Tiny buckyball grown around metal atom

Chemistry WorldJon Cartwright

Published in Chemistry World, 30 May 2012

An international team of researchers has observed the smallest fullerene to form spontaneously to date using metal atoms for stabilisation. It is now possible that the fullerene, which contains 28 carbon atoms surrounding a single atom of titanium, zirconium or uranium, could be tested for desirable properties such as high-temperature superconductivity, the researchers say.

Fullerenes are molecules containing only carbon – either enclosed as in a sphere, or open-ended as in a nanotube. The first fullerene, buckminsterfullerene, was discovered in 1985 and was a spherical shell containing 60 carbon atoms. Since then, scientists have been interested to create smaller spherical fullerenes. The smaller the fullerenes’ size, the greater their surface curvature, and the more unusual their properties should be. In particular, the spherical fullerene containing 28 carbon atoms, C28, has been predicted to exhibit various exciting properties such as room temperature superconductivity. […]

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ScienceShot: The Science of Collapsing Staples

ScienceJon Cartwright

Published in ScienceNOW, 25 May 2012

It might strike you as an office experiment devised in boredom: piling up staples and seeing how long it takes for them to collapse. But the researchers behind the investigation are serious, and they think it could help explain how “entangled ensembles” benefit the animal kingdom. The team created a mound of staples by pouring them into a cylinder roughly the size of an espresso mug. After removing the cylinder, they subjected the staples to fast, 30-Hertz vibrations on a device technically known as a shaker and measured how long it took for the mound to collapse. […]

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Return of the Vacuum Tube

ScienceJon Cartwright

Published in ScienceNOW, 23 May 2012

Peer inside an antique radio and you’ll find what look like small light bulbs. They’re actually vacuum tubes—the predecessors of the silicon transistor. Vacuum tubes went the way of the dinosaurs in the 1960s, but researchers have now brought them back to life, creating a nano-sized version that’s faster and hardier than the transistor. It’s even able to survive the harsh radiation of outer space.

Developed early last century, vacuum tubes offered the first easy way to amplify electric signals. Like light bulbs, they are glass bulbs containing a heated filament. But above the filament are two additional electrodes: a metal grid and, at the top of the bulb, a positively charged plate. The heated filament emits a steady flow of electrons, which are attracted to the plate’s positive charge. The rate of electron flow can be controlled by the charge on the intervening grid, which means a small electric signal applied to the grid—say, the tiny output of a gramophone—is reproduced in the much stronger electron flow from filament to plate. As a result, the signal is amplified and can be sent to a loudspeaker. […]

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Physicists claim new quantum-teleportation record

Physics WorldJon Cartwright

Published in Physics World, 21 May 2012

Physicists in China claim to have teleported the quantum states of photons nearly 100 km in free space, breaking the previous record by a factor of 100. The development could pave the way for satellite-based quantum communication, or fundamental tests of quantum mechanics over long distances.

Quantum teleportation is a way of transferring a quantum state from one place to another without actually sending a particle in that state through space. In the normal arrangement, two people, Alice and Bob, each take one half of a pair of entangled particles and then go their separate ways. Whenever Alice wants to send a quantum state to Bob, she allows a third particle in that state to interact with her half of the entangled pair of particles. […]

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British Team Cancels Geoengineering Experiment

ScienceJon Cartwright

Published in ScienceInsider, 16 May 2012

A U.K. project that is examining the feasibility of geoengineering the Earth’s climate to reduce global warming will no longer involve an outdoor experiment that was scheduled to take place later this year. The Stratospheric Particle Injection for Climate Engineering (SPICE) project was set to test the delivery of aerosols high into Earth’s atmosphere. Today, however, planners announced that they have cancelled the test because of concerns that researchers involved in the project could have a commercial interest in its success.

