Domain: aip.org
Stories and comments across the archive that link to aip.org.
Stories · 90
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Finnish Scientist Provides Another Explanation For The 'Impossible' EM Drive (examiner.com)
MarkWhittington quotes a report from Examiner: Ever since the EmDrive entered the news about a year or so ago, it has sparked considerable controversy. The device is alleged to work by using microwaves that produce, in some fashion as yet unknown to science, thrust. Many scientists suggest that the EM drive is impossible as it violates known physics. However, a number of tests conducted in Great Britain, Germany, China, and at NASA's Eagleworks at the Johnson Spaceflight Center have resulted in thrust that cannot, as yet, be explained by experimental error. The International Business Times reported that a Finnish scientist has published an article in a peer-reviewed science journal with a possible explanation as to how the drive works. International Business Times writes, "A new peer-reviewed paper on the EmDrive from Finaland states that the controversial electromagnetic space propulsion technology does work due to microwaves fed into the device converting photons that leak out of the closed cavity, producing an exhaust. The research, entitled "On the exhaust of electromagnetic drive," is published in the journal AIP Advances 6 and is the brainchild of Dr Arto Annila, a physics professor at the University of Helsinki; Dr Erkki Kolehmainen, an organic chemistry professor at the University of Jyvaskyla; and Patrick Grahn, a multiphysicist at engineering software firm Comsol." -
Galloping Gertie, Engineering's Most Misunderstood Failure (vice.com)
tedlistens writes: Generations of physics teachers, textbooks, and articles have taught that the spectacular collapse of the Tacoma Narrows Bridge, 75 years ago, in November 1940, was caused by resonance. But this explanation is inaccurate, and despite the fact that the collapse is not a mystery—that the bridge, in a sense, twisted itself apart—the fallacy continues to spread. Not only that: according to a new study by Don Olson and colleagues at Texas State University and East Carolina University, parts of the famous footage that immortalized it are misleading too. According to the most complete recent research, he and his co-authors write, "the failure of the bridge was related to a wind-driven amplification of the torsional oscillation that, unlike a resonance, increases monotonically with increasing wind speed." Each time the deck of the bridge twisted now, it sought to return to its original position (inertial forces). And as it did so, twisting back with a matching speed and direction (elastic forces), the wind and the vortices caught it each time, pushing the deck just a little bit more in that direction (aerodynamic forces). With each twist and each twist back, the size of the twisting slightly increased. -
Chinese Researchers Reveal Active Stealthy Material (popsci.com)
hackingbear writes: Even after billions and billions of dollars spent on the stealthy skin used on F-22, F-35 and B-2, the material has weaknesses, and one of those is ultra-high-frequency (UHF) radar, which can pick up traces of the plane that other radar misses. Chinese researchers came to the rescue and created a material just 5/16 of an inch thick that can safeguard stealth planes against UHF detection. The material tunes itself to a range of detection frequencies, protecting against a large swath of radar scans. What's even more amazing? They published this seemingly top secret invention wide open in the Journal of Applied Physics . -
Stanford Creates Tricorder-Like Devices For Detecting Cancer and Explosives (stanford.edu)
An anonymous reader writes: A new technology has promise to safely find buried plastic explosives and maybe even spot fast-growing tumors. The technique involves the clever interplay of microwaves and ultrasound to develop a detector like the Star Trek tricorder. The careful manipulation of two scientific principles drives both the military and medical applications of the Stanford work. First, all materials expand and contract when stimulated with electromagnetic energy, such as light or microwaves. Second, this expansion and contraction produces ultrasound waves that travel to the surface and can be detected remotely.
