Domain: phys.org
Stories and comments across the archive that link to phys.org.
Stories · 260
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Traversable Wormholes Can Exist, But They're Not Very Useful For Space Travel, Physicists Say (phys.org)
A new study from physicists at Harvard and Stanford says that wormholes can exist but they're not very useful for humans to travel through. "It takes longer to get through these wormholes than to go directly, so they are not very useful for space travel," said the author of the study, Daniel Jafferis. From the report: Despite his pessimism for pan-galactic travel, he said that finding a way to construct a wormhole through which light could travel was a boost in the quest to develop a theory of quantum gravity. The new theory was inspired when Jafferis began thinking about two black holes that were entangled on a quantum level, as formulated in the ER=EPR correspondence by Juan Maldacena from the Institute for Advanced Study and Lenny Susskind from Stanford. Although this means the direct connection between the black holes is shorter than the wormhole connection -- and therefore the wormhole travel is not a shortcut -- the theory gives new insights into quantum mechanics.
"From the outside perspective, travel through the wormhole is equivalent to quantum teleportation using entangled black holes," Jafferis said. Jafferis based his theory on a setup first devised by Einstein and Rosen in 1935, consisting of a connection between two black holes (the term wormhole was coined in 1957). Because the wormhole is traversable, Jafferis said, it was a special case in which information could be extracted from a black hole. "It gives a causal probe of regions that would otherwise have been behind a horizon, a window to the experience of an observer inside a spacetime, that is accessible from the outside," said Jafferis. The physicists presented their results at the 2019 American Physical Society April Meeting in Denver, Colorado. -
'BlackHoles@Home' Will Use Your PC For DIY Gravitational Wave Analysis (phys.org)
West Virginia University assistant professor Zachariah Etienne is launching "a global volunteer computing effort" analyzing gravitational waves from colliding black holes, reports Phys.org: "As our gravitational wave detectors become more sensitive, we're going to need to greatly expand our efforts to understand all of the information encoded in gravitational waves from colliding binary black holes," Etienne said. "We are turning to the general public to help with these efforts, which involve generating unprecedented numbers of self-consistent simulations of these extremely energetic collisions. This will truly be an inclusive effort, and we especially hope to inspire the next generation of scientists in this growing field of gravitational wave astrophysics."
His team -- and the scientific community in general -- needs computing capacity to run the simulations required to cover all possibilities related to the properties and other information contained in gravitational waves. "Each desktop computer will be able to perform a single simulation of colliding black holes," said Etienne. By seeking public involvement through use of vast numbers of personal desktop computers, Etienne and others hope to dramatically increase the throughput of the theoretical gravitational wave predictions needed to extract information from observations of the collisions.
Etienne and his team are building a website with downloadable software based on the same Berkeley Open Infrastructure for Network Computing, or BOINC, system used for the SETI@Home project and other scientific applications. The free middleware system is designed to help harness the processing power of thousands of personal computers across the globe. The West Virginia team has named their project BlackHoles@Home and expects to have it up and running later this year.
They have already established a website where the public can begin learning more about the effort. -
Japanese Spacecraft Drops Explosive On Asteroid To Make Crater (phys.org)
William Robinson writes: The Hayabusa2 Japanese spacecraft on Friday dropped an explosive on the Ryugu asteroid (named after an undersea palace in a Japanese folktale) to make a crater on its surface. The spacecraft safely evacuated and remained intact after dropping a "small carry-on impactor" made of copper onto the asteroid. The Japan Aerospace Exploration Agency, or JAXA, said that they plan to send Hayabusa2 back to the site later, when the dust and debris settle, for observations from above and to collect samples from underground that have not been exposed to the sun or space rays. If successful, it would be the first time a spacecraft has taken such materials. In a 2005 "Deep Impact" mission to a comet, NASA observed fragments after blasting the surface but did not collect them. -
Renewable Energy Reduces the Highest Electric Rates In the Nation (phys.org)
An anonymous reader quotes a report from Phys.Org: Coal is the primary fuel source for Midwest electric utilities. Michigan Technological University researchers found that increasing renewable and distributed generation energy sources can save Michigan electric consumers money. As renewable energy technologies and access to distributed generation like residential solar panels improve, consumer costs for electricity decrease. Making electricity for yourself with solar has become more affordable than traditional electricity fuel sources like coal. However, as three Michigan Tech researchers contend in a new study, while utility fuel mixes are slowly shifting away from fossil fuels toward renewable sources, Michigan utilities, and U.S. utilities broadly, continue a relationship with fossil fuels that is detrimental to their customers.
In the paper, Prehoda and co-authors Joshua M. Pearce, Richard Witte Endowed Professor of Materials Science and Engineering, and Chelsea Schelly, associate professor of sociology, note that in the U.S., "70 percent of coal plants run at a higher cost than new renewable energy and by 2030 all of them will." The researchers provide a breakdown of savings per kilowatt hour by county that Michigan residents could achieve if they produce their own electricity with solar photovoltaic panels. The most significant impacts of distributed generation with solar are in the Upper Peninsula, where residential customers could see savings of approximately 7 cents per kilowatt hour. Assuming the average residential consumer uses 600 kilowatt hours of electricity monthly, this is a savings of $42 per utility bill. Downstate, the average savings per utility bill under the researchers' model is approximately $30 monthly. However, not all Michigan consumers can take advantage of the opportunity to self-generate, as some utilities are blocking additional net-metered distributed generation in their areas. The study has been published in the journal Energies. -
Physicists Reverse Time Using Quantum Computer (phys.org)
fahrbot-bot shares a report from Phys.Org: Researchers from the Moscow Institute of Physics and Technology teamed up with colleagues from the U.S. and Switzerland and returned the state of a quantum computer a fraction of a second into the past. They also calculated the probability that an electron in empty interstellar space will spontaneously travel back into its recent past. The study is published in Scientific Reports.
Quantum physicists from MIPT decided to check if time could spontaneously reverse itself at least for an individual particle and for a tiny fraction of a second. That is, instead of colliding billiard balls, they examined a solitary electron in empty interstellar space. "Suppose the electron is localized when we begin observing it. This means that we're pretty sure about its position in space. The laws of quantum mechanics prevent us from knowing it with absolute precision, but we can outline a small region where the electron is localized," says study co-author Andrey Lebedev from MIPT and ETH Zurich. The physicist explains that the evolution of the electron state is governed by Schrodinger's equation. Although it makes no distinction between the future and the past, the region of space containing the electron will spread out very quickly. That is, the system tends to become more chaotic. The uncertainty of the electron's position is growing. This is analogous to the increasing disorder in a large-scale system -- such as a billiard table -- due to the second law of thermodynamics.
"However, Schrodinger's equation is reversible," adds Valerii Vinokur, a co-author of the paper, from the Argonne National Laboratory, U.S. "Mathematically, it means that under a certain transformation called complex conjugation, the equation will describe a 'smeared' electron localizing back into a small region of space over the same time period." Although this phenomenon is not observed in nature, it could theoretically happen due to a random fluctuation in the cosmic microwave background permeating the universe. The team set out to calculate the probability to observe an electron "smeared out" over a fraction of a second spontaneously localizing into its recent past. It turned out that even across the entire lifetime of the universe -- 13.7 billion years -- observing 10 billion freshly localized electrons every second, the reverse evolution of the particle's state would only happen once. And even then, the electron would travel no more than a mere one ten-billionth of a second into the past. The researchers then attempted to reverse time in a four-stage experiment by observing the state of a quantum computer made of superconducting qubits, instead of an electron. The researchers "found that in 85 percent of the cases, the two-qubit quantum computer returned back into the initial state," reports Phys.Org. "When three qubits were involved, more errors happened, resulting in a roughly 50 percent success rate. According to the authors, these errors are due to imperfections in the actual quantum computer. As more sophisticated devices are designed, the error rate is expected to drop." -
NASA Captures Unprecedented Images of Supersonic Shockwaves (phys.org)
As NASA looks into developing planes that can fly faster than sound without creating "sonic booms," the space agency has captured unprecedented photos of the interaction of shockwaves from two supersonic aircraft. Phys.Org reports: When an aircraft crosses that threshold -- around 1,225 kilometers (760 miles) per hour at sea level -- it produces waves from the pressure it puts on the air around it, which merge to cause the ear-splitting sound. In an intricate maneuver by "rock star" pilots at NASA's Armstrong Flight Research Center in California, two supersonic T-38 jets flew just 30 feet (nine meters) apart below another plane waiting to photograph them with an advanced, high-speed camera, the agency said. The rendezvous -- at an altitude of around 30,000 feet -- yielded mesmerizing images of the shockwaves emanating from both planes. You can view all of the photos via NASA. -
Welding Glass To Metal Is Now Possible Using An Ultrafast Laser System, Researchers Report (phys.org)
An anonymous reader quotes a report from Phys.Org: Scientists from Heriot-Watt University have welded glass and metal together using an ultrafast laser system, in a breakthrough for the manufacturing industry. Various optical materials such as quartz, borosilicate glass and even sapphire were all successfully welded to metals like aluminum, titanium and stainless steel using the Heriot-Watt laser system, which provides very short, picosecond pulses of infrared light in tracks along the materials to fuse them together. The new process could transform the manufacturing sector and have direct applications in the aerospace, defense, optical technology and even healthcare fields. Professor Duncan Hand, director of the five-university EPSRC Center for Innovative Manufacturing in Laser-based Production Processes based at Heriot-Watt, said: "Traditionally it has been very difficult to weld together dissimilar materials like glass and metal due to their different thermal properties -- the high temperatures and highly different thermal expansions involved cause the glass to shatter. Being able to weld glass and metals together will be a huge step forward in manufacturing and design flexibility."
