the disturbance. Finally, he hands the coin back to Alice, who looks at its state and discards all coins that come back heads – which is post-selection.

Very occasionally, Alice will receive a coin that is tails. Because all the coins were pre-selected heads, she assumes that Bob had measured heads and then flipped the coin during the disturbance process.

If heads is given the value +1 and tails –1, and if Alice concludes that Bob flips one in every 100 coins, the mathematical operations outlined by Aharonov and colleagues suggest that the weak value for Bob's weak measurements is 100. Like Aharonov's "spin 100" weak value, this is an anomalous result, because the values assigned to heads and tails are +1 and –1, and one would expect the weak value to be somewhere between the two.

Ferrie and Combes say that their example shows that weak measurements are merely an artefact of classical statistics and classical disturbances, and they argue that when a classical explanation suffices, there is no need to invoke a quantum explanation. "Statistics can fool you," says Combes. "We think this particular weak-value puzzle is a statistical question, not a fundamentally quantum question. There might be something genuinely quantum about weak values, but to my eye that's not clear yet."

Rainer Kaltenbaek of the Quantum Foundations and Quantum Information group at the University of Vienna found the general idea underlying Ferrie and Combe's analysis very interesting. "In particular, it shows that there's often still confusion about what to make of weak values," he says. He points out other research, carried out by Franco Nori of the University of Michigan and colleagues, which Combes and Ferrie refer to in their current work. Nori's team has interpreted Steinberg's experiment in completely classical terms.

Referring to Steinberg's experiment with the photon trajectories, Kaltenbaek says that a weak value can be calculated if one averages over many photons. "It only becomes complicated if you try to infer something from that for a single photon – in my opinion, it [a weak value] does not tell you anything useful at all for a single photon," he says, and that Combes and Ferrie's recent research illustrates that quite well.

Combes and Ferrie's analysis is published in Physical Review Letters.

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Dolphin-inspired sonar overcomes size-wavelength limitation PDF Print E-mail

(Phys.org) —In a typical man-made sonar system, pulses of sound emitted by the projector bounce off hidden objects underwater. The echoes are then detected by the receiver to infer the location and size of the hidden objects.

A highly focused or "directional" acoustic source offers the advantages of reducing noise interference, increasing the detection resolution, and enhancing sound intensity in the direction of interest. However, high directivity also requires an acoustic projector of large size in comparison with the wavelength, or high-frequency sound beams. Most sources consist of large arrays, and the total size of the arrays is much larger than the wavelength. This problem is known as the size-wavelength limitation.

While this problem plagues man-made sonar, Yangtze finless porpoises don't seem to have the same limitation. Through millions of years of evolution and natural selection, the animal has developed a relatively small head (compared to man-made sonar) that can manipulate acoustic waves into a beam with high directivity. Porpoises and dolphins use these highly efficient biosonars for foraging, avoiding predators, and group coordination. Studies have shown that, despite serious vision degradation in water, can locate centimeter-sized objects 100 meters away using echolocation.

Now a team of researchers from Xiamen University and the Institute of Hydrobiology of the Chinese Academy of Sciences in China, as well as The Pennsylvania State University in the USA, has designed and constructed a biomimetic sonar projector based on dolphin biosonar that achieves high directivity with a subwavelength sound source, overcoming the size-wavelength limitation. Their work is published in a recent issue of Applied Physics Letters.

"The biomimetic projector breaks the size-wavelength limitation of traditional man-made sonar systems and provides a new concept for the realization of directional acoustic devices in the subwavelength regime," coauthor Wenwu Cao, Professor at The Pennsylvania State University, told Phys.org.

(a) CT image of a neonate finless porpoise’s head. The region bounded by dashed lines represents the acoustic path. (b) Schematic diagram of the biomimetic projector. Credit: Zhang, et al. ©2014 AIP Publishing

"[Before now,] the compromise in size or frequency has inevitably brought many serious problems, including large physical size for low-frequency sound beams, high power consumption, and strong attenuation at high frequencies that reduces the detection distance," he explained. "Therefore, it is important to be able to operate a directional sonar in the subwavelength range, which allows the sonar device to be made in small size with high resolution."

