Lifeboat Foundation: Safeguarding Humanity
Toggle light / dark theme

Blog

Category: physics – Page 141

O.o!!

On Sunday, October 9, Judith Racusin was 35,000 feet in the air, en route to a high-energy astrophysics conference, when the biggest cosmic explosion in history took place. “I landed, looked at my phone, and had dozens of messages,” said Racusin, an astrophysicist at NASA’s Goddard Space Flight Center in Maryland. “It was really exceptional.”

The explosion was a long gamma-ray burst, a cosmic event where a massive dying star unleashes powerful jets of energy as it collapses into a black hole or neutron star. This particular burst was so bright that it oversaturated the Fermi Gamma-ray Space Telescope, an orbiting NASA telescope designed in part to observe such events. “There were so many photons per second that they couldn’t keep up,” said Andrew Levan, an astrophysicist at Radboud University in the Netherlands. The burst even appears to have caused Earth’s ionosphere, the upper layer of Earth’s atmosphere, to swell in size for several hours. “The fact you can change Earth’s ionosphere from an object halfway across the universe is pretty incredible,” said Doug Welch, an astronomer at McMaster University in Canada.

Astronomers cheekily called it the BOAT—“brightest of all time”—and began to squeeze it for information about gamma-ray bursts and the cosmos more generally. “Even 10 years from now there’ll be new understanding from this data set,” said Eric Burns, an astrophysicist at Louisiana State University. “It still hasn’t quite hit me that this really happened.”

Continue reading “Brightest-Ever Space Explosion Reveals Possible Hints of Dark Matter” | >

Prof. Zhang Tao’s group at the Ningbo Institute of Materials Technology and Engineering (NIMTE) of the Chinese Academy of Sciences (CAS), in collaboration with Prof. Hou Yang from Zhejiang University and Prof. Xiao Jianping from the Dalian Institute of Chemical Physics of CAS, proposed a novel two-dimensional (2D) nanoconfinement strategy to strongly enhance the oxygen evolution reaction (OER) activity of low-conductivity metal-organic frameworks (MOFs). Results were published in Nature Communications.

The development of high-efficiency electrocatalysts for the electrochemical conversion of water to generate environmentally friendly and sustainable hydrogen energy has drawn tremendous attention for decades.

Despite the crucial role the OER plays in water splitting, OER at the anode requires a relatively high thermodynamic potential to accelerate water splitting kinetics. Thanks to the large surface area, tunable porosity, diverse compositions and metal centers, MOFs have emerged as promising candidates for efficient OER electrocatalysts. However, the intrinsically poor conductivity of the most MOFs seriously impede their .

Read more | >

Over the last three decades, the digital world that we access through smartphones and computers has grown so rich and detailed that much of our physical world has a corresponding life in this digital reality. Today, the physical and digital realities are on a steady course to merging, as robots, Augmented Reality (AR) and wearable digital devices enter our physical world, and physical items get their digital twin computer representations in the digital world.

These digital twins can be uniquely identified and protected from manipulation thanks to crypto technologies like blockchains. The trust that these technologies provide is extremely powerful, helping to fight counterfeiting, increase supply chain transparency, and enable the circular economy. However, a weak point is that there is no versatile and generally applicable identifier of physical items that is as trustworthy as a blockchain. This breaks the connection between the physical and digital twins and therefore limits the potential of technical solutions.

In a new paper published in Light: Science & Applications, an interdisciplinary team of scientists led by Professors Jan Lagerwall (physics) and Holger Voos (robotics) from the University of Luxembourg, Luxembourg, and Prof. Mathew Schwartz (architecture, construction of the built environment) from the New Jersey Institute of Technology, U.S., propose an innovative solution to this problem where physical items are given unique and unclonable fingerprints realized using cholesteric spherical reflectors, or CSRs for short.

