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Nov 09

Reported by Mike Ross, in Stanford News Report, 27 September 2013.

The tiny new technology could spawn new generations of smaller, less expensive devices for science and medicine.

The nanostructured glass chip is smaller than a grain of rice (by Brad Plummer).

In an advance that could dramatically shrink particle accelerators for science and medicine, researchers used a laser to accelerate electrons at a rate 10 times higher than conventional technology in a nanostructured glass chip smaller than a grain of rice.

The achievement was reported today in the journal Nature by a team including scientists from the U.S. Department of Energy’s SLAC National Accelerator Laboratory and Stanford University.

“We still have a number of challenges before this technology becomes practical for real-world use, but eventually it would substantially reduce the size and cost of future high-energy particle colliders for exploring the world of fundamental particles and forces,” said Joel England, the SLAC physicist who led the experiments. Continue reading »

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Oct 08

Reported by Adam Mann, in Wired Science, 8th October 2013.

Data from the CMS experiment, one of the main Higgs-searching experiments at the Large Hadron Collider. Image: CERN

More than a year ago, scientists found the Higgs boson. This morning, two physicists who 50 years ago theorized the existence of this particle, which is responsible for conferring mass to all other known particles in the universe, got the Nobel, the highest prize in science.

For all the excitement the award has already generated, finding the Higgs — arguably the most important discovery in more than a generation — has left physicists without a clear roadmap of where to go next. While popular articles often describe how the Higgs might help theorists investigating the weird worlds of string theory, multiple universes, or supersymmetry, the truth is that evidence for these ideas is scant to nonexistent. Continue reading »

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Sep 05

Reported by Aviva Hope Rutkin, in Brookhaven National Laboratory News, 02 Sep. 2012.

Atomic scale visualization of the single molecule junctions formed with two equivalent pathways (left) and one pathway (right), including the bonding to the tips of two gold electrodes and a schematic of the external electrical circuit.

In a paper published in Nature Nanontechnology on September 2, 2012, scientists from the U.S. Department of Energy’s (DOE) Brookhaven National Laboratory and Columbia University’s departments of Chemistry and of Applied Physics explore the laws that govern electronic conductance in molecular scale circuits.

“Everyone who has worked with basic electronic circuits knows that there are some simple rules of the road, like Ohm’s Law,” explains collaborator Mark Hybertsen, a physicist at Brookhaven’s Center for Functional Nanomaterials (CFN). Hybertsen provided the theory to model the observed circuit behavior with the CFN’s computational tools. “For several years we have been asking fundamental questions to probe how those rules might be different if the electronic circuit is shrunk down to the scale of a single molecule.” Continue reading »

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Feb 26

Reported by , in Wired Science, 22 Feb. 2012.

The sensational result that neutrinos can travel faster than the speed of light may be undone by nothing more than a simple mechanical error.

Scientists from the OPERA collaboration at the Gran Sasso National Laboratory in Italy have “identified two issues that could significantly affect the reported result,” wrote OPERA spokesman Antonio Ereditato in an email.

The first issue is a faulty connection of the fiber-optic cable bringing the GPS signal to the experiment’s master clock. The experiment’s GPS may also have been providing the wrong timestamps during synchronization between events.

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Jan 08

Reported by Brian Owens (on behalf of Eugenie Samuel Reich), in Nature blogs, 06 Jan 2012.

An Irish mathematician has used a complex algorithm and millions of hours of supercomputing time to solve an important open problem in the mathematics of Sudoku, the game popularized in Japan that involves filling out a 9X9 grid of squares with the numbers 1-9 according to certain rules.

Gary McGuire of University College Dublin shows in a proof posted online 1 January that the minimum number of clues – or starting digits – needed to complete a puzzle is 17 (see sample puzzle, pictured, from McGuire’s paper), as puzzles with 16 clues or less do not have an unique solution. In comparison most newspaper puzzles have around 25 clues, with the difficulty of the puzzle decreasing as more clues are given.

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Jan 06

Reported by Moti Fridman,1 , Alessandro Farsi,1, Yoshitomo Okawachi1 & Alexander L. Gaeta1 in Nature, vol. 481, Pages: 62–65, 05 Jan. 2012.