The researchers' work builds on their recent computed tomography (CT) studies of the complex structure of dolphin biosonar. The CT results show that the Yangtze finless porpoise has three main acoustic elements in its head: a skull, melon (fatty tissue), and air sacs. The researchers designed elements to mimic each of these features: a steel structure to mimic the skull, a gradient-index material to mimic the melon, and an air cavity to mimic the air sacs.

"These three elements collectively could manipulate the omnidirectional wave generated from a subwavelength source into a highly directional one," said Yu Zhang, project leader and Professor at the Key Laboratory of Underwater Acoustic Communication and Marine Information Technology of the Ministry of Education, Xiamen University.

By successfully mimicking a dolphin's acoustic elements, the researchers could achieve a very high-performing sonar system using a single sound source. Experiments and simulations showed that the bio-inspired sonar system could have both a miniature size and high directivity, breaking the size-wavelength limitation.

Compared to the traditional strategy of using a horn for making directional beams with a bare subwavelength source (without all of the dolphin-inspired acoustic elements), the new biomimetic projector has superior angular resolution by an order of magnitude, in addition to other advantages. As it does not require complex circuitry, such a also has low energy consumption and very low cost.

These properties make the bio-inspired sound projector promising for applications in underwater sonar, medical ultrasound, and other related areas. The researchers also want to investigate what happens when part of a dolphin's biosonar is damaged.

"In the future, we will focus more on the function of each component and the physical mechanism of beam focusing using gradient materials," Cao said. "In principle, a dolphin's acoustic structure should affect its biosonar function. But, we found a dolphin with partially damaged acoustic structure that lives independently and is able to avoid vessels, which suggests its echolocation ability is still intact. Our next goal is to find out why such acoustic structure damage did not cause catastrophe in the dolphin's life. In addition, the biomimetic structure will be further optimized using artificial materials having an impedance gradient much larger than in the dolphin bisonar system. Hopefully we could apply the principle of the research finding to build better sonar systems in the near future."

Explore further: For bats and dolphins, hearing gene prestin adapted for echolocation

More information: Yu Zhang, et al. "A biomimetic projector with high subwavelength directivity based on dolphin biosonar." Applied Physics Letters. DOI: 10.1063/1.4896509

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Superposition revisited: Proposed resolution of double-slit experiment paradox using Feynman path integral formalism PDF Print E-mail

(Phys.org) —The Schrödinger's Cat thought experiment, published in 1926 by Erwin Schrödinger, may be the most widely-known metaphorical explanation of quantum superposition and collapse. (Superposition is a fundamental principle of quantum mechanics stating that a physical system – such as a photon or electron – simultaneously exists partly in all theoretically possible states; but when measured or observed gives a result corresponding to only one of the possible states.)

That being said, the earlier foundational has the advantage of being, well, an actual experiment that provides a window into this often counterintuitive realm. (As a somewhat surprising aside, while the Michelson–Morley experiment, published in 1887 by Albert A. Michelson and Edward W. Morley, demonstrated temporal coherence, a much earlier device – Thomas Young's 1803 double-slit interferometer – demonstrated spatial coherence, contradicting Newtonian physics a century before quantum mechanics and special relativity by showing that light, like sound, was also a wave motion.) Despite its long legacy, however, the double-slit experiment remains the subject of research. One such focus is a curious discrepancy: The Schrödinger (yes, the same Schrödinger) equation, or wavefunction– which describes how the quantum state of a physical system changes with time – when both slits are open differs slightly from the sum of the wavefunctions with the two slits alternately open. The problem is that the three alternatives (slits A and B, slit A, slit B) correspond to separate boundary conditions – equations that specify the behavior of the solution to a system of differential equations at the boundary of that system's domain – meaning that superposition does not apply.

