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Animated gif of a moving knot

Knot theorists proved the validity of a mathematical formula about knots after using machine learning to guess what the formula should be.Credit: DeepMind

DeepMind’s AI untangles knots

Artificial-intelligence (AI) powerhouse DeepMind has teamed up with mathematicians to spot previously unseen patterns and seek new discoveries. Researchers trained a machine-learning algorithm on vast amounts of data about knots and revealed a formula linking two properties of knots — which the mathematicians then proved rigorously. In a separate test, the team found a potential pattern related to symmetries, which had been sought for decades. “I was very struck at just how useful the machine-learning tools could be as a guide for intuition,” says knot theorist Marc Lackenby.

Nature | 6 min read

Reference: Nature paper

World commits to a pandemic response pact

This week, world leaders met to negotiate how to ensure that a crisis on the scale of the COVID-19 pandemic never happens again. Initially on the table was a legally binding pandemic treaty that would dictate how nations should respond to future outbreaks. A fuzzier form of that proposal is now moving forward, to be sharpened in the months and years to come. Nature explains the negotiations and the prospects for revamping global cooperation.

Nature | 7 min read

Maddox Prize rewards science under fire

Science-integrity advocate Elisabeth Bik has won this year’s John Maddox Prize, given by the charity Sense About Science and Nature, for advancing science and evidence in the face of difficulty or hostility. Physician-scientist Mohammad Sharif Razai won the early-career prize for his work on publicising an evidence-based understanding of racial health inequalities. In his speech, Razai — who sought asylum in the United Kingdom at age 15 — paid tribute to family members who had just fled Afghanistan. “No matter what obstacles and challenges we may face as scientists in the global north, it is not the same as Afghan scientists, especially women and those from racial minorities, who literally pay with their lives in speaking truth and standing up for their rights,” he said. “I remember them and dedicate this prize to them.”

Research Professional News | 3 min read

Features & opinion

What a healthy, sustainable diet looks like

As the world population continues to rise, researchers are grappling with the question of what we should eat to stay healthy and save the planet. A 2019 report from a consortium of nutritionists, ecologists and other experts recommended that people adopt a ‘flexitarian’ diet by eating plants on most days and occasionally a small amount of meat or fish. The commission estimates that this diet would save the lives of about 11 million people every year, but others question whether it is practical, affordable and nutritious enough. Scientists are now trying to test environmentally sustainable diets in local contexts, without compromising nutrition or damaging livelihoods.

Nature | 11 min read

Reference: EAT–Lancet Commission report

Geoengineering research should be global

Injecting aerosol sulfates into Earth’s stratosphere is the fastest known solar-geoengineering technique for cooling the planet, and it’s comparatively inexpensive. So it is crucial to improve our murky understanding of its consequences, says climate scientist Kate Ricke. The involvement of scientists worldwide is crucial before some entity is tempted to use the technique, she argues. “I'm having a hard time seeing how we’re not going to do it at this point, actually,” says Ricke. “But in order to have collective decision-making at the global scale, you need science that's viewed as legitimate by everyone.”

Wired | 10 min read

News & views

Scanning electron micrograph of coccolithophores

Figure 1 | Coccolithophores. These marine phytoplankton make intricate oval structures intracellularly — called coccoliths — that are then extruded to surround the organism’s surface (the species shown is Emiliania huxleyi). Beaufort et al. analysed coccoliths in ancient marine sediments, and their findings indicate that eccentricity in Earth’s orbit had a role in shaping phytoplankton evolution.Credit: Steve Gschmeissner/Science Photo Library

Plankton evolution follows Earth’s orbit

Variations in Earth’s orbit might help to determine the evolution of marine phytoplankton. Researchers analysed fossils of coccolithophores that lived in the Pleistocene period (from 2.6 million to 11,700 years ago) alongside deviations in the circularity of Earth’s annual orbit, which cycles approximately every 100,000 and 400,000 years. They found that the diversity of plankton species increased during periods of high eccentricity of Earth’s orbit, when the seasons vary more in equatorial regions. Because the calcium carbonate skeletons of phytoplankton make a significant contribution to our planet’s carbon cycle, “such a link between orbital change, climate and phytoplankton evolution could be an intrinsic beat that underscores the Earth system”, writes biogeochemist Rosalind Rickaby.

Nature | 8 min read (Nature paywall) & Sky News | 2 min read (free)

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Reference: Nature paper

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