Lifeboat Foundation

Black holes have two fundamental properties: their mass (how much they weigh) and their spin (how quickly they rotate). Determining either of these two values tells scientists a great deal about any black hole and how it behaves. In the past, astronomers made several other estimates of Sgr A*’s rotation speed using different techniques, with results ranging from Sgr A* not spinning at all to it spinning at almost the maximum rate.

The new study suggests that Sgr A* is, in fact, spinning very rapidly, which causes the spacetime around it to be squashed down. The illustration shows a cross-section of Sgr A* and material swirling around it in a disk. The black sphere in the center represents the so-called event horizon of the black hole, the point of no return from which nothing, not even light, can escape.

Continue reading “Telescopes Reveal Rapid Spin of Milky Way’s Black Hole Warping Spacetime” »

A coating that can hide objects in plain sight, or an implant that behaves exactly like bone tissue—these extraordinary objects are already made from “metamaterials.” Researchers from TU Delft have now developed an AI tool that not only can discover such extraordinary materials but also makes them fabrication-ready and durable. This makes it possible to create devices with unprecedented functionalities. They have published their findings in Advanced Materials.

The properties of normal materials, such as stiffness and flexibility, are determined by the molecular composition of the material, but the properties of metamaterials are determined by the geometry of the structure from which they are built. Researchers design these structures digitally and then have it 3D-printed. The resulting metamaterials can exhibit unnatural and extreme properties. Researchers have, for instance, designed metamaterials that, despite being solid, behave like a fluid.

Continue reading “New AI tool discovers realistic ‘metamaterials’ with unusual properties” »

A coating that can hide objects in plain sight, or an implant that behaves exactly like bone tissue. These extraordinary objects are already made from metamaterials. Researchers from TU Delft have now developed an AI tool that not only can discover such extraordinary materials but also makes them fabrication-ready and durable. This makes it possible to create devices with unprecedented functionalities.

They published their findings in Advanced Materials (“Deep Learning for Size-Agnostic Inverse Design of Random-Network 3D Printed Mechanical Metamaterials”).

Continue reading “New AI tool discovers realistic metamaterials with unusual properties (w/video)” »

Researchers achieve EV battery breakthrough with silicon-based materials and gel electrolytes, moving closer to a 1,000-kilometer range on a single charge.

A LK99 researcher from Hubei, China, said that his paper might not be released before the Lunar New Year because of patent issues, announced the main findings of the paper, which detected three specific magnetic pointing superconductivity in the samples. He also described improved synthesis methods.

The LK99 researcher from Hubei, China, who said that the paper might not be released before the Lunar New Year because of patent issues, announced the main findings of the paper, which detected three specific magnetic pointing superconductivity in the samples. pic.twitter.com/7ytSWO0zN2

— peoplewar2 (@REDLFLAG) February 1, 2024

Cooper-Pair Splitting on Demand.

A proposed device can repeatedly grab pairs of electrons from a superconductor and separate them while preserving their entangled state.

By adiabatically changing the energy levels of two quantum dots, theoreticians predict that it should be possible to control the splitting of Cooper pairs from a superconductor. Such an adiabatic Cooper pair splitter could serve as an on-demand source of entangled electrons in future solid-state quantum technologies.

Scientists have yet to obtain a complete microscopic understanding of how a supercooled liquid behaves as it turns into a glass. Different theories can capture different aspects of the spatial and temporal dynamics of this process, but the assumptions behind these theories are, in some cases, mutually exclusive. Now Yoshihiko Nishikawa at Tohoku University, Japan, and Ludovic Berthier at the University of Montpellier, France, reconcile two competing descriptions of this glass-transition behavior using a recently developed lattice model [1].

A prominent glass-transition theory known as random first-order transition theory holds that a cooling glass-forming liquid adopts a mosaic-like static structure with finite-range order. In this framework, so-called dynamic fluctuations—reorganizations of a material’s particles—occur when boundaries between mosaic “tiles” collectively rearrange. These fluctuations are fundamentally tied to static, region-to-region variations in a material’s structure. A competing theory known as dynamic-facilitation theory contains no assumptions about the system’s static structure or region-to-region variations. This theory postulates that dynamic fluctuations occur via local, small-scale particle rearrangements that trigger a reorganizational chain reaction that then propagates through the material.

For their study, Nishikawa and Berthier used a different theory to probe the glass transition of a supercooled liquid. Their three-dimensional lattice theory exhibits mosaic-like structural variations that are consistent with those from random first-order transition theory. However, the researchers found that the model’s predictions for the dynamic fluctuations more closely resemble those of the dynamic-facilitation framework. Nishikawa says that no current experiments can directly confirm the occurrence of these behaviors in real glass-forming materials. But he hopes to use the three-dimensional lattice model to reproduce some recently observed indirect experimental data.

A theoretical study finds that the most energy-efficient way to control an active-matter system is to drive it at finite speed—unlike passive-matter systems.

The control of active matter, a class of systems in which each constituent constantly converts energy into directed motion, holds great potential for applications ranging from the targeted delivery of drugs to the creation of smart materials. Using an active-matter system to achieve a particular goal requires that one can efficiently drive it from one state to another. However, active matter’s intrinsic nonequilibrium condition presents a major challenge for theoretical treatments, meaning the most efficient way of driving a system is often difficult to predict. Now Luke Davis at the University of Luxembourg and colleagues have introduced a general framework to determine thermodynamically optimal protocols to drive active systems between different states in a way that minimizes the associated heat dissipation [1].

A proposed device can repeatedly grab pairs of electrons from a superconductor and separate them while preserving their entangled state.