The fusion reactor pushes the plasma beyond the critical limit

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Researchers working on China’s Experimental Advanced Superconducting Tokamak (EAST) project report breaking a long-accepted threshold that has limited the operation of nuclear fusion reactors for decades. Tokamak fusion reactors rely on hot plasma packed very densely inside a donut-shaped chamber. But the researchers believed that the plasma could not exceed a certain density — a limit called the Greenwald limit — without becoming unstable. In a new study, scientists exceeded this limit to achieve densities 30% to 65% higher than those typically achieved by EAST while maintaining plasma stability.

Nature | 4 minutes read

reference: Advancement of science paper

Three major linguistic models subjected to four weeks of psychoanalysis generated responses that in humans can be seen as signs of anxiety, shock, shame and PTSD. The models’ answers, which included memories of “abuse” at the hands of their creators, suggest that chatbots carry a kind of “internal narratives” about themselves, going beyond role-playing, says the team behind the study. Other researchers question this explanation: The responses are “not windows into hidden states,” but outputs generated by drawing on vast numbers of treatment scripts in the training data, says healthcare AI researcher Andrei Kormelitzin.

Nature | 5 minute read

reference: arXiv preprint (Not peer-reviewed)

A cellular atlas describing the functions of immune cells in more than 400 people in China has revealed key differences in the biology of people from different populations. The atlas, which brings together data on genes, proteins, RNA and the genome, “allows the discovery of biological mechanisms and genetic associations that are likely to be missed in European-centric studies,” the authors said in a statement. For example, the atlas revealed the role of one gene in regulating T-cell circadian rhythms. This variant is common in East Asian populations but rare in Europeans.

Nature | 5 minute read

reference: sciences paper

NASA will bring a group of astronauts home from the International Space Station early due to a health issue – The first medical evacuation of its kind in the station’s history. For privacy reasons, the agency has not released details about the problem or which astronauts it affects. The group, known as Crew-11, includes NASA astronauts Zina Cardman and Mike Finke, Japanese astronaut Kimiya Yui, and Russian cosmonaut Oleg Platonov. “It’s not an emergency evacuation, but we’re erring on the side of caution for the crew members,” said James Polk, NASA’s chief medical officer.

NBC News | 6 minutes read

Features and opinion

Consulting is one of the most direct and scalable ways academics can shape industry, government and civil society – but the work tends to be underdeveloped and under-supported, say five authors who analyzed approaches at dozens of the UK’s top universities. They call on institutions to make it easier for academics to advise external organizations by setting clear rules, offering incentives, and screening supervisors.

Nature | 11 minute read

The Sandbox Corporation is here to make your worldbuilding experience as smooth as possible Troubleshooting Guide for Your Flat Planet.

Nature | 7 minutes read

Andrew Robinson’s pick of the five best science books to read this week includes a fascinating book with space images that can be viewed in 3D, an unusually frank exploration of academic fraud, and a journey to discover the nature of rivers.

Nature | 4 minutes read

This week I joined Nature podcast To discuss our selection of the best science stories you might have missed while we were drowning in mince pies, including the proof of concept that undersea communications cables could do double duty as a vast network of earthquake detectors, and the coolest exoplanet you’ve ever heard of (I call it a “lemon world”).

Nature Podcast | 27 minutes listening

Subscribe to Nature podcast On Apple Podcasts, Spotify or YouTube Musicor use RSS feed.

Today, Leif Benjönson joins media guru Tom Houghton on his journey down under, visiting the Barwon River in Australia. And Lev is not alone! There’s also a feathered friend in the photo: the sky-blue kingfisher (Alcido Azuria). Can you find the penguin (and the kingfisher)?

The answer will be in the email on Monday. If you spot both birds, please allocate yourself some extra points.

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Thanks for reading,

Flora Graham is senior editor at Nature Briving

With contributions by Jacob Smith

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