He added: "The parts to be welded are placed in close contact, and the laser is focused through the optical material to provide a very small and highly intense spot at the interface between the two materials -- we achieved megawatt peak power over an area just a few microns across. This creates a microplasma, like a tiny ball of lightning, inside the material, surrounded by a highly-confined melt region. We tested the welds at -50C to 90C and the welds remained intact, so we know they are robust enough to cope with extreme conditions." -
Did A US Navy Scientist Just Invent A Room-Temperature Superconductor? (phys.org)
"A scientist working for the U.S. Navy has filed for a patent on a room-temperature superconductor, representing a potential paradigm shift in energy transmission and computer systems," reports Phys.org: Salvatore Cezar Pais is listed as the inventor on the Navy's patent application made public by the U.S. Patent and Trademark Office on Thursday. The application claims that a room-temperature superconductor can be built using a wire with an insulator core and an aluminum PZT (lead zirconate titanate) coating deposited by vacuum evaporation with a thickness of the London penetration depth and polarized after deposition.
An electromagnetic coil is circumferentially positioned around the coating such that when the coil is activated with a pulsed current, a non-linear vibration is induced, enabling room temperature superconductivity. "This concept enables the transmission of electrical power without any losses and exhibits optimal thermal management (no heat dissipation)," according to the patent document, "which leads to the design and development of novel energy generation and harvesting devices with enormous benefits to civilization."
Long-time Slashdot reader resistant writes: NextBigFuture says the same individual appears to have made other startling claims that arguably stretch the boundaries of belief, such as a "high-frequency gravitational wave generator" that could supposedly drive a spaceship without conventional propellants as well as an "inertial mass reduction device." Prudence would appear to dictate examining these and other claims by Mr. Salvatore Cezar Pais with great caution. -
Researchers Make Coldest Quantum Gas of Molecules (phys.org)
An anonymous reader quotes a report from Phys.Org: JILA researchers have made a long-lived, record-cold gas of molecules that follow the wave patterns of quantum mechanics instead of the strictly particle nature of ordinary classical physics. The creation of this gas boosts the odds for advances in fields such as designer chemistry and quantum computing. As featured on the cover of the Feb. 22 issue of Science, the team produced a gas of potassium-rubidium (KRb) molecules at temperatures as low as 50 nanokelvin (nK). That's 50 billionths of a Kelvin, or just a smidge above absolute zero, the lowest theoretically possible temperature. The molecules are in the lowest-possible energy states, making up what is known as a degenerate Fermi gas.
In a quantum gas, all of the molecules' properties are restricted to specific values, or quantized, like rungs on a ladder or notes on a musical scale. Chilling the gas to the lowest temperatures gives researchers maximum control over the molecules. The two atoms involved are in different classes: Potassium is a fermion (with an odd number of subatomic components called protons and neutrons) and rubidium is a boson (with an even number of subatomic components). The resulting molecules have a Fermi character. Before now, the coldest two-atom molecules were produced in maximum numbers of tens of thousands and at temperatures no lower than a few hundred nanoKelvin. JILA's latest gas temperature record is much lower than (about one-third of) the level where quantum effects start to take over from classical effects, and the molecules last for a few seconds -- remarkable longevity. These new ultra-low temperatures will enable researchers to compare chemical reactions in quantum versus classical environments and study how electric fields affect the polar interactions, since these newly created molecules have a positive electric charge at the rubidium atom and a negative charge at the potassium atom. Some practical benefits could include new chemical processes, new methods for quantum computing using charged molecules as quantum bits, and new precision measurement tools such as molecular clocks. -
All-Photonic Quantum Repeaters Could Lead To a Faster, More Secure Global Quantum Internet (phys.org)
"University of Toronto Engineering professor Hoi-Kwong Lo and his collaborators have developed a prototype for a key element for all-photonic quantum repeaters, a critical step in long-distance quantum communication," reports Phys.Org. This proof-of-principle device could serve as the backbone of a future quantum internet. From the report: In light of [the security issues with today's internet], researchers have proposed other ways of transmitting data that would leverage key features of quantum physics to provide virtually unbreakable encryption. One of the most promising technologies involves a technique known as quantum key distribution (QKD). QKD exploits the fact that the simple act of sensing or measuring the state of a quantum system disturbs that system. Because of this, any third-party eavesdropping would leave behind a clearly detectable trace, and the communication can be aborted before any sensitive information is lost. Until now, this type of quantum security has been demonstrated in small-scale systems. Lo and his team are among a group of researchers around the world who are laying the groundwork for a future quantum Internet by working to address some of the challenges in transmitting quantum information over great distances, using optical fiber communication.
Because light signals lose potency as they travel long distances through fiber-optic cables, devices called repeaters are inserted at regular intervals along the line. These repeaters boost and amplify the signals to help transmit the information along the line. But quantum information is different, and existing repeaters for quantum information are highly problematic. They require storage of the quantum state at the repeater sites, making the repeaters much more error prone, difficult to build, and very expensive because they often operate at cryogenic temperatures. Lo and his team have proposed a different approach. They are working on the development of the next generation of repeaters, called all-photonic quantum repeaters, that would eliminate or reduce many of the shortcomings of standard quantum repeaters. "We have developed all-photonic repeaters that allow time-reversed adaptive Bell measurement," says Lo. "Because these repeaters are all-optical, they offer advantages that traditional -- quantum-memory-based matter -- repeaters do not. For example, this method could work at room temperature." -
Ancient Climate Change Triggered Warming That Lasted Thousands of Years (phys.org)
An anonymous reader quotes a report from Phys.Org: A rapid rise in temperature on ancient Earth triggered a climate response that may have prolonged the warming for many thousands of years, according to scientists. Their study, published online in Nature Geoscience, provides new evidence of a climate feedback that could explain the long duration of the Paleocene-Eocene Thermal Maximum (PETM), which is considered the best analogue for modern climate change. The findings also suggest that climate change today could have long-lasting impacts on global temperature even if humans are able to curb greenhouse gas emissions.
Increased erosion during the PETM, approximately 56 million years ago, freed large amounts of fossil carbon stored in rocks and released enough carbon dioxide, a greenhouse gas, into the atmosphere to impact temperatures long term, researchers said. Scientists found evidence for the massive carbon release in coastal sediment fossil cores. They analyzed the samples using an innovative molecular technique that enabled them to trace how processes like erosion moved carbon in deep time. Global temperatures increased by about 9 to 14.4 degrees Fahrenheit during the PETM, radically changing conditions on Earth. Severe storms and flooding became more common, and the warm, wet weather led to increased erosion of rocks. As erosion wore down mountains over thousands of years, carbon was released from rocks and transported by rivers to oceans, where some was reburied in coastal sediments. Along the way, some of the carbon entered the atmosphere as greenhouse gas. -
Researchers Created Artificial Cells That Can Communicate With Each Other (phys.org)
An anonymous reader quotes a report from Phys.Org: Friedrich Simmel and Aurore Dupin, researchers at the Technical University of Munich (TUM), have for the first time created artificial cell assemblies that can communicate with each other. The cells, separated by fatty membranes, exchange small chemical signaling molecules to trigger more complex reactions, such as the production of RNA and other proteins. Scientists around the world are working on creating artificial, cell-like systems that mimic the behavior of living organisms. Friedrich Simmel and Aurore Dupin have created such artificial cell assemblies in a fixed spatial arrangement. The highlight is that the cells are able to communicate with each other.
