Feed aggregator

Most writing and talking embraces our usual illusions on human motives. In our book The Elephant in the Brain (with Kevin Simler) we instead expose such illusions. Which many have told us feels depressing and demotivating; it’s not what they wanted to hear. It’s right there in the title, an analogy to “The Elephant in the Room”, which is a big topic which people in a room pointedly ignore.

Yet we’ve sold over 60K copies over 8 years, which is quite good for an academic book. We got some pretty high profile early reviews. And have even been on few class syllabi. So there is clearly an audience for our message. But why, if it tells things people don’t want to hear?

The most prestigious intellectuals in our world are writers of op-eds, and givers of TED and keynote talks. And such luminaries often offer policies and stances based on their claims that ordinary people are typically mistaken on key things. For example, this is the usual rationale for paternalism, which justifies over half of government intervention (as well as legal rules of evidence). So there is in fact a big audience for claims that most other people are wrong; that’s why you say the world should let your people take control. As another example, consider how popular was Al Gore’s An Inconvenient Truth, another title that telegraphs such a message.

However, a different kind of deep illusion finds a far smaller audience. Our most prestigious intellectuals are cultural warriors, who to be popular and effective must project a graceful and compelling confidence in their moral stance, a stance that they convince readers is shared between them. Their key culture war stance is that we, our side, correctly feels a clear and compelling impulse to push hard to get our way. As we are obviously morally right, and they are wrong.

Alas, this is the sort of illusion that I must apparently try to expose in order to get people to see our key modern problem of cultural drift. I can explain the logic of this problem easily enough, if I can get people to stand outside of their particular culture, and see the cultural evolution process in the abstract. Yet, alas, from that vantage point, few feel much motivation to care. I haven’t succeeded at all at the key op-ed writer task of projecting a graceful confidence in a supporting moral stance, a stance I convince readers that they share with me, in opposition to an evil other side.

In order to understand the addressable market case for many of the AI and space markets you must understand replatforming. Replatforming is when a fundamentally better technology platform displaces or layers on top of the old infrastructure and business models. It wins because it offers lower costs, vastly better scalability, broader accessibility, and new capabilities ...

Read more

An extremely rare piece of Olympics history hits the auction block this week. Sports enthusiasts with deep pockets have the chance to own an original gold medal from the 1924 Paris Summer Olympics. 

The harp on this side of the medal represents the Cultural Olympiad, an artistic and cultural program that ran alongside the athletic competition. Image: Nate D. Sanders Auctions.

The 1924 Paris Games were a hallmark of Olympics and sports history. More than 3,000 athletes from 44 countries competed in the first Olympics to include a Closing Ceremony. American swimmer Johnny Weissmuller won three gold medals and later went on to play Tarzan in 12 films. Swiss tennis player Richard Norris Williams won gold, after surviving the sinking of the RMS Titanic in 1912. He almost lost both his legs after jumping into the freezing water, but made a full recovery. The Paris Games were also featured in the award-winning film Chariots of Fire.

The 1924 Paris Games were also the first to officially feature the iconic five-ring Olympic symbol. The rings were designed by Baron Pierre de Coubertin, the founder of the modern Olympics and symbolize five continents and athletic unity. 

This symbol of sportsmanship set the standard for future medals. Image: Nate D. Sanders Auctions. 

The medals were designed by sculptor André Rivaud. The obverse side shows a winning athlete reaching out to help a fallen competitor, an image of sportsmanship that set the standard for future Olympic medal design. The five Olympic rings are beneath this scene. The reverse side features sports equipment alongside a harp, a nod to the Cultural Olympiad. This artistic and cultural program ran alongside the athletic competition to explore the links between art and sport and the values they both share.

The medal is about 2 inches in diameter and weighs 2.7 ounces. It is listed as “near fine condition,” is made from gold-plated gilt silver and has the “2ARGENT” stamp on the rim as a mark of authenticity. Only 304 gold medals were originally produced, making them one of the   rarest and most coveted pieces of Olympic history in existence. The auction will take place on May 28 with a minimum bid of $14,000.

