Curiosity survives Mars through software fixes sent 200 million kilometres. Also: molten salt keeps a Gobi solar plant running after dark, and a voice AI maps baguette prices across France. [DVYio Newsletter](https://newsletter.dvy.io/visit/ih9EwHyF) Good morning! I’ve changed the format a little this week. If you’ve been a subscriber for a while, you might have noticed that I often add my own “take” to each item. This week’s issue mixes longer stories with shorter link notes. That means more links worth opening and less commentary added just for the sake of it. I’ll still add detail when something deserves unpacking. There’s a poll at the end, and I’d love to know which format you prefer. This Week I Learnt [Two gladiators face off in an arena, one holding a sword and shield, the other holding a net and trident.](https://newsletter.dvy.io/visit/waK5WkQ5) [Roman gladiators rarely fought to the death because trained fighters were expensive](https://newsletter.dvy.io/visit/waK5WkQ5) [I’d assumed Roman gladiator fights were essentially public executions. In fact, gladiators were trained performers who entertained crowds for more than 600 years, and most fights did not end with a death. Many gladiators were enslaved people or condemned prisoners. Later, some free men volunteered for prize money and fame, including retired soldiers and even nobles keen to prove themselves. Agents scouted promising fighters and sent them to specialist schools. Those schools mixed prison-like control with rather practical care. Fighters followed gruelling schedules, sometimes lived in shackles, and could not speak during meals. But they received three meals a day and some of the best medical treatment available. A trained gladiator cost money, so killing one was a bit like shooting an expensive racehorse after its first race. Gladiators were also matched by fighting style. A heavily protected swordsman might face a retiarius, who wore little armour and fought with a weighted net and trident. The aim was not simply to overpower someone, but to use one set of strengths against another. The source cites estimates that 10% to 20% of gladiators died in combat. That is still brutally high, and the emperor could decide whether a defeated fighter lived. But death was usually a costly failure, not the point of every match.](https://newsletter.dvy.io/visit/waK5WkQ5) Tech [A clear dental mouthpiece with an integrated gold-colored touchpad and microchips connected by winding circuits.](https://newsletter.dvy.io/visit/mQCFpcuE) [MouthPad puts a 1 mm-thick Bluetooth touchpad on the roof of your mouth](https://newsletter.dvy.io/visit/mQCFpcuE) [Think of a laptop touchpad that sits on the roof of your mouth. That’s what MouthPad is. It starts with a dental scan, then Augmental 3D prints a custom mouthpiece roughly 1 mm thick. You use tongue, head, and sip gestures to move the cursor, click, scroll, and drag across macOS, Windows, Linux, iOS, and Android. The 10g device is aimed mainly at people with limited hand movement, giving them one discreet controller for phones, tablets, and computers. Augmental says it has little effect on speech and runs for more than seven hours per charge. Each MouthPad costs $1,400 and is custom-made in the US (your dentist needs to provide the scan).](https://newsletter.dvy.io/visit/mQCFpcuE) [Anthropic’s new Claude Science app queries more than 60 scientific databases and traces every result back to its code](https://newsletter.dvy.io/visit/SvpnDs29) Claude Science isn’t a new model, but a beta app that lets Claude query more than 60 scientific databases, run analyses, and manage jobs across laptops, lab clusters, and GPUs. Anthropic says every figure and table is linked to the exact code, computing environment, and conversation that produced it, while a background reviewer flags citations and numbers it can’t trace (rather more useful than an AI simply sounding confident). [Early iPhone access tied to a sharper fall in US teen births, study finds](https://newsletter.dvy.io/visit/dQod8NxE) From 2007 to 2011, teen birth rates fell 26% in US counties where AT&T’s 3G network covered more than 90% of residents, compared with 14% where it covered fewer than 10%. Economists Caitlin Myers and Ezekiel Hooper argue that