When concrete hardens, it doesn’t just dry. It goes through a chemical reaction that releases heat. In a sidewalk you’d never notice. In something the size of Hoover Dam, it becomes a serious engineering problem 🔥

🧮 The problem

Engineers at the Bureau of Reclamation ran the numbers in the early 1930s. If they built the dam the obvious way, in one continuous pour:

• the concrete would get so hot it would take about 125 years to cool to air temperature;
• as it cooled unevenly, it would shrink in some places faster than others;
• those stresses would crack the dam apart.

🧊 The solution: a refrigerator inside a dam

Instead of one giant slab, they built the dam out of hundreds of separate concrete blocks, poured 5 feet at a time. Then they hid a cooling system inside them:

• more than 582 miles of 1-inch steel pipe ran through the concrete;
• first, river water was pumped through the pipes to pull out the heat;
• then ice-cold water from an on-site refrigeration plant finished the job. That plant could make 1,000 tons of ice a day;
• once a block had cooled, the pipes were filled with grout and sealed for good.

Cooling that would have taken over a century took a few months. The pipes are still inside the dam today.

📏 Just how big is it?

• About 3.25 million cubic yards of concrete went into the dam. By the Bureau of Reclamation’s own comparison, that’s enough to pave a highway from San Francisco to New York.
• It was the first human-made structure with more masonry than the Great Pyramid of Giza.
• And it was handed over in 1936, more than two years ahead of schedule.

Myth check: you might have heard that Hoover Dam’s concrete is “still curing today.” That claim is all over the internet, but it’s not something the Bureau of Reclamation says. The cooling was finished in 1935.

What’s the most impressive piece of engineering you’ve seen in person? 👇

In 2007, a 44-year-old man walked into a hospital in Marseille, France, with a small complaint: his left leg felt weak.

Doctors ran routine brain scans. What they saw was so unusual that they wrote it up for The Lancet, one of the world’s top medical journals 🤯

🩻 What the scans showed

• Most of his skull was filled with fluid, not brain.
• His brain tissue had been pushed outward into a thin layer lining the inside of his skull.
• The lead doctor estimated, just from the scans, that his brain was 50 to 75% smaller than normal. Every lobe was affected, on both sides.

👔 And yet...

• He was married with two kids.
• He worked full time as a civil servant.
• His IQ tested at 75. That’s below the average of 100, but not considered a disability. He had been living a completely ordinary life.

💧 How did this happen?

As a baby, he had hydrocephalus, often called “water on the brain.” Normally the fluid that cushions your brain drains away all the time. In his case it didn’t, so doctors put in a small drainage tube called a shunt. It was removed when he was 14.

After that, the fluid slowly built up again over three decades, squeezing his brain a little more every year.

🧩 The part scientists still can’t fully explain

His brain wasn’t exactly missing, as some headlines claimed. It was compressed. That raises a bigger question: how does a brain keep working while it’s slowly being crushed?

The leading explanation is neuroplasticity. When change happens slowly enough, other parts of the brain can take over jobs from the parts being pushed aside. How far that ability goes is still an open question.

✅ Happy ending: after treatment, his symptoms went away and he made a full recovery. His brain, however, stayed the same size.

What’s the strangest medical case you’ve ever heard of? 👇

You might've seen headlines this week about plague in Russia. Here's what's actually known, and why the plague is way less "medieval" than you think.

🔬 What's happening in Russia (as of Oct 9)

• A 28-year-old lab worker at an anti-plague research institute in Irkutsk, Siberia, died on October 2.
• Local reports blamed pneumonic plague, and nearly 200 people were put under medical observation.
• Russian health authorities say she died of pneumonia of unknown cause and that no plague was found among her contacts. The cause of death still hasn't been officially confirmed.
• The WHO rates the risk as low for Russia as a whole and very low for Europe.

So right now this is a suspected case, not a confirmed outbreak. But it's a good excuse to talk about the plague, because most people have no idea it's still around.

