This demonstartes that a radioactive source produces radiation that will ionise the air. The conducting air completes a circuit to charge an electroscope. Use the circuit to show the ionising effect of the radiation and present it as a means of detecting ionising radiation.
August 31, 2011
A team of European astronomers has used ESO’s Very Large Telescope (VLT) to track down a star in the Milky Way that many thought was impossible. They discovered that this star is composed almost entirely of hydrogen and helium, with only remarkably small amounts of other chemical elements in it. This intriguing composition places it… [Read more…]
August 31, 2011
George Contopoulos, Mirella Harsoula Abstract: We study the role of asymptotic curves in supporting the spiral structure of a N-body model simulating a barred spiral galaxy. Chaotic orbits with initial conditions on the unstable asymptotic curves of the main unstable periodic orbits follow the shape of the periodic orbits for an initial interval of time and… [Read more…]
August 31, 2011
The Rabi model (RM) describes the simplest interaction between light and matter. In its semiclassical form, this model describes the coupling of a two-level system and a classical monochromatic field. The fully quantum model considers the same situation, with the light field quantized. Although this model has had an impressive impact on many fields of… [Read more…]
August 30, 2011
Water droplets have been created by shooting lasers into the air. The technique might be used to create or prevent rain Ever since ancient farmers called on the gods to send rain to save their harvests, humans have longed to have the weather at their command. That dream has now received a boost after researchers used a… [Read more…]
August 30, 2011
First glimpse into birth of the Milky Way – For almost 20 years astrophysicists have been trying to recreate the formation of spiral galaxies such as our Milky Way realistically. Now astrophysicists from the University of Zurich present the world’s first realistic simulation of the formation of our home galaxy together with astronomers from the… [Read more…]
August 30, 2011
The Canada-France-Hawaii Telescope in Hawaii sees the barred spiral galaxy NGC 2903 almost face-on in this photograph. The central bulge glows yellow with older stars, while the spiral arms contain younger stars as determined by their blue color, and star formation regions of red. http://www.space.com/34-image-day.html
August 30, 2011
By Enrico Uva Wizards exist in real life, beyond the films and books of Harry Potter. They cook willow bark extract in car battery acid and wood alcohol and convert it into a pleasant-smelling component of candy or of a rubbing compound. In their glassware, petroleum products turn into life-saving medicines. The vastly underrated wizards… [Read more…]
August 30, 2011
We discuss theoretical predictions for the thermal Casimir force and compare them with available experimental data. Special attention is paid to the recent claim of the observation of that effect, as predicted by the Drude model approach. We show that this claim is in contradiction with a number of experiments reported so far. We suggest… [Read more…]
August 30, 2011
— After nine months of number-crunching on a powerful supercomputer, a beautiful spiral galaxy matching our own Milky Way emerged from a computer simulation of the physics involved in galaxy formation and evolution. The simulation by researchers at the University of California, Santa Cruz, and the Institute for Theoretical Physics in Zurich solves a longstanding… [Read more…]
August 29, 2011
Despite the hopes of most and the preconceptions of many, news from the Lepton-Photon conference in Mumbay, India, report that the Standard Model is as alive and strong as it has ever been. Indeed, the recent searches for Supersymmetry by ATLAS and CMS, now analyzing datasets that by all standards must be considered “a heck… [Read more…]
August 29, 2011
This incredible cosmic image shows a nebula with an open cluster of stars inside it. Described by Nasa as ‘a busy workshop of star formation’, NGC 281 is better known as the Pac-Man Nebula due to its distinctive shape. It is powered by IC 1590, the open star cluster at its very centre. Τhese young… [Read more…]
August 29, 2011
Regulating Brownian Fluctuations with Tunable Microscopic Magnetic Traps A. Chen, G. Vieira, T. Henighan, M. Howdyshell, J. A. North, A. J. Hauser, F. Y. Yang, M. G. Poirier, C. Jayaprakash, and R. Sooryakumar Phys. Rev. Lett. 107, 087206 (Published August 18, 2011) Magnetic particles can be guided with external fields through small-scale fluidic environments, bringing… [Read more…]
August 28, 2011
In this talk, I would like to speculate a little, on the development of life in the universe, and in particular, the development of intelligent life. I shall take this to include the human race, even though much of its behaviour through out history, has been pretty stupid, and not calculated to aid the survival… [Read more…]
August 27, 2011
Cameras mounted on the International Space Station captured new views of Hurricane Irene at 4:27 p.m. EDT on August 26, 2011 as the storm bore down on the east coast of the United States. Accompanied by narration from Expedition 28 Flight Engineer Mike Fossum of NASA, the video showed the massive system moving north at… [Read more…]