In a potential battlefield application, the microwaves would heat the suspect area, causing the muddy ground to expand and thus squeeze the plastic (abstract). Pulsing the microwaves would generate a series of ultrasound pressure waves that could be detected and interpreted to disclose the presence of buried plastic explosives. Solving the technical challenges of detecting ultrasound after it left the ground gave the Stanford researchers the experience to take aim at their ultimate goal – using the device in medical applications without touching the skin. -
Volkswagen Diesel Scandal Logistics Imply Sizable Conspiracy
Guinnessy writes with an interesting analysis of the Volkswagen software cheating scandal: Physics Today's Charles Day takes a look at how diesel engines work, and why it's clear it's not just a lone software engineer who came up with the cheat. "...[S]oftware is impotent without hardware. To recognize when a car was being tested and not driven, the defeat device required data from a range of sensors -- sensors that a noncheating car might not need.... Whereas it's conceivable that a single software engineer, directed by a single manager, could have secretly written and uploaded the code that ran the defeat device, installing its associated hardware would require a larger and more diverse team of conspirators," he says. -
3-D Ultrasonic Fingerprint Scanning Could Strengthen Smartphone Security
Zothecula sends news that researchers from the University of California are developing new fingerprint scanning technology that could one day enhance the security of mobile devices. The new technique scans a fingertip in 3D, capturing the tiny ridges and valleys that make up a fingerprint, as well as the tissue beneath the surface. This guards against attackers unlocking a device with an image of the fingerprint, or by attempting to dust the scanner. The basic concepts behind the researchers’ technology are akin to those of medical ultrasound imaging. They created a tiny ultrasound imager, designed to observe only a shallow layer of tissue near the finger’s surface. "Ultrasound images are collected in the same way that medical ultrasound is conducted," said [Professor David] Horsley. "Transducers on the chip’s surface emit a pulse of ultrasound, and these same transducers receive echoes returning from the ridges and valleys of your fingerprint’s surface." The basis for the ultrasound sensor is an array of MEMS ultrasound devices with highly uniform characteristics, and therefore very similar frequency response characteristics. ... To fabricate their imager, the group employed existing microelectromechanical systems (MEMS) technology, which smartphones rely on for such functions as microphones and directional orientation. They used a modified version of the manufacturing process used to make the MEMS accelerometer and gyroscope found in the iPhone and many other consumer electronics devices. -
3-D Ultrasonic Fingerprint Scanning Could Strengthen Smartphone Security
Zothecula sends news that researchers from the University of California are developing new fingerprint scanning technology that could one day enhance the security of mobile devices. The new technique scans a fingertip in 3D, capturing the tiny ridges and valleys that make up a fingerprint, as well as the tissue beneath the surface. This guards against attackers unlocking a device with an image of the fingerprint, or by attempting to dust the scanner. The basic concepts behind the researchers’ technology are akin to those of medical ultrasound imaging. They created a tiny ultrasound imager, designed to observe only a shallow layer of tissue near the finger’s surface. "Ultrasound images are collected in the same way that medical ultrasound is conducted," said [Professor David] Horsley. "Transducers on the chip’s surface emit a pulse of ultrasound, and these same transducers receive echoes returning from the ridges and valleys of your fingerprint’s surface." The basis for the ultrasound sensor is an array of MEMS ultrasound devices with highly uniform characteristics, and therefore very similar frequency response characteristics. ... To fabricate their imager, the group employed existing microelectromechanical systems (MEMS) technology, which smartphones rely on for such functions as microphones and directional orientation. They used a modified version of the manufacturing process used to make the MEMS accelerometer and gyroscope found in the iPhone and many other consumer electronics devices. -
Mystery Company Blazes a Trail In Fusion Energy
sciencehabit writes: Of the handful of startup companies trying to achieve fusion energy via nontraditional methods, Tri Alpha Energy Inc. has always been the enigma. Publishing little and with no website, but apparently sitting on a cash pile in the hundreds of millions, the Foothill Ranch, California-based company has been the subject of intense curiosity and speculation. But last month Tri Alpha lifted the veil slightly with two papers, revealing that its device, dubbed the colliding beam fusion reactor, has shown a 10-fold improvement in its ability to contain the hot particles needed for fusion over earlier devices at U.S. universities and national labs. 'They've improved things greatly and are moving in a direction that is quite promising,' says plasma physicist John Santarius of the Fusion Technology Institute at the University of Wisconsin, Madison. -
