Thanks for reading Axios Science. Please send me your feedback at firstname.lastname@example.org or just reply to this email.
Illustration: Aïda Amer/Axios
Two parallel quests to understand learning — in machines and in our own heads — are converging in a small group of scientists who think that artificial intelligence may hold an answer to the deep-rooted mystery of how our brains learn, Kaveh Waddell and I write.
Why it matters: If machines and animals do learn in similar ways — still an open question among researchers — figuring out how could simultaneously help neuroscientists unravel the mechanics of knowledge or addiction, and help computer scientists build much more capable AI.
The big picture: For decades, researchers compared human and machine learning and largely rejected the notion that they are closely linked.
"There is a big undercurrent in neuroscience [saying] we should go back to neural networks," says Konrad Kording, a neuroscientist at UPenn, referring to a reigning AI technique that relies on backprop.
A trio of scientists in Toronto and a DeepMind researcher are searching for that evidence in the brains of mice. In their experiment, animals watch patterns on a screen as their brain activity is recorded.
But, but, but: The brain doesn't just learn from error. Some of our knowledge is based on intuition and some is acquired throughout our lives.
The bottom line: Researchers know learning hinges on the strengthening and weakening of the synapses between individual neurons. But how that change plays out globally among the roughly 100 trillion synapses in the human brain — so we can recognize someone's face, for example — is unknown.
Curiosity on Mars in 2018. Photo: NASA/JPL-Caltech/MSSS
NASA's Curiosity rover just completed its 7th year on Mars, during which the car-sized spacecraft has changed the way we understand the Red Planet, Axios' Miriam Kramer writes.
By the numbers: Mission controllers experienced "7 minutes of terror" during its 2012 landing when a complex series of maneuvers brought Curiosity to the surface.
What's next: Curiosity discovered that Mars was likely habitable for millions of years. The rover will use its remaining years to try to solve the mystery of why that habitability ended.
Where the taps could run dry (Dave Lawler — Axios)
America's mental health problem isn't mass shootings (Caitlin Owens — Axios)
A sedative epidemic is taking root (Nambi J. Ndugga, Elsa Pearson, Melissa Garrido — Axios Expert Voices)
The unknown risks of radiation in space (Miriam Kramer — Axios)
The climate peril from land degradation (Ben Geman — Axios)
Researchers say they've discovered more than 4,000 new, small protein families generated in the human microbiome, Axios' Eileen Drage O'Reilly writes.
What they did: Over a 4-year period, Ami Bhatt of Stanford and her colleagues collected large amounts of microbiome data from humans, animals and the environment and sequenced their DNA, they report in a study published Thursday in the journal Cell.
What they found: They discovered more than 4,000 protein families, 90% of which have no known function and almost half have not been previously catalogued.
What they're saying: Nicola Segata, associate professor and principal investigator at University of Trento's Centre for Integrative Biology, tells Axios the study offers a first, "crucial step" but "it is premature to speculate on whether and how this discovery will be relevant for future therapies."
Gender-neutral pronouns reduce biases (Ian Sample — The Guardian)
Pediatricians warn racism has devastating effects on children (William Wan — Washington Post)
A vicious disease is wiping out China's pig population (Chris Baraniuk — OneZero)
A tale of elephants, ants, trees and fire shows how complex nature is (The Economist)
Researchers at a lava flow site in Haleakala National Park, Hawaii. Photo: Brad Singer/University of Wisconsin-Madison
About 773,000 years ago, Earth's magnetic north and south poles reversed — a complex process that took about 22,000 years, according to new research.
The big picture: Throughout our planet's history, the poles have flipped every several hundred thousand years or so. How long that process takes, what's involved and when it might happen again aren't well understood, but they are much debated.
How it works: During "excursions," Earth's magnetic field intensity decreases globally and compasses start to point in intermediate directions.
What's new: In research published this week in Science Advances, geologist Brad Singer of the University of Wisconsin-Madison and his colleagues homed in on the last reversal event in search of the steps leading up to it.
But, but, but: The geological record has its limits — samples can be disrupted and the details of the reversal smeared out by the slow deposition of material over time. Singer says data from multiple volcanoes and other observations strengthen the findings but some researchers disagree.
What's next: Some scientists think we may be going into a reversal now as Earth's magnetic field strength is declining about 5% per century.
Still, researchers want to understand the potential effects of a magnetic reversal on life on Earth.