Category Physics

Charging ahead to Higher Energy Batteries

Image (a) is a cross-sectional SEM image of the Li5La3Nb2O12 crystal layer and image (b) shows computationally simulated trajectories of the Li, La, Nb, and O framework atoms obtained for ?3 (2-1-1) = (1-21) at a temperature of 1300 K. Credit: Nobuyuki Zettsu Ph.D., the Center for Energy and Environmental Science, the Department of Materials Chemistry, Shinshu University

Image (a) is a cross-sectional SEM image of the Li5La3Nb2O12 crystal layer and image (b) shows computationally simulated trajectories of the Li, La, Nb, and O framework atoms obtained for ?3 (2-1-1) = (1-21) at a temperature of 1300 K. Credit: Nobuyuki Zettsu Ph.D., the Center for Energy and Environmental Science, the Department of Materials Chemistry, Shinshu University

Researchers have developed a new way to improve lithium ion battery efficiency. Through the growth of a cubic crystal layer, the scientists have created a thin and dense connecting layer between the electrodes of the battery...

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Using a Laser to Wirelessly Charge a Smartphone Safely across a Room

The wireless charging system created by University of Washington engineers. The charging laser and guard lasers are normally invisible to the human eye, but red beams have been inserted in place of the guard beams for demonstration purposes.

The wireless charging system created by University of Washington engineers. The charging laser and guard lasers are normally invisible to the human eye, but red beams have been inserted in place of the guard beams for demonstration purposes.Mark Stone/University of Washington

Although mobile devices such as tablets and smartphones let us communicate, work and access information wirelessly, their batteries must still be charged by plugging them in to an outlet. But engineers at the University of Washington have for the first time developed a method to safely charge a smartphone wirelessly using a laser. A narrow, invisible beam from a laser emitter can deliver charge to a smartphone sitting across a room – and can potentially charge a smartphone as quickly as a standard USB cable...

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Hidden talents: Converting Heat into Electricity with Pencil and Paper

This is a sketch of the experiment. Credit: HZB

This is a sketch of the experiment. Credit: HZB

Thermoelectric materials can use thermal differences to generate electricity. Now there is an inexpensive and environmentally friendly way of producing them with the simplest of components: a normal pencil, photocopy paper, and conductive paint are sufficient to convert a temperature difference into electricity via the thermoelectric effect. Thermoelectric materials need to have low thermal conductivity despite their high electrical conductivity. Thermoelectric devices made of inorganic semiconductor materials such as bismuth telluride are already being used today in certain technological applications. However, such material systems are expensive and their use only pays off in certain situations...

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Some Black Holes Erase your Past

A spacetime diagram of the gravitational collapse of a charged spherical star to form a charged black hole. An observer traveling across the event horizon will eventually encounter the Cauchy horizon, the boundary of the region of spacetime that can be predicted from the initial data. UC Berkeley's Peter Hintz and his colleagues found that a region of spacetime, denoted by a question mark, cannot be predicted from the initial data in a universe with accelerating expansion, like our own. This violates the principle of strong cosmic censorship. Credit: APS/Alan Stonebraker

A spacetime diagram of the gravitational collapse of a charged spherical star to form a charged black hole. An observer traveling across the event horizon will eventually encounter the Cauchy horizon, the boundary of the region of spacetime that can be predicted from the initial data. UC Berkeley’s Peter Hintz and his colleagues found that a region of spacetime, denoted by a question mark, cannot be predicted from the initial data in a universe with accelerating expansion, like our own. This violates the principle of strong cosmic censorship. Credit: APS/Alan Stonebraker

Einstein’s equations allow a non-determinist future inside some black holes. Physicists insist on determinism: your past and present determine your future uniquely, per Einstein’s equations of general relativity...

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