P. Aleahmad et al.
Physical Review Letters (forthcoming)
P. Zheng et al. Physical Review Letters, 109, 193901 (2012)
Bending light around corners is usually done with mirrors, but now scientists have realized self-bending light beams that propagate along curved paths.
Two independent groups have reported experiments on special light waves that can skid around curves. The researchers demonstrated that modified laser beams can be made to move along parabolic and elliptical paths. Furthermore, if obstacles are in their path, these beams can self-heal, regrouping and continuing on their way. The research shows that such self-bending behavior can be achieved in both two and three dimensions. These sort of "optical boomerangs" could be used to move particles around with laser tweezers, or to manipulate optical data on an optoelectronic chip.
Ultralight Fractal Materials
Daniel Rayneau-Kirkhope, Yong Mao (contact author), Robert Farr Physical Review Letters (forthcoming)
Researchers have studied theoretically how ultralight materials can be built based on a fractal design: a geometry whose patterns look the same when observed at different scales.
Their design strategy is based on a hierarchical approach: elementary units are first assembled that can be used as building blocks for the next level of assembly. The resulting structures, reminiscent of the metal frame of the Eiffel Tower, are to a large extent hollow, yet they are predicted to retain the same mechanical properties of standard materials. The scheme is particularly suited to design large structures with limited load, such as solar sails that propel spacecrafts, whose weight may be reduced by a factor of 100 or more.
Meson Decay Shows the Arrow of Time
Jean-Pierre Lees et al.
Physical Review Letters '/>"/>
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