Only 780 days to go until the 2028 Summer Olympic Games in Los Angeles, California. 

The post Extremely rare 1924 Olympic gold medal up for auction appeared first on Popular Science.

For a woman in her mid-40s to mid-50s, it arrives without warning. She wakes up, overheated, wondering why it’s so hot in the house—until she sees the thermostat is set for 70 degrees, same as always. Or, she’s midway through a work presentation when heat rises from her chest to her face, and she wonders if the flush on her cheeks is visible to everyone in the room. 

It’s a hot flash—a rite of passage for the majority of women in either perimenopause, the years leading up to menopause, or the years beyond it. Menopause itself is diagnosed after 12 consecutive months without a period, but the hot flashes don’t always get the memo.

Here’s everything doctors currently know about hot flashes.

What is a hot flash, and who gets them?

Hot flashes are a sudden heat flare up often paired with flushed skin and sweating. They don’t usually last long, between a minute and five minutes in duration.

Most women experience a hot flash about four and a half to five years after their last period, Dr. Monica Christmas, an OB/GYN at University of Chicago Medicine and director of its menopause program tells Popular Science. She also is the associate medical director of the nonprofit Menopause Society, which provides healthcare professionals with tools and resources to support women through the transition.

Women have grappled with hot flashes—whether simply annoying or genuinely debilitating—for centuries. In 1582, Dr. Jean Liebault of France was among the first to document the phenomenon. But while we know much more about hot flashes and night sweats than Liebault ever did, one question still stumps experts. 

“What we can’t answer is why doesn’t everybody get them,” Christmas says. “Because everybody doesn’t get them. I have patients that will say, ‘I don’t know,’ if I say, ‘Are you having any hot flashes or night sweats?’ And as soon as they say that, I’m like, ‘You’re not having them.’” 

What’s actually happening inside women’s bodies during a hot flash? 

During a hot flash, a woman might feel like she’s spiking a high fever, but physiologically, that’s not what is happening. As women approach menopause and the ovaries begin to make less estrogen, the brain’s internal thermostat—the hypothalamus—becomes hypersensitive to even small shifts in temperature, Christmas says.

The body “thinks” it’s overheating, even when the actual temperature hasn’t changed much. In response, our bodies try to cool us down. Blood vessels dilate, which is supposed to help dissipate some of that heat, but then that triggers a sweating reflex.

“Many people will say, ‘I feel this out of nowhere, this surge of warmth that typically is from the nipple line up,’” she says. “And then as soon as the heat came on, and I felt like I was internally heated up or on fire, I start to sweat.” 

Related 'Ask Us Anything' Stories

Can you overdose on cough drops? Short answer: Yes.

Why scars never disappear

Why do your joints hurt when it’s cold? We asked a doctor.

What’s a brain freeze and why do they happen?

Why do we even have baby teeth?

Why we have two nostrils instead of one big hole

How do women experience hot flashes differently? 

Exactly how an individual woman experiences hot flashes varies wildly. Some describe very mild symptoms. Others grapple with profuse sweating. Some experience only hot flashes during the day, while some have regular night sweats. About four in five women experience them at some point during the menopause transition, according to the American College of Obstetricians & Gynecologists.

“There’s a lot of variability,” Christmas says. Common triggers include alcohol, caffeine, high-sugar and highly processed foods, along with stress.

Black women also are more likely to experience more severe and longer-lasting symptoms, sometimes up to 11 years, she says. And research also shows that women with more severe, longer-lasting hot flashes and night sweats appear to be at higher risk of cardiovascular disease.

That doesn’t mean treating hot flashes automatically lowers heart risk, Christmas says. But it does reinforce that these women deserve particularly careful attention to blood pressure, cholesterol, and lifestyle. “I want to make sure I’m doing everything possible to minimize that risk,” she says when she treats her patients. 

