Next Big Future April 6, 2019 By 2030, the countries with top defense spending are expected to be: USA with over 1 trillion (had $611 billion in 2016), China with $736 billion (had 215 billion in 2016), and India with $213 billion (had 56 billion in 2016). China, with $228 billion military expenditure in 2017 is the world’s second largest spender, with its share representing 13% of world’s total, compared to 5.8% a decade ago. By 2020, Asia-Pacific military spending will be about the same as North America. North America will be 33% of global defense spending down from about […]
Researchers develop way to control speed of light, send it backward
Phys.org April 4, 2019 Controlling the group velocity of an optical pulse typically requires traversing a material or structure whose dispersion is judiciously crafted. Alternatively, the group velocity can be modified in free space by spatially structuring the beam profile. A team of researchers in the US (University of Central Florida, Purdue University) has demonstrated precise and versatile control over the group velocity of a propagation-invariant optical wave packet in free space through sculpting its spatio-temporal spectrum. By jointly modulating the spatial and temporal degrees of freedom, arbitrary group velocities are unambiguously observed in free space above or below the […]
A new type of airplane wing that adapts midflight could change air travel
MIT Technology Review April 1, 2019 A team of researchers in the US (NASA, MIT) has designed wing that is made from an open, lightweight lattice framework that is covered with a thin layer of polymer material. It looks like thousands of matchstick-type struts welded together in small triangle shapes. This design lets it adapt and deform in many ways so that it is the optimal shape for the different stages of flight—takeoff, landing, cruising, and so on. It is also far lighter than conventional wings and would therefore use much less energy. The manufacturing process incorporates 3D printing and […]
Mystery of negative capacitance in perovskite solar cells solved
Eurekalert April 5, 2019 An international team of researchers (Switzerland, Iran) found that the large perovskite capacitances are not classical capacitances in the sense of charge storage, but just appear as capacitances because of the cells’ slow response time. They found that the origin of the apparent capacitance is a slow modification of the current passing the contact of the solar cells, which is regulated by a slow accumulation of mobile ionic charge. A slowly increasing current appears like a negative capacitance in the impedance spectra. The work sheds light on the interaction between the photovoltaic effect in these devices […]
Low-bandwidth radar technology provides improved detection of objects
Phys.org April 2, 2019 Researchers in Israel have demonstrated a ranging system which possesses superior range resolution that is almost completely free of bandwidth limitations. By sweeping over the coherence length of the transmitted signal, the partially coherent radar experimentally demonstrates an improvement of over an order of magnitude in resolving targets, compared to standard coherent radars with the same bandwidth. They developed a theoretical framework to show that the resolution could be further improved without a bound, revealing a tradeoff between bandwidth and sweep time. This concept offers solutions to problems which require high range resolution and accuracy, but […]
Liquid crystals could help deflect laser pointer attacks on aircraft
Optics.org April 2, 2019 Researchers at Lewis University, Illinois, focused on the polarization and absorbance properties of liquid crystal materials to block incoming laser light. To decrease the intensity of incoming laser light, the liquid crystal N-(4-Methoxybenzylidene)-4-butylaniline was deposited between two pieces of conductive indium tin oxide-coated glass. The test cell can decrease up to 80 percent of incoming laser light by transitioning from its transparent, liquid phase to its opaque, pseudo-crystalline phase, with the cell being able to return to its transparent phase in less than three seconds. The phase change is controlled by an electric current applied to […]
Intel buys into an AI chip that can transfer data 1,000 times faster
MIT Technology Review April 2, 2019 Untether, based in Toronto, Canada, has developed a prototype inference chip which is akin to a chip that runs on a device like a smartphone or a camera. It can transfer data between different parts of the chip 1,000 times more quickly than a conventional AI chip. It uses “near-memory computing” to reduce the physical distance between memory and the processing tasks, which speeds up data transfer and lowers power consumption…read more.
High-capacity transmission over multi-core fiber link with 19-core optical amplifier
Eurekalert April 8, 2019 The successful development of Space-Division-Multiplexing (SDM) amplifiers is crucial for commercial realization of SDM technologies. Researchers in Japan developed a 19-core Erbium-doped-fiber amplifier utilizing cladding-pumping technology in order to share electrical power between the large number of spatial channels. The amplifier was integrated into a transmission test bed of for a record transmission demonstration. Fully decoded optical data transmission of 715 Tb/s was achieved over 2,009 km using coded polarization division multiplexed (PDM) -16 quadrature-amplitude modulation (QAM) of 345 carriers over the C and L band in a re-circulating transmission loop. The research enables development of […]
Engineers develop novel techniques to trick object detection systems
Science Daily April 4, 2019 To understand and document vulnerabilities in deep and machine-learning algorithms, researchers at the Southwestern Research Institute have developed patterns when worn or mounted on a vehicle, cause the algorithms in the camera to either misclassify or mislocate objects, creating a vulnerability. Malicious parties could place these patterns near roadways, potentially creating chaos for vehicles equipped with object detectors. The researchers call these patterns ‘perception invariant’ adversarial examples because they don’t need to cover the entire object or be parallel to the camera to trick the algorithm. The algorithms can misclassify the object as long as […]
Copper-based alternative for next-generation electronics
Science Daily April 1, 2019 In the existing techniques for the preparation of copper nanoparticles, impurities can be removed via extremely high temperatures hence those prepared at room temperature could not solidify into usable parts. Researchers in Japan have synthesised copper nanoparticles with the ability to solidify at much lower temperatures, remain pure; they altered the structure of the copper nanoparticles and rendered them more stable so that they do not degrade at low temperatures. With the new technique copper nanoparticle-based materials can be utilized in various types of on-demand flexible and wearable devices which can be fabricated easily via […]