Gels or emulsion droplets encapsulated in thin fat or polymer membranes serve as the basic building blocks for the artificial cells. Inside these 10- to 100-micron units, chemical and biochemical reactions can proceed uninhibited. The research team used droplets enclosed by lipid membranes and assembled them into artificial multicellular structures called micro-tissues. The biochemical reaction solutions used in the droplets can produce RNA and proteins, giving the cells a of a kind of gene expression ability. Small signal molecules can be exchanged between cells via their membranes or protein channels built into the membranes. This allows them to couple with each other temporally and spatially. The systems thus become dynamic, as in real life. Chemical pulses thus propagate through the cell structures and pass on information. The signals can also act as triggers, allowing initially identical cells to develop differently. "Our system is the first example of a multicellular system in which artificial cells with gene expression have a fixed arrangement and are coupled via chemical signals. In this way, we achieved a form of spatial differentiation," says Friedrich Simmel, Professor of Physics of Synthetic Biosystems at Technical University of Munich. -
World's Oldest Periodic Table Chart Found At University of St Andrews In Scotland (phys.org)
An anonymous reader quotes a report from Phys.Org: A periodic table chart discovered at the University of St Andrews is thought to be the oldest in the world. The chart of elements, dating from 1885, was discovered in the University's School of Chemistry in 2014 by Dr. Alan Aitken during a clear out. The storage area was full of chemicals, equipment and laboratory paraphernalia that had accumulated since the opening of the chemistry department at its current location in 1968. Following months of clearing and sorting the various materials a stash of rolled up teaching charts was discovered. Within the collection was a large, extremely fragile periodic table that flaked upon handling. Suggestions that the discovery may be the earliest surviving example of a classroom periodic table in the world meant the document required urgent attention to be authenticated, repaired and restored.
Mendeleev made his famous disclosure on periodicity in 1869, the newly unearthed table was rather similar, but not identical to Mendeleev's second table of 1871. However, the St Andrews table was clearly an early specimen. The table is annotated in German, and an inscription at the bottom left -- "Verlag v. Lenoir & Forster, Wien" -- identifies a scientific printer who operated in Vienna between 1875 and 1888. Another inscription -- "Lith. von Ant. Hartinger & Sohn, Wien" -- identifies the chart's lithographer, who died in 1890. Working with the University's Special Collections team, the University sought advice from a series of international experts. Following further investigations, no earlier lecture chart of the table appears to exist. Professor Eric Scerri, an expert on the history of the periodic table based at the University of California, Los Angeles, dated the table to between 1879 and 1886 based on the represented elements. For example, both gallium and scandium, discovered in 1875 and 1879 respectively, are present, while germanium, discovered in 1886, is not. -
Researchers Report Breakthrough In Ice-Repelling Materials (phys.org)
"Researchers from the University of Houston have reported a new theory in physics called stress localization, which they used to tune and predict the properties of new materials," reports Phys.Org. "Based on those predictions, the researchers reported in Materials Horizons that they have created a durable silicone polymer coating capable of repelling ice from any surface." The new research has huge implications for aircraft, power transmission lines, and more. From the report: Hadi Ghasemi, Bill D. Cook Assistant Professor of mechanical engineering at UH and corresponding author for the work, said the findings suggest a way to take trial and error out of the search for new materials, in keeping with the movement of materials science toward a physics-driven approach. "You put in the properties you want, and the principle will tell you what material you need to synthesize," he said, noting that the concept can also be used to predict materials with superb antibacterial or other desirable properties.
The new material uses elastic energy localization where ice meets the material, triggering cracks at the interface that slough off the ice. Ghasemi said it requires minimal force to cause the cracks; the flow of air over the surface of an airplane acts as a trigger, for example. The material, which is applied as a spray, can be used on any surface, and Ghasemi said testing showed it is not only mechanically durable and unaffected by ultraviolet rays -- important for aircraft which face constant sun exposure -- but also does not change the aircraft's aerodynamic performance. Testing indicates it will last for more than 10 years, with no need to reapply, he said. -
Elon Musk Offered Chinese Green Card (politico.com)
hackingbear writes: During Elon Musk's trip to China for the ground-breaking of Tesla's first overseas factory, which will allow it to sell vehicles directly in the world's largest market for electric vehicles, he was offered a Chinese green card when he met with Premier Li Keqiang on Wednesday in Beijing, where they discussed Tesla's China ambitions. "I love China and want to come here more often," Musk was quoted as saying in the report. "If you do, we can issue you a Chinese green card," the premier replied. Getting a Chinese "green card" has been described as "one of the most difficult tasks in the world." By 2017, only about 10,000 foreigners had been granted permanent residency since the program was introduced in 2004, out of an estimated 1 million foreigners living in China; recipients include Dutch scientist Bernard Feringa, who won the 2016 Nobel Prize in chemistry. -
Researchers Demonstrate Teleportation Using On-Demand Photons From Quantum Dots (phys.org)
An anonymous reader quotes a report from Phys.Org: A team of researchers from Austria, Italy and Sweden has successfully demonstrated teleportation using on-demand photons from quantum dots. In their paper published in the journal Science Advances, the group explains how they accomplished this feat and how it applies to future quantum communications networks. Scientists and many others are very interested in developing truly quantum communications networks -- it is believed that such networks will be safe from hacking or eavesdropping due to their very nature. But, as the researchers with this new effort point out, there are still some problems standing in the way. One of these is the difficulty in amplifying quantum signals. One way to get around this problem, they note, is to generate photons on-demand as part of a quantum repeater -- this helps to effectively handle the high clock rates. In this new effort, they have done just that, using semiconductor quantum dots.
Prior work surrounding the possibility of using semiconductor quantum dots has shown that it is a feasible way to demonstrate teleportation, but only under certain conditions, none of which allowed for on-demand applications. Because of that, they have not been considered a push-button technology. In this new effort, the researchers overcame this problem by creating quantum dots that were highly symmetrical using an etching method to create the hole pairs in which the quantum dots develop. The process they used was called a XX (biexciton)--X (exciton) cascade. They then employed a dual-pulsed excitation scheme to populate the desired XX state (after two pairs shed photons, they retained their entanglement). Doing so allowed for the production of on-demand single photons suitable for use in teleportation. The dual pulsed excitation scheme was critical to the process, the team notes, because it minimized re-excitation. -
Germany Refuses To Ban Huawei, Citing Lack of Real Evidence (phys.org)
hackingbear writes: Germany's IT watchdog has expressed skepticism about calls for a boycott of Chinese telecoms giant Huawei, saying it has seen no evidence the firm could use its equipment to spy for Beijing, news weekly Spiegel reported. "For such serious decisions like a ban, you need proof," the head of Germany's Federal Office for Information Security (BSI), Arne Schoenbohm, told Spiegel, adding that his agency had no such evidence. The U.S. has been pressuring German authorities for months to drop Huawei, according to people familiar with the matter, but the Germans have asked for more specific evidence to demonstrate the security threat. German authorities and telecom executives have yet to turn up any evidence of security problems with Chinese equipment vendors, according to a person familiar with the matter.