August 27, 2011
Astronomers using the Hubble Space Telescope may have solved the mystery of how the Milky Way continues to spawn new stars at a consistent rate despite its diminishing gas reserves. They say the galaxy is being supplied by clouds of gas originating from outside of the Milky Way, and that these findings could help refine… [Read more…]
August 27, 2011
The machine, which is responsible for keeping Britain’s clocks on track and also contributes to the international measure of time, is accurate to within two 10 million billionths of a second. It is one of a handful of similar clocks which determine the exact length of a second by measuring microwaves as they cause reactions… [Read more…]
August 27, 2011
THEY would make supernovae look like firecrackers. Giant gas clouds in the early universe could have powered the most energetic eruptions since the big bang. Evidence for supermassive black holes – weighing millions or billions of suns – has been found in the early universe, but no one knows how they grew so big so… [Read more…]
August 27, 2011
By Pallab Ghosh Results from the Large Hadron Collider (LHC) have all but killed the simplest version of an enticing theory of sub-atomic physics. Researchers failed to find evidence of so-called “supersymmetric” particles, which many physicists had hoped would plug holes in the current theory. Theorists working in the field have told BBC News that… [Read more…]
August 26, 2011
Talk about seeing a world in a grain of sand. A sprinkling of asteroid dust that slipped into Japan’s Hayabusa probe when it touched down on the asteroid Itokawa six years ago has revealed surprising details about the space rock’s past and its likely future. Hayabusa was meant to land on the 500-metre-wide asteroid in… [Read more…]
August 25, 2011
If you work in experimental high-energy physics you soon acquire a particular sensitivity to the economical display of relevant information. Producing figures that convey the most meaning with the minimum effort is sort of an art, and it is a necessary consequence that HEP experimentalists -the smart ones- end up converging on the definition of… [Read more…]
August 24, 2011
The way gravity effects quantum particles proves that it cannot be an emergent phenomenon, says physicist. One of the most exciting ideas in modern physics is that gravity is not a traditional force, like electromagnetic or nuclear forces. Instead, it is an emergent phenomenon that merely looks like a traditional force. This approach has been… [Read more…]
August 24, 2011
Who discovered that E = mc2? It’s not as easy a question as you might think. Scientists ranging from James Clerk Maxwell and Max von Laue to a string of now-obscure early 20th-century physicists have been proposed as the true discovers of the mass–energy equivalence now popularly credited to Einstein’s theory of special relativity. These… [Read more…]
August 23, 2011
Physicists use DNA assembly technique to create a ‘metafluid’ capable of manipulating visible light in new ways Back in 2003, the first metamaterial was designed to bend microwaves in ways that ordinary materials can never achieve. The material was made from c-shaped pieces of metal and wires assembled into a kind of honeycomb structure the… [Read more…]
August 23, 2011
Astronomers at the California Institute of Technology (Caltech) have discovered that the dwarf planet 2007 OR10 — nicknamed Snow White — is an icy world, with about half its surface covered in water ice that once flowed from ancient, slush-spewing volcanoes. The new findings also suggest that the red-tinged dwarf planet may be covered in… [Read more…]
August 23, 2011
Lava, not water, may have carved the biggest channels on Mars. Ever since NASA’s Mariner 9 spacecraft beamed back the first images of the channels in the 1970s, most people have assumed they were created by massive floods. But David Leverington of Texas Tech University in Lubbock says flowing water would have left behind much more sediment… [Read more…]
August 22, 2011
By Tommaso Dorigo Much awaited, the results of searches for the Higgs boson at the Large Hadron Collider have been released by the ATLAS collaboration, and are being shown at the Lepton-Photon conference in Mumbay, India. I will provide here just the main results, with little commentary – I wish to let the cake cool down… [Read more…]
August 22, 2011
A CSIRO study has shown why the lights are going out in the Universe. The Universe forms fewer stars than it used to, and a CSIRO study has now shown why: the galaxies are running out of gas. Dr Robert Braun (CSIRO Astronomy and Space Science) and his colleagues used CSIRO’s Mopra radio telescope near… [Read more…]
August 22, 2011
In 1842, the first American author of tales of horror, Edgar Allen Poe (1809-1849) wrote a short story entitled, The Pit and the Pendulum. Poe’s stories often contained a strong element of terror, in part, because he left many of the details quite vague, just as a standard technique of psychological terror is to keep… [Read more…]
August 22, 2011
Cern scientist says he sees ‘no striking evidence of anything that could resemble a discovery’ in hunt for Higgs boson Ripples of excitement swept through the physics community last month when Cern scientists reported what looked like glimpses of the long-sought Higgs boson. But the hopes have been dashed as it was revealed that the tantalising hints had all but… [Read more…]
