An OpenAI model disproves a 1946 Erdős geometry conjecture, Ontario auditors find AI medical note-takers inventing drug information, and photons apparently spending negative time inside atom clouds. Plus cotton-bale warships, CIA-funded abstract art, and a pigeon-deterring computer vision turret. [DVYio Newsletter](https://newsletter.dvy.io/visit/dRfWtk3u) Tech [A graphic showing the text 'Unit Distance Problem' alongside a geometric point-plane diagram and the formula n to the power of 1 plus delta.](https://newsletter.dvy.io/visit/P5eXgfQH) [OpenAI model has disproves a central conjecture in discrete geometry](https://newsletter.dvy.io/visit/P5eXgfQH) Imagine you're scattering points randomly across a flat surface. Some pairs of points will end up exactly one unit apart. The question Paul Erdős asked in 1946 is: what's the maximum number of those "exactly one unit apart" pairs you can get, if you place n points as cleverly as possible? It sounds like a puzzle you could sketch on a napkin. Mathematicians have described it as possibly the simplest problem in combinatorial geometry to explain. For 80 years, nobody could fully solve it. The working assumption was that a square grid pattern (think graph paper) was roughly the best you could do. An OpenAI reasoning model has now shown that's wrong, producing an infinite family of point arrangements that beat the grid by a measurable, polynomial margin. The proof has been verified by external mathematicians. What's notable about how it happened: this wasn't a system trained specifically on mathematics or pointed directly at this problem. It's a general-purpose reasoning model that OpenAI tested against a set of open Erdős problems and it produced a valid proof on this one. It's not just that AI solved a hard maths problem, but that a general reasoner wandered into a subfield, picked up an 80-year-old open question, and closed it. [A doctor looks at a clipboard where a robot's transcription is filled with errors, missed data, and garbled symbols.](https://newsletter.dvy.io/visit/Ln7f6Gd3) [Doctors' AI note takers routinely miss or completely make up basic facts](https://newsletter.dvy.io/visit/Ln7f6Gd3) Twelve of the 20 AI transcription tools approved for Ontario doctors inserted wrong drug information into patient notes. Nine invented treatment suggestions that were never discussed. Seventeen missed key mental health details from the recordings used to test them. These aren't obscure edge cases from unusual inputs. Ontario's Auditor General tested all 20 approved systems using simulated doctor-patient conversations, then had medical professionals compare the recordings to the AI-generated notes. The failures turned up in basic, structured clinical scenarios. The practical consequence is that a GP using one of these tools to document an appointment might end up with a note saying a patient showed anxiety they never mentioned, or listing a medication that was never prescribed. If the doctor doesn't catch it, that note goes into the patient's record and shapes future care. OntarioMD, the body that helped procure these systems, has told doctors to manually review their AI-generated notes. But none of the approved systems have a mandatory sign-off step built in, which means "review carefully" is just advice, not a guardrail. [Students sit around a table in a classroom, using varied manual typewriters to write on plain paper.](https://newsletter.dvy.io/visit/M2eRfKn4) [A college instructor turns to typewriters to curb AI-written work](https://newsletter.dvy.io/visit/M2eRfKn4) Cornell German instructor Grit Matthias Phelps hands out manual typewriters once a semester and takes away every digital crutch students normally reach for: no spellchecker, no delete key, no browser tab open to a translation site. The assignment, running since 2023, forces students to plan a sentence before committing it to paper, because correcting a mistake means crossing it out with a pencil. That constraint is the point. When you can't paste into ChatGPT or quietly run a paragraph through Google Translate, you have to actually know the language, or at least honestly show where you don't. The typewriter isn't just an AI detector; it's a different kind of thinking environment. One task, no tabs, no autocomplete whispering in your ear. Cornell isn't alone in this. Oral exams, handwritten in-class essays, and other screen-free assessments are all making a comeback at universities trying to distinguish what a student knows from what a model can produce on their behalf. The solution to a 2020s problem turns out to be a 1950s machine. This Week I Learnt [A silhouette of a person sits in profil, examining a single small feather against a backdrop of swirling