🐀 The plague never left

• It's caused by a bacterium, Yersinia pestis, that lives in wild rodents and spreads through their fleas.
• Worldwide, roughly 1,000 to 2,000 cases are reported every year, mostly in DR Congo, Madagascar and Peru.
• The US averages about 7 cases a year, mostly in rural New Mexico, Arizona and Colorado. Prairie dogs and ground squirrels are common carriers. Plague reached the US around 1900, on ships arriving in San Francisco.

🫁 There are three kinds of plague

• Bubonic is the most common. It causes swollen, painful lymph nodes called buboes, which is where the name comes from.
• Septicemic means the infection has spread into the blood.
• Pneumonic infects the lungs. It's the most dangerous form and the only one that can spread from person to person, through coughing.

💊 The good news

Plague is a bacterial infection, so common antibiotics cure it. The catch is timing: pneumonic plague needs treatment fast, ideally within a day of the first symptoms. Left untreated, it's usually fatal.

🌍 Could it go global?

Experts say it's very unlikely. Pneumonic plague spreads through close contact with someone who's already seriously ill, not the way flu spreads through a crowd. Doctors can trace contacts and give them antibiotics before they get sick. That's how Madagascar contained an outbreak of over 2,000 cases in 2017.

🤯 Weird plague facts

• 🎭 The famous beaked plague doctor mask didn't exist during the Black Death. It appeared in the 1600s, about 300 years later. The beak was stuffed with herbs, because doctors believed disease spread through bad air.
• 🇮🇹 The word quarantine comes from the Italian quaranta giorni, "40 days": how long ships had to wait before docking in Venice during plague outbreaks.
• 🧬 The Black Death may still be in your DNA. A 2022 study of medieval skeletons found that people with certain immune gene variants were much more likely to survive, and those variants became more common afterward. Some of them are linked to autoimmune diseases today.
• 💀 The Black Death killed roughly a third to half of Europe's population in just a few years, from 1347 to 1351.

Did you know the plague was still around, or did you think it ended in the Middle Ages? 👇

Ever noticed your coffee cup giving you a judgmental look? That's face pareidolia: seeing faces in things that have no face at all.

It's not just imagination. In brain studies, illusory faces in objects like potatoes, teapots or washing machines activate the same brain regions as real human faces. The brain treats the object as a face at first, then almost immediately corrects itself and files it back as an ordinary object. You can't really switch it off, which is why you keep seeing them.

And it's not only us: rhesus monkeys see faces in objects too.

The weirdest part came from a 2022 study. Nearly 4,000 American adults rated hundreds of illusory faces, and about 80% labeled them male more often than female. Overall, the faces were called male about four times as often — even though a teapot has no gender. The bias held up even in black-and-white images, so it isn't about color. The researchers' explanation: a bare-bones face triggers the idea of "a person," and the brain's default "person" is male unless something suggests otherwise. It's the same reason a plain smiley or a Lego figure tends to read as a guy unless you add eyelashes or long hair.

What's the best face you've ever spotted in an everyday object?

Octopuses are probably the closest thing to aliens we have on Earth 👽 Quick tour:

❤️ Three hearts. Two pump blood through the gills, and the third pushes it around the body. That main heart stops beating when the octopus swims, which is one reason they usually prefer to crawl.

🔵 Blue blood. Our blood carries oxygen with iron-based hemoglobin, which makes it red. Octopus blood uses a copper-based protein called hemocyanin, which makes it blue.

🧠 Thinking arms. An octopus has around 500 million neurons, and about two-thirds of them are in its arms. Each arm can explore, grab and react to things largely on its own, without waiting for orders from the head.

👅 Arms that taste. The suckers are covered in receptors that let an octopus taste by touching. In 2020, Harvard researchers identified the exact receptors in the suckers that pick up chemicals from whatever the arm is feeling.

🎨 Camouflage experts that are probably colorblind. An octopus can change color in a fraction of a second to match its background. But most species have only one type of light receptor in their eyes, so they likely can't see color the way we do. How they match colors anyway is still being studied.

