Toggle light / dark theme

Get the latest international news and world events from around the world.

Log in for authorized contributors

Oxygen vacancies unlock fast lithium-ion transport in battery material

Lithium titanate (LTO, Li4Ti5O12) is a well-established battery material that in its pristine state is a poor conductor of lithium ions. It develops high ionic conductivity only during charging, when additional lithium ions and electrons are incorporated into the material.

Bernhard Gadermaier and Martin Wilkening from the Institute of Chemistry and Technology of Materials at TU Graz have taken an entirely different approach: They transformed pure, non-lithiated LTO in its original composition, Li4Ti5O12, into a significantly better ion conductor by deliberately introducing defects into the crystal lattice.

Specifically, they removed individual oxygen atoms, thereby creating oxygen vacancies that activate a previously blocked migration pathway for lithium ions. “This diffusion pathway is already pre-formed in the LTO structure but is only activated by the defect structure,” Wilkening explains.

Copper’s surprising melting behavior provides insights into future fusion design

Future fusion power plants aim to recreate the heart of a star here on Earth to power our future energy needs. While the core fusion plasma will burn at hundreds of millions of degrees, the surrounding structural components must handle sudden, punishing heat loads that rival the extreme temperatures faced by spacecraft upon reentry into Earth’s atmosphere. Copper and its alloys are primary candidates for handling these intense heat fluctuations, making it vital to understand exactly how the metal behaves when pushed to its melting point.

Now, researchers at the Department of Energy’s SLAC National Accelerator Laboratory and collaborators have captured a detailed, step-by-step look at copper atoms as they underwent extreme heating. Published in Nature Communications, the results revealed a key parameter that allowed copper’s crystal lattice to melt steadily rather than collapse instantaneously, as earlier simulations predicted.

“These results greatly improve the simulations we use to predict which materials have the best shot at surviving the extreme conditions of future fusion reaction chambers,” said Mianzhen Mo, a SLAC staff scientist who led the research. “They also demonstrate the incredible, atomic-scale resolution imaging we can achieve at SLAC’s electron camera.”

Melting diamond could unlock triple fusion gain and the secrets of ice giant planets

Diamond is more than a dazzling gem—the extremely hard form of carbon makes up the pellet that encases fuel for inertial confinement fusion, and scientists believe it rains down deep inside ice giant planets like Neptune and Uranus. In both cases, the material experiences enormous pressures. Until now, experiments and simulations have disagreed about how it actually behaves under those conditions.

In a new study, published in Nature Physics, researchers at Lawrence Livermore National Laboratory (LLNL) document how diamond melts under pressures three times greater than conditions at Earth’s core.

“We were able to take tiny diamond samples and shock-compress them to temperatures hotter than the surface of the sun and to pressures higher than the centers of Neptune and Uranus—and still measure atomic structure, temperature, density and optical reflectivity,” said author and LLNL scientist Marius Millot.

Microbes turn CO₂ into protein and vitamin B9 at commercially viable prices

Researchers are developing biotechnological processes that enable microbes to produce proteins and vitamins for human consumption using basic chemical ingredients, such as carbon dioxide, hydrogen and oxygen—entirely bypassing livestock farming and agriculture. Because these methods also require energy input, they are popularly called “power-to-protein” and “power-to-vitamin” processes.

Environmental biotechnologist Lars Angenent, of the University of Tübingen’s excellence cluster, Control of Microorganisms to Fight Infections (CMFI), has optimized one such process in the laboratory; it produces proteins as well as vitamin B9, also known as folic acid.

The process is unique in that it comprises two steps, using two different microbes sequentially. Angenent and his team have been working to find out whether it can be scaled up to technically and economically viable industrial production. They have found that a production facility capable of supplying 5.6 million people with the recommended daily dose of vitamin B9 and contributing to their protein intake at market prices would pay for itself after just five years. The study has been published in the Proceedings of the National Academy of Sciences.

