Science Daily May 5, 2020 Researchers in China propose a prototype design of a propulsion thruster that utilizes air plasma induced by microwave ionization. They used a microwave air plasma jet thruster using high-temperature and high-pressure plasma generated by a 2.45 GHz microwave ionization chamber for injected pressurized air. They measured the lifting force and jet pressure at various settings of microwave power and the air flow rate and demonstrated that, given the same power consumption, its propulsion pressure is comparable to that of conventional airplane jet engines using fossil fuels. A carbon-emission free thruster could potentially be used as […]
How many jobs do robots really replace?
MIT News May 4, 2020 In this three part series, a team of researchers in the US (MIT, Boston University) shows theoretically that robots may reduce employment and wages and that their local impacts can be estimated using variation in exposure to robots—defined from industry-level advances in robotics and local industry employment. They estimate robust negative effects of robots on employment and wages across commuting zones. According to the researchers the areas most exposed to robots after 1990 do not exhibit any differential trends before then, and robots’ impact is distinct from other capital and technologies. One more robot per […]
How growth of the scientific enterprise influenced a century of quantum physics
MIT News April 29, 2020 In a new book, “Quantum Legacies: Dispatches from an Uncertain World,” Professor David Kaiser of MIT describes dramatic shifts in the history of an evolving discipline. Moving between vignettes of key physicists, original research about the growth of the field, and accounts of his own work in cosmology, the author emphasizes the vast changes in the field over time…read more. Book: “Quantum Legacies: Dispatches from an Uncertain World”
In pursuit of open science, open access is not enough
Science Magazine May 7, 2020 Despite uncertainty about the long-term sustainability of OA models, many publishers who had been reluctant to abandon the subscription business model are showing openness to OA The healthy functioning of the academic community, including fair terms and conditions from commercial partners, requires that the global marketplace for data analytics and knowledge infrastructure be kept open to real competition. The dominance of a limited number of social networks, shopping services, and search engines shows us how internet platforms based on data and analytics can tend toward monopoly. In the research information space, contracts are being negotiated, […]
Laser loop couples quantum systems over a distance
Science Daily May 7, 2020 An international team of researchers (Switzerland, Germany) used laser light to couple the vibrations of a 100 nanometer thin membrane to the motion of the spin of atoms over a distance of one meter. As a result, each vibration of the membrane sets the spin of the atoms in motion and vice versa. In this laser loop, the properties of the light can be controlled such that no information about the motion of the two systems is lost to the environment, thus ensuring that the quantum mechanical interaction is not disturbed. It is possible to […]
Light, sound, action: Extending the life of acoustic waves on microchips
EurekAlert May 6, 2020 An international team of researchers (Australia, Germany, Denmark) propose to use phonons to store and transfer information that chips receive from fibre-optic cables. They show a way to counteract the intrinsic acoustic decay of the phonons in a waveguide by resonantly reinforcing the acoustic wave via synchronized optical pulses. They experimentally demonstrated coherent on-chip storage in amplitude and phase up to 40 ns, 4 times the intrinsic acoustic lifetime in the waveguide. Through theoretical considerations, they anticipate that this concept allows for storage times up to microseconds within realistic experimental limitations while maintaining a GHz bandwidth […]
Making Materials Mimic Each Other
American Physical Society May 6, 2020 Based on the 2017 research confirming that spectral mimicry is theoretically possible, an international team of researchers (USA – Tulane University, US Army Research Laboratory, UMass Boston, Louisiana State University, UK) proposed a new way to make one material behave like another by applying specially designed time-dependent fields such as laser pulse. They derived a field-free, nonlinear equation of motion for controlling the expectation value of an essentially arbitrary observable together with rigorous constraints that determine the limits of controllability. They discuss the experimental feasibility of implementing the control fields generated by this model…read […]
New findings suggest laws of nature ‘downright weird,’ not as constant as previously thought
Phys.org April 27, 2020 An international team of researchers (Australia, UK, Poland, USA – Lawrence Berkeley National Laboratory, Harvard University, Portugal, Germany, Italy) reported that four new measurements of light emitted from a quasar 13 billion light years away reaffirm past studies that found tiny variations in the fine structure constant which is used as a measure of the strength of the electromagnetic force. They made four measurements of the fine constant along the one line of sight to this quasar. Individual measurements did not provide any conclusive answer as to whether there were perceptible changes in the electromagnetic force. […]
Researchers pave the way to designing omnidirectional invisible materials
EurekAlert May 7, 2020 Researchers in Spain have demonstrated that Maxwell’s equations, as well as the acoustic and elastic wave equations, also possess an underlying supersymmetry in the time domain. They explored the consequences of this property in the field of optics, obtaining a simple analytic relation between the scattering coefficients of numerous time-varying systems, and uncovering a wide class of reflectionless, three dimensional, all-dielectric, isotropic, omnidirectional, polarisation-independent, non-complex media. These unprecedented features may enable the creation of novel reconfigurable devices, including invisible materials, frequency shifters, isolators, and pulse-shape transformers…read more. Open Access TECHNICAL ARTICLE
Russia Conducts Direct-Ascent Anti Satellite Weapon from Plesetsk
Defense Update April 22, 2020 Russia has been engaged in direct ascent anti-satellite (DA-ASAT) anti-satellite weapon tests in the past months. On April 15, a missile launch from the Plesetsk test site on the arctic circle. Russian media sources reports said the missile tested called ‘Nudol’ has reached over 7,000 m/sec, thus positioned in the ‘hypersonic‘ category. Prior to the test, large airspace along the missile’s flight path was closed, with an area typical for a two-staged missile. Other tests of anti-satellite weapon systems were previously conducted under the “Sistema A-235 / RTTS-181M Nudol” program which has been tested at […]