There’s more to hot flashes than hormonal changes

For decades, the entire process was blamed purely on estrogen loss, Christmas says. But that explanation left some unanswered questions. 

“That doesn’t explain why every menopausal woman doesn’t have night sweats,” she says. “And it also doesn’t quite explain why we can sometimes start to experience them during the perimenopause transition because during perimenopause, people still have some estrogen.” 

Newer research now is telling a more complex story. When the brain recognizes that a woman’s estrogen levels are low, nerve cells in the hypothalamus called KNDy neurons (pronounced “candy”) become overactive, releasing neurotransmitters, which are chemical signals the brain uses to send messages throughout the body. These neurotransmitters include kisspeptin, dynorphin, and neurokinin B. 

“It’s actually those neurotransmitters that seem to have more of an impact on our ability to regulate our internal temperature,” Christmas says. “They’re not hormones.” 

What to do if you get a hot flash

For women in the middle of their hot flash years—along with the 10 percent of menopausal women who continue to experience them—there are treatments. 

Estrogen-based hormone therapy can help, but not every woman, including those with a history of blood clots or breast cancer, can take hormone therapy. 

Hormone therapy can help alleviate hot flashes. Video: Hormone therapy – Four things a Mayo Clinic women’s health specialist wants you to know., Mayo Clinic

Fortunately, researchers’ new understanding about the role of KNDy neurons has allowed for new treatments that block the brain signals that trigger hot flashes in the first place. The FDA approved a new drug called Veozah (it’s chemical name is fezolinetant) in 2023. It targets the neurokinin 3 receptor, which plays a key role in regulating body temperature. 

Lynkuet, another drug (with the chemical name elinzanetant), came along in 2025. It blocks both the neurokinin 1 and neurokinin 3 receptors, interrupting the process that triggers hot flashes at two points instead of one. 

Other medications can also provide relief, though weren’t originally developed for hot flashes, Christmas says. Some SSRIs and SNRIs; gabapentin, a neurologic medication; and oxybutynin, used for overactive bladder, are all used off-label for hot flashes and night sweats. 

Cognitive behavioral therapy and hypnosis also have been shown to reduce hot flashes. “I’m menopausal, too, so I know if I’m under a lot of stress or in a stressful situation, I’m going to probably have more hot flashes than not,” Christmas says. 

“So there’s certainly something about being able to calm our central nervous system down that seems to have an impact, too.”

If you’re struggling with hot flashes, Christmas recommends seeing your healthcare provider for help. Treatments are available. What’s more, in some cases, hot flashes or night sweats could signal other issues, including thyroid disorders, cancer, and infections, among others. 

But bottom line, when it comes to hot flashes, you don’t have to sweat them out.

In Ask Us Anything, Popular Science answers your most outlandish, mind-burning questions, from the everyday things you’ve always wondered to the bizarre things you never thought to ask. Have something you’ve always wanted to know? Ask us.

The post What happens inside your body during a hot flash appeared first on Popular Science.

SpaceX will be able to more than double its revenue every year from 2026-2028 and beyond. Most of the revenue and profits will come from AI. AI infrastructure at the data centers they build 4 times faster than competitors and at thousands of Tesla energy locations and then in space. This will enable more revenue ...

Read more

In my last post I reported:

For the last century, … averaging over [3] LLMs, 89% of culture trends that can be classified are toward-forager.

And 81% of such trends can be so classified. For the prior two centuries this explanatory power was weaker (59%,65%), but still substantial. This suggests a way to predict the next century: predict toward forager trend changes.

So I collected 22 future trends that would plausibly be predicted by a continuing toward-forager-style trend. I then set aside these 7 trends as ones that could also be as plausibly predicted by increased wealth, education, or world connection:

↓ Fertility; ↑ Travel, Migration;↓ Nationalism;↓ Religion, ↑ Spirituality; ↑ Emotion Talk, Legitimacy; ↑ Flexible Work Hrs, Places; ↑ Casual Dress, Etiquette.