Separately, at a (secret lobster-themed) meeting in Canada in July 2018, espionage chiefs from Australia, Canada, New Zealand, the U.K. and the U.S. -- all signatories to a treaty on signals intelligence, and often referred to as the "Five Eyes" -- agreed to do their best to contain the global growth of Chinese telecom (vendor) Huawei, the Australian Financial Review reported (paywalled). On the other hand, documents leaked by WikiLeaks and Snowden claimed that the NSA, the leader of the Five Eyes, tapped German Chancellery for decades and bugged routers made by Cisco, the leading American networking equipment vendor. -
Researchers Develop Hydrogel-Based Electrodes For Brain Implants (phys.org)
An anonymous reader quotes a report from Phys.Org: Hydrogels are physical and chemical polymer networks capable of retaining large quantities of liquid in aqueous conditions without losing their dimensional stability. They are used in a whole host of applications, and in combination with other components and they acquire specific properties such as electrical conductivity. The Materials + Technology research group in the Department of Chemical Engineering and Environment of the UPV/EHU's Faculty of Engineering selected a biopolymer that had not previously been used for applications of this type: starch. They created the hydrogel for use in neural interfaces. "Due to the fact that electrodes of neural interfaces made of platinum or gold are rigid, they require conductive polymer coatings to bring their flexibility closer to that of neural tissue. Right now, however, smaller devices are required that offer better mechanical, electrical and biological properties," explained the researcher.
The hydrogels "address these demands very well." To provide the hydrogel with electrical conductivity, they used graphene. "It provides electrical properties that are highly suited to the hydrogel, but this also has a drawback: It is not easily stabilized in water. We used extracts of salvia to overcome this obstacle and to render the graphene stable in an aqueous medium. These extracts also make the hydrogel even more suitable, if that is possible, for use in medicine as it also has antimicrobial and anti-inflammatory properties." The researchers used "click chemistry" to produce the hydrogel. "Unlike other means of synthesis, click chemistry does not tend to use catalysts in the reactions; in addition, no by-products are generated and they are high-performance reactions." -
CERN Begins New Antimatter Gravity Experiments (phys.org)
An anonymous reader quotes a report from Phys.Org: We learn it at high school: Release two objects of different masses in the absence of friction forces and they fall down at the same rate in Earth's gravity. What we haven't learned, because it hasn't been directly measured in experiments, is whether antimatter falls down at the same rate as ordinary matter or if it might behave differently. Two new experiments at CERN, ALPHA-g and GBAR, have now started their journey towards answering this question.
After months of round-the-clock work by researchers and engineers to put together the experiments, ALPHA-g and GBAR have received the first beams of antiprotons, marking the beginning of both experiments. ALPHA-g began taking beam on October 30, after receiving the necessary safety approvals. ELENA sent its first beam to GBAR on July 20, and since then the decelerator and GBAR researchers have been trying to perfect the delivery of the beam. The ALPHA-g and GBAR teams are now racing to commission their experiments before CERN's accelerators shut down in a few weeks for a two-year period of maintenance work. -
Stephen Hawking's Last Paper Is Now Online (vice.com)
An anonymous reader quotes a report from Motherboard: When Stephen Hawking died in March at the age of 76, the world mourned a beloved and visionary scientist. But it is some consolation that Hawking's final paper has now been published on the preprint journal ArXiv, demonstrating that even during his last days, he was still pursuing the epic cosmic questions that defined his career. Entitled "Black hole entropy and soft hair," the paper was authored by Hawking along with physicists Sasha Haco, Malcolm Perry, and Andrew Strominger. The work is the third in a series from the team and addresses Hawking's famous brainchild -- the black hole information paradox. Like many physics conundrums, the paradox emerges from the lack of coherence between quantum field theory and general relativity. On the smallest scales of matter, where atoms and quarks abound, there exists a different and seemingly contradictory set of rules to the largest scale of matter, involving stars and galaxies. The search for a "theory of everything" that reconciles these two models is one of the holy grails of modern physics, and was a lifelong fascination for Hawking.
Black holes are notable flashpoints for this tension between quantum field theory and general relativity. According to the quantum rulebook, it should be impossible for information about a particle -- its spin, configuration, mass, and other features -- to be permanently deleted from the universe. But what about matter that falls into black holes, objects with a reputation of not letting anything escape once it passes the event horizon? Can information be scrubbed inside black holes? Hawking suggested that information could indeed be deleted through Hawking radiation, which is a type of theoretical radiation that can escape from inside a black hole. This process has never been empirically observed, but the radiation would supposedly be stripped of all information about its original properties -- and that would violate the rules of the universe as we know them. In his last paper, Hawking and his colleagues speculated that a phenomenon called "soft hair" might resolve the black hole information paradox. The idea is that trails of light and gravity particles might encircle the event horizon, and could store, at the very least, entropic information about matter that fell into the black hole. -
US Military Program Could Be Seen As a Bioweapon, Scientists Warn (phys.org)
An anonymous reader quotes a report from Phys.Org: A research arm of the U.S. military is exploring the possibility of deploying insects to make plants more resilient by altering their genes. Some experts say the work may be seen as a potential biological weapon. In an opinion paper published Thursday in the journal Science, the authors say the U.S. needs to provide greater justification for the peace-time purpose of its Insect Allies project to avoid being perceived as hostile to other countries. Other experts expressed ethical and security concerns with the research, which seeks to transmit protective traits to crops already growing in the field. That would mark a departure from the current widely used procedure of genetically modifying seeds for crops such as corn and soy, before they grow into plants.
The military research agency says its goal is to protect the nation's food supply from threats like drought, crop disease and bioterrorism by using insects to infect plants with viruses that protect against such dangers. The State Department said the project is for peaceful purposes and does not violate the Biological Weapons Convention. The U.S. Department of Agriculture said its scientists are part of the research, which is being conducted in contained labs. The technology could work in different ways. In the first phase, aphids -- tiny bugs that feed by sucking sap from plants -- infected plants with a virus that temporarily brought about a trait. But researchers are also trying to see if viruses can alter the plant's genes themselves to be resistant to dangers throughout the plant's life. -
Rechargeable Zinc-Air Battery Nears Commercial Release (phys.org)
Long-time Slashdot reader necro81 writes: Reported in the NYTimes and in Phys.org: NantEnergy, a company backed by California billionaire Patrick Soon-Shiong, announced Wednesday that it has developed a rechargeable zinc-air battery that can store energy at far less cost than lithium-ion. The technology avoids some of the downsides of li-ion, like flammability and the use of cobalt.
Unlike many battery-related announcements, this one is backed by real-world use. Over the past several years, NantEnergy has deployed their batteries for stationary, micro-grid and cell-tower use in nine countries — about 55 MWh of capacity so far. They claim they can now take commercial orders, for delivery next year, at less than $100/kWh of capacity, which is one-half to one-fifth the cost of available lithium-ion grid storage. -
Scientists Formulate New Method To Create Low-Cost High Efficiency Solar Cells (phys.org)
An anonymous reader quotes a report from Phys.Org: Scientists from the Energy Materials and Surface Sciences Unit at the Okinawa Institute of Science and Technology Graduate University (OIST) believe they've found a winning formula in a new method to fabricate low-cost high-efficiency solar cells. Prof. Yabing Qi and his team from OIST in collaboration with Prof. Shengzhong Liu from Shaanxi Normal University, China, developed the cells using the materials and compounds that mimic the crystalline structure of the naturally occurring mineral perovskite. They describe their technique in a study published in the journal Nature Communications. Perovskite offers a more affordable solution, Prof. Qi says. Perovskite was first used to make solar cells in 2009 by Prof. Tsutomu Miyasaka's research team at Toin University of Yokohama, Japan, and since then it has been rapidly gaining importance. The fabrication method he and his research team have developed produces perovskite solar cells with an efficiency comparable to crystalline silicon cells, but it is potentially much cheaper than making silicon solar cells.