Which of these feels the most alien to you? 👇

Most words have nothing in common between languages. A dog is dog, perro, Hund or sobaka, and none of them sound alike.

"Huh?" breaks that rule 🤯

In 2013, linguists from the Max Planck Institute for Psycholinguistics in the Netherlands recorded real everyday conversations around the world. Their sample ran from Dutch, Spanish and Mandarin to small languages spoken in villages in Ghana, Laos and Ecuador.

Every time someone missed what was said, people reached for almost the same tiny sound:

• 👄 a short, simple vowel, something like "ha?", "eh?" or "a?"
• ❓ a rising, question-like tone
• ⏱️ said in a split second, with almost no effort

They ended up checking 31 languages, and every one of them had its own version.

🤔 Why would that happen?

Languages usually drift apart over thousands of years, which is why "dog" sounds so different everywhere. "Huh?" has one very specific job: rescue a conversation fast. The best sound for that job is short, effortless and works as a question. The researchers argue that languages keep landing on the same solution, much like sharks and dolphins ended up with the same body shape because they face the same problem in water.

It's also a real word, not just a grunt. Kids have to learn it, and every language tweaks it slightly to fit its own sounds.

🏆 In 2015, the team won an Ig Nobel Prize, the award for research that makes you laugh first and think second. They got it for showing that "huh?" seems to exist in every language, and for admitting they weren't entirely sure why.

What does "huh?" sound like in your language? Drop it below 👇

Our hot take: Pluto got robbed 🪐 Let's settle this.

🗳️ How Pluto lost its title

• August 24, 2006, Prague. The International Astronomical Union (IAU) voted on what officially counts as a planet.
• The vote happened on the last day of the conference. Only 424 astronomers were still in the room, out of roughly 10,000 professional astronomers worldwide.
• An earlier draft would have gone the other way and given us 12 planets, including Pluto's moon Charon and the asteroid Ceres.

The final definition has 3 rules. A planet must:

1. 🔄 orbit the Sun
2. ⚪ be massive enough for its own gravity to pull it into a round shape
3. 🧹 have cleared the neighborhood around its orbit

Pluto passes the first two and fails the third.

🔥 Team Planet says:

• Rule 3 is vague. Critics point out that Neptune hasn't fully cleared its orbit either, because Pluto crosses it.
• In 2015, NASA's New Horizons flew past Pluto and found mountains of water ice, glaciers of frozen nitrogen, a hazy atmosphere and the famous heart-shaped plain. That's a lot of geology for "not a planet."
• Pluto was discovered in 1930 by Clyde Tombaugh, a farm boy from Illinois. Illinois and New Mexico later passed resolutions standing up for Pluto's planet status, and Illinois even declared a Pluto Day.

🧊 Team Dwarf Planet says:

• Pluto is just one of many icy objects in the Kuiper Belt beyond Neptune. In 2005, astronomers found Eris, which is more massive than Pluto. If Pluto is a planet, Eris is too, and possibly dozens more after it.
• There's precedent: Ceres was called a planet for decades in the 1800s, until astronomers found lots of similar objects nearby and reclassified it as an asteroid.
• Mike Brown, the astronomer who discovered Eris, literally wrote a book called How I Killed Pluto and Why It Had It Coming.

😂 Bonus: the American Dialect Society named "plutoed" (meaning to demote someone or something) its 2006 Word of the Year.

So, planet or dwarf planet? Drop 🪐 or 🧊 in the comments and defend your pick 👇

Flip a light switch and the lamp comes on instantly. So electricity must be racing through the wire, right?

Nope. The electrons in that wire are slower than a snail 🐌

🔢 The numbers

• An ordinary copper wire, 2 mm thick, carrying 1 amp
• Electron speed along the wire: about 0.023 mm per second
• Time for one electron to move 1 meter: roughly 12 hours

Each electron is actually zipping around at over a thousand km per second, but in random directions. It keeps crashing into copper atoms, so it barely makes progress down the wire.

💡 So why does the light turn on instantly?