Recent research has uncovered a remarkable ability to manipulate and control electromagnetic fields to produce effects such as perfect imaging and spatial cloaking1, 2. To achieve spatial cloaking, the index of refraction is manipulated to flow light from a probe around an object in such a way that a ‘hole’ in space is created, and the object remains hidden3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14. Alternatively, it may be desirable to cloak the occurrence of an event over a finite time period, and the idea of temporal cloaking has been proposed in which the dispersion of the material is manipulated in time, producing a ‘time hole’ in the probe beam to hide the occurrence of the event from the observer15. This approach is based on accelerating the front part of a probe light beam and slowing down its rear part to create a well controlled temporal gap—inside which an event occurs—such that the probe beam is not modified in any way by the event. The probe beam is then restored to its original form by the reverse manipulation of the dispersion. Here we present an experimental demonstration of temporal cloaking in an optical fibre-based system by applying concepts from the space–time duality between diffraction and dispersive broadening16. We characterize the performance of our temporal cloak by detecting the spectral modification of a probe beam due to an optical interaction and show that the amplitude of the event (at the picosecond timescale) is reduced by more than an order of magnitude when the cloak is turned on. These results are a significant step towards the development of full spatio-temporal cloaking.

Read more in “Demonstration of temporal cloaking”, Nature, vol. 481, Pages: 62–65, 05 Jan. 2012.

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Dec 12

Reported by Brandon Keim, in Wired Science, 6 Dec. 2011.

Physicists have found the strongest evidence yet of quantum effects fueling photosynthesis.

Multiple experiments in recent years have suggested as much, but it’s been hard to be sure. Quantum effects were clearly present in the light-harvesting antenna proteins of plant cells, but their precise role in processing incoming photons remained unclear.

In an experiment published Dec. 6 in Proceedings of the National Academy of Sciences, a connection between coherence — far-flung molecules interacting as one, separated by space but not time — and energy flow is established.

“There was a smoking gun before,” said study co-author Greg Engel of the University of Chicago. “Here we can watch the relationship between coherence and energy transfer. This is the first paper showing that coherence affects the probability of transport. It really does change the chemical dynamics.” Continue reading »

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Oct 12

Reported by PhysOrg, 11 Oct. 2011.

Chance and probability play a natural role in statistical physics. Inspired by confetti, researchers at the University of Gothenburg, Sweden, gain better understanding of random phenomena and refine the tools that can be used to study them.

“The result of small disturbances to random systems can be illustrated by throwing confetti. If simple rules are constructed at a small scale, it is possible to study the characteristics at a broad level. Small changes at local level can result in widely differing phenomena at global level,” says Daniel Ahlberg at the Department of of the University of Gothenburg.

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Oct 11

Reported by Melissa Van De Werfhorst, University of California – Santa Barbara, 11 Oct. 2011.

New equation developed by UCSB chemical engineers solves the mystery of forces between water-repelling and water-attracting molecules that are critical to industrial and medical applications.

(Santa Barbara, Calif. – ) The physical model to describe the hydrophobic interactions of molecules has been a mystery that has challenged scientists and engineers since the 19th century. Hydrophobic interactions are central to explaining why oil and water don’t mix, how proteins are structured, and what holds biological membranes together. Chemical engineering researchers at UC Santa Barbara have developed a novel method to study these forces at the atomic level, and have for the first time defined a mathematical equation to measure a substance’s hydrophobic character.

“This discovery represents a breakthrough that is a culmination of decades of research,” says Professor Jacob Israelachvili. “The equation is intended to be a tool for scientists to begin quantifying and predicting molecular and surface forces between organic substances in water.” Continue reading »

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Sep 25

Reported by Ars Technica (John Timmer), in Wired Science, 23 Sep. 2011.

Last night, in response to a worldwide surge in interest, the OPERA experiment released a paper that describes the experiments that appear to show neutrinos traveling faster than the speed of light. And today, CERN broadcast a live seminar in which one of the work’s authors described the content of the paper. Both of those emphasized the point of our initial coverage: figuring out whether anything is traveling beyond the speed of light requires incredibly accurate measurements of time and distance, and the OPERA team has made an extensive effort to make its work as accurate as possible.

As a spokesperson for the MINOS neutrino experiment told Ars yesterday, there are three potential sources of error in the timing measurements: distance errors, time-of-flight errors, and errors in the timing of neutrino production. The vast majority of both the paper and the lecture were dedicated to discussing how these errors were reduced (the actual detection of the neutrinos was only a small portion of the paper).

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