Lifeboat Foundation

Ocean currents spin off huge gyres, whose kinetic energy is transferred to ever-smaller turbulent structures until viscosity has erased velocity gradients and water molecules jiggle with thermal randomness. A similar cascade plays out in space when the solar wind slams into the magnetopause, the outer boundary of Earth’s magnetic field. The encounter launches large-scale magnetic, or Alfvén, waves whose energy ends up heating the plasma inside the magnetosphere. Here, however, the plasma is too thin for viscosity to mediate the cascade. Since 1971 researchers have progressively developed their understanding of how Alfvén waves in space plasmas generate heat. These studies later culminated in a specific hypothesis: Alfvén waves accelerate ion beams, which create small-scale acoustic waves, which generate heat. Now Xin An of UCLA and his collaborators have found direct evidence of that proposed mechanism [1]. What’s more, the mechanism is likely at work in the solar wind and other space plasmas.

Laboratory-scale experiments struggle to capture the dynamics of rotating plasmas, and real-world observations are even more scarce. The observations that An and his collaborators analyzed were made in 2015 by the four-spacecraft Magnetospheric Multiscale (MMS) mission. Launched that year, the MMS was designed to study magnetic reconnection, a process in which the topology of magnetic-field lines is violently transformed. The field rearrangements wrought by reconnection can be large, on the scale of the huge loops that sprout from the Sun’s photosphere. But the events that initiate reconnection take place in a much smaller region where neighboring field lines meet, the X-line. The four spacecraft of MMS can fly in a configuration in which all of them witness the large-scale topological transformation while one of them could happen to fly through the X-line—a place where no spacecraft had deliberately been sent before.

On September 8, 2015, the orbits of the MMS spacecraft took them through the magnetopause on the dusk side of Earth. They were far enough apart that together they could detect the passage of a large-scale Alfvén wave, while each of them could individually detect the motion of ions in the surrounding plasma. An and his collaborators later realized that these observations could be used to test the theory that ion beams and the acoustic waves that they generate mediate the conversion of Alfvén-wave energy to heat.

Scientists have a problem with cosmic rays—they produce too many muons at the Earth’s surface. Cascades of muons are byproducts of high-energy cosmic rays as they collide with nuclei in the upper atmosphere, and scientists see more muons at Earth’s surface than standard physics models predict.

Scientists made a major advancement in X-ray science by creating high-power attosecond hard X-ray pulses with megahertz repetition rates, allowing for ultrafast electron dynamics study and atomic-level non-destructive measurements.

These pulses are significant due to their ability to capture quick electron movements, leading to potential applications in attosecond crystallography and transformative impacts across various scientific disciplines.

Breakthrough in X-Ray Pulse Technology.

https://www.eurekalert.org/news-releases/1065953

Researchers have explored a fascinating cooling phenomenon within halide perovskite-based “dots-in-crystal” materials, uncovering both their promise and challenges.

In a groundbreaking study, scientists from Chiba University investigated the potential of solid-state optical cooling through perovskite quantum dots. Central to their research was anti-Stokes photoluminescence, a rare process where materials emit photons with higher energy than those absorbed. This innovative approach could transform cooling technology, offering a path to more efficient, energy-saving solutions. Their work not only highlights the immense promise of this technique but also reveals key limitations that pave the way for further advancements in the field.

Trials have been completed on a new weapon system that directs a number of high-powered beams onto a single target.

Data is power. According to Dinesh Bharadia, an associate professor at UC San Diego in the Department of Electrical and Computer Engineering with an affiliate appointment in the Department of Computer Science and Engineering and the Qualcomm Institute (QI), “data will be the next decade’s ‘silicon.’”

The rapid growth of the Internet of Things means that data is more readily available and easily accessible than ever. Sensors, “smart” devices and software connect our world to the cloud, gathering information and enabling new types of data sharing and analysis. However, most of these tools are battery-powered and have difficulty sensing changes in real time.

Now, the tide is turning.

Researchers reveal a way to use antiferromagnets to create data-storage devices without moving parts.

Scientists have transformed memory device technology by utilizing antiferromagnetic materials and magnetic octupoles, achieving high speeds and low power consumption, paving the way for smaller, more efficient devices.

Advanced Magnetic Memory

Radiative heat transfer is one of the most critical energy transfer mechanisms in nature. However, traditional blackbody radiation, due to its inherent characteristics, such as its non-directional, incoherent, broad-spectrum, and unpolarized nature, results in energy exchange between the radiating body and all surrounding objects, significantly limiting heat transfer efficiency and thermal flow control. These limitations hinder its practical application.

A recent study published in Science utilized thermal photonics to achieve cross-band synergistic control of thermal radiation in both angle and spectrum. The researchers then designed a directional emitter with cross-scale symmetry-breaking, angularly asymmetric and spectrally selective thermal emission, achieving daytime subambient radiative cooling on vertical surfaces.

The research team was led by Prof. Wei Li from the Changchun Institute of Optics, Fine Mechanics and Physics (CIOMP) of the Chinese Academy of Sciences, in collaboration with Prof. Shanhui Fan’s team from Stanford University and Prof. Andrea Alu’s team from the City University of New York.

The ability of plants to convert sunlight into food is an enviable superpower. Now, researchers have shown they can get animal cells to do the same thing.

Photosynthesis in plants and algae is performed by tiny organelles known as chloroplasts, which convert sunlight into oxygen and chemical energy. While the origins of these structures are hazy, scientists believe they may have been photosynthetic bacteria absorbed by primordial cells.

Our ancestors weren’t so lucky, but now researchers from the University of Tokyo have managed to rewrite evolutionary history. In a recent paper, the team reported they had successfully implanted chloroplasts into hamster cells where they generated energy for at least two days via the photosynthetic electron transport process.