To make the new cells, the researchers coated transparent conductive substrates with perovskite films that absorb sunlight very efficiently. They used a gas-solid reaction-based technique in which the substrate is first coated with a layer of hydrogen lead triiodide incorporated with a small amount of chlorine ions and methylamine gas -- allowing them to reproducibly make large uniform panels, each consisting of multiple solar cells. In developing the method, the scientists realized that making the perovskite layer 1 micron thick increased the working life of the solar cell significantly. In addition, a thicker coating not only boosted the stability of the solar cells but also facilitated the fabrication processes, thereby lowering its production costs. The team is now working on increasing the size of their newly designed solar cell prototype to large commercial-sized panels that can be several feet long. They have reportedly built a working model of their new perovskite solar modules, thanks to funding from OIST's Technology Development and Innovation Center, but "the process of upscaing has reduced the efficiency of the cells from 20% to 15%," reports Phys.Org. "[T]he researchers are optimistic that they will be able to improve the way they work in the coming years and successfully commercialize their use." -
Delta's Fully Biometric Terminal Is the First In the US (engadget.com)
In what Delta is calling the first "biometric terminal" in the country, they will reportedly use facial recognition at check-in, security and boarding inside the international terminal at Atlanta's Hartsfield-Jackson airport. Engadget reports: Passengers that want to use facial recognition can approach a kiosk in the lobby and click "Look," or approach a camera at the ticket counter, TSA checkpoint or when boarding. Once a green check mark flashes on the screen, they can proceed. Delta -- which plans to introduce fingerprint scanning to fold, too -- says passengers can use this system instead of the passports to get through these checkpoints, but you'll still need your passport for use in other non-biometric-equipped airports (although maybe one day we'll do away with passports altogether). Privacy advocates are concerned about the security risks present in facial scans, especially as it's an opt-out process. Others, however, say it makes air travel a more streamlined process. -
Spheres Can Make Concrete Leaner, Greener (phys.org)
An anonymous reader quotes a report from Phys.Org: Rice University scientists have developed micron-sized calcium silicate spheres that could lead to stronger and greener concrete, the world's most-used synthetic material. The researchers formed the spheres in a solution around nanoscale seeds of a common detergent-like surfactant. The spheres can be prompted to self-assemble into solids that are stronger, harder, more elastic and more durable than ubiquitous Portland cement. He said the spheres are suitable for bone-tissue engineering, insulation, ceramic and composite applications as well as cement. The research appears in the American Chemical Society journal Langmuir.
In tests, the researchers used two common surfactants to make spheres and compressed their products into pellets for testing. They learned that DTAB-based pellets compacted best and were tougher, with a higher elastic modulus, than either CTAB pellets or common cement. They also showed high electrical resistance. [Rice materials scientist Rouzbeh Shahsavari] said the size and shape of particles in general have a significant effect on the mechanical properties and durability of bulk materials like concrete. He said increasing the strength of cement allows manufacturers to use less concrete, decreasing not only weight but also the energy required to make it and the carbon emissions associated with cement's manufacture. Because spheres pack more efficiently than the ragged particles found in common cement, the resulting material will be more resistant to damaging ions from water and other contaminants and should require less maintenance and less-frequent replacement. -
Scientists Discover a 'Tuneable' Novel Quantum State of Matter (phys.org)
An anonymous reader quotes a report from Phys.Org: An international team of researchers led by Princeton physicist Zahid Hasan has discovered a quantum state of matter that can be "tuned" at will -- and it's 10 times more tuneable than existing theories can explain. This level of manipulability opens enormous possibilities for next-generation nanotechnologies and quantum computing. Hasan and his colleagues, whose research appears in the current issue of Nature, are calling their discovery a "novel" quantum state of matter because it is not explained by existing theories of material properties. The classical phases of matter -- solids, liquids and gases -- arise from interactions between atoms or molecules. In a quantum phase of matter, the interactions take place between electrons, and are much more complex.
[Hasan] and his colleagues arranged atoms on the surface of crystals in many different patterns and watched what happened. They used various materials prepared by collaborating groups in China, Taiwan and Princeton. One particular arrangement, a six-fold honeycomb shape called a "kagome lattice" for its resemblance to a Japanese basket-weaving pattern, led to something startling -- but only when examined under a spectromicroscope in the presence of a strong magnetic field [...]. All the known theories of physics predicted that the electrons would adhere to the six-fold underlying pattern, but instead, the electrons hovering above their atoms decided to march to their own drummer -- in a straight line, with two-fold symmetry. The decoupling between the electrons and the arrangement of atoms was surprising enough, but then the researchers applied a magnetic field and discovered that they could turn that one line in any direction they chose. Without moving the crystal lattice, [one] could rotate the line of electrons just by controlling the magnetic field around them. -
Japan To Test Mini 'Space Elevator' (phys.org)
Zorro shares a report from Phys.Org: A Japanese team working to develop a "space elevator" will conduct a first trial this month, blasting off a miniature version on satellites to test the technology. The test equipment, produced by researchers at Shizuoka University, will hitch a ride on an H-2B rocket being launched by Japan's space agency from southern island of Tanegashima next week. The test involves a miniature elevator stand-in -- a box just six centimeters (2.4 inches) long, three centimeters wide, and three centimeters high. If all goes well, it will provide proof of concept by moving along a 10-meter cable suspended in space between two mini satellites that will keep it taut. The mini-elevator will travel along the cable from a container in one of the satellites. The movement of the motorized "elevator" box will be monitored with cameras in the satellites. -
Nanotubes Can Shape Water Molecules Into 'Two-Dimensional Ice' (phys.org)
Iwastheone quotes Phys.org: First, according to Rice University engineers, get a nanotube hole. Then insert water. If the nanotube is just the right width, the water molecules will align into a square rod. Rice materials scientist Rouzbeh Shahsavari and his team used molecular models to demonstrate their theory that weak van der Waals forces between the inner surface of the nanotube and the water molecules are strong enough to snap the oxygen and hydrogen atoms into place. Shahsavari referred to the contents as two-dimensional "ice," because the molecules freeze regardless of the temperature.
He said the research provides valuable insight on ways to leverage atomic interactions between nanotubes and water molecules to fabricate nanochannels and energy-storing nanocapacitors... The researchers already knew that hydrogen atoms in tightly confined water take on interesting structural properties. Recent experiments by other labs showed strong evidence for the formation of nanotube ice and prompted the researchers to build density functional theory models to analyze the forces responsible... They discovered that nanotubes in the middle diameters had the most impact on the balance between molecular interactions and van der Waals pressure that prompted the transition from a square water tube to ice.
The paper describes "solid-like water nanotubes," and the head of the research team believes they could have practical applications, according to the article.
"Nanotube ice could find use in molecular machines or as nanoscale capillaries, or foster ways to deliver a few molecules of water or sequestered drugs to targeted cells, like a nanoscale syringe." -
H-1B Visa Use Soared Last Year At Major Tech Firms (phys.org)
"Even as the White House began cracking down on U.S. work visas, major Silicon Valley technology firms last year dramatically ramped up hiring of workers under the controversial H-1B visa program," reports the Mercury News. Menlo Park-based Facebook in 2017 received 720 H-1B approvals, a 53 percent increase over 2016, according to the National Foundation for American Policy, which obtained federal government data. Mountain View's Google received 1,213 H-1B approvals, a 31 percent increase. The number of H-1B approvals at Intel in Santa Clara rose 19 percent and Cupertino-based Apple received 673, a 7 percent increase.... [E]xperts say the data doesn't show how many additional H-1B contractors tech companies may get from staffing agencies or outsourcing companies. In response to this news organization's inquiries, Facebook said it does not publicly discuss its use of H-1B workers or contractors. Google, Apple and Intel did not respond to requests for information about their use of H-1B workers or contractors....
Amazon chalked up the largest increase in H-1B approvals, with 2,515 in 2017, a 78 percent leap. Microsoft received 1,479 approvals, an increase of 29 percent. Neither company responded to a request for comment.
A distinguished fellow at Carnegie Mellon's School of Engineering at Silicon Valley believes that the threat of a U.S. crackdown on H-1B visas may simply have prompted companies to secure as many visas as possible while they could. -
Scientists Find Way To Make Mineral Which Can Remove CO2 From Atmosphere (phys.org)
An anonymous reader quotes a report from Phys.Org: Scientists have found a rapid way of producing magnesite, a mineral which stores carbon dioxide. If this can be developed to an industrial scale, it opens the door to removing CO2 from the atmosphere for long-term storage, thus countering the global warming effect of atmospheric CO2. This work is presented at the Goldschmidt conference in Boston. Now, for the first time, researchers have explained how magnesite forms at low temperature, and offered a route to dramatically accelerating its crystallization. A tonne of naturally-occurring magnesite can remove around half a tonne of CO2 from the atmosphere, but the rate of formation is very slow. The researchers were able to show that by using polystyrene microspheres as a catalyst, magnesite would form within 72 days. The microspheres themselves are unchanged by the production process, so they can ideally be reused. Project leader, Professor Ian Power from Trent University in Ontario added: "Using microspheres means that we were able to speed up magnesite formation by orders of magnitude. This process takes place at room temperature, meaning that magnesite production is extremely energy efficient. For now, we recognize that this is an experimental process, and will need to be scaled up before we can be sure that magnesite can be used in carbon sequestration (taking CO2 from the atmosphere and permanently storing it as magnesite). This depends on several variables, including the price of carbon and the refinement of the sequestration technology, but we now know that the science makes it do-able." -
Study Finds Flaw In Emergent Gravity (phys.org)
An anonymous reader quotes a report from Phys.Org: In recent years, some physicists have been investigating the possibility that gravity is not actually a fundamental force, but rather an emergent phenomenon that arises from the collective motion of small bits of information encoded on spacetime surfaces called holographic screens. The theory, called emergent gravity, hinges on the existence of a close connection between gravity and thermodynamics. Emergent gravity has received its share of criticism, however, and a new paper adds to this by showing that the holographic screen surfaces described by the theory do not actually behave thermodynamically, undermining a key assumption of the theory.