dust.](https://newsletter.dvy.io/visit/ZAr6qpZr) [floccinaucinihilipilification](https://newsletter.dvy.io/visit/ZAr6qpZr) [The 29-letter word means "the act of deciding something is worthless." A self-aware kind of irony, given how much effort it takes to say it. It started as a joke. Eton schoolboys in the 17th or 18th century strung together four Latin words that all meant roughly "nothing" or "trifle" (floccus, a wisp of wool; naucum, a trifle; nihilum, nothing; pilus, a hair) and bolted on "-fication" to make it a noun. The source was a line in William Lily's Latin grammar, which listed those words as examples of things used to express contempt or worthlessness. Cambridge now lists it as the longest non-technical word in English, which means it holds that title purely by virtue of being a very elaborate way to say "meh."](https://newsletter.dvy.io/visit/ZAr6qpZr) Poll What do you do when you can't remember if you locked the front door? Trust myself and carry on Go back to check Check via a camera or app Last Week's Poll On balance, has social media been good for the world? Positive 5% Negative 79% Pretty neutral 12% Too early to tell 4% Science [A young bonobo looks directly into the lens while reaching a hand out toward the camera.](https://newsletter.dvy.io/visit/7m8mfadh) [Why is almost everyone right-handed?](https://newsletter.dvy.io/visit/7m8mfadh) [About 90% of humans across every culture are right-handed. No other primate comes close to that kind of lopsided consistency. An Oxford-led study published in PLOS Biology looked at 2,025 individuals across 41 species of monkeys and apes, using Bayesian modelling to test every major hypothesis going: tool use, diet, brain size, social organisation, body mass. Two factors stood out as explanatory: walking upright, and the dramatic expansion of the human brain. The thinking is that once our ancestors moved onto two legs, the hands were freed from locomotion entirely, and the brain had to coordinate them differently. A bigger, more lateralised brain seems to have pushed that coordination asymmetry further, until one hand reliably took the lead. Other primates show individual preferences, but nothing like a 90/10 split across a whole species. Every time you reach for a pen or a mug without thinking, you're running a habit that's millions of years in the making, baked in long before writing, tools, or any cultural reinforcement had a chance to tip the scales.](https://newsletter.dvy.io/visit/7m8mfadh) [A researcher wearing safety glasses and a blue lab coat works behind the glass screen of a laboratory fume hood.](https://newsletter.dvy.io/visit/kStRsbjc) [Does sunburn hold the key to long-term heat storage?](https://newsletter.dvy.io/visit/kStRsbjc) Most ways of storing solar energy work by converting sunlight into electricity, then storing that electricity in a battery. This approach skips both steps. Certain molecules change shape when sunlight hits them, a bit like a mousetrap being set, and then hold that strained shape until you trigger them to snap back, releasing the stored energy as heat. No battery, no electricity, just chemistry. The field is called molecular solar thermal (MOST) energy storage, and it has been around as an idea for decades. The problem has always been finding the right molecules: ones that are stable enough to hold their shape for months but sensitive enough to release heat reliably when you want them to. Grace Han, a chemistry professor at UC Santa Barbara, found a promising candidate in an unexpected place. She was reading about DNA photochemistry and realised that the same molecules damaged by sunburn in our skin had already been shaped by millions of years of evolution to do exactly what MOST researchers need: absorb UV light, change shape, and then reset cleanly with the help of an enzyme called photolyase. Small, stable, and capable of storing a lot of energy for their size. The appeal for heating is that you could, in theory, charge these molecules using sunlight in summer and release the heat months later in winter, with no energy lost to a battery in between. Whether it scales to something you could plumb into a house is still an open question, but the underlying chemistry looks more promising than it did. [A diagram shows a beam of blue photons entering a cloud of atoms, with some particles exiting at irregular angles.](https://newsletter.dvy.io/visit/8GM3bdYK) [Quantum particles can apparently spend negative time inside an atom cloud](https://newsletter.dvy.io/visit/8GM3bdYK) Quantum mechanics already does plenty of weird things, but this one is new: physicists have measured a photon (a particle of light) apparently spending negative time inside a cloud of atoms. When you fire