Today’s Visualized watches tiny flowers bloom. But first, catch up on the latest science news, including how the tides may have altered the course of civilization and the incredible accuracy of the Mayan calendar.
Medicine | News from Science
Raising an immune army
Early work on regulatory T cells, which can quell immune attacks on a body’s own tissues, earned three scientists a Nobel Prize this year. But researchers have struggled to make so-called Tregs work clinically because they don’t persist in the body and can’t be grown easily in the lab.
Now, one of the freshly minted Nobel laureates has debuted a new method to make abundant, long-lasting Tregs. In the first of two papers in this week’s Science Translational Medicine, immunologist Shimon Sakaguchi and colleagues describe how their lab-generated Tregs effectively suppress immune responses in mice. In the second, he and other researchers made Tregs to treat a specific autoimmune skin disorder in mice. Setting the stage for a clinical trial, they used a similar method to generate human Tregs from the blood of people with the painful condition.
Goodman extracted a soil core from below the surface of the Sumerian urban center Lagash, which sits near the modern-day Iraqi city of Nasiriyah, almost 200 kilometers from the coast. But the core sample revealed that some 7000 years ago, this city abutted the coast. Twice-daily tides in the Persian Gulf would have pushed saltwater up the Tigris and Euphrates, forcing freshwater back the way it came and making it available for farmers to water wheat fields, date palm groves, and vegetable gardens.
“This is confirming the foundation of the earliest known civilization wasn’t the kind of irrigation we usually think of,” says archaeologist Jennifer Pournelle, who wasn’t involved with the new research. “It wasn’t making a desert bloom; it was tidal irrigation in a delta.”
To the chagrin of doomsayers, the world didn’t end in 2012. The faulty prediction had been a misunderstanding of extremely accurate Mayan calendars, which showed 2012 as the last year of a 394-year cycle (not the last year of all time, thankfully). But the calendars have accurately predicted much less sinister events: eclipses.
To better understand Mayan eclipse timekeeping, a pair of researchers reanalyzed tables in the oldest surviving book written in the Americas, called the Dresden Codex. They ran the calculations of different possible systems for tracking solar eclipses with specific numbers of days, months, and years, and reconstructed when real eclipses would have occurred in each.
The researchers determined that, contrary to previous understanding, the Mayan timekeeping method doesn’t restart at the end of the table (405 months), but at the table’s 358th month. Every once in a while, the table would need to be restarted at the 223rd month to account for built-up deviations, sort of like our modern Leap Year procedure. The method keeps the table accurate at predicting eclipses, with only 51 minutes of deviation over 134 years.
While researchers may never know for sure why the Mayans decided to keep time this way, they can be sure the system was spot-on; it predicted a solar eclipse to within a day as recently as 1991.
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Microscopic “flowers” made from crystals and DNA open and close as the pH of the surrounding solution changes. Video first published in Nature Nanotechnology (2025) by Springer Nature
As the morning sun strikes a field of poppies, the flowers open, unfurling their petals. Chemist and material scientist Ronit Freeman was inspired to recreate such natural motion, but she was thinking small—really, really small. “We wanted to be able to mimic such autonomous behavior in soft robots, and specifically at the microscale, where current robotic programming is not straightforward to do,” she explained to ScienceAdviser. “The ability of DNA crystals to grow into flowers allowed us to mimic that architecture, while the interlaced DNA within their petals programs their shapeshifting.”
The microscopic “flowers” Freeman and her colleagues made grow naturally during the DNA-making process, thanks to an enzyme that can synthesize DNA without a template. This enzyme also creates long sections that change shape with acidity. “Depending on the length of these segments, and where they are within the petals, they fold and act like tiny springs, driving flowers to close, open, shrink, or swell,” said Freeman.
In experiments, the team showed that they could induce flower opening or closing in a matter of seconds. Indeed, they were able to code a hidden message in the flowers that’s only visible when the pH is lowered to 5. And they could pack the crystals with enzymes that are only released when the flower opens its petals. These abilities demonstrate the potential for using these flowers as targeted drug delivery devices.
“Imagine a future where ingesting smart capsules triggers the precise release of medication upon detecting a disease, only to deactivate once the ailment is cured,” she said.
Google has claimed that their new ‘quantum echoes’ algorithm can give quantum computers the ability to perform calculations much faster than classical ones. Experts, however, are skeptical. “Personally, I don’t think [they presented] enough to make such a big claim,” one said.
Neuroscientists are finally starting to figure out how, exactly, we fall asleep. “Our brains can really rapidly transform us from being aware of our environments to being unconscious, or even experiencing things that aren’t there,” noted one sleep researcher. “This raises deeply fascinating questions about our human experience.”
A tiny glass sphere levitated in a near-vacuum behaves as if it’s heated to 13 million Celsius. “It is moving as if you had put this object into a gas that was that hot,” explained one physicist. “It moves around like crazy.”
The program for the 2026 AAAS Meeting just dropped this week! I’m still combing through all the interesting sessions… Who’s going to be joining me in Phoenix?
Christie Wilcox, Editor, ScienceAdviser
With contributions from John Travis, Michael Price, and Hannah Richter
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