X-ray analysis reveals the inner life of leaves while advancing engineering efforts to reduce ‘crop sweat’

In the Midwestern summer, humans and plants have to breathe through the heat and humidity. Researchers hope that a retooled crop plant—one with an improved ventilation system within its leaves—could thrive while avoiding drought stress by reducing “crop sweat.” Thanks to next-generation imaging technology powered by Argonne National Laboratory’s particle collider beamline, a team of scientists now has precise schematics of the leaf’s interior and can refine approaches to breeding hardier crop plants.

The research, published in Plant Physiology, was led by postdoctoral researcher James Fischer in the laboratory of plant biology and crop sciences professor Andrew Leakey at the University of Illinois Urbana-Champaign. Their work represents the first detailed look at how the pores on the leaf surfaces of sorghum, a highly productive and resilient grass crop, connect to the air pathways, photosynthetic centers and veins beneath.

“There are connections between each component of the leaf… t’s a highly organized system,” Fischer said. “We are really defining the leaf beyond just carbon dioxide goes in, water comes out.”

No, Artificial Intelligence Is Not Conscious

Earlier this year, Anthropic released a “constitution” for Claude, its large language model and flagship product; Anthropic CEO Dario Amodei has said “we’re open to the idea” that AI could be conscious; and Anthropic’s in-house philosopher, Amanda Askell, said in an interview, “I want Claude to be very happy.”

“It’s enough to make you wonder: Should we seriously consider the possibility that Claude, or any large language model, might be conscious? And if it has feelings, is it capable of receiving moral instruction?” Ted Chiang asks. “Absolutely not.”

“LLM conversations are cleverly disguised examples of sentence continuation,” Chiang writes. Perhaps the most fruitful way to understand Claude’s constitution “is as an 83-page character sheet for a role-playing game. LLMs can generate dialogue for Julius Caesar because many books about him exist in the training data those models used. Claude’s constitution serves a similar role for delineating the helpful-chatbot character that customers interact with when they’re using Anthropic’s products.”

“The result is a sentence-continuation machine that is likelier to emit sentences resembling those that a thoughtful, moral person could utter,” Chiang continues. “However, for all the times that ‘honesty’ is mentioned in Claude’s constitution, I would argue that it is fundamentally dishonest to have a machine emit many categories of sentences including any sentences using first-person pronouns.”

“Whenever a person delegates a decision to an LLM, they are trying to off-load accountability for that decision, and if a company that sells an LLM portrays the product as having a moral center, it is offering a way for its customers to abdicate their responsibilities,” Chiang writes. “Off-loading tasks such as writing code might result in cognitive atrophy over the long term, and that is problematic in itself, but off-loading ethical decisions will result in an atrophy of moral reasoning, which is worse.”

“It’s fortunate that LLMs are not conscious,” Chiang continues, “or else the actions of the big AI firms would be even more scandalous than they already are.”


New brain wave theory explains cognition and consciousness

A new theory, published in The Journal of Neuroscience by three scientists in The Picower Institute for Learning and Memory at MIT, offers an explanation of how the brain produces cognition and consciousness: It uses traveling waves of rhythmic neural activity to coordinate nimble neural networks with analog computations.

The metaphor that the brain operates with “circuits” is incomplete, said Picower Professor Earl K. Miller, the paper’s senior author. Indubitably, the brain’s physically connected circuits provide the infrastructure to store our memories and represent our ongoing needs and goals. But when we need to make improvised use of that knowledge in the rapid-fire, anything goes sensory context the world constantly throws our way, we can’t just depend on the relatively slow chemical process of rewiring those circuit connections called “synapses,” he said. Instead, the brain needs a control system that can coordinate millions of neurons to process information in a fraction of a second. Brain waves, long understood to be the synchronized rhythmic fluctuations of large groups of neurons, turn out to be performing that crucial service, Miller and his colleagues argue, citing years of experimental evidence from his lab and many others.

Circuits and synapses are important and fundamental, that’s the start. But there is more going on. The brain generates waves, and wave dynamics are a highly efficient way to coordinate and perform computation

/* */