Recently, however, scientists at the Raman Research Institute and the Indian Institute of Science, both in Bangalore, India, theoretically resolved this paradox by quantifying nonclassical path contributions in quantum interference experiments using the Feynman path integral formalism, which involves an integration over all possible paths that can be taken by the particle through the two slits, thereby calculating a quantum amplitude by replacing the classical notion of a single, unique trajectory for a system with a sum, or functional integral, over an infinite number of possible trajectories. This allows them to replace the approximate wavefunction with both slits open (ψAB = ψA + ψB) with an integral that includes both the classical paths – the nearly straight paths from the source to the detector through either slit – and the nonclassical, or looped, paths that make a small but finite contribution to the total intensity at the detector screen (ψAB = ψA + ψB + ψL).

In so doing, they successfully quantified the effect of such nonclassical paths in interference experiments, which in turn quantifies the deviation from the common but incorrect application of the in different possible experimental conditions. Although the researchers acknowledge that it would be difficult to create a direct experimental demonstration of the existence of these nonclassical paths, they conclude that since contributions from such paths can be significant. They therefore propose simple three-slit interference experiments to directly confirm their existence.

Path integrals in a lab. The green line demonstrates a representative classical path. The purple line demonstrates a representative nonclassical path. The various length parameters are marked; d designates the interslit distance, w designates the slit width, h designates the slit height, L designates the distance from the source to the slit plane, and D designates the distance from the slit plane to the detector plane. Source: R. Sawant, J. Samuel, A. Sinha, S. Sinha, and U. Sinha, Nonclassical Paths in Quantum Interference Experiments, Phys. Rev. Lett. 113, 120406 (2014).

Prof. Urbasi Sinha, Raman Research Institute and Prof. Aninda Sinha, Indian Institute of Science discussed the paper that they and their co-authors published in Physical Review Letters. One of their main challenges was at the heart of their research: using the Feynman path integral formalism to quantify contributions from nonclassical paths to provide a measurable deviation from naive applications of the superposition principle. "In order to isolate the effect of the nonclassical paths we used the Sorkin parameter as proposed by Rafael D. Sorkin1," Aninda tells Phys.org. "Originally this parameter was proposed to test the Born rule, but it turned out to be a useful way to isolate the contribution of the curved paths." The Born rule (published by Max Born in his 1926 paper2) is a law of quantum mechanics which gives the probability that a measurement on a quantum system will yield a given result. "In addition, an earlier classical simulation of the Maxwell's equations3 led us into thinking about the problem in the realm of quantum mechanics."

Of equal import to the scientists – and a challenge that lies ahead of them, as well as to those researchers who respond to their proposal – is presenting a direct experimental demonstration for the existence of these nonclassical paths. "The nonclassical paths have always existed – the path integral formalism requires one to take into account the contribution from all possible paths," Urbasi explains. "However, these paths always tend to have contributions secondary to those from the classically dominant paths that extremize the action." This occurs in accordance with the action principle, which states that a particular functional of all paths that a particle can take between two points is extremized along the correct classical solution. "Thus, in spite of being present, the contribution to a certain propagator tends to be much smaller than the one from the classically dominant ones," Urbasi adds.

"This is what makes an experimental demonstration challenging," Urbasi continues, "since it requires a signal-to-noise ratio high enough to enable a non-zero measurement of a parameter known as kappa (κ) – the normalized version of the Sorkin parameter – as a function of detector position. Having said that, the path integral formalism enabled us to use the kappa symmetry to our advantage: Because it ensures that it is non-zero only in the presence of nonclassical paths, and zero otherwise, it provides a precise and convincing demonstration of the presence of these nonclassical paths."