Killer Whales Caught On Tape Speaking Dolphin
sciencehabit writes Two years ago, scientists showed that dolphins imitate the sounds of whales. Now, it seems, whales have returned the favor. Researchers analyzed the vocal repertoires of 10 captive orcas, three of which lived with bottlenose dolphins and the rest with their own kind. Of the 1551 vocalizations these seven latter orcas made, more than 95% were the typical pulsed calls of killer whales. In contrast, the three orcas that had only dolphins as pals busily whistled and emitted dolphinlike click trains and terminal buzzes, the scientists report in the October issue of The Journal of the Acoustical Society of America. The findings make orcas one of the few species of animals that, like humans, is capable of vocal learning (video)—a talent considered a key underpinning of language." -
Nobel Prize In Chemistry Awarded To Trio For Microscope Advancement
The 2014 Nobel Prize in Chemistry has been awarded to Eric Betzig, Stefan W. Hell, and William E. Moerner for their work in bypassing the limits of traditional optical microscopy. Hell developed a method called Simulated Emission Depletion microscopy, which uses one laser beam to cause a collection of molecules to fluoresce, and another laser beam to cancel out that fluorescence everywhere other than a nanometer-sized volume. Repeating this process over an entire sample provides nanometer resolution for the resulting image. Betzig and Moerner did important work on Single-Molecule microscopy. "The method relies upon the possibility to turn the fluorescence of individual molecules on and off. Scientists image the same area multiple times, letting just a few interspersed molecules glow each time. Superimposing these images yields a dense super-image resolved at the nanolevel." The three scientists' work was pivotal to enabling nano-scale microscopy and allowing detailed study of objects at the molecular level. -
Harvesting Energy From Humidity
rtoz writes: Last year, MIT researchers discovered that when water droplets spontaneously jump away from superhydrophobic surfaces during condensation, they can gain electric charge in the process. Now, the same team has demonstrated that this process can generate small amounts of electricity that might be used to power electronic devices. This approach could lead to devices that can charge cellphones or other electronics using just the humidity in the air. As a side benefit, the system could also produce clean water. The device itself could be simple, consisting of a series of interleaved flat metal plates. A cube measuring about 50 centimeters on a side — about the size of a typical camping cooler — could be sufficient to fully charge a cellphone in about 12 hours. While that may seem slow, people in remote areas may have few alternatives. -
Senate Budgetmakers Move To End US Participation In ITER
Graculus (3653645) writes Budgetmakers in the U.S. Senate have moved to halt U.S. participation in ITER, the huge international fusion experiment now under construction in Cadarache, France, that aims to demonstrate that nuclear fusion could be a viable source of energy. Although the details are not available, Senate sources confirm a report by Physics Today that the Senate's version of the budget for the Department of Energy (DOE) for fiscal year 2015, which begins 1 October, would provide just $75 million for the United States' part of the project. That would be half of what the White House had requested and just enough to wind down U.S. involvement in ITER. According to this story from April, the U.S. share of the ITER budget has jumped to "$3.9 billion — roughly four times as much as originally estimated." (That's a pretty big chunk; compare it, say, to NASA's entire annual budget.) -
Making Graphene Work For Real-World Devices
aarondubrow writes: "Graphene, a one-atom-thick form of the carbon material graphite, is strong, light, nearly transparent and an excellent conductor of electricity and heat, but a number of practical challenges must be overcome before it can emerge as a replacement for silicon in electronics or energy devices. One particular challenge concerns the question of how graphene diffuses heat, in the form of phonons. Thermal conductivity is critical in electronics, especially as components shrink to the nanoscale. Using the Stampede supercomputer at the Texas Advanced Computing Center, Professor Li Shi simulated how phonons (heat-carrying vibrations in solids) scatter as a function of the thickness of the graphene layers. He also investigated how graphene interacts with substrate materials and how phonon scattering can be controlled. The results were published in the Proceedings of the National Academy of Sciences, Applied Physical Letters and Energy and Environmental Science." -
Duke Univ. Device Converts Stray Wireless Energy Into Electricity For Charging
