Keyword: physics

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  • Pulsars: The universe's gift to physics

    03/28/2012 8:26:40 PM PDT · by U-238 · 13 replies
    Astronomy Magazine ^ | 2/20/2012 | NRAO
    Pulsars, superdense neutron stars, are perhaps the most extraordinary physics laboratories in the universe. Research on these extreme and exotic objects already has produced two Nobel Prizes. Pulsar researchers now are poised to learn otherwise-unavailable details of nuclear physics to test general relativity in conditions of extremely strong gravity, and to directly detect gravitational waves with a “telescope” nearly the size of our galaxy. Neutron stars are the remnants of massive stars that exploded as supernovae. They pack more than the mass of the Sun into a sphere no larger than a medium-sized city, making them the densest objects in...
  • New device invisible to magnetic fields

    03/24/2012 11:19:51 PM PDT · by U-238 · 26 replies · 1+ views
    Defense Talk ^ | 3/24/2012 | Defense Talk
    European researchers said Thursday they have created a device invisible to a static magnetic field that could have practical military and medical applications. Fedor Gomory and colleagues in Slovakia and Spain designed a cloak for a direct current, or dc, magnetic field that is static and produced by a permanent magnet or coil carrying a direct current. DC magnetic fields are used in MRI imaging devices, in hospitals and in security systems, such as those in airports. The researchers' device, described in a study in Friday's edition of the journal Science, features a cylinder with two concentric layers. While the...
  • Will Space Battles Be Fought with Laser Weapons?

    03/22/2012 1:34:51 AM PDT · by U-238 · 33 replies · 2+ views
    Life's Little Mysteries ^ | 3/16/2012 | Adam Hadhazy
    What would science fiction be without laser beams? From handheld ray guns to spaceship-mounted turbolasers, the futuristic weapon of choice definitely involves bright, colorful blasts of energy. In the early 21st century, projectiles still remain the standard means of inflicting damage from a distance. Yet continued research into "directed-energy" weapons by the United States military, among others, could someday bring lasers to a battlefield near you. Lasers are already used in guidance, targeting and communication applications, but significant technological obstacles stand in front of turning them into weapons by themselves. For certain niche scenarios, lasers might prove themselves ideal. It...
  • ScienceShot: Crystal Clear Nano-Gold

    03/21/2012 11:06:30 PM PDT · by neverdem · 9 replies
    ScienceNOW ^ | Robert F. Service | 21 March 2012
    Credit: Image courtesy of Nature Press Superman has nothing on Jianwei Miao, at least in the vision department. Miao, a physicist at the University of California, Los Angeles, and his colleagues have developed a way to image any type of nanoparticle with unprecedented accuracy. In the picture above, the technique, called electron tomography, shows a gold nanoparticle made up of 3871 atoms. Inside the nanoparticle, the researchers could easily resolve multiple "grains" (green, gold, blue, and red) in which atoms in each grain share a common atomic alignment that is offset from neighboring grains. The technique also manages to...
  • The Science of Rail Guns

    03/20/2012 9:44:57 PM PDT · by U-238 · 43 replies
    i09 ^ | 3/20/2012 | Keith Veronese
    Ubiquitous in science fiction, rail guns are a hot area of military research in real life too. But will we ever really get to use them the way people in science fiction do? And could rail guns be used for a non-violent reason — inexpensively launching payload into space? Halo Reach ends with your Spartan taking up a mounted rail gun to destroy an incoming Covenant ship. Rail guns are the basis for a funny aside in Mass Effect 2. They're used in Babylon 5 and Stargate Atlantis and The Last Starfighter. And they're a devastating hand-held weapon in the...
  • Recovering three-dimensional shape around a corner using ultrafast time-of-flight imaging

    03/20/2012 2:48:27 PM PDT · by Stoat · 4 replies · 2+ views
    Nature ^ | March 20, 2012 | Andreas Velten, et al
    The recovery of objects obscured by scattering is an important goal in imaging and has been approached by exploiting, for example, coherence properties, ballistic photons or penetrating wavelengths. Common methods use scattered light transmitted through an occluding material, although these fail if the occluder is opaque. Light is scattered not only by transmission through objects, but also by multiple reflection from diffuse surfaces in a scene. This reflected light contains information about the scene that becomes mixed by the diffuse reflections before reaching the image sensor. This mixing is difficult to decode using traditional cameras. Here we report the combination...
  • Retest of neutrino speed suggests Einstein was right, after all

    03/19/2012 4:22:37 PM PDT · by U-238 · 16 replies · 1+ views
    Christian Science Monitor ^ | 3/19/2012 | By Clara Moskowi
    Six months after physicists shocked the world by announcing they'd found particles seemingly traveling faster than light, the growing scientific consensus seems to be that the results were flawed. Neutrinos are the vampires of physics. Researchers at the ICARUS project in Italy have recreated an independent version of the original Switzerland-based experiment, called OPERA, and found that their particles traveled at a respectable, sub-light speed. Though the results don't automatically disprove OPERA's findings, they add to most scientists' sense that the shocking finding was an anomaly "The evidence is beginning to point towards the OPERA result being an artifact of...
  • Message Encoded in Neutrino Beam Transmitted through Solid Rock