early iPhone access caused much of this gap, but their working paper cannot explain how, and other researchers point out that teen birth rates had already been falling since the 1950s. [What does a baguette cost across France? An AI called thousands of bakeries to find out.](https://newsletter.dvy.io/visit/WvRs9PT9) Brigitte, a voice AI, phoned 5,173 bakeries and collected 1,638 prices for the hand-shaped baguette tradition. Brothers Charles and Louis-Marie Lorin plotted the results by city, Paris arrondissement, bakery type, weight, and Google rating (including a handy “tourist trap” quadrant). Poll Would you choose a guaranteed $50,000 or a 50% chance at $1 million? Guaranteed $50,000 50% chance at $1 million Last Week's Poll When you’re stuck on a problem, what actually unsticks you? Stepping away from it 37% Talking it through with someone 21% Writing it out 16% Brute-forcing more attempts 5% Sleeping on it 21% Science [Bright lounge with green and orange chairs around tables, blue striped carpet, large windows, and yellow walls.](https://newsletter.dvy.io/visit/WJ39B87t) [Why striped floors and flickering LEDs can be physically hard to look at](https://newsletter.dvy.io/visit/WJ39B87t) A supermarket combines several common triggers for visual discomfort: bright glare, repeated shelves, striped signs, and aisles packed with competing colours. A scientific review led by Paul Hibbard at the University of Stirling links these artificial patterns to headaches, nausea, eye strain, and visual distortion in some people. The authors think our visual system is better tuned to the varied patterns found in forests, rivers, and other natural scenes. High-contrast stripes and repeated grids can produce stronger activity in the brain’s visual areas, possibly increasing the amount of oxygen those areas use. The review pulls together decades of research, but this proposed link between extra brain activity and physical discomfort has not yet been fully tested. LEDs add a separate problem. Many LEDs control brightness by switching on and off hundreds of times per second. You may not notice the flicker while looking straight ahead, but moving your eyes can reveal a trail of ghost images (a bit like waving a sparkler at night). People with migraines, autism, ADHD, dyslexia, epilepsy, and several other conditions report stronger reactions to the same kinds of visual input. One possible explanation is that their brains may be less able to suppress overactive visual signals, though researchers do not yet know the biological mechanism. The fixes are fairly ordinary: reduce glare, soften the contrast in repeated patterns, avoid striped panels, and use LED systems with better-controlled flicker. The researchers argue that these changes can cost little when designed in from the start. Retrofitting an office full of headache-inducing lights is the expensive version. [NASA’s Curiosity rover sits on a rocky Martian plain under a dusty orange sky.](https://newsletter.dvy.io/visit/eiN2R2up) [Keeping a 13-year-old Mars rover alive with software updates and no spare parts](https://newsletter.dvy.io/visit/eiN2R2up) Every fix for Curiosity has to arrive as software sent across roughly 200 million kilometres, because nobody can replace its worn wheels, fading power source, or failing memory. When its backup computer became unreliable, JPL repurposed 64 MB reserved for old flight software, allowing that computer to run the rover with less than 1% of its original memory (slowly, but still with every core capability). [A tiny black surgical robot sits on a person’s palm, shown against a blurred background.](https://newsletter.dvy.io/visit/yifHf88n) [A fingertip-sized robot that can cut tissue, deliver drugs, collect samples, and apply heat](https://newsletter.dvy.io/visit/yifHf88n) A 4.4 mm robot from Nanyang Technological University could let doctors cut tissue, deliver drugs, collect samples, and apply heat through much smaller incisions. The prototype switches between five functions in under a second using external magnetic fields, though it has yet to prove reliable enough for use in patients. [Aerial view of concentric fields of mirrors surrounding a tall solar tower in China's Gobi Desert.](https://newsletter.dvy.io/visit/cDuDheds) [China’s