Funded by the U.K. government, SPICE was set up in 2010 by British research institutions to investigate whether aerosols, such as sulfate particles, could be injected into Earth’s stratosphere to scatter sunlight back into space, thereby stalling global warming. Aerosols are already known to reduce global warming: The vast clouds of sulfates thrown up in the 1991 eruption of Mount Pinatubo in the Philippines, for example, reduced average global temperatures by about half a degree Celsius. Releasing aerosols on purpose is controversial, however, so scientists are keen to understand how such geoengineering might proceed before any policy decisions are made. They would like to understand what sort of aerosols could be used, how they would impact different aspects of climate, and how they would be delivered to the atmosphere. […]

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Cracks break the rules of nanofabrication

Chemistry WorldJon Cartwright

Published in Chemistry World, 10 May 2012

When it comes to nanofabrication, cracks are usually best avoided. But now researchers in South Korea have discovered that cracks aren’t always bad – if harnessed, they can be used to make controlled patterns. The technique is inexpensive and straightforward, and could have benefits for electronics and microfluidics.

Koo Hyun Nam, the lead author of the study who is based at Ewha Womans University in Seoul, says his group’s technique is similar to the way that ancient Egyptian masons created rocks of just the right size for pyramid construction. Rather than cut rocks by hand, the masons would force a wooden wedge into a small hole in the rock, and soak it with water. The wedge would expand, concentrating force at its tip, neatly breaking the rock apart. […]

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Heat Trickery Paves Way for Thermal Computers

ScienceJon Cartwright

Published in ScienceNOW, 10 May 2012

Heat is the great enemy of modern electronics—it can spawn errors and fry components. But now scientists have turned heat to their advantage by creating devices that run on heat instead of electricity. The advance could lead to thermal computers that run off of body heat or other waste heat from our surroundings.

A heat current is simply the flow of energy from a hotter object to a colder object. Imagine heating a metal pipe at one end: Heat flows from the hot end to the cold end, and at every point along the pipe the temperature diminishes. In physics terms, there’s a “uniform temperature gradient.” The heat takes this simple path because the pipe conducts the same amount of heat in every place and in every direction. […]

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Gamma-Ray Bending Opens New Door for Optics

ScienceJon Cartwright

Published in ScienceNOW, 8 May 2012

Lenses are a part of everyday life—they help us focus words on a page, the light from stars, and the tiniest details of microorganisms. But making a lens for highly energetic light known as gamma rays had been thought impossible. Now, physicists have created such a lens, and they believe it will open up a new field of gamma-ray optics for medical imaging, detecting illicit nuclear material, and getting rid of nuclear waste.

Glass is the material of choice for conventional lenses, and like other materials, it contains atoms which are orbited by electrons. In an opaque material, these electrons would absorb or reflect light. But in glass, the electrons respond to incoming light by shaking about, pushing away the light in a different direction. Physicists describe the amount of bending as the glass’s “refractive index”: A refractive index equal to one results in no bending, while anything more or less results in bending one way or the other. […]

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The Physics of Spilled Coffee

ScienceJon Cartwright

Published in ScienceNOW, 4 May 2012

Scientists face many obstacles on the path to greater knowledge. But new research suggests how to avoid one of the more common pitfalls: spilled coffee.

“I cannot say for sure if coffee spilling has been detrimental to scientific research to any significant extent,” says study author Rouslan Krechetnikov, a mechanical engineer at the University of California, Santa Barbara. “But it can certainly be disruptive for a train of thought.” […]

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‘Missing silicon problem’ solved, say geophysicists

Physics WorldJon Cartwright

Published in Physics World, 3 May 2012

Researchers in Japan have new evidence that the Earth’s lower mantle contains more silicon than its upper mantle. The results suggest that the composition of the Earth’s silicates match the type of meteorites thought to exist in the solar nebula from which the Earth was created.

The Earth’s mantle can be divided into three sections: the upper mantle, which stretches from the thin crust down to about 400 km in depth; a transition zone of about 250 km; and finally the lower mantle, which stretches from the transition zone to about 2900 km in depth. Most geoscientists agree that the upper mantle is composed mostly of peridotite, a dense igneous rock containing a high proportion of the mineral olivine (Mg,Fe)2SiO4. At the transition zone, a change in the way seismic waves propagate has generally been explained by a phase transition in the structure of the olivine, suggesting that the lower mantle, too, is peridotite in composition. If this is true, however, the Earth would contain far less silicon than chondritic meteorites – the type of meteorites thought to exist at the time of the Earth’s formation. […]

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