Science

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Graphene slides smoothly across gold: Professor Xinliang Feng co-authors publication in Science journal

Since it produces almost no friction at all, it could drastically reduce energy loss in machines when used as a coating, as the researchers report in the journal Science.

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A graphene nanoribbon was anchored at the tip of an atomic force microscope and dragged over a gold surface. The observed friction force was extremely low.

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Hubble Team Breaks Cosmic Distance Record

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Hubble Space Telescope astronomers, studying the northern hemisphere field from the Great Observatories Origins Deep Survey (GOODS), have measured the distance to the farthest galaxy ever seen. The survey field contains tens of thousands of galaxies stretching far back into time. Galaxy GN-z11, shown in the inset, is seen as it was 13.4 billion years in the past, just 400 million years after the big bang, when the universe was only three percent of its current age. The galaxy is ablaze with bright, young, blue stars, but looks red in this image because its light has been stretched to longer spectral wavelengths by the expansion of the universe.

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What makes penguin feathers ice-proof

Humboldt penguins live in places that dip below freezing in the winter, and despite getting wet, their feathers stay sleek and free of ice. Scientists have now figured out what could make that possible. They report, that the key is in the microstructure of penguins' feathers. Based on their findings, the scientists replicated the architecture in a nanofiber membrane that could be developed into an ice-proof material.

The range of Humboldt penguins extends from coastal Peru to the tip of southern Chile. Some of these areas can get frigid, and the water the birds swim in is part of a cold ocean current that sweeps up the coast from the Antarctic.

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Remote predictions of fluid flow in fractures possible with new finding

Approaching a universal scaling relationship between fracture stiffness and fluid flow A goal of subsurface geophysical monitoring is the detection and characterization of fracture alterations that affect the hydraulic integrity of a site. Achievement of this goal requires a link between the mechanical and hydraulic properties of a fracture. Here we present a scaling relationship between fluid flow and fracture-specific stiffness that approaches universality. Fracture-specific stiffness is a mechanical property dependent on fracture geometry that can be monitored remotely using seismic techniques. A Monte Carlo numerical approach demonstrates that a scaling relationship exists between flow and stiffness for fractures with strongly correlated aperture distributions, and continues to hold for fractures deformed by applied stress and by chemical erosion as well. This new scaling relationship provides a foundation for simulating changes in fracture behavior as a function of stress or depth in the Earth and will aid risk assessment of the hydraulic integrity of subsurface sites.

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A graph of the scaling relationship between fluid flow and fracture stiffness is shown. The shape of the symbol indicates the fracture length scale from 0.0625 meter (circles) to 1 meter (triangle) and the colors correspond to different apertures.

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LIGO's Twin Black Holes Might Have Been Born Inside a Single Star

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Topological insulators: Magnetism is not causing loss of conductivity

Topological insulators appeared to be rather well-understood from theory until now. The electrons that can only occupy "allowed" quantum states in the crystal lattice are free to move in only two dimensions, namely along the surface, behaving like massless particles. Topological insulators are therefore highly conductive at their surfaces and electrically insulating within. Only magnetic fields should destroy this mobility, according to theory. Now physicists headed by Oliver Rader and Jaime Sánchez-Barriga from HZB along with teams from other HZB departments, groups from Austria, the Czech Republic, Russia, and theoreticians in Munich have disproved this hypothesis.

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In pure bismuth-selenide (left) no bandgap is found. With the addition of magnetic manganese (4 percent; 8 percent), a band gap (dashed line) arises, and electrical conductivity disappears. This effect shows even at room temperature.

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Quantum phase transition underpins superconductivity in copper oxides: CIFAR researchers in Canada and France unveil key organizing principle of high-temperature superconductivity

Physicists have zoomed in on the transition that could explain why copper-oxides have such impressive superconducting powers.

Settling a 20-year debate in the field, they found that a mysterious quantum phase transition associated with the termination of a regime called the "pseudogap" causes a sharp drop in the number of conducting electrons available to pair up for superconductivity. The team hypothesizes that whatever is happening at this point is probably the reason that cuprates support superconductivity at much higher temperatures than other materials -- about half way to room temperature.

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Researchers demonstrate 'quantum surrealism'

New research demonstrates that particles at the quantum level can in fact be seen as behaving something like billiard balls rolling along a table, and not merely as the probabilistic smears that the standard interpretation of quantum mechanics suggests. But there's a catch - the tracks the particles follow do not always behave as one would expect from "realistic" trajectories, but often in a fashion that has been termed "surrealistic."

In a new version of an old experiment, CIFAR Senior Fellow Aephraim Steinberg (University of Toronto) and colleagues tracked the trajectories of photons as the particles traced a path through one of two slits and onto a screen. But the researchers went further, and observed the "nonlocal" influence of another photon that the first photon had been entangled with.

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NASA Introduces New, Wider Set of Eyes on the Universe

After years of preparatory studies, NASA is formally starting an astrophysics mission designed to help unlock the secrets of the universe -- the Wide Field Infrared Survey Telescope (WFIRST).

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Stretchable nano-devices towards smart contact lenses: Researchers at RMIT University and the University of Adelaide have joined forces to create a stretchable nano-scale device to manipulate light

Researchers at RMIT University and the University of Adelaide have joined forces to create a stretchable nano-scale device to manipulate light.

The device manipulates light to such an extent that it can filter specific colours while still being transparent and could be used in the future to make smart contact lenses.