giant Gobi solar plant stores heat in molten salt to run after dark](https://newsletter.dvy.io/visit/cDuDheds) China Three Gorges’ Hami plant uses 260,000 mirrors to heat molten salt to 550°C, storing enough energy to generate power for up to eight hours after sunset. The evening output comes from the 100 MW thermal unit, not the full 1 GW plant (the other 900 MW comes from standard solar panels that generate only in daylight). [A modern long gray house with a pitched metal roof sits built into a grassy hill, featuring a curved glass facade.](https://newsletter.dvy.io/visit/pH4r2HKp) [Interior view through a large glass window looking out at a grassy yard and a curved subterranean structure.](https://newsletter.dvy.io/visit/pH4r2HKp) [A person stands at the entrance of a modern white building featuring a sharply angled, overhanging triangular roof.](https://newsletter.dvy.io/visit/pH4r2HKp) [A modern house with a pitched roof viewed through a large elliptical opening in a curved concrete wall, framing a circular lawn.](https://newsletter.dvy.io/visit/pH4r2HKp) [An aerial view of a long, modern house with a pitched roof and a curving green lawn that swoops down to the ground.](https://newsletter.dvy.io/visit/pH4r2HKp) [Yaw House](https://newsletter.dvy.io/visit/pH4r2HKp) [Beskid Mountains, Poland](https://newsletter.dvy.io/visit/pH4r2HKp) Data [Bulls-eye charts showing seasonal visitor trends for national parks across different US regions.](https://newsletter.dvy.io/visit/8VtmZgRx) [When is each US national park quiet and dry?](https://newsletter.dvy.io/visit/8VtmZgRx) [Bloomberg combined AllTrails visitor data with rainfall and maximum temperatures to show when each park is quiet, dry, and reasonably mild. It replaces vague advice to “visit off-season” with the useful question: which off-season? Each park gets a bullseye chart aligning crowds, rain, and heat across all 12 months. Radar charts have a fairly committed group of haters, but the circular layout works here: you can quickly spot the gap between “everyone’s here” and “bring waterproof trousers”.](https://newsletter.dvy.io/visit/8VtmZgRx) History [A person wearing white gloves and a blue apron holds up a large, ornate brass astrolabe covered in engraved Arabic script.](https://newsletter.dvy.io/visit/AcCkGuRf) [The 17th-century brass astrolabe that could tell the time, map stars, and cast horoscopes sold for more than £2 million](https://newsletter.dvy.io/visit/AcCkGuRf) [The 8.2 kg brass instrument is nearly 30 cm wide and stands 46 cm tall, roughly four times the size of a typical astrolabe from 17th-century India. Made in Lahore by brothers Qa’im Muhammad and Muhammad Muqim, it contains 94 cities, 38 star pointers, and five finely calibrated plates. Sotheby’s says the sale set an auction record for an astronomical instrument from the Islamic world. An astrolabe compresses the three-dimensional sky onto rotating metal discs. By lining up its parts with a star, someone could tell the time, find the direction of Mecca, measure the height of a building or the depth of a well, and, with an almanac, cast a horoscope (Oxford historian Federica Gigante compares it to a smartphone). This one later entered Jaipur’s royal collection before passing to Maharani Gayatri Devi and then into private hands.](https://newsletter.dvy.io/visit/AcCkGuRf) [Black-and-white view of a historic American city centre, with two ornate skyscrapers beside a busy avenue.](https://newsletter.dvy.io/visit/ryogWJ27) [How lifts and air conditioning let American architecture ignore the land](https://newsletter.dvy.io/visit/ryogWJ27) Elisha Otis patented a safer lift in 1861, and less than 50 years later Willis Carrier worked out how to cool a building. Together, they removed old limits: stairs no longer capped height, windows did not need to open, and indoor temperature no longer had to follow the weather. That is how someone can spend a summer day 40 floors up, inside a sealed office kept at the same temperature, whatever is happening outside. The building’s surroundings become almost incidental (until the machinery stops). The author argues that plentiful timber and cheap oil pushed the same idea further. The US built balloon-frame houses, sprawling suburbs, motorways, vinyl