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A SQUIRT of bubbles can act like a liquid or a solid depending on its density - a feat thought unique to grainy materials such as sand. Pour sand, seeds or powder down a chute and they can flow like a liquid. But if the grains are packed so that they fill 64 per cent or more of the chute, they jam up and behave like a solid.
Bubbles exhibit weird sandy behaviour - physics-math - 30 April 2011
UK scientists invent artificial petrol - Business News - Manufacturing Digital
Boffins at Rutherford Appleton Laboratory, near Oxford have invented an ‘artificial’ petrol, which costs just 90 pence per gallon and could run in existing cars. Motorists could even be able to drive for 300 to 400 miles before needing to fill up. The breakthrough comes as average UK fuel prices have hit a record high. The new hydrogen-based fuel produces no greenhouse gases and could be available in as little as three years. Professor Stephen Bennington, the project’s lead scientist, said: “In some senses, hydrogen is the perfect fuel. It has three times more energy than petrol per unit of weight, and when it burns, it produces nothing but water.
Originally published March 11, 2011 at 8:41 PM | Page modified March 11, 2011 at 9:12 PM The earthquake that struck Friday off the coast of Japan was so strong it moved the island of Honshu 8 feet to the east and sped up the Earth's rotation by 1.6 microseconds, making the day just a little shorter, scientists said. By The Associated Press and Bloomberg News
Nation & World | Quake sped up Earth's rotation
IS GRAVITY left-handed? An answer could provide a clue to a long-sought theory of quantum gravity - and might be within our grasp by 2013. General relativity describes gravity's actions at large scales. For tiny scales however, a theory of quantum gravity , incorporating quantum mechanics, is needed.
Gravity's bias for left may be writ in the sky - space - 05 March 2011
Welcome to the Elementary Particle Explorer, designed by Garrett Lisi and Troy Gardner . Every known elementary particle is identified by its charges with respect to the electromagnetic, weak, strong, and gravitational forces. Electrons have electric charge -1, up quarks 2/3, down quarks -1/3, and neutrinos 0, with antiparticles having opposite electric charges.
Elementary Particle Explorer
Fail an alcohol test and you could lose your job. But confidence is draining from the blood and urine tests that are supposed to show conclusively whether someone has been drinking – and the US government has decided it's time to take another look at them. Typically, the body destroys alcohol within 6 hours, so the tests are designed to pick up tiny amounts of substances such as ethyl glucuronide (EtG) and ethyl sulphate (EtS) that are formed exclusively from the breakdown of alcohol.
Incriminating booze tests face fresh scrutiny - health - 10 February 2011
A BALL spinning in a vacuum should never slow down, since no outside forces are acting on it. At least that's what Newton would have said. But what if the vacuum itself creates a type of friction that puts the brakes on spinning objects? The effect, which might soon be detectable, could act on interstellar dust grains. In quantum mechanics, the uncertainty principle says we can never be sure that an apparent vacuum is truly empty. Instead, space is fizzing with photons that are constantly popping into and out of existence before they can be measured directly.
Vacuum has friction after all - space - 11 February 2011
ABSOLUTE zero sounds like an unbreachable limit beyond which it is impossible to explore. In fact there is a weird realm of negative temperatures that not only exists in theory, but has also proved accessible in practice. An improved way of getting there, outlined last week, could reveal new states of matter. Temperature is defined by how the addition or removal of energy affects the amount of disorder, or entropy, in a system.
How to create temperatures below absolute zero - physics-math - 01 December 2010
'Lightfoil' soars on a stream of photons - physics-math - 06 December 2010
Light has been used to generate aerodynamic-like lift for the first time. The technique, which takes advantage of the fact that light bends, or refracts, when moving from one medium to another, could be used to create solar-sail spacecraft that could steer using light itself. Photons create pressure when they bounce off objects. Solar sail prototypes are made highly reflective to maximise this push, but the effect does not allow the sails to be easily steered. "It's well known you can use a light source to push on something, but the steering mechanisms are still up for grabs," says Grover Swartzlander of the Rochester Institute of Technology in New York.
Higgs hunt may delay LHC's planned shutdown - physics-math - 13 December 2010
Physicists are considering delaying a planned shutdown of the Large Hadron Collider by a year to keep hot on the trail of the elusive Higgs particle. Located near Geneva, Switzerland, the LHC is the most powerful particle smasher ever built, designed to produce collisions at energies up to 14 trillion electron volts (TeV). It was built to look for the Higgs particle, which is thought to endow other subatomic particles, such as electrons, with mass. But the LHC's ramp-up to full energy has been slower than expected.
IF YOU want to look at individual atoms, it helps to have a powerful microscope. But for delicate situations such as a lone atom on the edge of a sheet of carbon atoms, a high-energy beam can disturb the bonds that hold such atoms in place, making them difficult to study. Now, for the first time, a low-energy beam has been used to count these bonds. In the past, beams of high-energy electrons have been used to probe individual atoms. For example, such an electron beam was used to identify single atoms of so-called "rare earth" elements that were trapped inside buckyballs , round cages made of carbon atoms. By looking at the energy spectra of the electrons that bounced back, researchers could deduce the size of the atom inside, and so identify it.
Less is more when measuring fragile atomic bonds - physics-math - 15 December 2010
No black holes found at LHC – yet - physics-math - 17 December 2010
The Large Hadron Collider has not yet seen any of the microscopic black holes that inspired numerous scare stories in recent years. Many theorists actually hope the collider, based near Geneva, Switzerland, will create short-lived, miniature black holes . These would not pose a threat to Earth , but they would provide evidence for hypothetical extra dimensions that might lie beyond the 3D world we normally experience. If these dimensions exist, gravitons, the particles thought to transmit the force of gravity, could leak into them, providing a much-needed explanation for why gravity is much weaker than the other forces. At the high energies created inside the LHC, though, colliding protons could be affected even by gravitons in the extra dimensions, making gravity strong enough to create fleeting black holes. So far, however, they have not emerged.New Scientist Short Sharp Science Blog: Why the world WON'T end on September 10
Hurray for the European Court of Human Rights. It has rejected an emergency injunction to block the Large Hadron Collider from turning on on 10 September. It's the latest legal case brought against the LHC by scientists who fear that the world's largest particle accelerator will produce fearsome entities that could destroy the Earth. I'm thrilled that the ECHR has understood the science and has given the LHC the green light. Because let's get something straight: the world is not going to end on 10 September. Here's why.Meet PG5, the largest stable synthetic molecule ever made. With a diameter of 10 nanometres and a mass equal to 200 million hydrogen atoms, this huge molecule festooned with tree-like appendages, paves the way to sophisticated structures capable of storing drugs within their folds, or bonding to a wide variety of different substances. Complex macromolecules abound in nature and PG5 is about the same size as tobacco mosaic virus . But making such large molecules in the lab is tough, as they tend to fall apart while they are being made. "Synthetic chemistry so far was simply not capable of approaching the size range of such functional units," says Dieter Schlüter at the Swiss Federal Institute of Technology in Zürich. Previously, polystyrene was the largest stable synthetic molecule, at 40 million hydrogen masses.