In the new paper, the scientists tested whether different kinds of surfaces obey an analogue of the first law of thermodynamics, which is a special form of energy conservation. Their results reveal that, while surfaces near black holes (called stretched horizons) do obey the first law, ordinary surfaces -- including holographic screens -- generally do not. The only exception is that ordinary surfaces that are spherically symmetric do obey the first law. As the scientists explain, the finding that stretched horizons obey the first law is not surprising, since these surfaces inherit much of their behavior from the nearby horizons. Still, the scientists caution that the results do not necessarily imply that stretched horizons obey all of the laws of thermodynamics. On the other hand, the finding that ordinary surfaces do not obey the first law is more unexpected, especially as it is one of the key assumptions of emergent gravity. Going forward, researchers will work to understand what this means for the future of emergent gravity, as well as explore other possible implications. -
Chemists Discover How Blue Light Speeds Blindness
Isao writes: It (apparently) has been known that blue light damages eyes and accelerates macular degeneration. A new article on Phys.org may have identified how this happens. It seems that unlike other light colors, blue causes a necessary molecule (retinal) to permanently kill photoreceptor cells. "The researcher found that a molecule called alpha Tocopherol, a Vitamin E derivative and a natural antioxidant in the eye and body, stops the cells from dying," reports Phys.org. "However, as a person ages or the immune system is suppressed, people lose the ability to fight against the attack by retinal and blue light." The authors will continue their research and recommend filtering and blue-light reduction in the meantime. The study has been published in the journal Scientific Reports. -
Pentagon Restricts Use of Location-Logging Fitness Trackers (cnn.com)
In the beginning of the year, Strava released a data visualization map that showed all the activity tracked by users of its app. The map was detailed enough to potentially give away extremely sensitive information about military personnel on active service in locations across the world. After reviewing their GPS policies, the Pentagon is banning soldiers and other personnel at sensitive bases and warzone areas from using location features on fitness trackers and other devices. Engadget reports: The Department of Defense is not issuing an outright ban on GPS devices and apps, but declared that the location features must be turned off in certain areas. "These geolocation capabilities can expose personal information, locations, routines, and numbers of DOD personnel, and potentially create unintended security consequences and increased risk to the joint force and mission," a memo obtained by the Associated Press said. It's up to ranking officers in less-sensitive areas to decide whether their charges can use GPS functions, based on the threat level in that location. The Defense Department will also provide training on the risks that fitness trackers bring. -
A Material Found To Carry Current In a Way Never Before Observed (phys.org)
An anonymous reader quotes a report from Phys.Org: Scientists at the Florida State University-headquartered National High Magnetic Field Laboratory have discovered a behavior in materials called cuprates that suggests they carry current in a way entirely different from conventional metals such as copper. The research, published today in the journal Science, adds new meaning to the materials' moniker, "strange metals." Cuprates are high-temperature superconductors (HTS), meaning they can carry current without any loss of energy at somewhat warmer temperatures than conventional, low-temperature superconductors (LTS). Although scientists understand the physics of LTS, they haven't yet cracked the nut of HTS materials. Exactly how the electrons travel through these materials remains the biggest mystery in the field.
For their research on one specific cuprate, lanthanum strontium copper oxide (LSCO), a team led by MagLab physicist Arkady Shekhter focused on its normal, metallic state -- the state from which superconductivity eventually emerges when the temperature dips low enough. This normal state of cuprates is known as a "strange" or "bad" metal, in part because the electrons don't conduct electricity particularly well. Scientists have studied conventional metals for more than a century and generally agree on how electricity travels through them. They call the units that carry charge through those metals "quasiparticles," which are essentially electrons after factoring in their environment. These quasiparticles act nearly independently of each other as they carry electric charge through a conductor. But does quasiparticle flow also explain how electric current travels in the cuprates? At the National MagLab's Pulsed Field Facility in Los Alamos, New Mexico, Shekhter and his team investigated the question. They put LSCO in a very high magnetic field, applied a current to it, then measured the resistance. The resulting data revealed that the current cannot, in fact, travel via conventional quasiparticles, as it does in copper or doped silicon. The normal metallic state of the cuprate, it appeared, was anything but normal. -
Fields Medals Awarded To 4 Mathematicians (nytimes.com)
Every four years, at an international gathering of mathematicians, the subject's youngest and brightest are honored with the Fields Medal, often described as the Nobel Prize of mathematics. The New York Times: This year's recipients, announced on Wednesday at the International Congress of Mathematicians in Rio de Janeiro, include one of the youngest ever: Peter Scholze, a professor of mathematics at the University of Bonn who is 30 years old. Two weeks ago, Peter Woit, a professor at Columbia University who blogs about mathematics and physics, was among those who anticipated that Dr. Scholze would receive the medal. Dr. Woit said Dr. Scholze was "by far the most talented arithmetic geometer of his generation." By custom, Fields medals are bestowed to mathematicians 40 years old or younger. That means Dr. Scholze would have still been eligible for another two rounds of medals. The medal, first awarded in 1936, was conceived by John Charles Fields, a Canadian mathematician. The youngest winner, Jean-Pierre Serre in 1954, was 27. The other Fields medalists this year are Caucher Birkar, 40, of the University of Cambridge in England; Alessio Figalli, 34, of the Swiss Federal Institute of Technology in Zurich; and Akshay Venkatesh, 36, of the Institute for Advanced Study in Princeton and Stanford University in California. Peter Scholze's award cites "the revolution that he launched in arithmetic geometry," the study of shapes that arise from the rational-number solutions to polynomial equations (like xy3 + x2 = 1 or x2 â" y3z = 3). More about him here. As a mathematician, Caucher Birkar has helped bring order to the infinite variety of polynomial equations -- those equations that consist of different variables raised to various powers. No two equations are exactly alike, but Birkar has helped reveal that many can be neatly categorized into a small number of families. [As a reader pointed out, Birkar's award was stolen within minutes of him receiving it.] UPDATE (8/4/18): Organizers have announced they'll provide an identical replacement medal.
Once a classics student with no particular affinity for mathematics, Alessio Figalli has gone on to shake the venerable mathematical discipline of analysis, which concerns the properties of certain types of equations. Figalli's results have provided a refined mathematical understanding of everything from the shape of crystals to weather patterns, to the way ice melts in water. Akshay Venkatesh, a former prodigy who struggled with the genius stereotype, has won a Fields Medal for his "profound contributions to an exceptionally broad range of subjects in mathematics." -
Social Media Manipulation Rising Globally, New Oxford Report Warns (phys.org)
A new report from Oxford University found that manipulation of public opinion over social media platforms is growing at a large scale, despite efforts to combat it. "Around the world, government agencies and political parties are exploiting social media platforms to spread junk news and disinformation, exercise censorship and control, and undermine trust in media, public institutions and science," reports Phys.Org. From the report: "The number of countries where formally organized social media manipulation occurs has greatly increased, from 28 to 48 countries globally," says Samantha Bradshaw, co-author of the report. "The majority of growth comes from political parties who spread disinformation and junk news around election periods. There are more political parties learning from the strategies deployed during Brexit and the U.S. 2016 Presidential election: more campaigns are using bots, junk news, and disinformation to polarize and manipulate voters."