siding, and air-conditioned towers, often treating land as raw material rather than something to work around. Durability came second: the average American home is just 46 years old. Her point is that American architecture’s size and boldness share a mechanism with its wastefulness. Engineering made it possible to build almost anywhere, at almost any scale, then replace the result when fashions or economics changed. [Solid black square.](https://newsletter.dvy.io/visit/hNZSss9Y) [Queen Elizabeth Digital Memorial: Court Circulars (1952–2022)](https://newsletter.dvy.io/visit/hNZSss9Y) The complete record of Queen Elizabeth II’s official engagements across her 70-year reign, from 1952 to 2022, is now digitised and searchable in the Queen Elizabeth Digital Memorial. The records come from the daily Court Circular, reportedly started by George III in 1803 because newspapers kept getting royal events wrong (an impressively long-running correction). [An ornate architectural tile relief featuring the spelling Pittsburg above the year 1900.](https://newsletter.dvy.io/visit/AyWjJA2D) [Pittsburgh was spelt “Pittsburg” in federal documents for 20 years](https://newsletter.dvy.io/visit/AyWjJA2D) From 1891 to 1911, Pittsburgh was “Pittsburg” to the US government but still “Pittsburgh” to its own city government, after a federal naming board dropped the final h from every place ending in -burgh. The board reversed itself on 19 July 1911, but the famous 1909 Honus Wagner baseball card still carries the shorter spelling. Random [Blue-lit road tunnel with a sign pointing towards Klaksvík in the Faroe Islands.](https://newsletter.dvy.io/visit/Me9igYRh) [The Faroe Islands put a roundabout 72 metres beneath the sea](https://newsletter.dvy.io/visit/Me9igYRh) [The Eysturoyartunnil halves the drive from Tórshavn to Klaksvík, but its three branches meet at a tourist attraction 72 m below sea level: an 80 m steel ring of life-sized figures glowing blue around a rock pillar. Drivers can even tune to 97.0 FM for music composed for the eight-minute trip beneath the seabed.](https://newsletter.dvy.io/visit/Me9igYRh) [Hexagon map puzzle with green and orange districts, one boundary shown as a dashed line.](https://newsletter.dvy.io/visit/taLCr2iR) [A daily puzzle game about gerrymandering](https://newsletter.dvy.io/visit/taLCr2iR) Gerrymandle gives you a hex-grid map of coloured houses and asks you to draw connected districts that make green win. Put most orange voters into one district, giving orange an easy win, then spread the rest thinly across the others. Green can take most seats with fewer votes overall (democracy, but as a logic puzzle). [An interactive globe shows the 2026 total solar eclipse path and shadow layers across the North Atlantic and Europe.](https://newsletter.dvy.io/visit/W4Bf6iKo) [Every solar eclipse from 2024 to 2100, mapped interactively](https://newsletter.dvy.io/visit/W4Bf6iKo) Fred Espenak spent decades at NASA calculating eclipse predictions; this interactive map turns his data into animations of every solar eclipse from 2024 to 2100. Drop a pin anywhere to see exactly how much of the Sun will be blocked, while the umbral shadow (the small, dark patch where the eclipse is total) sweeps across Earth. [A person sitting on a bench outside an unusual Brutalist building with a circular base and a pointed roof.](https://newsletter.dvy.io/visit/HoCfqvs3) [France’s strange roadside architecture, catalogued in 10,000 photos](https://newsletter.dvy.io/visit/HoCfqvs3) Eric Tabuchi and Nelly Monnier have spent over two decades photographing France’s pigeon forts, flying-saucer swimming pools, abandoned Brutalist buildings, and other roadside oddities. Their Atlas des Régions Naturelles now holds more than 10,000 images, searchable by map, period, material, or even roof shape. [“The art of being wise is the art of knowing what to overlook.”](https://newsletter.dvy.io/visit/HMFK8nd7) [William James](https://newsletter.dvy.io/visit/HMFK8nd7) Poll Which newsletter format do you prefer? More links, less commentary (this style) Fewer links, deeper commentary (the old style) [Web](https://newsletter.dvy.io/visit/PXbVDgnb) · [Twitter](https://newsletter.dvy.io/visit/GVvZzVB9) · [LinkedIn](https://newsletter.dvy.io/visit/KbRydCrH)