Lucas123 writes "Engineers at Duke University say they've constructed a device that can collect stray wireless signals and convert them into energy to charge batteries in devices such as cell phones and tablets. The WiFi collection device, made of cheap copper coils and fiberglass, can even aggregate energy from satellite signals and sound waves (abstract). The researchers created a series of five fiberglass and copper energy conductors on a circuit board, which was able to convert microwaves into 7.3V of electrical energy. By comparison, Universal Serial Bus (USB) chargers for small electronic devices provide about 5V of power. The device, the researchers say, is as efficient as solar cells with an energy conversion rate of 37%." -
Return of the Vacuum Tube
sciencehabit writes "Peer inside an antique radio and you'll find what look like small light bulbs. They're actually vacuum tubes — the predecessors of the silicon transistor. Vacuum tubes went the way of the dinosaurs in the 1960s, but researchers have now brought them back to life, creating a nano-sized version that's faster and hardier than the transistor (abstract). It's even able to survive the harsh radiation of outer space." -
Salmon DNA Used In Data Storage Device
Zothecula writes "Scientists from National Tsing Hua University in Taiwan and the Karlsruhe Institute of Technology in Germany have created a 'write-once-read-many-times' (WORM) memory device that combines electrodes, silver nanoparticles, and salmon DNA. While the current device is simply a proof-of-concept model, the researchers have stated that DNA could turn out to be a less expensive alternative to traditional inorganic materials such as silicon." -
Solar Breakthrough Could Provide Power Without Solar Cells
An anonymous reader tips a University of Michigan news release about the creation of what's being called an "optical battery" that could lead to the use of solar power without traditional solar cells (abstract). Quoting: "Light has electric and magnetic components. Until now, scientists thought the effects of the magnetic field were so weak that they could be ignored. What Rand and his colleagues found is that at the right intensity, when light is traveling through a material that does not conduct electricity, the light field can generate magnetic effects that are 100 million times stronger than previously expected. Under these circumstances, the magnetic effects develop strength equivalent to a strong electric effect. 'This could lead to a new kind of solar cell without semiconductors and without absorption to produce charge separation,' Rand said. 'In solar cells, the light goes into a material, gets absorbed and creates heat. Here, we expect to have a very low heat load. Instead of the light being absorbed, energy is stored in the magnetic moment. Intense magnetization can be induced by intense light and then it is ultimately capable of providing a capacitive power source.'" -
STIX Project Releases v1.0 of Its Scientific Fonts Set
starseeker writes "The Scientific and Technical Information Exchange (STIX) font creation project has released version 1.0 of its font set. This release is the product of almost 15 years of work, with the goal of creating a comprehensive set of fonts for scientific and engineering manuscript creation. The fonts have been released under the SIL Open Font License, and can be downloaded here. Among the many potential applications is proper universal support for MathML in web browsers." If you want a peek, here's "a page for viewing the thousands of glyphs (as a first approximation, think of a glyph as an individual character)." -
Body Heat Energy Generation
BuzzSkyline writes "Researchers in Belgium have developed devices to harvest the waste heat our bodies throw off in order to convert it to electricity to run devices such as a wristband blood oxygen sensor and an electrocardiogram shirt. As a side benefit, the power sources help cool you down and keep you looking cool, all while running sundry micropower devices. In fact, the researchers mention that the energy harvesting head band works so well that it can get uncomfortably cold. In that case, they say, 'This problem is solved in exactly the same way as someone solves it on the body level in cold weather: a headgear should be worn on top of the system to limit the heat flow and make it comfortable.' But it would be such a shame to cover up the golden heat-harvesting headband with a hat." -
The Chemistry of Firework Displays
Ponca City, We love you writes "David Ropeik writes at MSNBC that there's a lot more to making a basic firework display than putting a fuel source and an oxidizer together. Pyrotechnic chemists, who are trying to create bedazzlement instead of bang, don't want their work to explode, but to burn for a bit, so it gives a good visual show. To achieve the desired effect, the sizes of the particles of each ingredient have to be just right, and the ingredients have to be blended together just right. To slow down the burning, chemists use big grains of chemicals, in the range of 250 to 300 microns, and they don't blend the ingredients together very well, making it harder for the fuel and oxidizer to combine and burn, thus producing a longer and brighter effect. Surprisingly few emitters are used in pyrotechnics, and there are no commercially useful emitters in blue-green to emerald green in the 490-520 nm region. Energy from the fire in the basic fuel is transferred to the atoms of the colorant chemicals, exciting the electrons in those chemicals into a higher energy state. As they cool down, they move back to a lower state of energy, emitting light. So, you actually see the colors in fireworks as they're cooling down. To get the really tricky shapes, like stars or hearts, the colorant pellets are pasted on a piece of paper in the desired pattern. That paper is put in the middle of the shell with explosive charges above it, and below. When those charges go off, they burn up the paper, and send the ignited colorant pellets out in the same pattern they were in on the sheet of paper, spreading wider apart as they fly." -
