Category Physics

A new pencil-like wireless spectrometer can be used with a smartphone to collect 3-D spectral images of the body and other objects. This design could make the device useful for point-of-care diagnostics. Credit: Dan Wang, Beijing University of Chemical Technology

Easy-to-use spectrometer less than $300, holds promise for remote medical diagnostics. A new smartphone-compatible device that is held like a pencil could make it practical to acquire spectral images of everyday objects and may eventually be used for point-of-care medical diagnosis in remote locations. Spectral images, which contain more color information than is obtainable with a typical camera, reveal characteristics of tissue and other biological samples that can’t be seen by the naked eye...

The Burton lab studies tiny, plastic particles as a model for more complex systems. The particles are suspended in a vacuum chamber filled with a plasma — ionized argon gas. Credit: Justin Burton, Emory University

Complex behavior emerges from a simple system in a fixed environment. Physicists at Emory University have shown how a system of lifeless particles can become “life-like” by collectively switching back and forth between crystalline and fluid states – even when the environment remains stable. “We’ve discovered perhaps the simplest physical system that can consistently keep changing behavior over time in a fixed environment,” says Justin Burton, Emory assistant professor of physics. “In fact, the system is so simple we never expected to see such a complex property emerge from it.”

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The first crop of tomatoes and cucumbers grown inside electricity-generating solar greenhouses was as healthy and robust as those raised in conventional greenhouses, signaling that “smart” greenhouses hold great promise for farming and energy conservation.

Magenta panes also help plants save water. The first crops of tomatoes and cucumbers grown inside electricity-generating solar greenhouses were as healthy as those raised in conventional greenhouses, signaling that “smart” greenhouses hold great promise for dual-use farming and renewable electricity production...

Cosimo Rusconi (l.) and Oriol Romero-Isart (r.) play with a levitron to illustrate their work on nano magnets.
Credit: IQOQI Innsbruck/M.R.Knabl

Quantum physicists have now shown that, despite Earnshaw’s theorem, nanomagnets can be stably levitated in an external static magnetic field owing to quantum mechanical principles. The quantum angular momentum of electrons, which also causes magnetism, is accountable for this mechanism.

Already in 1842, British mathematician Samuel Earnshaw proved that there is no stable configuration of levitating permanent magnets. If one magnet is levitated above another, the smallest disturbance will cause the system to crash...