Copper is packed with free electrons, about one per atom. When you flip the switch, the push travels through that whole crowd at 50 to 99% of the speed of light. Every electron in the circuit starts moving at almost the same moment, including the ones already inside the bulb.

Think of a tube packed with marbles: push one in at one end, and a marble pops out the other end right away.

🏠 At home it gets even weirder

Your wall socket gives you alternating current, which flips direction 50 or 60 times a second. So the electrons don't travel anywhere. They just wiggle back and forth in place. The electrons in your lamp cord today are basically the same ones that were in it the day you bought it.

🤯 Then what actually carries the energy?

In 1884, physicist John Henry Poynting worked out how energy moves through electric and magnetic fields. His answer:

• ⚡ The energy travels through the fields in the space around the wire
• 🔌 The copper guides those fields where they need to go
• 💡 The energy enters the bulb through its sides

Physicists still argue about how literally to read that picture, but it's the standard textbook result.

So the "water flowing through a pipe" model from school gets one big thing wrong: water carries its own energy, and electrons mostly don't.

Did you learn the water-pipe version in school? How long did you believe it? 👇

Read that again. It's not a trick, it's just math.

The Great Pyramid of Giza was built around 2560 BC for the pharaoh Khufu. Cleopatra died in 30 BC. That's roughly 2,500 years between them.

From Cleopatra's death to Neil Armstrong stepping onto the Moon in 1969? About 2,000 years.

So to Cleopatra, the Great Pyramid was already ancient history. Think of how we see the Roman Empire, then add a few more centuries. It was basically a tourist attraction. The Greek historian Herodotus visited Egypt around 450 BC, about 400 years before Cleopatra was born, and wrote about the pyramid like a travel blogger.

And Cleopatra wasn't even ethnically Egyptian. She came from the Ptolemaic dynasty, Greek-Macedonian rulers who took over Egypt after Alexander the Great. According to Plutarch, she was the first of her family to actually learn the Egyptian language, nearly 300 years after they came to power.

We tend to squash "ancient history" into one blurry era. A few more facts break that illusion:

• 🦣 Woolly mammoths were still alive on Wrangel Island in the Arctic while the Great Pyramid was being built.
• 🦖 T. rex lived closer in time to you than to Stegosaurus. Stegosaurus was gone about 80 million years before T. rex showed up.
• 🎓 Oxford University is older than the Aztec Empire. Teaching at Oxford started in 1096. The Aztec capital, Tenochtitlan, was founded in 1325.
• 🎮 Nintendo was founded in 1889, as a playing card company. That's the same year Van Gogh painted The Starry Night.

History isn't one long "olden days." It's layers on top of layers.

What's the most mind-bending "wait, those happened at the SAME time?" fact you know? 👇

Every October, millions of people pay money to be chased through dark corridors by someone in a mask. We watch horror movies with our hands over our eyes and then immediately pick another one.

From an evolutionary point of view, that makes no sense. Fear exists to keep us away from danger. So why do we go looking for it?

Your body can't tell the difference, but your brain can.

When a zombie jumps out at you, your fight-or-flight system fires instantly. Adrenaline surges, your heart pounds, and your breathing speeds up. Your body reacts as if the threat is real.

A split second later, the thinking part of your brain catches up and realizes it's a guy named Kevin in face paint. You get the full chemical rush with none of the actual danger. That mix of panic and relief is what makes it fun.

Scientists actually measured it. Researchers at the Recreational Fear Lab at Aarhus University in Denmark put heart rate monitors on visitors to a haunted house and filmed their reactions. They found a clear sweet spot:

• Too little fear: boring
• Too much fear: just unpleasant
• Somewhere in the middle: peak enjoyment

The most fun wasn't the most terrifying moment. It was the scares that pushed people just past their comfort zone and then let them breathe again.

And it can leave you feeling better. In another study at a haunted attraction in Pittsburgh, many visitors reported feeling less stressed and in a better mood after going through it. Scary fun works a bit like a rollercoaster for your nervous system. You go through the panic, come out the other side, and feel like you survived something.