More Spacecraft Velocity Anomalies
ZonkerWilliam recommends a bulletin from the American Institute of Physics, which discusses a study noting that recent spacecraft, such as NEAR, appear to display velocity anomalies much like those seen in Pioneer 10 (which were observed beginning ten years ago). The anomalies amount to up to 13 mm/sec., with a measurement accuracy of 0.1 mm/sec. Quoting: "A new look at the trajectories for various spacecraft as they fly past the Earth finds in each case a tiny amount of surplus velocity. For craft that pursue a path mostly symmetrical with respect to the equator, the effect is minimal. For craft that pursue a more unsymmetrical path, the effect is larger." -
Major Breakthrough In Spintronics Research
Invisible Pink Unicorn writes "Spintronics is the field of research into developing devices that rely on electron spin rather than electron charge to carry information. A major advance has been made by the Naval Research Laboratory (NRL), where they have for the first time generated, modulated, and electrically detected a pure spin current in silicon. Progress in this field is expected to lead to devices which provide higher performance with lower power consumption and heat dissipation. Basic research efforts at NRL and elsewhere have shown that spin angular momentum, another fundamental property of the electron, can be used to store and process information in metal and semiconductor based devices. The article abstract is available from Applied Physics Letters." -
New Type of Fatigue Discovered in Silicon
Invisible Pink Unicorn writes "Researchers at the National Institute of Standards and Technology (NIST) have discovered a phenomenon long thought not to exist. They have demonstrated a mechanical fatigue process that eventually leads to cracks and breakdown in bulk silicon crystals. Silicon — the backbone of the semiconductor industry — has long been believed to be immune to fatigue from cyclic stresses because of the nature of its crystal structure and chemical bonds. However, NIST examination of the silicon used in microscopic systems that incorporate tiny gears, vibrating reeds and other mechanical features reveals stress-induced cracks that can lead to failure. This has important implications for the design of new silicon-based micro-electromechanical system (MEMS) devices that have been proposed for a wide variety of uses. The article abstract is available from Applied Physics Letters." -
Stix Scientific Fonts Reach Beta Release
starseeker writes "At long last, the STIX project has posted a Beta release of their scientific fonts. The mission of the STIX project has been the 'preparation of a comprehensive set of fonts that serve the scientific and engineering community in the process from manuscript creation through final publication, both in electronic and print formats.' The result is a font set containing thousands of characters, and hopefully a font set that will become a staple for scientific publishing. Among other uses, it has long been hoped that this would make the wide scale use of MathML in browsers possible. Despite rather long delays the project has persisted and is now showing concrete results." -
Science In Islamic Countries
biohack sends us to Physics Today for a thought-provoking article on the status of and prospects for science in Islamic countries. The author, a Pakistani physicist, posits that 'Internal causes led to the decline of Islam's scientific greatness long before the era of mercantile imperialism. To contribute once again, Muslims must be introspective and ask what went wrong.' The author makes a few strong conclusions, many of which are relevant to the general debate between science and religion. From the article: "Science finds every soil barren in which miracles are taken literally and seriously and revelation is considered to provide authentic knowledge of the physical world. If the scientific method is trashed, no amount of resources or loud declarations of intent to develop science can compensate. In those circumstances, scientific research becomes, at best, a kind of cataloging or 'butterfly-collecting' activity. It cannot be a creative process of genuine inquiry in which bold hypotheses are made and checked." -
World's Smallest Robotic Hand
BuzzSkyline writes "The world's smallest robotic hand has been built by Yen-Wen Lu and Chang-Jin "CJ" Kim at UCLA's Mechanical and Aerospace Engineering Department. The microhand can make a fist that can grasp objects smaller than a millimeter across. Check out the freaky video on the researchers' website of the microhand grabbing a blob that looks like a fish egg. The tiny hand is made of inert materials, making it ideal for handling gooey biological samples. Lu and Kim describe their microhand in a paper published October 16 in the journal Applied Physics Letters." -
