Dense ensembles of laser-cooled molecules allow the observation of molecular collisions—a result that could lead to applications of cold molecular gases in quantum simulation and fundamental physics tests.
More than 97% of the stars in our Galaxy will end their lives with a whimper—slowly cooling as stellar remnants known as white dwarfs. The cooling of white dwarfs follows a pattern that was thought to be so predictable that the temperatures of white dwarfs are used to determine the age of surrounding stars. New findings, however, indicate this pattern may need revision [1]. Predictions made by Antoine Bédard of the University of Warwick, UK, and his colleagues now indicate that some white dwarfs may undergo a process that “reinvigorates” the stars, significantly slowing down the cooling process. That change could alter the calculated ages of white dwarfs by billions of years.
When a small star (one with a mass 8 times or less that of the Sun) runs out of nuclear fuel, it sheds its outer layers to form a planetary nebula. The core of the star then collapses into a white dwarf. Producing no heat, white dwarfs spend their existences radiating their remaining energy into space, cooling and solidifying from the inside out. Or so astrophysicists thought.
In 2019, this model was disrupted by astronomers analyzing data from the European Space Agency’s Gaia mission. The researchers identified a previously unknown population of white dwarfs within the Milky Way with anomalous properties [2]. As stars age, their velocities increase with respect to nearby stars because of repeated gravitational interactions with those stars. The newly identified white dwarfs, dubbed the Q branch, have much higher average velocities than models indicate they should have based on their temperatures, a finding that suggests that the Q-branch white dwarfs are older than previously thought. Some process is slowing down the cooling.
From tsinghua university, SIGS, & meta reality labs.
MultiBooth.
Towards Generating All Your Concepts in an Image from Text https://huggingface.co/papers/2404.
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New paper from OpenAI on prompt injection.
Open AI presents The Instruction Hierarchy.
Training llms to prioritize privileged instructions.
The International Space Station has long been known as a unique — and uniquely gross — environment. But according to a new NASA study, it has stuff growing on it that is straight-up alien, too.
In a press release, NASA said that when scientists from the Jet Propulsion Lab looked at samples of the drug-resistant Enterobacter bugandensis bacteria found on the orbital outpost, they found that the strains had mutated into something that literally doesn’t exist on Earth.
“Study findings indicate that under stress, the ISS isolated strains were mutated and became genetically and functionally distinct compared to their Earth counterparts,” the press release reads. “The strains were able to viably persist in the ISS over time in significant abundances.”
The process, called primary endosymbiosis, has only happened twice in the history of the Earth, with the first time giving rise to all complex life as we know it through mitochondria. The second time that it happened saw the emergence of plants.
Now, an international team of scientists have observed the evolutionary event happening between a species of algae commonly found in the ocean and a bacterium.
“The first time we think it happened, it gave rise to all complex life,” said Tyler Coale, a postdoctoral researcher at University of California, Santa Cruz, who led the research on one of two recent studies that uncovered the phenomenon.
Early tests suggest that a new tool that requires only a single drop of blood could detect three of the deadliest forms of cancer.
A memristor that uses changes in ion concentrations and mechanical deformations to store information has been developed by researchers at EPFL in Switzerland.
Research could lead to the development of electrolytic computers.
Quantum physics requires high-precision sensing techniques to delve deeper into the microscopic properties of materials. From the analog quantum processors that have emerged recently, quantum-gas microscopes have proven to be powerful tools for understanding quantum systems at the atomic level. These devices produce images of quantum gases with very high resolution: They allow individual atoms to be detected.
In China, scientists say they’re developing technology that uses lasers to propel submarines nearly as fast as a jet engine.
As the South China Morning Post reports, engineers at the Harbin Engineering University in Heilongjiang province — where, notably, China’s first experimental submarine was developed — claim that the country’s military is close to achieving this colossal feat.
The idea behind the burgeoning technology is ingenious: lasers generate plasma underwater, which then creates a so-called “detonation wave” to propel a submarine vessel forward. As the SCMP notes, Japanese researchers first proposed this sort of laser propulsion methodology 20 years ago, and in China, scientists have been trying to figure out how to hack it for at least a decade.
