Physics and Astronomy

Carving a telephone pole is easy if you have the right tools, say a power saw and some large chisels. And with some much tinier tools you could even carve a design into a paper clip if you wanted to. But shrink your sights down to the nanoscale, to a nanowire that is 1,000 times smaller than the diameter of a paper clip, and you find there are no physical tools to do the job properly.

So a team of Northwestern University scientists turned to chemistry and developed a new method th

Physicists at the University of Pennsylvania have experimentally discovered a fundamental principal about how solid materials melt. Their studies have shown explicitly that melting begins at defects within the crystalline structure of solid matter, beginning along the cracks, grain boundaries and dislocations that are present in the otherwise orderly array of atoms. Their findings, which will appear today in the journal Science, answer longstanding fundamental questions about melting and will

Zone Plate Lenses Capable of Better than 15-Nanometer Resolution

Progress in nanoscience and nanotechnology depends not only on examining the surfaces of things but on seeing deep inside biological organisms and material structures to identify what they’re made of — and what electronic, magnetic, optical, and chemical processes may be in play.

For measuring internal variations in shape, organization, magnetism, polarization, or chemical make-up over distances of a fe

Physics researchers working at the High Energy Accelerator Research Organization (KEK) Laboratory in Japan have observed a new type of interaction among the most fundamental of particles, the quark. The scientists reported at the Symposium on Lepton-Photon Interactions at High Energies, June 30-July 5 in Uppsala, Sweden, that they had produced first evidence of a beauty quark converting to the lightest of quarks, the down quark.

“Observation of this very rare phenomenon allows us t

The University of Chicago’s Nicolas Dauphas has developed a new way to calculate the age of the Milky Way that is free of the unvalidated assumptions that have plagued previous methods. Dauphas’ method, which he reports in the June 29 issue of the journal Nature, can now be used to tackle other mysteries of the cosmos that have remained unsolved for decades.

“Age determinations are crucial to a fundamental understanding of the universe,” said Thomas Rauscher, an ass

Physicists have a pretty good idea of what to expect when friction and adhesion occur in the visible world. You jam on the brakes, for instance, and your tires and the highway interact to stop your car. You glue two pieces of wood together, and they stick.
But how slippery or sticky are things that are too small to see? When solid surfaces no more than a thousand atoms across brush past each other, will they respond like the rubber and the road? Will they adhere like the wood and the glue?