photons through a cloud of rubidium atoms, most get absorbed and scattered. The ones that make it straight through are the interesting ones. If you compare when those survivors were expected to arrive versus when they actually did, they show up early, as if they spent less than no time inside the cloud. The team didn't just clock the photons. They also asked the atoms. Because a photon passing through can briefly excite an atom (bump it into a higher energy state), the atoms carry a record of the interaction. Those atomic "witnesses" corroborated the negative dwell time, not just the photon's suspiciously early arrival. The explanation isn't time travel. It's a filtering effect. The photons that scatter are the ones that spent longer dwelling with the atoms, so they never arrive at the detector. The survivors are statistically the ones that barely interacted at all, skewing the average dwell time below zero. It's a bit like if you only asked people who left a party early how long they stayed: the average would look shorter than the party actually ran. Whether "negative time" is a real physical quantity or a useful accounting trick is still an open question. But the atoms agreed with the photons, and that agreement is harder to dismiss. [A white digital rendering of a spacecraft with a glowing blue engine thruster orbiting a large, cratered orange planet.](https://newsletter.dvy.io/visit/KPXh5qKj) [Nuclear fission in space: NASA's plan to reach Mars by 2028](https://newsletter.dvy.io/visit/KPXh5qKj) Jared Isaacman, NASA's newly confirmed administrator, announced that the agency will build and launch a nuclear reactor-powered spacecraft to Mars by the end of 2028. The craft is called SR-1 Freedom (Space Reactor-1 Freedom), and nothing like it has flown before. The appeal of nuclear propulsion is speed. Chemical rockets (the kind that have taken every interplanetary probe so far) burn fuel in a burst and then coast. A nuclear thermal engine can sustain thrust far longer, cutting months off journey times. That matters for crewed missions in particular, where every extra week in deep space means more radiation exposure and more consumables. NASA hasn't responded publicly with engineering details yet, and SR-1 is still largely a name and a deadline rather than a finished design. China has its own Mars ambitions, and a crewed landing on another planet would be a defining moment for whoever gets there first. SR-1 is partly a response to that pressure. [A modern courtyard house with dark timber cladding over concrete block walls, featuring a pond and stone path leading through a breezeway.](https://newsletter.dvy.io/visit/rXe6bT5q) [Sunken concrete living room with tan leather seating next to a modern fireplace and a large opening to a garden courtyard.](https://newsletter.dvy.io/visit/rXe6bT5q) [A courtyard with a concrete table connects two dark timber and grey block buildings through wide open glass walls.](https://newsletter.dvy.io/visit/rXe6bT5q) [A dark outdoor dining area with a stone floor and integrated BBQ, looking out over rolling green hills and a distant bay.](https://newsletter.dvy.io/visit/rXe6bT5q) [Merricks Farmhouse](https://newsletter.dvy.io/visit/rXe6bT5q) [Merricks, Australia](https://newsletter.dvy.io/visit/rXe6bT5q) Data [A bar chart from Our World in Data shows China's 497 TWh electricity increase in 2025 (mostly solar and wind) is roughly equal to Germany's total annual generation.](https://newsletter.dvy.io/visit/mxS5m64X) [China added a Germany-sized electricity grid last year](https://newsletter.dvy.io/visit/mxS5m64X) [In 2025, China's electricity generation grew by almost 500 terawatt-hours (TWh). To put that in terms you can feel: Germany's entire grid, every power station, every wind turbine, every solar panel it has, produces about that much in a year. China added that in twelve months. Solar alone contributed 340 TWh more than the year before. That's more electricity than the UK and Spain generate from all their sources combined. Wind added most of the rest. The consequence: coal generation in China actually fell slightly last year, not because China is burning less energy, but because renewables grew fast enough to cover new demand and then some. That's a different story from the usual "China is building coal plants" headline, which is also sometimes true, but misses the bigger shift in the numbers.](https://newsletter.dvy.io/visit/mxS5m64X) History [A 19th-century etching shows a steamboat fortified with stacks of cotton bales on its deck, functioning as improvised armour.](https://newsletter.dvy.io/visit/S3qFELuk) [How Civil War ships used cotton bales as armour](https://newsletter.dvy.io/visit/S3qFELuk) [During the American Civil War, both