Atoms are spaced periodically in one direction on a surface perpendicular to a quasicrystals 10-fold rotational axis. But at right angles they are spaced in a Fibonacci sequence, in which the ratio of short to long spacings is an irrational number like that of the Golden Mean. Friction is eight times greater in the periodic direction than in the aperiodic direction.
The Da Vinci Code, the best selling novel and soon-to-be-blockbuster film, may also be linked some day to the solving of a scientific mystery as old as Leonardo Da Vinci himself — friction. A collaboration of scientists from Lawrence Berkeley National Laboratory (Berkeley Lab) and the Ames Laboratory at Iowa State University have used Da Vinci’s principles of friction and the geometric oddities known as quasicrystals to open a new pathway towards a better understanding of friction at the atomic level.
In a paper published in the August 26 issue of the journal Science, a research collaboration led by Miquel Salmeron, a physicist with Berkeley Lab’s Materials Sciences Division, reports on the first study to measure the frictional effects of periodicity in a crystalline lattice. Using a combined Atomic Force Microscope (AFM) and Scanning Tunneling Microscope (STM), the researchers showed that friction along the surface of a quasicrystal in the direction of a periodic geometric configuration is about eight times greater than in the direction where the geometric configuration is aperiodic (without regularity).
Geometric periodicity was confirmed via rows of atoms that formed a Fibonacci sequence, a numerical pattern often observed in quasicrystals — and which was one of the clues to solving the Da Vinci code in the novel by Dan Brown.
Lynn Yarris | EurekAlert!
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The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.
Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...
Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.
That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...
Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.
During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....
The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.
Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...
Pillared graphene would transfer heat better if the theoretical material had a few asymmetric junctions that caused wrinkles, according to Rice University...
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