August 21, 2011
…Presenting a New Target for Astrobiology Clusters of islands poked through hot oceans 3.4 billion years ago, when the world still had no oxygen and the seas churned under a pallid, overcast sky. But life thrived on Earth even then, scientists say — and now they have the world’s oldest fossils to prove it. There… [Read more…]
August 21, 2011
We discuss the observable effects of enhanced black hole mass loss in a black hole-neutron star (BH-NS) binary, due to the presence of a warped extra spatial dimension of curvature radius L in the braneworld scenario. For some masses and orbital parameters in the expected ranges the binary components would outspiral—the opposite of the behavior due to… [Read more…]
August 20, 2011
Benjamin K. Tippett In light of the surge in popularity of electromagnetic cloaking devices, we consider whether it is possible to use general relativity to cloak a volume of spacetime through gravitational lensing. A metric for such a spacetime geometry is presented, and its geometric and physical implications are explained. In general relativity, there is… [Read more…]
August 20, 2011
The Pioneer anomaly is a tiny, unexplained deceleration of the Pioneer 10 and 11 spacecraft, which are now at the edge of the Solar System. A 19 August report inPhysical Review Letters describes an arduous, multi-year effort to accurately define the anomaly by gathering and analyzing all available tracking data for the two probes. The analysis shows… [Read more…]
August 20, 2011
The Niels Bohr Library and Archives is pleased to announce that it has digitized the complete Samuel A. Goudsmit Papers (1921–1979, 30 linear feet, approximately 67,000 images). The Goudsmit Papers are a major international collection of correspondence, research notebooks, reports, World War II science documents, and other material of Goudsmit, a Dutch physicist who spent most of… [Read more…]
August 19, 2011
Sascha Vongehr The public repulsion against dark matter and dark energy is really annoying. Rob Knop at scientopia compares it to 17th century catholic church mentality; Ethan picks it up and bangs the dark matter explains everything drum although dark matter does not fit very well to galaxy rotation curves – Modified Newtonian Dynamics (MOND) fits much better: (From: Begeman, Broeils,… [Read more…]
August 19, 2011
A belt of antimatter has been discovered circling the Earth, which in future could be used to fuel voyages that race at breakneck speeds to other planets in the Solar System. Antimatter has properties that are opposite those of normal matter – for example the positive charge on a proton is negative in an antiproton.… [Read more…]
August 19, 2011
The role of the third law of thermodynamics in the Szilard engine has been addressed. If the ground state is non-degenerate, the entropy production defined as the work extractable from the engine divided by temperature vanishes as temperature approaches zero due to the third law. The degenerate ground state induced by the symmetry or by… [Read more…]
August 19, 2011
This paper is prepared as a contribution to the proceedings after the 12th ICSSUR/Feynfest Conference held in Foz do Iguacu (Brazil) from 2 to 6 May 2011. In the first part I briefy report the topic of entropic uncertainty relations for position and momentum variables. Then I investigate the discrete Shannon entropies related to the… [Read more…]
August 19, 2011
NASA’s STEREO spacecraft and new data processing techniques have succeeded in tracking space weather events from their origin in the sun’s corona to impact with the Earth, resolving a 40-year mystery about the structure of the structures that cause space weather: how the structures that impact the Earth relate to the corresponding structures in the… [Read more…]
August 19, 2011
….say scientists Rising greenhouse emissions may tip off aliens that we are a rapidly expanding threat, warns a report for Nasa It may not rank as the most compelling reason to curb greenhouse gases, but reducing our emissions might just save humanity from a pre-emptive alien attack, scientists claim. Watching from afar, extraterrestrial beings might… [Read more…]
August 18, 2011
A small shove could prevent a global catastrophe, according to Chinese plans Apophis is a 46 million tonne asteroid that will pass within a hair’s breath of Earth in 2029. However, Apophis’s trajectory is likely to take it through a region of space near Earth known as a keyhole that will ensure the asteroid returns… [Read more…]
August 18, 2011
By Christine Lavelle Candle flames contain millions of tiny diamond particles, a university professor has discovered. Research by Wuzong Zhou, a professor of chemistry at the University of St Andrews in Fife, revealed that around 1.5 million diamond nanoparticles are created in a candle flame every second it is burning. Dr Zhou used a new… [Read more…]
August 18, 2011
A quantum clock working as a control device is examined. The quality of the control process is characterized by the magnitude of deviation of perturbed state from unperturbed state of the controlled system. Uncertainty relations that relate the time duration of the process and energy of the clock to the quality of the control are… [Read more…]
August 17, 2011