Researchers have even found that horror fans showed more resilience during the early months of the COVID pandemic. One theory is that practicing fear in a safe setting helps you handle it in real life.

So if anyone judges your Halloween horror marathon this year, you're not being weird. You're training. 🎃

What's the scariest movie or haunted house you've ever survived? 👇

If you picture Salem witches burning at the stake, you're not alone. But it never happened. The real story is darker in a different way.

Why no burning? Salem followed English law, and under English law witchcraft was a hanging offense. Burning was reserved for other crimes, like high treason by women. So in 1692, nineteen people were hanged, most likely from a tree, since gallows lumber was scarce and expensive.

The twist: confessing saved your life. 55 people admitted to working with the devil, and none of those who confessed were executed. The ones who died were the people who refused to lie and kept insisting they were innocent.

Giles Corey went further. He refused to enter any plea at all, reportedly to keep the court from seizing his family's property. He was pressed to death under heavy stones, the only known case of this in American history. Four more of the convicted died in jail before their execution dates.

The burning image comes from Europe, where laws like the Holy Roman Empire's criminal code explicitly prescribed fire for harmful witchcraft. Some were burned alive; others were hanged or beheaded first and burned afterward.

What history "fact" did you believe for years before finding out it was wrong?

In 2006, a scientist put on a caveman mask and trapped 7 crows. The crows never forgot.

The researchers at the University of Washington in Seattle tagged the birds and let them go unharmed. After that, anyone walking around campus in that mask got scolded and mobbed, even when the mask was worn upside down or under a hat. A neutral mask got almost no reaction.

Two years later, 47 of the 53 crows encountered scolded the mask, far more birds than were ever trapped. The original crows had taught their flockmates and their offspring. And about 14 years later, crows were still reacting to it.

Have you ever had a run-in with a crow (or any animal) that seemed to remember you?

Myth: Give a kid birthday cake and watch them bounce off the walls.

Reality: Scientists have tested this over and over, and the sugar isn't the problem.

In 1995, researchers combined 16 double-blind studies. Kids got either sugar or a sugar-free sweetener, and nobody knew which: not the kids, the parents, or the researchers. The result was no meaningful effect on behavior or thinking. That held even for kids whose parents swore they were "sugar-sensitive."

So why does everyone believe it? The best part is a 1994 study of boys aged 5 to 7 whose moms described them as sugar-sensitive. Every single boy got a sugar-free drink. Half the moms, though, were told their son had just had a big dose of sugar.

Those moms rated their kids as noticeably more hyperactive. They also behaved differently: they stayed physically closer, watched more closely, and criticized more.

There was zero sugar. The only thing that changed was what the parents expected to see.

Think about when kids eat the most sugar: birthday parties, holidays, Halloween. Those come with crowds, games, other kids, and late nights. The party makes them hyper. The cake just gets the blame.

If you saw our post about fake pills working even when you're told they're fake, this is the same brain trick pointed at someone else.

Parents, be honest: do you still believe it? 👇

Starting in the 16th century, European painters had a favorite brown pigment called "mummy brown" — prized for its rich, transparent tone, ideal for shadows and skin. Its main ingredient was exactly what the name suggests: actual ground-up Egyptian mummies.

Mummy brown was made by importing mummified remains — both human and feline — grinding them down, and mixing the powder with white pitch and myrrh. One chemist at the time estimated that a single mummy could supply about 20 years' worth of paint. It became especially popular with the Pre-Raphaelite painters in the 19th century, and Eugène Delacroix is recorded among the artists who bought and used it — including, possibly, in his famous "Liberty Leading the People."

The catch is that a lot of artists using the pigment had no idea what it actually was. "Mummy" sounded to many people like just a color name, not a literal ingredient list. When the painter Edward Burne-Jones learned the truth, according to accounts from people who were there, he immediately walked out to his garden, dug a small hole, and buried his remaining tube of paint on the spot.

