Researchers at the University of Warwick and Oxford University have developed a form of crystal that can deliver highly accurate temperature readings, down to individual milli-kelvins, over a very broad range of temperatures: -120 to +680 degrees centigrade.

The researchers used a “birefringent” crystal which splits light passing through it into two separate rays. Research has already shown that the size of the effect will increase or decrease in proportion to the temperature of the crystal. Therefore, in theory, you could calibrate such crystals to be highly accurate temperature gauges.

However, the use of birefringence in this way has significant problems in practice. This temperature measuring ability of highly birefringent crystals is badly compromised by changes in the thickness and orientation of the crystal. This adds expense to the manufacture and calibration of such crystals and makes them almost unusable in situations where, for example, vibration could alter the orientation of the crystal.

However the Warwick and Oxford researchers have developed a reproducible and low-cost method of modifying the properties of crystalline lithium tantalate so that its birefringence is virtually independent of the crystal’s thickness and position making it resistant to vibration and cheaper to manufacture. In fact, they have made the birefringence almost zero in magnitude in all directions (the material is close to being optically isotropic just like ordinary glass). However, the slightest temperature change induces a rapid increase in birefringence in these materials, making this a reliable, robust and very sensitive method for measuring temperature. The inventors have named their device a Zero-Birefringence Optical Temperature Sensor (Z-BotS) and are currently seeking follow-on funding to develop the device from the bench-top proof-of-concept to a miniaturized commercially-viable package.

(via Research gives crystal clear temperature readings from toughest environments)

Berkeley Scientists Discover an “Instant Cosmic Classic” Supernova

A supernova discovered yesterday five days ago is closer to Earth — approximately 21 million light-years away — than any other of its kind in a generation. Astronomers believe they caught the supernova within hours of its explosion, a rare feat made possible with a specialized survey telescope and state-of-the-art computational tools.

The finding of such a supernova so early and so close has energized the astronomical community as they are scrambling to observe it with as many telescopes as possible, including the Hubble Space Telescope.

Joshua Bloom, assistant professor of astronomy at the University of California, Berkeley, called it “the supernova of a generation.” Astronomers at Lawrence Berkeley National Laboratory (Berkeley Lab) and UC Berkeley, who made the discovery predict that it will be a target for research for the next decade, making it one of the most-studied supernova in history.

The supernova, dubbed PTF 11kly, occurred in the Pinwheel Galaxy, located in the “Big Dipper,” otherwise known as the Ursa Major constellation. It was discovered by the Palomar Transient Factory (PTF) survey, which is designed to observe and uncover astronomical events as they happen.

“We caught this supernova very soon after explosion. PTF 11kly is getting brighter by the minute. It’s already 20 times brighter than it was yesterday,” said Peter Nugent, the senior scientist at Berkeley Lab who first spotted the supernova. Nugent is also an adjunct professor of astronomy at UC Berkeley. “Observing PTF 11kly unfold should be a wild ride. It is an instant cosmic classic.”

He credits supercomputers at the National Energy Research Scientific Computing Center (NERSC), a Department of Energy supercomputing center at Berkeley Lab, as well as high-speed networks with uncovering this rare event in the nick of time.

(via Berkeley Lab News Center)

Astronomers find ice and possibly methane on Snow White, a distant dwarf planet

Astronomers at the California Institute of Technology (Caltech) have discovered that the dwarf planet 2007 OR10—nicknamed Snow White—is an icy world, with about half its surface covered in water ice that once flowed from ancient, slush-spewing volcanoes. The new findings also suggest that the red-tinged dwarf planet may be covered in a thin layer of methane, the remnants of an atmosphere that’s slowly being lost into space.

“You get to see this nice picture of what once was an active little world with water volcanoes and an atmosphere, and it’s now just frozen, dead, with an atmosphere that’s slowly slipping away,” says Mike Brown, the Richard and Barbara Rosenberg Professor and professor of planetary astronomy, who is the lead author on a paper to be published in the Astrophysical Journal Letters describing the findings. The paper is now in press.

Snow White—which was discovered in 2007 as part of the PhD thesis of Brown’s former graduate student Meg Schwamb—orbits the sun at the edge of the solar system and is about half the size of Pluto, making it the fifth largest dwarf planet. At the time, Brown had guessed incorrectly that it was an icy body that had broken off from another dwarf planet named Haumea; he nicknamed it Snow White for its presumed white color.