sides scrambled to adapt civilian riverboats into warships. The famous solution was ironclads, ships armoured with metal plating. But iron was expensive and hard to come by, especially in the Confederate South. Texas, in particular, had almost no budget for proper warships. What it did have was cotton, in enormous quantities. Confederate Commander John B. Magruder's solution was to stack compressed cotton bales along the sides of converted steamboats. Tightly packed cotton isn't as soft as it sounds: the fibres absorb and spread the energy of an incoming projectile rather than letting it punch straight through. It wouldn't stop a heavy cannon ball, but it held up surprisingly well against rifle fire and lighter artillery, which was much of what these river and coastal engagements actually involved. The resulting vessels, nicknamed "cottonclads", were essentially floating forts made of agricultural surplus. Heavy guns were impractical (you can't easily mount artillery among bales of cotton), so the main weapons were sharpshooters firing from behind the bales, and a ram bolted to the bow, sitting just below the waterline. The tactic was blunt: steam directly at an enemy ship and punch a hole in its hull. The most notable engagement came at the Battle of Galveston in January 1863, where the CS Bayou City and CS Neptune went up against Union warships that had been holding the port since late 1862. The cottonclads helped retake the city, which remained under Confederate control for the rest of the war.](https://newsletter.dvy.io/visit/S3qFELuk) [An abstract painting on pink canvas featuring a grid-like layout of black, red, and orange shapes, including a large central brown circle.](https://newsletter.dvy.io/visit/oxRZZ92p) [The CIA Secretly Funded Abstract Expressionism During the Cold War](https://newsletter.dvy.io/visit/oxRZZ92p) During the Cold War, the CIA secretly bankrolled tours of Abstract Expressionist painting across Europe. Jackson Pollock, Mark Rothko, Willem de Kooning: their work travelled major cities under the programme "The New American Painting" in 1958–59. The artists had no idea. The logic was surprisingly coherent. Abstract Expressionism was everything Soviet socialist realism wasn't: chaotic, individual, impossible to conscript into a slogan. Showing it to European audiences was a way of saying "look what freedom produces" without saying anything at all. The propaganda worked precisely because it didn't look like propaganda. The irony: this was art most Americans actively disliked. Congress periodically erupted over public arts funding for exactly this kind of difficult, experimental work. The CIA was, in effect, exporting a culture that domestic politics kept trying to suppress. Random [A DIY water gun turret fires a precise stream of water at a pigeon on a metal roof from a balcony window.](https://newsletter.dvy.io/visit/UGnpAWGB) [A pigeon-detecting, servo-aimed water gun that runs 24/7 on a balcony computer](https://newsletter.dvy.io/visit/UGnpAWGB) [/u/muxamilian got tired of pigeons on his balcony and built a computer vision turret to deal with it. The setup: a USB camera feeds live video to an Orange Pi 5 (a small single-board computer, similar to a Raspberry Pi), which runs a vision model called YOLO World v2 directly on the chip's built-in neural processing unit. When it spots a pigeon, two servo motors aim a disassembled electric water gun at it and fire. However, "pigeon" isn't hardcoded. YOLO World v2 uses open-vocabulary detection, meaning you describe the target in plain language rather than training a custom model for each species. Change the label to "squirrel" or "cat" and it hunts that instead. Total parts list: one Orange Pi 5, one USB camera, two small servo motors, a disassembled water gun, and a handful of resistors and a transistor to trigger the pump.](https://newsletter.dvy.io/visit/UGnpAWGB) [A darkened architectural rendering of high-rise apartment towers, with a spotlight on a couple walking near a cafe.](https://newsletter.dvy.io/visit/Dkq8DyWH) [Jacques and Claudette: the fictional couple hidden in New York's architectural renderings](https://newsletter.dvy.io/visit/Dkq8DyWH) Architectural renderings are full of people who don't exist. They walk past gleaming towers, sit in sunlit courtyards, push prams along new waterfront paths. Most of them are generic enough to ignore. But one couple keeps showing up. Urban planner Daphne Lundi noticed them about a decade ago while trawling New York YIMBY and Crain's for development news. He's bald, blue dress shirt, khaki trousers, brown loafers. She's got hoop earrings, a pink T-shirt, bootcut jeans. Lundi named them Jacques and Claudette. They are scalies: stock human figures