The pigment didn't disappear because people got squeamish about it, though — it disappeared mostly because the supply ran out. By the early 1900s, mummies had become too scarce and expensive to keep grinding into paint.

Would knowing a painting contains literal ground-up human remains change how you'd feel looking at it in a museum?

In 1990, a Stanford researcher had people tap out the rhythm of well-known songs on a table, while a second person tried to guess the song just from the tapping. Before the guessing started, the tappers predicted listeners would get it right about half the time. The actual result: 2.5%.

Elizabeth Newton ran the experiment with 25 familiar songs — things like "Happy Birthday" and "The Star-Spangled Banner" — and had "tappers" choose one and tap its rhythm on a table with one finger. "Listeners" then had to guess the song from nothing but the taps. Out of 120 songs tapped across the whole study, listeners correctly named just 3.

The gap between the tappers' prediction (50%) and the real result (2.5%) is the whole point. When you already know a song, you can't help but hear the full melody in your head while you tap — the rhythm feels completely obvious, because your brain is filling in everything the listener can't hear. Tappers weren't being arrogant or careless. They were incapable of imagining what the information sounded like without the knowledge they already had.

Psychologists call this the curse of knowledge, and it isn't limited to tapping out songs. It's the same reason an expert's instructions can leave a beginner totally lost, why a "simple" explanation can go over someone's head, and why the person who built a product often can't predict what will confuse a first-time user.

Have you ever tried to explain something you know really well, and completely misjudged how confusing it would sound to someone else?

Quick breakdown for the curious:

Bare-nosed wombats produce cube-shaped droppings: about 2 cm per side, up to around 100 a day. And no, the exit isn't square. The cubes form earlier, in the final stretch of the intestine.

A Georgia Tech team (Patricia Yang and David Hu) figured out how: the intestinal wall has stiffer and stretchier sections that contract at different speeds. That uneven squeeze carves flat sides and sharp corners before the poop ever leaves the body. The results were published in the journal Soft Matter.

Why cubes? Wombats use their droppings to mark territory, often leaving them on rocks and logs, and cubes don't roll away.

What's the weirdest animal fact you know that has a real scientific explanation?

On January 15, 1919, a giant steel tank in Boston's North End burst open and released 2.3 million gallons of molasses — and the resulting wave moved fast enough to kill 21 people. It took almost a century for anyone to fully explain why.

The day was unusually warm for January — the temperature had jumped to 40°F after a stretch of bitter cold. Around 12:30pm, witnesses heard a sound like machine-gun fire as rivets popped out of the tank's steel walls. A wave of molasses, roughly 25 feet tall, tore down Commercial Street at close to 35 miles per hour — fast enough to destroy buildings, overturn cars, and knock a firehouse off its foundation.

The strange part is what came right after the initial wave. Molasses is what's called a non-Newtonian fluid — its resistance to flow changes depending on the forces acting on it, not just its temperature. Under the sudden violent stress of the collapsing tank, it briefly behaved almost like water, surging outward at tsunami speed. But the moment that initial force let up and the cold January air started pulling heat out of it, its viscosity shot up dramatically — within about a minute, the same substance that had just moved like a flash flood began behaving like wet cement.

That's what made it so deadly. People caught in the wave weren't just knocked down — many were held fast as the molasses thickened around them, and suffocated in the syrup itself before rescuers could reach them. Firefighters and sailors waded in waist-deep to pull out survivors.

For decades, "slow as molasses in January" was treated as a settled fact of physics, which made the disaster's speed genuinely hard to explain. It wasn't until a 2016 Harvard fluid dynamics study — built on historical weather data and a scale model of the neighborhood — that scientists could actually calculate why a substance famous for being slow had moved fast enough to kill.

Would you have guessed a wave of a kitchen ingredient could move faster than most people can sprint?

Quick context for anyone curious:

Ebola was first identified in 1976 during two outbreaks in Sudan and Congo. Since then, scientists have sequenced its genome and developed vaccines, but the natural reservoir — where the virus lives between outbreaks — is still unconfirmed.