Soon, however, follow-up observations revealed that Snow White is actually one of the reddest objects in the solar system. A few other dwarf planets at the edge of the solar system are also red. These distant dwarf planets are themselves part of a larger group of icy bodies called Kuiper Belt Objects (KBOs). As far as the researchers could tell, Snow White, though relatively large, was unremarkable—just one out of more than 400 potential dwarf planets that are among hundreds of thousands of KBOs.

(via PhysOrg.com)

Advanced Electrodes for Better Li-Ion Batteries

Lithium-ion batteries could last longer if their electrodes stored more charge. Korean researchers have now made a new type of anode that holds three times more charge than the conventional graphite anodes used in batteries.

The new anode is made of germanium nanotubes. It charges and discharges five times faster than previously reported silicon anodes, lasts through twice as many charging cycles, and is easier to fabricate. Its 400-cycle life matches that of graphite and is long enough for portable-electronics batteries, says Jaephil Cho, a researcher at South Korea’s Ulsan National Institute of Science and Technology, who led the new work. “These anodes meet the practical requirements of lithium-ion cells,” Cho says.

Cho collaborated with researchers at LG Chem, the Korean company that makes the lithium-ion batteries used in the Chevy Volt. Their results will soon be published online in the journal Angewandte Chemie. The researchers are also working on silicon nanotube anodes.

These advances are part of a broader push by LG Chem to develop better anode materials for higher-capacity batteries. “The company is looking for a breakthrough technology using both silicon and germanium materials for lithium-ion battery anodes,” Cho says.

(via Technology Review)

Humans glow in the dark | Science

Amazing pictures of “glittering” human bodies have been released by Japanese scientists who have captured the first ever images of human “bioluminescence”.

Although it has been known for many years that all living creatures produce a small amount of light as a result of chemical reactions within their cells, this is the first time light produced by humans has been captured on camera.

Writing in the online journal PLoS ONE, the researchers describe how they imaged volunteers’ upper bodies using ultra-sensitive cameras over a period of several days. Their results show that the amount of light emitted follows a 24-hour cycle, at its highest in late afternoon and lowest late at night, and that the brightest light is emitted from the cheeks, forehead and neck.

Strangely, the areas that produced the brightest light did not correspond with the brightest areas on thermal images of the volunteers’ bodies.

(via guardian.co.uk)

Bats navigate with visual map, additional unknown cues

A number of animal species are capable of astonishing navigational feats. This ability appears to be widespread, with groups as diverse as birds, turtles, insects, and fish all showing navigational skills. Now, we can apparently add bats to the list of species that can manage to find their way, even after researchers have played a variety of tricks on their homing systems. Those tricks weren’t just cruel, however, as the researchers’ work showed that the bats probably use at least two systems to orient themselves and navigate using a three-dimensional representation of their usual surroundings.

The species in question is the Egyptian fruit bat (Rousettus aegyptiacus), which is native to Israel’s Negev Desert and, conveniently, large enough to wear a GPS tracking device. When released near their cave, tagged bats went straight to a small collection of fruit trees about 15km away, typically at speeds of over 35km an hour. And when we say straight, we mean it: the bats passed by other fruit trees on the way, and deviated by less than 3 percent of the total distance traveled. Most bats returned straight to the same trees on consecutive nights. So, from both the consistency and directness perspectives, these bats are superb navigators.

(via Ars Technica)

New nanostructured glass for imaging and recording

University of Southampton researchers have developed new nano-structured glass, turning it into new type of computer memory, which has applications in optical manipulation and will significantly reduce the cost of medical imaging.

In a paper entitled Radially polarized optical vortex converter created by femtosecond laser nanostructuring of glass published in Applied Physics Letters, a team led by Professor Peter Kazansky at the University’s Optoelectronics Research Centre, describe how they have used nano-structures to develop new monolithic glass space-variant polarisation converters. These millimetre-sized devices change the way light travels through glass, generating ‘whirlpools’ of light that can then be read in much the same way as data in optical fibres. This enables more precise laser material processing, optical manipulation of atom-sized objects, ultra-high resolution imaging and potentially, table-top particle accelerators. Information can be written, wiped and rewritten into the molecular structure of the glass using a laser.

