Phys.org August 30, 2024 Thermochemical inhomogeneities in the Earth’s outer core that enhance our understanding of the geodynamo have been elusive. Seismic constraints on such inhomogeneities would provide clues on the amount and distribution of light elements in the core apart from iron and nickel. Researchers in Australia found evidence for a low-velocity volume within the outer core via the global coda correlation wavefield. Several key correlogram features with a unique sensitivity to the liquid core showed variations with wave paths remarkably slower in the equatorial than polar planes constrained a torus structure at low latitudes with lower velocity than […]
Electricity generated by earthquakes might be the secret behind giant gold nuggets
Phys.org September 2, 2024 Gold nuggets occur predominantly in quartz veins, and the current paradigm posits that gold precipitates from dilute (<1 mg kg−1 gold), hot, water ± carbon dioxide-rich fluids owing to changes in temperature, pressure and/or fluid chemistry. However, the widespread occurrence of large gold nuggets is at odds with the dilute nature of these fluids and the chemical inertness of quartz. Using quartz deformation experiments and piezoelectric modelling researchers in Australia investigated if piezoelectric discharge from quartz could explain the ubiquitous gold–quartz association and the formation of gold nuggets. They found that stress on quartz crystals could generate enough voltage to […]
Enhancing microbe memory to better upcycle excess COâ‚‚
Phys.org August 30, 2024 Microbial cells often lose the multicopy expression plasmids during long-term cultivations. Because of the advantages related to titers, yields, and productivities plasmid stability is essential for industrially relevant biobased processes. Researchers in the UK designed and tested plasmid addiction systems based on the complementation of essential genes. They stabilized a multicopy plasmid by implementing a plasmid addiction tool based on the complementation of mutants lacking RubisCO, which is essential for CO2 fixation. Expressing the mevalonate pathway operon (MvaES) using this addiction system resulted in the production of carbon yields of ∼25%. According to the researchers the […]
Entangled photon pairs enable hidden image encoding
Phys.org September 4, 2024 Photon-pair correlations in spontaneous parametric down-conversion are ubiquitous in quantum photonics. The ability to engineer their properties for optimizing a specific task is essential, but often challenging in practice. Researchers in France demonstrated the shaping of spatial correlations between entangled photons in the form of arbitrary amplitude and phase objects. By doing this, they encoded image information within the pair correlations, making it undetectable by conventional intensity measurements. It enabled the transmission of complex, high-dimensional information using quantum correlations of photons, which could be useful for developing quantum communication and imaging protocols… read more. TECHNICAL ARTICLE
Geophysicist’s method could give months’ warning of major earthquakes
Phys.org August 30, 2024 Earthquake precursors are ambiguous, but recent experimental studies suggest that robust warning signs may precede large seismic events in the short (day-to-months) term. An international team of researchers (USA – University of Alaska Fairbanks, Germany) showed that Ridgecrest sequence (California) and Anchorage earthquake (Alaska) were preceded by up to ~3 months of tectonic unrest on regional scales, as evidenced by abnormal low-magnitude seismicity spreading over the ~15-25% of Southern California and Southcentral Alaska. This precursory unrest had been discovered with an algorithm that integrates an innovative random forest machine learning approach and statistical features built from […]
Higher-order topological simulation unlocks new potential in quantum computers
Phys. org August 30, 2024 At present the range of viable applications with noisy intermediate-scale quantum (NISQ) devices remains limited by gate errors and the number of high-quality qubits. An international team of researchers (USA – Caltech, MIT, Singapore) developed an approach that places digital NISQ hardware as a versatile platform for simulating multi-dimensional condensed matter systems. Their method encoded a high-dimensional lattice in terms of many-body interactions on a reduced-dimension model, thereby taking full advantage of the exponentially large Hilbert space of the host quantum system. With circuit optimization and error mitigation techniques, they measured the topological state dynamics […]
Hypersonic drones by 2026-2027
Next Big Future August 30, 2024 A startup company is developing hypersonic propulsion system for their Quarterhorse and Darkhorse vehicles. This could achieve Mach 5 speeds in 2026 to 2027. Mk 2: Scheduled for 2025, Mk 2 will be powered by a Pratt and Whitney F100 engine, enabling supersonic flight. Mk 3: Expected to be developed by 2026, Mk 3 will incorporate the Chimera II propulsion system. This version aims to achieve speeds faster than Mach 3.3, supporting Defense Department testing. This created their own precooler that helps bridge the gap between turbojet and ramjet modes, increasing the performance of […]
On the way to optical logic gates: Study demonstrates the basics for purely optical processing of information
Phys.org September 2, 2024 An international team of researchers (Germany, Australia) created arrays of polymer beads (photonic units) incorporating photo-switchable DAE molecules using surface-templated electrophoretic deposition. They could be reversibly and individually switched between high and low emission states by direct photoexcitation, without any energy or electron transfer processes within the molecular system. The micropatterned array of these photonic units was spectroscopically characterized in detail and optimized with respect to both signal contrast and crosstalk. The optimum optical parameters were determined. 500 cycles were demonstrated with no obvious on/off contrast attenuation. They demonstrated the possibility of continuous recording. According to […]
Predicting avalanches: Fracture characteristics of anticracks in highly porous materials
Phys.org September 2, 2024 When porous materials are subjected to compressive loads, localized failure chains or anticracks, can occur and cause large-scale structural failure. The resistance to anticrack growth is governed by fracture toughness. To understand more about the mixed-mode fracture toughness for highly porous materials subjected to shear and compression, an international team of researchers (Germany, Switzerland) designed fracture mechanical field experiments tailored for weak layers in a natural snowpack. Using a mechanical model for interpretation, they calculated the fracture toughness for anticrack growth for the full range of mode interactions, from pure shear to pure collapse. The measurements […]
Researchers create entangled quantum magnets with protected quantum excitations
Phys.org August 29, 2024 Artificial quantum systems have emerged as platforms to realize topological matter in a well-controlled manner. However, the realization of many-body topological phases in solid-state platforms with atomic resolution has remained challenging. An international team of researchers (USA – Stevens Institute of Technology, China, Finland) engineered both topological and trivial phases of the quantum spin model and realized first- and second-order topological quantum magnets. They probed the many-body excitations of the quantum magnets by single-atom electron spin resonance with an energy resolution better than 100 neV. Using the atomically localized magnetic field of the scanning tunnelling microscope tip, […]