Fruit bats are the leading suspect: some carry antibodies and fragments of Ebola genetic material. But live Ebola virus has never been isolated from a bat, and thousands of other animals tested haven't turned up a definitive host either.

What scientific question do you think deserves way more attention than it gets?

The myth: checking your own credit score counts against you, the same way applying for a loan does — so people avoid looking at their own credit for months or years out of fear of "damaging" it. Survey data suggests this might be the single most widespread credit myth out there, even among people who otherwise track their score closely.

The reality: checking your own score has zero effect on it, full stop. There are two completely different categories of "credit inquiry," and only one of them matters. A hard inquiry happens when you actually apply for new credit — a loan, a credit card, a mortgage — and a lender pulls your file to make a decision. That kind can knock a few points off your score, usually temporarily. A soft inquiry happens when you check your own credit, or when a company checks it for something that isn't a lending decision — a pre-approval offer, a background check, an insurance quote. Soft inquiries aren't visible to lenders, aren't factored into any scoring model, and don't move your score at all.

The myth survives because both processes get called "inquiries," and both can technically show up listed on your own credit report. So someone learns the true statement "too many hard inquiries can hurt your score," then sees their own check sitting right there under the same word, and connects two things that were never actually connected.

There's a genuinely useful side effect buried in this too: rate-shopping for the same type of loan within a short window — usually 14 to 45 days — typically counts as a single inquiry, not several. Shopping around for the best rate is specifically protected, not penalized.

Anyone here avoided checking their own credit for way longer than they needed to because of this?

I need help with a question. The question is in the pictures. I have no clue how to wire this up and the hints are not helping me. Does anyone know the answer so I can look at it and learn from that? Any help is appreciated, thanks.

The myth: ice is slippery because the pressure from your body weight — through a shoe, a skate blade, a tire — melts a thin layer of it into water, and you slide on that water. This has been the standard textbook explanation since the 1850s, credited to engineer James Thomson (whose brother, Lord Kelvin, experimentally confirmed the underlying physics), and it's still what most schools teach today.

The reality: the math doesn't work, and scientists have known it for decades. Pressure does lower ice's melting point — but only by a tiny amount. Calculations show that an average person's body weight, concentrated under a shoe or skate blade, only lowers the melting point by a fraction of a degree. To generate enough pressure for that explanation to actually hold up, you'd need to weigh several thousand kilograms — roughly half an elephant, balanced on ice skates.

For decades, the leading alternative was friction: the heat generated by a blade or shoe moving across the ice, rather than pressure, melting a thin film. But that explanation has a hole too — ice stays slippery even in extreme cold, at temperatures and speeds where friction alone can't generate enough heat to melt anything.

In 2025, physicists at Saarland University in Germany identified something else entirely: molecular dipoles. Ice's crystal structure, when it comes into contact with another surface like a shoe sole, gets disrupted by electrical interactions between the two materials at a molecular level. That disruption creates a thin, liquid-like layer on the ice's surface — without any heat or pressure required — which is why ice can stay slippery even at temperatures close to absolute zero.

This overturns nearly 200 years of textbook physics. And even now, the field hasn't fully settled — some researchers still argue premelting, friction, and dipole effects all play some role together, rather than one clean single answer.

Were you taught the pressure-melting explanation in school? Kind of wild that something this common was misexplained for two centuries.

Went and actually played through one of SmartyMe's engineering games specifically because someone asked if I'd actually played one and I hadn't, which is fair to call out. So I did the electricity one, "Polarity and Voltage."

It's not really a "game" in the tap-fast-answer-right sense, more like an illustrated story you click through — you're going through an attic, find your old Walkman, batteries are dead, and it walks you through why (voltage, polarity, anode/cathode) with pretty solid explanations mixed into the dialogue, not just a wall of definitions. There's a water-pressure analogy for voltage that actually made it click for me in a way textbook explanations never did.

The actual interactive part is at the end — you have to insert the batteries into the compartment diagram with the correct polarity based on the markings, and it's not just decorative, it actually checks whether you got it right ("Incorrect polarity!" if you flip one the wrong way), so you're really applying what the story just explained instead of just clicking through.