Moving forward, Urbasi notes that using nonclassical path effects to model possible decoherence mechanisms in interferometer-based quantum computing applications is a direction the scientists wish to investigate in the near future. "Any quantum simulation which appeals to the phenomenon of interference should benefit from our approach – and regarding quantum computing itself, an interferometer-based quantum computing architecture immediately comes to mind. Our work highlights and suggests an experimental proposal to quantify non classical paths in interference experiments and hence comments on the commonly used naive application of the superposition principle in interference experiments. If a successful experiment is performed, then that will prove our assertions. Completing the picture in so far as application of the superposition principle in interference phenomena is concerned should definitely have ramifications in situations where interference is used as a resource."

Other areas of research will benefit from their study, Urbasi says, because their work gives them a more complete understanding of slit-based interference. "Richard Feynman famously said that 'the double-slit experiment has in it the heart of . In reality, it contains the only mystery.4' Therefore, a more complete understanding there will be useful in all areas where interference is considered a resource. These include interferometer-based quantum computing protocols as well as observational radio astronomy data related to the early universe. In fact," Aninda points out, referring to the potential role of Feynman's path integral formalism and thereby looped nonclassical paths in the effort to construct a unified theory of quantum gravity, "there have been recent proposals in the cosmology literature which deal with a potential modification to the Born rule. For such modifications to be experimentally testable one will need precision calculation such as ours."

Explore further: Duality principle is 'safe and sound': Researchers clear up apparent violation of wave-particle duality

More information: Nonclassical Paths in Quantum Interference Experiments, Physical Review Letters 113, 120406: Published 19 September 2014, doi:10.1103/PhysRevLett.113.120406

Related:

1Quantum Mechanics As Quantum Measure Theory, Modern Physics Letters A 09, 3119 (1994), doi:10.1142/S021773239400294X (Earlier PDF version: arXiv:gr-qc/9401003v2)

2Zur Quantenmechanik der Stoßvorgänge, Max Born, Zeitschrift für Physik, 37, #12 (Dec. 1926), pp. 863–867 (German); English translation, On the quantum mechanics of collisions, in Quantum theory and measurement, Section I.2, J. A. Wheeler and W. H. Zurek, eds., Princeton, New Jersey: Princeton University Press (Paperback Edition, July 14, 2014), ISBN-13: 978-0691613161

3Analysis of multipath interference in three-slit experiments, Physical Review A 85, 012101 (4 January 2012), doi:10.1103/PhysRevA.85.012101

4The Feynman Lectures on Physics, Vol. I: The New Millennium Edition: Mainly Mechanics, Radiation, and Heat (October 4, 2011), Chapter 37 (Quantum Behavior), page 37-2 (An experiment with bullets). Paperback ISBN-13: 978-0465024933 | Online

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Self-powered smart window also functions as a self-rechargeable transparent battery PDF Print E-mail

(Phys.org) —Smart windows have the ability to become darker or lighter in response to the brightness and heat of sunlight, offering the potential to greatly reduce heating and cooling costs, among other benefits. However, current smart windows require an external power supply to operate, causing an additional energy consumption that cuts into their overall cost savings.

Now in a new study published in Nature Communications, a group led by Professor Xiong Wen (David) Lou and Professor Xiao Wei Sun at Nanyang Technological University in Singapore have designed and fabricated a completely self-powered smart window. The window can change its color from transparent to blue depending on its exposure to air by using electrochromic materials, which are capable of storing and releasing ions and electrons, similar to a . These characteristics also enable the smart window to function as a self-rechargeable transparent battery to power other devices.

The key to the new smart window is the electrochromic (EC) material Prussian blue (PB). In the early 1980s, scientists discovered that PB can be transformed into colorless Prussian white (PW) by electrochemical reactions. Specifically, the color change occurs when the iron in the PB is reduced, so that it gains an electron from another material that can easily lose electrons. Here, the researchers used aluminum (Al) as the electron-donating anode, to complement the PB cathode.

When the PB and Al electrodes are connected to each other, the smart glass can be "bleached" to colorless PW in just 4 seconds. The researchers found that the smart window's transmittance changes by about 52% between the blue and colorless states. This bleaching process of the PB/Al smart window also corresponds to the discharging of the PB/Al cell. When the smart window becomes fully transparent, it can no longer light up an LED, indicating that it is fully discharged.