(via University of Southampton)

Physicists Weigh Antimatter with Amazing Accuracy

A new measurement provides the most accurate weight yet of antimatter, revealing the mass of the antiproton (the proton’s antiparticle) down to one part in a billion, researchers announced today (July 28).

To give a sense of just how accurate their measurement was, researcher Masaki Hori said: “Imagine measuring the weight of the Eiffel Tower. The accuracy we’ve achieved here is roughly equivalent to making that measurement to within less than the weight of a sparrow perched on top. Next time it will be a feather.”

The result, detailed this week in the journal Nature, may help scientists investigate the mystery of why the universe is made of regular matter even though they suspect roughly equal parts of matter and antimatter were around just after the universe formed. When a particle, such as a proton, meets with its antimatter partner, the antiproton, the two annihilate each other in a powerful explosion.

(via LiveScience)

Device captures ambient electromagnetic energy to drive small electronic devices

Power from the air

Researchers have discovered a way to capture and harness energy transmitted by such sources as radio and television transmitters, cell phone networks and satellite communications systems. By scavenging this ambient energy from the air around us, the technique could provide a new way to power networks of wireless sensors, microprocessors and communications chips.

“There is a large amount of electromagnetic energy all around us, but nobody has been able to tap into it,” said Manos Tentzeris, a professor in the Georgia Tech School of Electrical and Computer Engineering who is leading the research. “We are using an ultra-wideband antenna that lets us exploit a variety of signals in different frequency ranges, giving us greatly increased power-gathering capability.”

Tentzeris and his team are using inkjet printers to combine sensors, antennas and energy scavenging capabilities on paper or flexible polymers. The resulting self powered wireless sensors could be used for chemical, biological, heat and stress sensing for defense and industry; radio frequency identification (RFID) tagging for manufacturing and shipping, and monitoring tasks in many fields including communications and power usage.

A presentation on this energy scavenging technology was given July 6 at the IEEE Antennas and Propagation Symposium in Spokane, Wash. The discovery is based on research supported by multiple sponsors, including the National Science Foundation, the Federal Highway Administration and Japan’s New Energy and Industrial Technology Development Organization (NEDO).

Communications devices transmit energy in many different frequency ranges, or bands. The team’s scavenging devices can capture this energy, convert it from AC to DC, and then store it in capacitors and batteries. The scavenging technology can take advantage presently of frequencies from FM radio to radar, a range spanning 100 megahertz (MHz) to 15 gigahertz (GHz) or higher.

Scavenging experiments utilizing TV bands have already yielded power amounting to hundreds of microwatts, and multi-band systems are expected to generate one milliwatt or more. That amount of power is enough to operate many small electronic devices, including a variety of sensors and microprocessors.

And by combining energy scavenging technology with supercapacitors and cycled operation, the Georgia Tech team expects to power devices requiring above 50 milliwatts. In this approach, energy builds up in a battery-like supercapacitor and is utilized when the required power level is reached.

The researchers have already successfully operated a temperature sensor using electromagnetic energy captured from a television station that was half a kilometer distant. They are preparing another demonstration in which a microprocessor-based microcontroller would be activated simply by holding it in the air.

(via eurekalert.org)

Electric Airplane Sets Speedy Distance Record

A team from the University of Stuttgart has set a new milestone for electric aviation after averaging more than 100 mph for a little more than two hours. Not only did eGenius push the limits of speed and endurance for electric aviation, it did so with two people aboard.

The eGenius is essentially a motor glider with a high-aspect-ratio wing that spans more than 55 feet. A 60-kilowatt (80.5-horsepower) motor is mounted on the tail, allowing for a larger, more efficient propeller. Power is supplied by a 56-kilowatt-hour battery pack. The team didn’t say how much power it used during the flight, but said it still had juice in the pack upon landing.

(via Wired.com)

Neutrinos: Delta force

EVEN by the elevated standards of particle physics neutrinos are weird beasts. They travel within a whisker of the speed of light, have no electric charge, practically no mass and precious little will to interact with anything else. Billions penetrate every square centimetre of the Earth’s surface every second without so much as a quiver. This makes them rather hard to detect. So hard that Wolfgang Pauli, the Austrian physicist who postulated their existence in 1930, wagered a case of champagne that no one would ever do so. He lost the bet in 1956. Since then, neutrinos (of which there are now known to be three fundamentally different sorts) have allowed researchers to glimpse inside the sun, study exploding stars and examine the universe’s distant past.