Element 118 Created
BuzzSkyline writes, "The heaviest element yet, Element 118, has been created in Dubna, Russia by a collaboration of researchers from Russia's Joint Institute for Nuclear Research and Lawrence Livermore National Laboratory in the US. They created the new element by fusing together Californium (element 98) and Calcium atoms. The achievement comes five years after the scandal-plagued retraction of an earlier claim, which was based on fabricated data, that three atoms of element 118 had been produced at the Lawrence Berkeley National Laboratory in California. The achievement was reported on October 9 in the journal Physical Review C (subscription needed to read more than the abstract)." -
Yet Another Method Of Achieving Nuclear Fusion
deglr6328 writes "Recent research has seen the use of the pyroelectric effect, the compression of bubbles using ultrasound and gas jet irradiation for producing nuclear fusion on small tabletop-scales. Yet another method can now be added to the list which uses ultraintense laser irradiation striking a borated plastic target to heat a plasma to billion kelvin temperatures and achieves aneutronic (clean) proton-boron fusion. (The PRL paper can be read online.) Though, like the other recently discovered exotic methods of attaining fusion, it does not look like a method which can be scaled up to ignition or even anywhere near break even, it still may have important use in the laboratory for the examination of such incredibly high temperature plasmas." -
New Nanophotonic Waveguides developed at MIT
SimilarityEngine writes "Physicists at MIT have developed a new kind of nanophotonic waveguide, overcoming 'several long-standing obstacles' to move us one step closer to optical computers. Photonics strives to improve on electronics in terms of space requirements, speed and energy consumption - but until recently, it was not possible to perform well in all three areas simultaneously. In their paper, John Joannopoulos et al. demonstrate how to reliably encode a signal as surface plasmons which side-steps such limitations." -
Qbits unstable: May Limit Quantum Computing
museumpeace writes "Netherlands Organiztion for Scientific Research provies a human-readable description of research into the stability of Qbits conducted at Leiden University. The bad news: " Much to their surprise they discovered that the coherence tends to spontaneously disappear, even without external influences." The whole story in physicist-readable form is in the June 17 Physical Review Letters by van Wezel, van den Brink, Zaanen [click abstract or huge PDF]. I am not buying any quantum computing startups 'til they nail this matter down...you can't build a computer if state information is going to evaportate in a second or less." -
Researchers Control the Flip of Electron Spin
karvind writes "According to PhysOrg, physicists in Europe, California and at Ohio University now have found a way to manipulate the spin of an electron with a jolt of voltage from a battery. In this experiment voltage was applied to Indium Arsenide based quantum dot which flipped the spin of electron inside it and emitted a photon. The scientists were able to manipulate how long it would take for the electron to flip its spin and emit a photon - from one to 20 nanoseconds. This may have possible applications in optoelectronics and quantum cryptography. Results were published in the latest issue of Physics Review Letters" -
Free STIX Fonts to be Released in September
tbspit writes "The STIX fonts project has announced that version 1.0 of the STIX fonts should be released in September 2005. The comprehensive font set is to include mathematical symbols and alphabets, and is intended to serve the scientific and engineering community for electronic and print publication. The STIX fonts should be available as fully hinted Type 1 and True Type fonts. The STIX project will also create a TeX implementation. Progress towards release can be monitored here." -
Nanotech Motors, Biotransistors, DNA Fractals
FleaPlus writes "The American Institute of Physics has a news bulletin describing a couple of interesting nanotech advances. The first is the smallest electric motor in the world, made by Alex Zettl's group at UC Berkeley. The second is a single-protein wet biotransistor. Additionally, Technology Research News reports on algorithmic self-assembly of DNA Sierpinski triangles, by Erik Winfree's group at Caltech." -
Nanotech Motors, Biotransistors, DNA Fractals
FleaPlus writes "The American Institute of Physics has a news bulletin describing a couple of interesting nanotech advances. The first is the smallest electric motor in the world, made by Alex Zettl's group at UC Berkeley. The second is a single-protein wet biotransistor. Additionally, Technology Research News reports on algorithmic self-assembly of DNA Sierpinski triangles, by Erik Winfree's group at Caltech." -
Happy 100th To The Vacuum Tube