Read more | >

When a volcanic eruption occurs in an inhabited area, rapid and accurate lava flow forecasts can save lives and reduce infrastructure and property losses. To ensure that current lava forecasting models can provide outputs fast enough to be useful in practice, they unfortunately must incorporate physical simplifications that limit their accuracy.

To aid evacuation plans, forecast models must predict a ’s speed, direction, and extent. These attributes are intimately connected to how the lava solidifies as it cools. Yet to achieve real-time speed, most assume that a flow has a uniform temperature. This is a major simplification that directly influences modeled rates of cooling; generally, are much cooler at their boundaries, where they are in contact with air or the ground, than they are internally.

Aiming to strike a better compromise between speed and realism, David Hyman and a team developed a 2D, physics-based lava flow model called Lava2d. They extended the traditional, vertically averaged treatment of a lava packet by considering it as three distinct regions: the portion near the lava-air boundary, the portion near the lava-ground boundary, and the fluidlike central core. The top and bottom regions of a modeled flow cool based on the physics of heat transfer to the air and ground, while the temperature in the center remains uniform, as in prior approaches. This setup enables the model to account for a without requiring a computationally expensive 3D approach.

Read more | >

The findings could help pave the way for greater use of machine learning in materials science, a field that still relies heavily on laboratory experimentation. Also, the technique of using machine learning to make predictions that are then checked in the lab could be adapted for discovery in other fields, such as chemistry and physics, say experts in materials science.

To understand why it’s a significant development, it’s worth looking at the traditional way new compounds are usually created, says Michael Titus, an assistant professor of materials engineering at Purdue University, who was not involved in the research. The process of tinkering in the lab is painstaking and inefficient.

Read more | >

Until recently, it was widely believed among physicists that it was impossible to compress light below the so-called diffraction limit (see below), except when using metal nanoparticles, which unfortunately also absorb light. It therefore seemed impossible to compress light strongly in dielectric materials such as silicon, which are key materials in information technologies and come with the important advantage that they do not absorb light.

Interestingly, it was shown theoretically in 2006 that the diffraction limit also does not apply to dielectrics. Still, no one has succeeded in showing this in the , simply because no one has been able to build the necessary nanostructures until now.

A research team from DTU has successfully designed and built a structure, a so-called dielectric nanocavity, which concentrates light in a volume 12 times below the diffraction limit. The result is groundbreaking in optical research and has just been published in Nature Communications.

Read more | >

On October 17th, a NASA official speaking at an Astrophysics Advisory Committee meeting revealed that the European Space Agency (ESA) had begun “exploring options” and studying the feasibility of launching the Euclid near-infrared space telescope on SpaceX’s Falcon 9 rocket.

In a major upset, director Josef Aschbacher confirmed less than three days later that ESA will contract with SpaceX to launch the Euclid telescope and Hera, a multi-spacecraft mission to a near-Earth asteroid, after all domestic alternatives fell through.

The European Union and, by proxy, ESA, are infamously insular and parochial about rocket launch services. That attitude was largely cultivated by ESA and the French company Arianespace’s success in the international commercial launch market in the 1980s, 1990s, and 2000s – a hard-fought position that all parties eventually seemed to take for granted. When that golden era slammed headfirst into the brick wall erected by SpaceX in the mid-2010s, Arianespace found itself facing a truly threatening competitor for the first time in 15+ years.

Read more | >

It would consist of magnetic ropes.

A Dunlap Institute astronomer is speculating that our solar system may be surrounded by a magnetic tunnel that can be seen in radio waves, according to a press release by the institution published October 14.

Rope-like filaments surrounding our planet

Dr. Jennifer West, Research Associate at the Dunlap Institute for Astronomy and Astrophysics, is claiming that the two bright structures seen on opposite sides of the sky that were previously considered to be separate are actually connected. They are further made of rope-like filaments that form a tunnel around our solar system.

Continue reading “Is our planet surrounded by a giant magnetic tunnel? Let’s find out” | >