Functioning mechanisms of the bi-functional self-powered EC smart window and self-recharging battery: (a-d) shows the bleaching process of the device serving as a self-powered EC smart window, (e-h) shows the discharging and self-recharging processes of the device functioning as a self-rechargeable battery. Credit: Wang, et al. ©2014 Macmillan Publishers Limited

To recharge the smart window/battery, the researchers simply disconnected the PB and Al electrodes, exposing them to oxygen. The battery then spontaneously recharges itself by oxidizing the iron in the electrode, causing the smart window to slowly regain its blue color. After about an hour of the electrodes being disconnected, the battery can light up the LED again, indicating that it is partially recharged.

"We need to connect the electrodes to turn it from blue to transparent," Sun told Phys.org. "If we want it to become blue again, we need to disconnect the electrodes and expose the electrolyte to air. Oxygen here is used to react with PW to form PB. When PB is formed, the battery is recharged."

Self-bleaching (discharging) of the self-powered EC device by connecting the PB electrode and Al electrode. Credit: Wang, et al. ©2014 Macmillan Publishers Limited

As Sun explained, the PB/Al cell's ability to recharge itself is due to the fact that PW spontaneously reverts to PB in the presence of oxygen. Interestingly, this property is generally regarded as a drawback in making a battery because it decreases the battery's voltage, so batteries are usually isolated from oxygen. However, here oxygen is critical for recharging the battery. The researchers note that the PB/Al cell is different than Al-air or Li-air batteries in which aluminum or lithium serves as the anode and oxygen as the cathode. In the PB/Al cell, PB is the cathode and oxygen is only involved in the self-recharging process.

The researchers also explain that, when Al is eventually used up, the battery will no longer function. In this sense, the battery is not truly self-rechargeable, and after all a truly self-rechargeable battery cannot exist due to the first law of thermodynamics. However, the battery contains enough Al to last for the reasonable lifetime of a normal rechargeable battery.

As a battery, the PB/Al cell shows fair performance. Although its specific capacity is relatively low compared to that of lithium batteries, it has a reasonably large total capacity considering its thin-layered structure. If an external power source is applied instead of self-charging in air, both the charge capacity and charge time can be significantly improved.

As a two-in-one device, functioning as both a self-powered smart window and self-rechargeable transparent battery, the new technology could have some novel dual applications. Its properties allow it to be simultaneously used for indoor light and heat management and as a power source for some low-power devices. In the future, the researchers plan to make further improvements.

"Future research is needed to expand the reliability, i.e., lifetime of the device," Sun said. "It is also needed to think of ways of exposing electrolyte to oxygen, for the device to breathe."

Explore further: New, high-energy rechargeable batteries

More information: Jinmin Wang, et al. "A bi-functional device for self-powered electrochromic window and self-rechargeable transparent battery applications." Nature Communications. DOI: 10.1038/ncomms5921

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Snake Robots! Slithering Machines Could Aid Search-and-Rescue Efforts PDF Print E-mail

One snake's ability to shimmy up slippery sand dunes could inspire new technologies for robots that could perform search and rescue missions, carry out inspections of hazardous wastes and even explore ancient pyramids.

A new study looked at the North American desert-dwelling sidewinder rattlesnake (Crotalus cerastes), a creature better known for its venomous bite than its graceful movements. But this snake can climb up sandy slopes without sliding back down to the bottom — a feat that few snake species can accomplish.

Snakelike, or limbless, robots are intriguing to scientists for several reasons. First, their lack of legs, wheels or tracks means they don't often get stuck in ruts or held up by bumps in their path. They could also be used to access areas that other bots can't get to, or to explore places that aren't safe for humans. [Biomimicry: 7 Clever Technologies Inspired by Nature]

The sidewinder shimmy

To get a closer look at their live study subjects, the researchers headed to Zoo Atlanta, where they were able to examine six sidewinder rattlesnakes. They tested the snakes on a specially designed inclined table covered with loosely packed sand.