williamw83 writes "Today, November 16, 2004 has been declared as the centennial of the birth of modern electronics by the American Vacuum Society. As the AIP Physics News Update reports, this marks 'British scientist John Ambrose Fleming's 1904 invention of the first practical electronic device. Known as the thermionic diode, this first simple vacuum tube, containing only two electrodes, could be used to convert an alternating current (AC) to a direct current (DC).' Today's celebration takes place as part of the AVS's 51st Annual Symposium & Exhibition in Anaheim, CA. Being a guitar player myself, I've come to truly appreciate the technology of the vacuum tube every time I crank up my amplifier. This 100-year-old grandfather of electronics, used by musicians and audiophiles across the world, has proven that profound advances in technology do not always render old technologies obsolete." -
Happy 100th To The Vacuum Tube
williamw83 writes "Today, November 16, 2004 has been declared as the centennial of the birth of modern electronics by the American Vacuum Society. As the AIP Physics News Update reports, this marks 'British scientist John Ambrose Fleming's 1904 invention of the first practical electronic device. Known as the thermionic diode, this first simple vacuum tube, containing only two electrodes, could be used to convert an alternating current (AC) to a direct current (DC).' Today's celebration takes place as part of the AVS's 51st Annual Symposium & Exhibition in Anaheim, CA. Being a guitar player myself, I've come to truly appreciate the technology of the vacuum tube every time I crank up my amplifier. This 100-year-old grandfather of electronics, used by musicians and audiophiles across the world, has proven that profound advances in technology do not always render old technologies obsolete." -
AIP Probes Bush, Kerry On Science Issues
martensitic writes "Physics Today (the 50-year-old monthly publication of the American Institute of Physics) continues their election-year tradition with this special report, posing nine questions 'in an effort to get the candidates to specifically address questions of interest to the science community'. The 'sometimes direct and sometimes vague' written responses 'show fundamental differences on several key issues.'" -
Carbon Nanotube Antenna for Light
Suidae writes "Researchers at Boston College are reporting that carbon nanotubes can be used to build an antenna that receives optical wavelengths in much the same way a radio antenna receives longer wavelengths. The electrical effects can not yet be directly measured as diodes that operate at optical frequencies would be required, but secondary radiation from the excitation can be observed. Potential applications include fiber optic data transmission and photovoltaics." -
Carbon Nanotube Antenna for Light
Suidae writes "Researchers at Boston College are reporting that carbon nanotubes can be used to build an antenna that receives optical wavelengths in much the same way a radio antenna receives longer wavelengths. The electrical effects can not yet be directly measured as diodes that operate at optical frequencies would be required, but secondary radiation from the excitation can be observed. Potential applications include fiber optic data transmission and photovoltaics." -
Amorphous Steel
pfdietz writes "Researchers at Oak Ridge have achieved a holy grail of materials science: they have figured out how to produce amorphous (glassy) steel. The material is reported to be twice as hard and have twice the tensile strength of the strongest ultra-high tensile strength steel alloy." -
Whale Flippers Make Better Airplane Wings
phreakmonkey writes "The bumpy, ridged surface on humpback whale flippers provide more lift, less drag, and exhibit better stall characteristics than traditional aircraft wing designs, according to Duke University, West Chester University, and the U.S. Naval Academy. This could help improve the design of airfoils used on everything from aircraft wings to underwater vehicles. The results were published in the May 2004 issue of Physics of Fluids and reported on Innovations Report." -
MagLev Trains Annoyingly Loud
crem_d_genes writes "You might hear that whistle blowing from that train coming 'round the bend, but tapes of the sounds produced by magnetically levitated and normal trains produced a result that was something of a surprise: Most people rated maglev trains as more disturbing than standard intercity trains. It had been previously known that the two types were about equally loud, but this study analyzed people's reactions to them. Since the effects on the environment will be part of the feasibilty studies for future development, acoustical engineers will have some new challenges. Some participants in the study said the sound made them 'feel insecure, some found it startling, and disliked the occasional shrill sound the maglevs produced.' The researcher postulated that unfamiliarity with the noise might be part of the problem." -
Weighing An Attogram
Roland Piquepaille writes "Researchers at Cornell University have reached a new level of precision by measuring objects with a mass of less than an attogram (10^-18 gram). They used a silicon cantilever oscillator to measure small dots of gold. But their real goal is to detect and identify viruses. The team also wants to reduce the size of the cantilever, extending the sensitivity well into the zeptogram (10^-21 gram) range. This summary contains more details and an image of a small gold dot resting on the silicon cantilever they used to achieve this breakthrough." -
Toward Micro-Diode Display Panels?