Giant Space Blob Glows from Within VLT finds primordial cloud of hydrogen to be centrally powered Observations from ESO’s Very Large Telescope have shed light on the power source of a rare vast cloud of glowing gas in the early Universe. The observations show for the first time that this giant “Lyman-alpha blob” — one… [Read more…]
August 17, 2011
We all remember the earthquake and ensuing tsunami that hit Japan (see figure 1) and caused major troubles in the Fukushima nuclear power plant, which was severely damaged. Problems with containing radiation followed, leading to the pumping of huge amounts of seawater into the reactor, in an attempt to cool it down. The question on… [Read more…]
August 17, 2011
We analyze cosmology assuming unitary quantum mechanics, using a tripartite partition into system, observer and environment degrees of freedom. This generalizes the second law of thermodynamics to “The system’s entropy can’t decrease unless it interacts with the observer, and it can’t increase unless it interacts with the environment.” We show that because of the long-range… [Read more…]
August 17, 2011
The derivation of the Heisenberg Uncertainty Principle (HUP) from the Uncertainty Theorem of Fourier Transform theory demonstrates that the HUP arises from the dependency of momentum on wave number that exists at the quantum level. It also establishes that the HUP is purely a relationship between the effective widths of Fourier transform pairs of variables… [Read more…]
August 17, 2011
Applications of Integrated Optics to quantum sources, detectors, interfaces, memories and linear optical quantum computing are described in this review. By their inherent compactness, efficiencies, and interconnectability, many of the demonstrated individual devices can clearly serve as building blocks for more complex quantum systems, that could also profit from the incorporation of other guided wave… [Read more…]
August 17, 2011
We summarize radio and optical SETI programs based at the University of California, Berkeley. The SEVENDIP optical pulse search looks for ns time scale pulses at visible wavelengths using an automated 30 inch telescope. The ongoing SERENDIP V.v sky survey searches for radio signals at the 300 meter Arecibo Observatory. The currently installed configuration supports… [Read more…]
August 16, 2011
Scientists plan mission to blow up an asteroid ‘hurtling towards Earth’ Plan is similar to the plot of Hollywood film Armageddon It seemed far-fetched on the silver screen. But the European Space Agency is planning to launch a mission similar to the plot of Hollywood movie Armageddon, in which Bruce Willis and his intrepid team… [Read more…]
August 16, 2011
An international collaboration of researchers is working on a new method of understanding what happens during chemical reactions. The approach is extremely complex, as it involves tracking the behavior of individual electrons as this happens. Doing so is a monumentally difficult task, considering that the elementary particle completes a full orbit around an atomic nucleus… [Read more…]
August 16, 2011
Honeycomb Carbon Crystals Possibly Detected in Space NASA’s Spitzer Space Telescope has spotted the signature of flat carbon flakes, called graphene, in space. If confirmed, this would be the first-ever cosmic detection of the material — which is arranged like chicken wire in flat sheets that are one atom thick. Graphene was first synthesized in… [Read more…]
August 16, 2011
As demonstrated by Chernodub, vacuum in a strong magnetic field behaves as a periodic Abrikosov vortex lattice in a type-II superconductor. We investigate electromagnetic behavior of vacuum in this state. Since superconductivity is realized along the axis of magnetic field only, strong anisotropy of the vacuum dielectric tensor is observed. The diagonal components of the… [Read more…]
August 16, 2011
The Daya Bay Reactor Neutrino Experiment has begun its quest to answer some of the most puzzling questions about the elusive elementary particles known as neutrinos. The experiment’s first completed set of twin detectors is now recording interactions of antineutrinos (antipartners of neutrinos) as they travel away from the powerful reactors of the China Guangdong… [Read more…]
August 16, 2011
Nuclear fusion will cost a fortune – or will it? A new wave of upstart companies think they’ve found cheaper, quicker ways to build a second sun A VAST earth platform looms into view above the treetops of Cadarache in France’s sultry south-east. It measures 1 kilometre long by 400 metres wide, and excavators dotted… [Read more…]
August 15, 2011
A black hole’s event horizon is the ultimate last-chance saloon: beyond this boundary nothing, not even light, can escape. But does this “anything” include information itself? Physicists have spent the best part of four decades grappling with the “information paradox”, but now a group of researchers from the UK thinks it can offer a solution.… [Read more…]
August 15, 2011
Life must have begun with a simple molecule that could reproduce itself – and now we think we know how to make one 4 BILLION years before present: the surface of a newly formed planet around a medium-sized star is beginning to cool down. It’s a violent place, bombarded by meteorites and riven by volcanic… [Read more…]
August 15, 2011
August 15, 2011