dropped into architectural renderings to make a building feel inhabited before a single brick is laid. The practice is standard across the industry, but what Lundi picks at is the pattern beneath it. Jacques and Claudette appear in renderings for megaprojects, rezoning proposals, housing lotteries, High Line expansions, Coney Island towers. They represent a particular vision of who belongs in a neighbourhood, often a historically Black one, and that vision is being projected before residents have had much say in the matter. The piece traces scalies back to their origins as anonymous Nordic-looking cutouts, and follows how they evolved into named, demographically deliberate characters. It's a small detail with a larger implication: the imagined future of a city is constructed before the city changes, and somebody is doing the imagining. [A three-by-three grid shows nine macro photographs of different sand types, ranging from translucent white glass and coral fragments to vibrant green olivine and deep red garnet grains.](https://newsletter.dvy.io/visit/RWrNaCm2) [A Visual Guide to Sand Classification](https://newsletter.dvy.io/visit/RWrNaCm2) [Sand doesn't have an official scientific classification. For something that covers roughly a third of the world's land surface, that's a bit of an oversight. Geologists do recognise distinct types, grouped loosely by what they're made of and where they came from. For example: - Coral sand is ground-up shells and reef material, pale and calcium-rich, found on tropical beaches. - Volcanic sand comes from eruptions, either dark basalt grains or fine shards of volcanic glass. - Ooid sand forms in warm, shallow water, each grain built up in tiny concentric layers like a miniature jawbreaker. - Gypsum sand, which you'll find at White Sands in New Mexico, is one of the rarer types. Then there's glass sand, which is ordinary human-made glass, ground down by the sea from dumped rubbish. Beautiful to look at, grim in origin. Worth a scroll if you've ever assumed sand was just, well, sand.](https://newsletter.dvy.io/visit/RWrNaCm2) Design [Three IDX-2 desk instruments in white, maple, and black finishes, each showing a physical needle inside a clear acrylic case.](https://newsletter.dvy.io/visit/HzBeF6uX) [IDX-2](https://newsletter.dvy.io/visit/HzBeF6uX) [The IDX-2 is a small desk instrument (about 80×100mm, roughly the size of a hockey puck) that connects to your WiFi and points a physical needle at whatever data you care about: Bitcoin price, a stock ticker, local air quality, or a sensor from your Home Assistant smart home setup. Rise or fall maps to right or left of centre. Absolute values like temperature map across the full sweep of the dial. It's hand-built in London in small batches, in three material finishes. The Reddit quote on the product page probably sums it up best: "I have zero need for a physical dial in my home... Why do I want this so bad then?"](https://newsletter.dvy.io/visit/HzBeF6uX) [Vintage matchbooks for Mid-century Malibu and Venice Beach restaurants laid out in diagonal rows on a bright yellow background.](https://newsletter.dvy.io/visit/FqWA3afU) [Matchbooks as a map of Malibu's vanished mid-century coastline](https://newsletter.dvy.io/visit/FqWA3afU) Before cheap lighters took over, matchbooks were everywhere: in jacket pockets, on restaurant counters, tucked into ashtrays. Every bar, motel, and diner printed its name and address on them and gave them away for free. Which means a collection of old matchbooks is, accidentally, a pretty good map of how a place used to look. The Eric Wienberg Collection at Pepperdine University holds matchbooks and other bits of printed ephemera from Malibu and the surrounding Southern California coast, spanning the late 1800s through the 1980s. Taken together, they sketch out a commercial strip that no longer exists: restaurants, motels, and small businesses that were swallowed up by decades of wildfires and redevelopment. Matchbooks hold up pretty well as historical evidence. They were designed to be thrown away, and most were. The ones that survived did so almost by accident, tucked into drawers or boxes and forgotten. Now they're the most detailed record we have of some of these places. [A translucent, flat-bottomed silicone cup standing upright, shaped like a thin envelope with an open top.](https://newsletter.dvy.io/visit/XC8ALLdY) [Muji Silicone Cup](https://newsletter.dvy.io/visit/XC8ALLdY) It sits flat until you add water, at which point it holds its shape on its own. No lid, no assembly, no disposable cup needed. [Web](https://newsletter.dvy.io/visit/pXDqG6Va) · [Twitter](https://newsletter.dvy.io/visit/vwpZjJMv) · [LinkedIn](https://newsletter.dvy.io/visit/n6iy3egx)