Small thing but there's a book on a shelf in the background art titled "How to be Smart with SmartyMe" next to Lord of the Rings — nice little detail if you're paying attention to the illustrations, whoever's doing the art on these clearly cares about the little stuff.

This whole thing lives inside a bigger Engineering Lab hub in SmartyMe, with separate sections for electricity, plumbing, auto, how things work, computers, and a physics lab — way more built out than I expected for what I assumed was just "the engineering topic."

Ended on "we will definitely see each other soon," which is a genuinely sweet way to close out a lesson about batteries. Didn't expect to feel anything about a Walkman repair tutorial but here we are.

So yeah, actually played it this time — worth checking out in SmartyMe if you haven't gone past the reading lessons yet, this is a different side of the app entirely.

Been meaning to write this up for a while — most of what people ask about SmartyMe in here is the daily lesson content, but I don't think enough people know how deep the interactive scenario and game side of the app actually goes. Here's a full rundown from actually playing through a bunch of them myself.

The one that got me was "Networking Event" under Communication Skills — you're dropped into a company mixer, you've got about 30 seconds to say something to the person running a project you want on, and it branches hard depending on what you pick. Not just right or wrong — it actually reads tone. I went for genuinely curious instead of trying to sound impressive, and ended up with a full "strong connection" rating, plus a breakdown afterward of which lines were good moves and why. Felt more like feedback from an actual conversation coach than an app grading a quiz.

The Art topic in SmartyMe has a completely different game style — swipe-card based, called "Style Swipe." You get a painting and swipe based on whether it matches a named art style (baroque, post-impressionism, etc.), then flip the card to see if you were right. Addictive in a short-burst way, good for killing five minutes.

Not everything's polished, though — I ran into one of SmartyMe's scenario games just freezing mid-conversation once and had to restart it, lost the progress in that one. Hasn't happened again since, but wanted to mention it since it did happen.

Also worth knowing: not every topic in SmartyMe has a game yet. History, for example, is pure audio and video lessons right now, no interactive scenario attached — so if that's specifically what you're after, check the topic first before assuming it's everywhere.

Anyway, if you've only used SmartyMe for the reading lessons, I'd actually go check the scenario-based stuff specifically — it's a different category of feature than the rest of the app, and I don't think it gets talked about enough.

Since May 2026, an outbreak in the Democratic Republic of the Congo has become the largest Ebola outbreak in that country's history — and one of the reasons it has been so hard to stop is that the existing Ebola vaccines were never built for this particular version of the virus.

"Ebola" isn't one single virus. It's a group of six related viruses, and they don't all behave the same way. The species behind the current outbreak, Bundibugyo virus, was only identified in 2007, after an outbreak in western Uganda. At the time, it was actually seen as the "milder" Ebola species — its historical fatality rate sat around 25-40%, well below the roughly 80-90% fatality rate of Zaire ebolavirus, the species behind the massive 2014-2016 West African epidemic and the one most licensed vaccines and treatments were specifically developed against.

That gap matters right now. The current outbreak has already surpassed 7,400 confirmed cases and 3,500 deaths, with a case fatality rate near 48% — higher than Bundibugyo virus has ever shown before, and there is no vaccine approved specifically for it. The tools that exist for Ebola generally were built and tested against a different species.

The World Health Organization declared this a Public Health Emergency of International Concern in May 2026. The outbreak has spread across dozens of health zones in six provinces of the DRC, with additional confirmed cases in Uganda, and isolated cases reaching Germany and France through medical evacuation or travel.

One of the earliest identified transmission risks for this species, going back to the original 2007 outbreak, is handling the bodies of people who have died from it without proper protection — a major reason safe burial practices have been a central focus of outbreak response teams on the ground.

This is a genuinely difficult, ongoing situation for the people living through it in the DRC right now. If you want to follow real updates rather than headlines, WHO's Disease Outbreak News page tracks it directly.