Month: February 2009
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Spiders ”n’ Mars
The best of the rest from the physics arXiv this week: Discovery of the Arsenic Isotope The Origin of the Universe as Revealed Through the Polarization of the Cosmic Microwave Background Chemical Self Assembly of Graphene Sheets Pricing Strategies for Viral Marketing on Social Networks Scale Invariance, Bounded Rationality and Non-Equilibrium Economics
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Why spiders’ silk is so much stronger than silkworms’
Spider silk and silkworm silk are almost identical in chemical composition and microscopic structure. And yet spider silk is far tougher. “One strand of pencil thick spider silk can stop a Boeing 747 in flight,” say Xiang Wu and colleagues at the National University of Singapore. Whereas a pencil thick strand of silkworm silk couldn’t.…
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Liquid film motors finally explained
Last year, a group of Iranian physicists made the extraordinary discovery that motors can be made of nothing more than a thin film of water sitting in a cell bathed in two perpendicular electric fields. The unexpected result of this set up is that the water begins to rotate. Divide the water into smaller cells…
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Calculating the cost of dirty bombs
One of the more frightening scenarios that civil defence teams worry about is the possibility that a bomb contaminated with radioactive material would be detonated in a heavily populated area. Various research teams have considered this problem and come to similar conclusions–that the actual threat to human health from such a device is low. Some…
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The coming of age of hadrontherapy
There’s a problem with conventional radiotherapy for tumours: the body absorbs the radiation as it passes through. So zap a deep seated tumour with X-rays and the dose decreases exponentially with the depth of target. This means that both diseased and healthy tissue end up getting targeted. In 1946, Robert Wilson, a physicist at FermiLab…
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First evidence of a supernova in an ice core
There hasn’t been a decent supernova in our part of the universe in living memory but astronomers in the 11th century were a little more fortunate. In 1006 AD, they witnessed what is still thought to be the brightest supernova ever seen on Earth (SN 1006) and just 48 years later saw the birth of…
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Adding ‘n’ tangling
The best of the rest from the physics arXiv this week: Hydrogen Storage by Polylithiated Molecules and Nanostructures Physical Properties of Biological Membranes A Brief Overview of the Major Contribution to Physics by Landau New Worlds: Evaluating Terrestrial Planets as Astrophysical Objects A Recursive Threshold Visual Cryptography Scheme Tradition Versus Fashion in Consumer Choice A…
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Ptarithmetic: reinventing logic for the computer age
In the last few years, a small group of logicians have attempted the ambitious task of re-inventing the discipline of formal logic. In the past, logic has been thought of as the formal theory of “truth”. Truth plays an important role in our society and as suchm a formal theory is entirely laudable and worthy.…
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Human eye could detect spooky action at a distance
It’s almost a year since Nicolas Gisin and colleagues at the University of Geneva announced that they had calculated that a human eye ought to be able to detect entangled photons. “Entanglement in principle could be seen,” they concluded. That’s extraordinary because it would mean that the humans involved in such an experiment would become…
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The puzzle of planet formation
“The formation of planets is one of the major unsolved problems in modern astrophysics.” That’s how Rafael Millan-Gabet at Caltech and John Monnier from the University of Michigan begin their account of how our understanding of planet formation is about to undergo a revolution. Driving this change will be a new generation of telelscopes and…