This is despite efforts by governments in many democracies introducing new legislation designed to combat fake news on the internet. "The problem with this is that these 'task forces' to combat fake news are being used as a new tool to legitimize censorship in authoritarian regimes," says Professor Phil Howard, co-author and lead researcher on the OII's Computational Propaganda project. "At best, these types of task forces are creating counter-narratives and building tools for citizen awareness and fact-checking." Another challenge is the evolution of the mediums individuals use to share news and information. "There is evidence that disinformation campaigns are moving on to chat applications and alternative platforms," says Bradshaw. "This is becoming increasingly common in the Global South, where large public groups on chat applications are more popular." -
Telescope Offers 'Clearest View Yet' of Milky Way - Including Plasma Filaments (ska.ac.za)
Chris Reeve writes: The MeerKAT radio telescope was inaugurated in South Africa this past Friday, revealing the clearest view yet of the center of the Milky Way. What is especially surprising about the produced image are the numerous prominent filaments which seem to appear in the foreground.
Herschel made a similar announcement just three years prior that "Observations with ESA's Herschel space observatory have revealed that our Galaxy is threaded with filamentary structures on every length scale." Intriguingly, close inspection of yesterday's SKA image show these filaments twisting around one another, yet without combining — a phenomenon observable in most novelty plasma globes when the filaments are conducting electricity... The SKA telescopes is one of the first telescopes to witness these filaments because it is 50 times more powerful than any former telescope, but also because it is apparently one of the few telescopes which can observe dark mode plasmas. For these reasons, the SKA telescope will inevitably revive the debate over the underlying physical reasons for filaments which exhibit coherent thin magnetic structure over light-year distances.
The original submission included a comment with more information about the theory of a plasma universe. -
Scientists Discover the World's Oldest Colors (phys.org)
1.1 billion-year-old bright pink pigments extracted from rocks deep beneath the Sahara desert in Africa are the oldest colors on record. They were discovered by scientists from The Australian National University (ANU), with support from Geoscience Australia and researchers in the United States and Japan. Phys.Org reports: Dr. Nur Gueneli from ANU said the pigments taken from marine black shales of the Taoudeni Basin in Mauritania, West Africa, were more than half a billion years older than previous pigment discoveries. The fossils range from blood red to deep purple in their concentrated form, and bright pink when diluted. The researchers crushed the billion-year-old rocks to powder, before extracting and analyzing molecules of ancient organisms from them.
"The precise analysis of the ancient pigments confirmed that tiny cyanobacteria dominated the base of the food chain in the oceans a billion years ago, which helps to explain why animals did not exist at the time," Dr. Gueneli said. Senior lead researcher Associate Professor Jochen Brocks from ANU said that the emergence of large, active organisms was likely to have been restrained by a limited supply of larger food particles, such as algae. "Algae, although still microscopic, are a thousand times larger in volume than cyanobacteria, and are a much richer food source," said. The study has been published in the journal PNAS. -
TV Coverage of Cycling Races Can Help Document the Effects of Climate Change (phys.org)
Researchers from Ghent University were able to detect climate change impacts on trees in Belgium by analyzing nearly four decades of archive footage from the Tour of Flanders. The findings were published in the journal Methods in Ecology and Evolution. Phys.Org reports: Focusing on trees and shrubs growing around recognizable climbs and other 'landmarks' along the route of this major annual road cycling race in Belgium, the team looked at video footage from 1981 to 2016 obtained by Flemish broadcaster VRT. They visually estimated how many leaves and flowers were present on the day of the course (usually in early April) and linked their scores to climate data. The ecologists found that the trees had advanced the timing of leafing and flowering in response to recent temperature changes. Before 1990, almost no trees had grown leaves at the time of the spring race. After that year, more and more trees visible in the television footage -- in particular magnolia, hawthorn, hornbeam and birch trees -- were already in full leaf. These shifts were most strongly related to warmer average temperatures in the area, which have increased by 1.5 degrees Celsius since 1980. -
How Microbes Survive Clean Rooms and Contaminate Spacecraft (phys.org)
An anonymous reader quotes a report from Phys.Org: Rakesh Mogul, a Cal Poly Pomona professor of biological chemistry, was the lead author of an article in the journal Astrobiology that offers the first biochemical evidence explaining the reason the contamination persists. To figure out how the spacecraft microbiome survives in the cleanroom facilities, the research team analyzed several Acinetobacter strains that were originally isolated from the Mars Odyssey and Phoenix spacecraft facilities. They found that under very nutrient-restricted conditions, most of the tested strains grew on and biodegraded the cleaning agents used during spacecraft assembly. The work showed that cultures grew on ethyl alcohol as a sole carbon source while displaying reasonable tolerances towards oxidative stress. This is important since oxidative stress is associated with desiccating and high radiation environments similar to Mars. The tested strains were also able to biodegrade isopropyl alcohol and Kleenol 30, two other cleaning agents commonly used, with these products potentially serving as energy sources for the microbiome. -
German Spy Agency Can Keep Tabs On Internet Hubs, Federal Court Rules (phys.org)
Earlier this week, a federal court in Germany threw out a challenge by the world's largest internet hub, the De-Cix exchange, against the tapping of its data flows by the BND foreign intelligence service. What this means is that the country's spy agency can continue to monitor major internet hubs if Berlin deems it necessary for strategic security interests. From a report: The operator had argued the agency was breaking the law by capturing German domestic communications along with international data. However, the court in the eastern city of Leipzig ruled that internet hubs "can be required by the federal interior ministry to assist with strategic communications surveillance by the BND." De-Cix says its Frankfurt hub is the world's biggest internet exchange, bundling data flows from as far as China, Russia, the Middle East and Africa, which handles more than six terabytes per second at peak traffic.
De-Cix Management GmbH, which is owned by eco Association, the European internet industry body, had filed suit against the interior ministry, which oversees the BND and its strategic signals intelligence. It said the BND, a partner of the US National Security Agency (NSA), has placed so-called Y-piece prisms into its data-carrying fibre optic cables that give it an unfiltered and complete copy of the data flow. The surveillance sifts through digital communications such as emails using certain search terms, which are then reviewed based on relevance. -
First Measurement of Distribution of Pressure Inside a Proton (phys.org)
Okian Warrior shares a report from Phys.Org: Inside every proton in every atom in the universe is a pressure cooker environment that surpasses the atom-crushing heart of a neutron star. That's according to the first measurement of a mechanical property of subatomic particles, the pressure distribution inside the proton, which was carried out by scientists at the Department of Energy's Thomas Jefferson National Accelerator Facility. The nuclear physicists found that the proton's building blocks, the quarks, are subjected to a pressure of 100 decillion Pascal (1035) near the center of a proton, which is about 10 times greater than the pressure in the heart of a neutron star. The result was recently published in the journal Nature. -
Who Has More of Your Personal Data Than Facebook? Try Google (wsj.com)
Facebook may be in the hot seat right now for its collection of personal data without our knowledge or explicit consent, but as The Wall Street Journal points out, "Google is a far bigger threat by many measures: the volume of information it gathers, the reach of its tracking and the time people spend on its sites and apps." From the report (alternative source): It's likely that Google has shadow profiles (data the company gathers on people without accounts) on as at least as many people as Facebook does, says Chandler Givens, CEO of TrackOff, which develops software to fight identity theft. Google allows everyone, whether they have a Google account or not, to opt out of its ad targeting, though, like Facebook, it continues to gather your data. Google Analytics is far and away the web's most dominant analytics platform. Used on the sites of about half of the biggest companies in the U.S., it has a total reach of 30 million to 50 million sites. Google Analytics tracks you whether or not you are logged in. Meanwhile, the billion-plus people who have Google accounts are tracked in even more ways. In 2016, Google changed its terms of service, allowing it to merge its massive trove of tracking and advertising data with the personally identifiable information from our Google accounts.
Google uses, among other things, our browsing and search history, apps we've installed, demographics like age and gender and, from its own analytics and other sources, where we've shopped in the real world. Google says it doesn't use information from "sensitive categories" such as race, religion, sexual orientation or health. Because it relies on cross-device tracking, it can spot logged-in users no matter which device they're on. Google fuels even more data harvesting through its dominant ad marketplaces. There are up to 4,000 data brokers in the U.S., and collectively they know everything about us we might otherwise prefer they didn't -- whether we're pregnant, divorced or trying to lose weight. Google works with some of these brokers directly but the company says it vets them to prevent targeting based on sensitive information. Google also is the biggest enabler of data harvesting, through the world's two billion active Android mobile devices. -
New Theory Suggests Dinosaurs Were Already Dying When Asteroid Hit (phys.org)
The new "biotic revenge hypothesis" suggests that dinosaurs were killed off by toxic plants. (And an inability to recognize the taste of a toxic plant.) the gmr summarizes a new paper reported at Phys.org: The dinosaur population had been drastically decreasing before the asteroid impact, [and] the appearance of the first flowering plants -- angiosperms -- in the fossil record coincides with the gradual disappearance of the dinosaurs... The scientists concluded that though the asteroid played a role in the extinction of dinosaurs, the "plants had already placed severe strain on the species."