    03/18/2012 11:29:14 PM PDT · by U-238 · 18 replies · 1+ views
    Scientific American ^ | 3/16/2012 | John Matson
    Neutrinos are having a moment. They’re speeding across Europe (just how fast is under review), they’re changing flavors in China and, now, they’re carrying rudimentary messages through bedrock in Illinois. A team of physicists encoded a short string of letters on a beam of neutrinos at Fermi National Accelerator Laboratory in Batavia, Ill., and sent the message to a detector more than a kilometer away. On the journey the neutrinos passed through 240 meters of solid rock, mostly shale. What was the word they transmitted in the preliminary demonstration? “Neutrino.” The experiment is described in a paper posted to the...
  • Hydrogen takes a new form

    03/10/2012 10:36:13 PM PST · by U-238 · 19 replies
    Science News ^ | 3/1/2012 | Alexandra Witze
    Squeezing hydrogen at extreme pressures changes it into a mix of honeycombed atoms layered with free-floating molecules — an entirely new state of the element and the first new phase found in decades. If confirmed, the discovery will be only the fourth known phase of hydrogen, the simplest element and one long probed for basic insights into the nature of matter. “I think we have pretty bulletproof evidence that there is a new phase,” says Eugene Gregoryanz of the University of Edinburgh, leader of the team that will report the work in an upcoming Physical Review Letters. Hydrogen’s first three...
  • Loose cable blamed for speedy neutrinos

    03/06/2012 1:16:25 AM PST · by U-238 · 41 replies
    Science News ^ | 2/23/2012 | Devin Powell
    Faulty wiring has been proposed as the glitch that caused a European physics experiment to clock particles flying faster than light. Scientists at Italy’s OPERA experiment reported in September that nearly weightless particles called neutrinos were apparently traveling from the CERN laboratory on the Swiss-French border to an underground detector in Italy, 730 kilometers away, faster than the speed of light. The apparent violation of Einstein’s theory of special relativity immediately produced a chorus of theorists offering reasons why neutrinos simply could not be going that fast (SN: 11/5/11, p. 10). “It was always clear to me that the results...
  • Graphyne Could Be Better Than Graphene

    03/04/2012 12:33:55 AM PST · by neverdem · 2 replies
    ScienceNOW ^ | 1 March 2012 | Jon Cartwright
    Enlarge Image The new graphene. Graphyne may be less famous than graphene, but it could have better electronic properties. Credit: D. Malko et al., Phys. Rev. Lett. (2012) Graphene, a layer of graphite just one atom thick, isn't called a wonder material for nothing. The subject of the 2010 Nobel Prize in physics, it is famed for its superlative mechanical and electronic properties. Yet new computer simulations suggest that the electronic properties of a little-known sister material of graphene—graphyne—may in some ways be better. The simulations show that graphyne's conduction electrons should travel extremely fast—as they do in graphene—but...
  • Proposed Cloaking Device for Water Waves Could Protect Ships at Sea

    03/03/2012 10:58:25 PM PST · by neverdem · 16 replies
    ScienceNOW ^ | 2 March 2012 | Adrian Cho
    Enlarge Image Underpass. Appropriately sculpted ripples on the ocean floor could convert surface waves into internal interfacial waves, allowing them to pass under a floating object and protecting the thing from jostling. Credit: M.-R. Alam, PhysRevLett, 108 (24 February, 2012) The weird science of invisibility has entered uncharted waters. By altering the sea floor in just the right way, it should be possible to hide an object floating on the sea from passing waves, a fluid mechanician predicts. The technique might help to protect ships and floating structures from rough seas. And because the scheme works entirely differently from...
  • Physicists Measure the Skin of a Nucleus

    03/03/2012 9:41:05 PM PST · by neverdem · 20 replies
    ScienceNOW ^ | 2 March 2012 | Adrian Cho
    Enlarge Image Nuclear dermatology clinic. The vessel containing the lead sample in the PREX experiment (left) and the massive spectrometers used to detect the electrons scattered from the lead nuclei and measure the nuclei's skin. Credit: Photos Courtesy of Robert Michaels A large atomic nucleus is like a chocolate truffle with a gooey interior and a harder shell. Inside, the nucleus contains a mixture of protons and neutrons. Outside, it's covered with a nearly pure layer of neutrons—the "neutron skin." Now, for the first time, nuclear physicists have measured the thickness of that skin in a fairly direct way....
  • Official Word on Superluminal Neutrinos Leaves Warp-Drive Fans a Shred of Hope—Barely

