Lifeboat Foundation

Sometimes a rotating molecule can transition to a new state only if an electron carries away some of the molecule’s angular momentum.

Breaking the problem into pieces makes it easier to design a fusion reactor’s coils for optimum energy confinement.

In magnetic-confinement fusion, different reactor designs pose different trade-offs. Stellarators use external magnetic fields to confine plasma in the shape of a twisted donut. Such fields are relatively easy to maintain in a steady state, but optimizing their geometry to minimize energy loss is much more difficult. Tokamaks, in contrast, confine plasma in an axisymmetric geometry using magnetic fields partially generated via currents induced in the plasma. This geometry provides near-perfect confinement at the expense of stability and operational simplicity. José Luis Velasco of Spain’s Center for Energy, Environmental and Technological Research (CIEMAT) and his colleagues now present a new family of stellarator magnetic-field configurations that benefit from tokamak-like energy confinement [1].

Magnetic fusion designs achieve confinement using nested magnetic-flux surfaces. Ideally, each charged particle remains tied to a given surface contour and the plasma as a whole exhibits near-zero radial drift. Such a condition results in perfect confinement, aside from losses due to collisions among particles on the same contour. Tokamaks inherently avoid radial drift, but to achieve the same level of confinement in a stellarator means imposing constraints on each magnetic surface’s topology, sometimes requiring infeasible coil designs.

A light beam with orbital angular momentum can produce the rotational analog of the Doppler effect on an ion.

A vortex light beam is one whose wave fronts rotate like a corkscrew, endowing the beam with orbital angular momentum. An atom subjected to this beam experiences the usual kick in the direction of the beam’s propagation but also a weaker, sideways kick from the beam’s orbital angular momentum. The Doppler effect causes a moving atom to absorb light at wavelengths that are shifted with respect to those of a stationary atom. Consequently, the sideways kick from a vortex beam can produce what is called a rotational Doppler effect (RDE) in an atom. Nicolás Nuñez Barreto of the University of Buenos Aires in Argentina and his collaborators have now characterized the RDE produced by infrared (IR) vortex beams on a single trapped calcium ion [1].

The researchers used IR lasers to drive a particular transition between electronic levels of the ion in a magnetic field. Two additional IR lasers created two identical copropagating vortex beams whose wavelengths could be adjusted. Thanks to the copropagation and the nature of the transition, the linear Doppler effects of the two beams canceled out. Only when the ion received different sideways kicks resulting from the beams’ unequal angular momenta did it absorb photons, revealing the presence and strength of the RDE.

Chinese researchers with ties to China’s People’s Liberation Army (PLA) have built an AI model called ChatBIT, designed for military applications using Meta’s open-source Llama model. According to Reuters, some researchers are associated with the Academy of Military Science (AMS), the PLA’s top research group.

Three academic papers and several analysts have confirmed the information, with ChatBIT using Meta’s Llama 13B large language model (LLM). This LLM has been modified for intelligence gathering and processing, allowing military planners to use it for operational decision-making.

The James Webb Space Telescope has just provided astronomers with the data that could change everything that we thought we knew about the cosmos. In a bizarre twist of fate, JWST observations indicate that ten extremely ancient galaxies exist in the universe, far older than the age of the universe itself. This extraordinary finding has excited much of the scientific world and debate, as scientists deal with what this might tell us about time, space, and the foundations of our understanding of cosmology.

Meteorites hold all five DNA and RNA bases, hinting that life’s ingredients may come from space!

Meteorites Contain All DNA and RNA Bases, Hinting at Space Origins for Life

A recent study published in Nature Communications reveals that meteorites contain the five nucleobases essential for life’s genetic code, suggesting a possible extraterrestrial origin for some of life’s building blocks. Scientists, including astrochemist Daniel Glavin from NASA’s Goddard Space Flight Center and geochemist Yasuhiro Oba from Hokkaido University, discovered adenine, guanine, cytosine, thymine, and uracil in meteorites that landed in various locations around the world. These nucleobases combine with sugars and phosphates to create DNA and RNA, the molecules responsible for storing genetic information in all life on Earth.

Cause and effect. We understand this concept from an early age. Tug on a pull toy’s string, and the toy follows. Naturally, things get much more complicated as a system grows, as the number of variables increases, and as noise enters the picture. Eventually, it can become almost impossible to tell whether a variable is causing an effect or is simply correlated or associated with it.

However, Dr. Robin Wordsworth of Harvard University and Dr. Charles S. Cockell of the University of Edinburgh argue that this focus has left unexplored possibilities for life in environments that don’t resemble our own.

In a preprint paper accepted for publication in the journal Astrobiology, researchers challenge conventional assumptions about extraterrestrial life and explore the feasibility of life existing in structures created by living organisms themselves.

As researchers suggest, life-supporting conditions created solely by biological structures could indeed exist, making it entirely possible for some forms of life to thrive in space habitats vastly different from those on Earth.

Changes to actin dynamics during brain aging are not well understood. Here, the authors report that there is an age-related increase in F-actin in Drosophila brain which disables autophagy within the tissue and limits the fly lifespan.