Crocodiles (believed to be descended from dinosaurs) also can't recognize the taste of toxic plants -- the researchers tested 10 different species. And they point out that not only did dinosaurs start to disappear before the asteroid impact -- they continued to "gradually disappear for millions of years afterward." -
Can Electricity Travel Through Space on Astrophysical Jets? (mdpi.com)
Slashdot reader Chris Reeve writes: An October 2017 paper titled Electric Currents along Astrophysical Jets reports that "Several researchers have reported direct evidence for large scale electric currents along astrophysical jets." A review of the citations at the end of that paper and others (here and here, for instance) would seem to suggest that one of the great Internet science debates has finally been settled: Electricity does indeed travel through space over vast cosmic distances.
What has been interesting to watch about this unexpected development is that science journalists have so far not explicitly reported this as a shift in theory, and commenters on sites like phys.org appear to deny that any change has even occurred: "The jets have been shown not to be electric currents, the energy and the physics involved are certainly not electromagnetic." This comment completely rejecting these new findings was highly rated by other phys.org readers, suggesting that the failure to explicitly report this as a change in theory has left this controversial topic in a highly confused state.
The paper summarizes what it calls "observational evidence for the existence of large scale electric currents and their associated grand design helical magnetic fields in kpc-scale astrophysical jets." And the original submitter details the history of the question in a follow-up comment arguing that at our current moment in time, "a mistaken bias against electricity in space continues to dominate conversations." -
73 Percent of Fish In the Northwestern Atlantic Have Microplastics In Their Guts
According to a new study published today in the journal Frontiers in Marine Science, microplastics have been found in the stomachs of nearly three out of every four mesopelagic fish caught in the Northwest Atlantic. "These findings are worrying, as the affected fish could spread microplastics throughout the ocean," reports Phys.Org. "The fish are also prey for fish eaten by humans, meaning that microplastics could indirectly contaminate our food supply through the transfer of associated microplastic toxins." From the report: Microplastics are small plastic fragments that have accumulated in the marine environment following decades of pollution. These fragments can cause significant issues for marine organisms that ingest them, including inflammation, reduced feeding and weight-loss. Microplastic contamination may also spread from organism to organism when prey is eaten by predators. Since the fragments can bind to chemical pollutants, these associated toxins could accumulate in predator species. Mesopelagic fish serve as a food source for a large variety of marine animals, including tuna, swordfish, dolphins, seals and sea birds. Typically living at depths of 200-1,000 meters, these fish swim to the surface at night to feed then return to deeper waters during the day.
The researchers caught mesopelagic fish at varying depths, then examined their stomachs for microplastics back in the lab. They used a specialized air filter so as not to introduce airborne plastic fibers from the lab environment. The team found a wide array of microplastics in the fish stomachs -- with a whopping 73% of the fish having ingested the pollutants. -
The Next Falcon Heavy Will Carry the Most Powerful Atomic Clock Ever Launched (space.com)
schwit1 shares a report from Space.com: This isn't your average timekeeper. The so-called Deep Space Atomic Clock (DSAC) is far smaller than Earth-bound atomic clocks, far more precise than the handful of other space-bound atomic clocks, and more resilient against the stresses of space travel than any clock ever made. According to a NASA statement, it's expected to lose no more than 2 nanoseconds (2 billionths of a second) over the course of a day. That comes to about 7 millionths of a second over the course of a decade. n an email to Live Science, Andrew Good, a Jet Propulsion Laboratory representative, said the first DSAC will hitch a ride on the second Falcon Heavy launch, scheduled for June.
Every deep-space mission that makes course corrections needs to send signals to ground stations on Earth. Those ground stations rely on atomic clocks to measure just how long those signals took to arrive, which allows them to locate the spacecrafts position down to the meter in the vast vacuum. They then send signals back, telling the craft where they are and where to go next. Thats a cumbersome process, and it means any given ground station can support only one spacecraft at a time. The goal of DSAC, according to a NASA fact sheet, is to allow spacecraft to make precise timing measurements onboard a spacecraft, without waiting for information from Earth. A DSAC-equipped spacecraft, according to NASAs statement, could calculate time without waiting for measurements from Earth -- allowing it to make course adjustments or perform precision science experiments without pausing to turn its antennas earthward and waiting for a reply. -
Researchers Discover Efficient Way To Filter Salt, Metal Ions From Water (phys.org)
schwit1 shares a report on a new study, published in Sciences Advances, that offers a new solution to providing clean drinking water for billions of people worldwide: It all comes down to metal-organic frameworks (MOFs), an amazing next generation material that have the largest internal surface area of any known substance. The sponge like crystals can be used to capture, store and release chemical compounds. In this case, the salt and ions in sea water. Dr Huacheng Zhang, Professor Huanting Wang and Associate Professor Zhe Liu and their team in the Faculty of Engineering at Monash University in Melbourne, Australia, in collaboration with Dr Anita Hill of CSIRO and Professor Benny Freeman of the McKetta Department of Chemical Engineering at The University of Texas at Austin, have recently discovered that MOF membranes can mimic the filtering function, or "ion selectivity," of organic cell membranes. With further development, these membranes have significant potential to perform the dual functions of removing salts from seawater and separating metal ions in a highly efficient and cost effective manner, offering a revolutionary new technological approach for the water and mining industries. Currently, reverse osmosis membranes are responsible for more than half of the world's desalination capacity, and the last stage of most water treatment processes, yet these membranes have room for improvement by a factor of 2 to 3 in energy consumption. They do not operate on the principles of dehydration of ions, or selective ion transport in biological channels. -
'Sinking' Pacific Nation Tuvalu Is Actually Getting Bigger (phys.org)
mi shares a report from Phys.Org: The Pacific nation of Tuvalu -- long seen as a prime candidate to disappear as climate change forces up sea levels -- is actually growing in size, new research shows. A University of Auckland study examined changes in the geography of Tuvalu's nine atolls and 101 reef islands between 1971 and 2014, using aerial photographs and satellite imagery. It found eight of the atolls and almost three-quarters of the islands grew during the study period, lifting Tuvalu's total land area by 2.9 percent, even though sea levels in the country rose at twice the global average. Co-author Paul Kench said the research, published Friday in the journal Nature Communications, challenged the assumption that low-lying island nations would be swamped as the sea rose. It found factors such as wave patterns and sediment dumped by storms could offset the erosion caused by rising water levels. -
Microbes May Help Astronauts Transform Human Waste Into Food (phys.org)
A Penn State researcher team has shown that it is possible to rapidly break down solid and liquid waste to grow food with a series of microbial reactors, while simultaneously minimizing pathogen growth. They reported their findings in the journal Life Sciences in Space Research. Phys.Org reports: To test their idea, the researchers used an artificial solid and liquid waste that's commonly used in waste management tests. They created an enclosed, cylindrical system, four feet long by four inches in diameter, in which select microbes came into contact with the waste. The microbes broke down waste using anaerobic digestion, a process similar to the way humans digest food. The team found that methane was readily produced during anaerobic digestion of human waste and could be used to grow a different microbe, Methylococcus capsulatus, which is used as animal feed today. The team concluded that such microbial growth could be used to produce a nutritious food for deep space flight. They reported in Life Sciences in Space Research that they grew M. capsulatus that was 52 percent protein and 36 percent fats, making it a potential source of nutrition for astronauts.
Because pathogens are also a concern with growing microbes in an enclosed, humid space, the team studied ways to grow microbes in either an alkaline environment or a high-heat environment. They raised the system's pH to 11 and were surprised to find a strain of the bacteria Halomonas desiderata that could thrive. The team found this bacteria to be 15 percent protein and 7 percent fats. At 158 degrees Fahrenheit, which kills most pathogens, they grew the edible Thermus aquaticus, which consisted of 61 percent protein and 16 percent fats.