    02/29/2012 4:45:22 PM PST · by neverdem · 13 replies · 1+ views
    ScienceInsider ^ | 24 February 2012 | Edwin Cartlidge
    The CERN particle physics laboratory in Geneva has confirmed Wednesday's report that a loose fiber-optic cable may be behind measurements that seemed to show neutrinos outpacing the speed of light. But the lab also says another glitch could have caused the experiment to underestimate the particles' speed. In a statement based on an earlier press release from the OPERA collaboration, CERN said two possible "effects" may have influenced the anomalous measurements. One of them, due to a possible faulty connection between the fiber-optic cable bringing the GPS signals to OPERA and the detector's master clock, would have caused the experiment...
  • What Would Happen If You Shot a Gun In Space?

    02/25/2012 3:43:56 PM PST · by U-238 · 142 replies · 1+ views
    Life Little Mysteries ^ | 2/17/2010 | Natalie Wolchover
    Fires can't burn in the oxygen-free vacuum of space, but guns can shoot. Modern ammunition contains its own oxidizer, a chemical that will trigger the explosion of gunpowder, and thus the firing of a bullet, wherever you are in the universe. No atmospheric oxygen required. The only difference between pulling the trigger on Earth and in space is the shape of the resulting smoke trail. In space, "it would be an expanding sphere of smoke from the tip of the barrel," said Peter Schultz an astronomer at Brown University who researches impact craters. The possibility of gunfire in space allows...
  • The Unusual Physics of Floating Pyramids

    02/17/2012 2:53:08 PM PST · by neverdem · 8 replies
    ScienceNOW ^ | 7 February 2012 | Kate McAlpine
    Enlarge Image Heavy bass. This subwoofer plays a constant beat that pumps the air up and down inside the wind tunnel. The diffusers allow air to flow without turbulence so that the paper pyramid floats inside. Credit: Bin Liu Think that floating pyramids are more metaphysics than physics? Think again. Results just in from an experiment that levitated open-bottomed paper pyramids on gusts of air reveal a curious phenomenon: When it comes to drifting through the air, top-heavy designs are more stable than bottom-heavy ones. The finding may lead to robots that fly not like insects or birds but...
  • Hot Idea for a Faster Hard Drive

    02/16/2012 8:16:39 PM PST · by neverdem · 29 replies
    ScienceNOW ^ | 7 February 2012 | Jim Heirbaut
    Enlarge Image Laser-induced switching. Experimental images showing two small domains with magnetic orientation up (white) and down (black). Each laser pulse reverses the direction repeatedly. Credit: Johan Mentink; Richard Evans (inset) An ultrashort heat pulse can predictably flip a bit in a magnetic memory like the one in your hard drive. The surprising effect could ultimately lead to magnetic memories hundreds of times faster and more energy efficient than today's hard drives. It also provides a way to control the direction in which a bit is magnetized without applying something else that has a direction, such as a magnetic...
  • 5 of the biggest unsolved mysteries in physics

    01/31/2012 2:06:57 PM PST · by NormsRevenge · 69 replies · 1+ views
    Yahoo ^ | 1/31/12 | Tecca - Today in Tech
    The mysteries of the universe are as vast and wide as existence itself. Throughout history, mankind has searched and struggled to find the answers tucked away inside the universe and everything we see around us. .. True, we have yet to come up with the answers to life, the universe, and everything — but oh do we have questions! Solving these mysteries may help to explain not only the creation of the universe, but also how it works, why it works, and possibly how it will end. 1. The Higgs boson The Higgs boson is a hypothetical particle whose accompanying...
  • Stripped down spectroscopy to probe single molecules

    01/16/2012 10:20:22 PM PST · by neverdem · 8 replies · 1+ views
    Chemistry World ^ | 16 January 2012 | Kate McAlpine
    Spectroscopy, a key method of identifying atoms and molecules with light, has been taken to its most fundamental level - a single photon absorbed by a single molecule. In addition to paving the way toward new experiments that observe the interaction between light and matter at its most basic level, the researchers that accomplished the feat suggest that their technique could also work with other photon-emitters, including those under study for quantum communication.Spectroscopy works by finding the frequencies of light that will put an atom or molecule into an excited state - these comprise the chemical's unique absorption and emission...
  • Any other fans out there of "Fabric of the Cosmos?"

    01/07/2012 4:45:46 AM PST · by PJ-Comix · 40 replies
    Self | January 6, 2012 | PJ-Comix
    Are there any other fans of FABRIC OF THE COSMOS out there? I found it to be perhaps the most fascinating science show ever produced. The information in the show is nothing less than stunning and definitely changed my view of the universe. Some of the information is so stunning that it is hard to comprehend. But guess what? Even physicists have a hard time getting their minds around it. And an oatmeal cookie to the first person who can post who the major backer of this series is.