VernonNemitz asks: "Light-Emitting Diodes (LEDs) have been around for decades, and they come in all colors. Here are the basic principles behind their operation, information on what's currently in production , and other practical info. Now, you would think it obvious that video displays should be made from LEDs, to take on the various competitors. Certainly this has been done on a large scale, and I am not the first to be interested in LED display technology for home viewing. The apparent goal of silicon LEDs these days seems to be tied up with optical communications between circuits, have they forgotten the possibility of making high-resolution display panels?""Achieving a good image will require smaller pixels, and now I have a better understanding of what has been holding it up, so would like to share what I found out. Basically, unlike a lot of electronic technology, LEDs are mostly -not- made from silicon. So, while silicon diodes are common, and large arrays of them are also made (for sensors), LEDs are not easy to incorporate into standard integrated-circuit manufacturing. Nevertheless, researchers have been pursuing and steadily making progress toward integrating silicon-based LEDs. Even whole arrays, 'suitable for large two-dimensional areas', of silicon laser LEDs have been made, as far back as three years ago."
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Using Cellophane For 3D Displays On Your Laptop
prestidigital writes "From the abstract: [the authors] present a novel, inexpensive, stereoscopic technique for generating 3D displays from cellophane and a laptop computer screen. (Once again my physnews update sends me email that doesn't suck!)" -
A Water Molecule's Chemical Formula Isn't Really H20
hackwrench writes "According to this article in Physics News Update, a water molecule's chemical formula is really not H2O, at least from the perspective of neutrons and electrons interacting with the molecule for only attoseconds (less than 10-15 seconds). According to new and recent experiments, neutrons and electrons colliding with water for just attoseconds will see a ratio of hydrogen to oxygen of roughly 1.5 to 1, so a more accurate formula for water under these circumstances would be H1.5O." -
Scientists Say Cosmic Rays May Cause Global Warming
Saint Aardvark writes "Researchers in Israel and Germany suggest that variations in cosmic radiation as the sun orbits the galactic core may be responsible for changes in the Earth's climate -- including more than half of the change in the 20th century. A PDF of their article is available from GSA Today or read the abstract for their Physical Review Letters article." -
Renaissance Potters Were Nanotechnologists
Roland Piquepaille writes "In this article, Nature says that "tiny metal particles give 15th century Italian ceramics lustre." Nature adds that iridescent glazes -- changing colour when viewed from different perspectives -- were achieved by using "particles of copper and silver of between 5 and 100 billionths of a metre across." And the story becomes even more interesting. Nanotechnology meets alchemy! "The ability to change colour was regarded as an alchemical property, making iridescence magic too." Read this summary for more details. And for more information, you can read the abstract of this research paper, "Copper in glazes of Renaissance luster pottery: Nanoparticles, ions, and local environment," published by the Journal of Applied Physics." -
Force Field. No, Really
tqft points out news of "a working force field, using plasma. Now to scale the sucker up." Here's the Brookhaven press release. I can think of so many uses for this. -
The Hulk and Gammasphere
BuzzSkyline writes "The Hulk may be animated, but the Gammasphere that turns Bruce Banner's hissy fits into raging rampages is real. It's based on a gamma ray detector used at the Berkeley and Argonne National Labs. The actual machine doesn't make monsters, but it helps in studies of nuclear monstrosities. The American Institute of Physics reports on Gammasphere and its role in the movie at Inside Science News Service."