The latest example of neutrinos’ weirdness comes from Japan. Researchers using a detector called Super-Kamiokande think they have observed the beasts changing their fundamental nature in a way not seen before. They are not yet quite sure. Their result has a 0.7% chance of being a fluke. But if it is confirmed, it will have implications for one of the deepest mysteries of the universe—why it is made of matter.

EDIT/UPDATE:  On June 24th it emerged that an American neutrino experiment produced results consistent with T2K’s.

(via The Economist)

Proton Somersault Study Could Explain Why Matter Still Exists

For the first time, physicists have watched a single proton flip over on its axis. Aside from being a technical triumph, the measurement may eventually help determine why the universe contains more matter than antimatter.

Cosmologists think the Big Bang should have produced the same amount of ordinary matter — the particles that make up stars, planets and people — and antimatter, which is just like matter, only with an opposite charge. But when matter and antimatter meet, they annihilate each other. That there’s enough matter left for us to exist is one of modern physics’ biggest puzzles.

One possibility is that, opposite charge aside, antimatter isn’t always truly identical to matter, and so it doesn’t meet the requirements for triggering annihilation. To determine if this is true, physicists need a way to compare matter and antimatter. In a June 24 Physical Review Letters study, physicists take an important step toward comparing protons and antiprotons by measuring a property called the magnetic moment.

“For the proton and the antiproton, magnetic moments have never been compared before,” said quantum physicist Stefan Ulmer of the Helmholtz Institute Mainz in Germany, co-author of the new paper. “Our new methods make this comparison possible.”

The magnetic moment is a description of how a magnetic field pulls on a particle. It has an intrinsic direction, similar to how a compass needle always points north, but can point up or down depending on what other magnetic forces act on it.

(via Wired.com)

Neutrino Transformation Could Help Explain Mystery of Matter

Two research teams have found new evidence of transformations in elusive elementary particles called neutrinos. The findings may finally help explain why the universe didn’t vanish shortly after its birth.

“These results are just the beginning of the story for neutrinos,” said physicist Robert Plunkett of Fermilab in Chicago. “They could lead to clues … and tell us why there’s now far more matter than antimatter.”

Most neutrinos are emitted by the sun, and are so small and ghostly that billions pass through our bodies every second. Most go right through Earth without hitting anything. But some human-built devices — slabs of iron and plastic, big chambers of oil or water lined with photon detectors, or detector arrays plunged into seawater or Antarctic ice — can record the blip of light when a neutrino occasionally slams into an atom.

Using these detection events, physicists have identified three types of neutrino, called muon, tau and electron neutrinos. Further discoveries suggested that each type can transform into another, with muon-to-tau neutrino transformations being dominant, at least in particle-accelerator-powered experiments.

Researchers proposed a third and weaker change, that of muon-to-electron neutrinos, but until now lacked evidence for its existence.

(via Wired.com, h/t to eirizu)

Squeezing DNA by trying to stretch it out

…it turns out that, for a critical frequency, DNA strands compress in the presence of AC electric fields.

The basic experiment is, at first glance, fairly simple. A microfluidic device has DNA flowing along its channels. These channels are narrow enough that the DNA is somewhat stretched out by restriction from the walls. The researchers then applied AC electric fields in the frequency range of around 300-700Hz. For the length of the DNA strands that they used, this frequency is high enough that the molecule as a whole has no time to respond. In effect, current models predict that the researchers should have observed nothing.

Indeed, when the electric field amplitude is low, the DNA really doesn’t respond. But, for a given frequency, there appears to be a critical electric field amplitude, above which the DNA rapidly collapses into a tight ball. (Actually, in their data, the balls are elongated because the DNA strands are traveling down a microfluidic channel during the measurement.) Further investigation revealed that the threshold voltage increased with frequency, and that the final compression depended on how large the applied field was. That is, once above the threshold, the degree of compression increased with strength of the applied field.

This almost certainly left the researchers befuddled. No one expected this at all and there are no DNA models that actually predict that it will compress in a given AC electric field. Zhou and co-workers propose a pair of mechanisms that would explain the behavior but, as they note, their models only explain the general trend, not the actual performance they saw.

(via Ars Technica)