It is generally believed that classical regime emerges as a limiting case of quantum theory. Exploring such quantum-classical correspondences in a more transparent manner is central to the deeper understanding of foundational aspects and has attracted a great deal of attention – starting from the early days of quantum theory. While it is often highlighted… [Read more…]
August 14, 2011
Perseid meteor shower lights up the night sky around the globe …===> …
August 13, 2011
Two Lehigh physicists have developed an imaging technique that makes it possible to directly observe light-emitting excitons as they diffuse in a new material that is being explored for its extraordinary electronic properties. Called rubrene, it is one of a new generation of single-crystal organic semiconductors. Excitons, which are created by light, play a central… [Read more…]
August 13, 2011
In a paper published in the August 12 issue of the esteemed journal Physical Review Letters, researchers at the University of York made a monumental discovery, when they found that black holes tend to gulp up all the matter in their surroundings, but leak information. The new data adds to the growing database of knowledge we have… [Read more…]
August 13, 2011
http://online.kitp.ucsb.edu/online/bblunch/frenkel/
August 12, 2011
Originally published in the Manchester Guardian on 12 August 1930 It would seem all doubts as to the existence of the new planet announced from the Lowell Observatory in March last have been set at rest. Fifteen years ago the late Dr. Percival Lowell published his “Memoir on a Trans Neptunian Planet,” in which he… [Read more…]
August 12, 2011
GAMBLERS already had enough to think about without factoring the end of time into their calculations. But a year after a group of cosmologists argued that they should, another team says time need not end after all. It all started with this thought experiment. In a back room in a Las Vegas casino, you are handed… [Read more…]
August 12, 2011
UFO sighting files released in UK The latest batch of UFO files released today contain sightings of mysterious lights over the Glastonbury Festival, a “flying saucer” outside Retford town hall and the bizarre story of “Mork and Mindy’s” visit to East Dulwich. Defence experts were called in to examine a 2004 photo of a “flying… [Read more…]
August 12, 2011
VV 340, also known as Arp 302, provides a textbook example of colliding galaxies seen in the early stages of their interaction. The edge-on galaxy near the top of the image is VV 340 North and the face-on galaxy at the bottom of the image is VV 340 South. Millions of years later these two… [Read more…]
August 12, 2011
A giant cosmic necklace glows brightly in this NASA Hubble Space Telescope image. The object, aptly named the Necklace Nebula, is a recently discovered planetary nebula, the glowing remains of an ordinary, Sun-like star. The nebula consists of a bright ring, measuring 12 trillion miles wide, dotted with dense, bright knots of gas that resemble… [Read more…]
August 12, 2011
Astronomers uncover alien world so ‘extraordinarily dark’ it makes coal look shiny Astronomers have discovered the darkest known planet. The exoplanet, known as TrES-2b, reflects less than 1 per cent of light, which makes it darker than any other planet or moon. The discovery, detailed in the journal Monthly Notices of the Royal Astronomical Society,… [Read more…]
August 12, 2011
One of the earliest lessons in science that students learn is that a ray or beam of light travels in a straight line. Students also learn that light rays fan out or diffract as they travel. Recently it was discovered that light rays can travel without diffraction in a curved arc in free space. These… [Read more…]
August 11, 2011
The resumption of operations at California’s Search for Extraterrestrial Intelligence Institute (SETI) was made possible by donations from celebrity supporters including Jodie Foster. Following an appeal on the website of the Allen Telescope Array project, named after its first financial backer, Microsoft co-founder Paul Allen, donations from more than 2,200 supporters – known as SETIStars… [Read more…]
August 11, 2011
Intense pressure can force neutrons into cubes rather than spheres, say physicists Inside atomic nuclei, protons and neutrons fill space with a packing density of 0.74, meaning that only 26 percent of the volume of the nucleus in is empty. That’s pretty efficient packing. Neutrons achieve a similar density inside neutron stars, where the force… [Read more…]
August 11, 2011
Observing quantum effects such as superpositions and entanglement in macroscopic systems requires not only a system that is well protected against environmental decoherence, but also sufficient measurement precision. Motivated by recent experiments, we study the effects of coarse-graining in photon number measurements on the observability of micro-macro entanglement that is created by greatly amplifying one… [Read more…]
August 10, 2011
Two independent groups of physicists have made important breakthroughs in the control of quantum computers based on trapped ions. Instead of controlling quantum bits (qubits) using multiple laser beams, the teams have used microwave sources, which are much easier to control and integrate within quantum circuits. The work could lead to practical quantum computers that… [Read more…]
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August 31, 2011
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