Category Physics

This image shows trajectory of (a) position and (b) orientation of pliers under repetitive laser irradiation without tracking. Grey lines indicate the projections of the trajectory in the respective coordinate planes. Credit: © the authors doi: 10.1117/1.OE.56.1.011007

Space debris from completed missions – inactive satellites, lens covers, fragments from spaceship disengagements – pose a serious and ongoing threat to active communication and navigation satellites used by billions of people on Earth. An article published by SPIE, the international society for optics and photonics, in Optical Engineering describes a new approach whereby debris orbiting in space could be pushed into Earth’s atmosphere by laser impulses, causing it to burn up.

High definition model of a set of pliers taken...

Some measurements of entanglement violate monogamy, yet are geometrically faithful; others are monogamous but not faithful. Credit: Lancien et al. ©2016 American Physical Society

As expected, “monogamous” and “faithful” mean something a little different in the quantum world than they do in everyday language. When quantified by standard means, entanglement cannot be both monogamous and faithful at the same time. The results may be relevant when assessing the security of quantum cryptographic schemes, which rely on the monogamy of entanglement, and may also help to better understand the long-standing “firewall debate” related to the behavior of black holes.

Monogamy is considered to be a defining property of entanglement. Eg...

A plasmonic detector that is directly coupled to a silicon optical waveguide and smaller than one micrometer was developed by KIT. Credit: Graphics: KIT

Data traffic is growing worldwide. Glass-fiber cables transmit information over long distances at the speed of light. These optical signals have to be converted into electrical signals for processing in the computer. KIT researchers have now developed a novel type of photodetector that needs far less space than conventional ones. The component has a base area of <1 millionth sq mm without data transmission rate being affected adversely.

The newly developed photodetectors, the smallest photodetectors worldwide for optical data transmission, can be used for integrated optical circuits that significantly enhance the performance of optical com...

An example of 3D printed food, created by one of Professor Hod Lipson’s students. Credit: Timothy Lee Photographers/Columbia Engineering

Prof. Lipson and his students have been developing a 3D food printer that can fabricate edible items through computer-guided software and the actual cooking of edible pastes, gels, powders, and liquid ingredients – all in a prototype that looks like an elegant coffee machine.”Food printers are not meant to replace conventional cooking – they won’t solve all of our nutritional needs, nor cook everything we should eat,” says Lipson, a pioneering roboticist who works in the areas of artificial intelligence and digital manufacturing at Columbia Engineering ...