Fifty-four trials were conducted, with each of the six snakes slithering up the sandy table nine times, three times each at varying degrees of steepness. As the snakes worked their way up the makeshift sand dune, high-speed cameras tracked their movements, taking note of exactly where their bodies came into contact with the sand as they moved upward.

The researchers found that sidewinder snakes live up to their name. The slithery creatures moved up the sandy incline in a sideways motion, with their heads pointing toward the top of the incline and the rest of their bodies moving horizontally up the slope. The researchers then looked more carefully at how sidewinders carry out these complex movements.

"The snakes tended to increase the amount of body in contact with the surface at any instant in time when they were sidewinding up the slope and the incline angle increased," said Daniel Goldman, co-author of the study and an associate professor of biomechanics at the Georgia Institute of Technology in Atlanta. Specifically, the snakes doubled the amount of their bodies touching the sand when navigating the slope, he added.

The Carnegie Mellon snake robot.

The Carnegie Mellon snake robot has finally mastered the art of slithering up a sandy slope.
Credit: Nico Zevallos and Chaohui Gong

And the parts of the snake's body that were touching the sand during the ascent never slipped back down the slope because the creature applied the right amount of force in its movements, keeping the sand under it from sliding, Goldman told Live Science.

Snake robots

To put their newfound understanding of sidewinding to good use, Goldman and his colleagues got in touch with Howie Choset, a professor at The Robotics Institute at Carnegie Mellon University in Pittsburgh. Choset, who has been developing limbless robots for years, already developed a snakelike bot that performs well both in the lab and in real-life situations. However, his slithering machine has run into one particular problem during field tests.

"These guys have been making a robot sidewind for years over a wide diversity of substrates, but they had a lot of trouble on sandy slopes," Goldman said.

To get the robot moving over sandy dunes, the researchers applied what they now know about the sidewinding rattlesnake's patterns of movement. They programmed the robot so that more of its body would come into contact with the ground as it slides up the slope. They also applied what they had learned about force, which enables the robot to move its weight in such a way that it keeps moving upward over the sand without rolling back down the slope.

Now that Choset's snake robot can move over tough terrain, it'll be better equipped to handle the tasks that it was built to tackle.

"Since these robots have a narrow cross section and they're relatively smooth, they can fit into places that people and machinery can't otherwise access," Choset told Live Science.

For example, these limbless robots could be used during search-and-rescue missions, since the slithery machines can crawl into a collapsed building and search for people trapped inside without disturbing the compromised structure. The snake bot could also be sent into containers that may hold dangerous substances, such as nuclear waste, to take samples and report back to hazmat specialists.

Choset also said these robotic sidewinding abilities could come in handy on archaeological sites. For instance, the robots could one day be used to explore the insides of pyramids or tombs, he said.

The research represents a key collaboration between biologists and roboticists, said Auke Ijspeert, head of the Biorobotics Laboratory at the Swiss Federal Institute of Technology at Lausanne (EPFL), who was not involved in the new study.

"I think it’s a very exciting project which managed to contribute to the two objectives of biorobotics," Ijspeert told Live Science.

"On one hand, they took inspiration from biology to design better control methods for the robot," Ijspeert said. "By looking at how sidewinding takes place in a snake, especially with slopes, they found out the strategy that the animal uses and, when they tested it on the robot, it could really improve the climbing capabilities of the robot."

The researchers also achieved the second goal of biorobotics, he said, which is to use a robot as a scientific tool. By testing the different speeds at which the robotic snake could successfully climb up the sand, the researchers were able to pinpoint exactly how fast real snakes make their way up these slippery slopes.

"It's a nice example of how robots can help in biology and how biology can help in robotics."

The study was published online today (Oct. 9) in the journal Science.

Follow Elizabeth Palermo @techEpalermo. Follow Live Science @livescience, Facebook & Google+. Original article on Live Science.

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