That left these 15 trends as better tests of the toward-forager hypothesis:

↑ Business Regulation; ↑ Kid Autonomy; ↑ Loose Drug Norms; ↑ Loose Sex Norms; ↑ Nature Sacred; ↑ Redistribution; ↓ Convict, Animal Cruelty; ↓ Family, ↑ Friends; ↓ Gender Roles; ↓ Institution Authority; ↓ Marriage; ↓ Militarism; ↓ Monogamy; ↓ Politics Via Orgs; ↓ Rank/$, ↑ Charisma.

To further consider this hypothesis, I asked poll respondents to rank, and 3 LLMs to predict, the chance that each will be a world trend over the next century. Here are human relative priorities and median LLM chances:

LLMs give a mean chance of 67%, about the fraction they said fit toward-forager trends in 1826-1926. So LLMs foresee a much lower predictive power for the next century, compared to the last century. But the correlation between humans and LLMs here is -0.06, so humans disagree with LLMs lots here. In a century we’ll have actual trend data to more directly see who was right.

In March, we reported on a wild bobcat that had been hit and dragged by a car, who also got her head stuck in the car’s grill. As if things could get any worse, the wild feline arrived at Raven Ridge Wildlife Center in Pennsylvania on a Sunday, and the nearby veterinary practice was closed. But thanks to two lucky acquaintances, a mobile x-ray machine was brought in, revealing that the bobcat had broken two legs. 

Thanks in part to the fact that her bone fractures were clean breaks, her team decided to risk a surgery. The next morning, two surgeons operated on the bobcat contemporaneously. After the operation, Tracie Young, director of the Raven Ridge Wildlife Center, told Popular Science that she was doing “fantastic” and “starting to act like a bobcat.” 

The female feline has been healing at Raven Ridge Wildlife Center for two months. Image: Dawn Rise Ekdahl / Raven Ridge Wildlife Center.

In her great misfortune, the cat has been rather lucky—and it seems like the luck is holding. Two striking coincidences have now come together to get her a custom-made cage for her rehabilitation. 

“After two months of recovery, the bobcat now needs to be moved outside for exercise and to begin building muscle tone,” the wildlife center wrote on social media. “We had to devise a safe and creative way to get her outdoors, necessitating the construction of special caging. We determined that a custom dog kennel would be the only viable option.”

However, the problems were twofold: time and money. The dog kennel builders the wildlife center contacted needed at least eight months to build the rehab cage, and the project would cost thousands of dollars. But then Raven Ridge’s photographer Dawn called her neighbor Glen for suggestions, who turned out to be the owner of a kennel-building business and could build the kennel in two weeks. 

The custom-built kennel was made for the bobcat in only two weeks. Image: Dawn Rise Ekdahl / Raven Ridge Wildlife Center.

And if you think that’s enough of a coincidence, it gets even better. The very day construction commenced, Raven Ridge Wildlife Center received a letter with a generous donation. A woman named Raven Minervino has passed away, and her husband wrote that she had consistently supported the wildlife center. After she died, her husband had asked that rather than getting flowers, people make donations in her memory. The letter had a donation in her memory large enough to pay for the custom bobcat cage.

“Thanks to all this support, we successfully moved the bobcat to the new enclosure, where she is now exploring, exercising, and much happier,” reads the social media post. Raven Ridge plans to (or perhaps already has) put a plaque in Minervino’s memory on the cage. 

Both of the bobcat’s broken legs have healed, and since having the custom cage, she has put on ten pounds, bringing her to the much healthier total of 19 pounds. Adult female bobcats weigh approximately 15 to 20 pounds on average

The post Bobcat that survived being hit by a car gets a custom-built kennel appeared first on Popular Science.

To effectively travel on Mars, rovers need to deal with a lot of sand. German engineers have created a new kind of ground rover that uses swimming motions to push through sand that may otherwise cause the  wheels to get stuck. Its inspiration: the African sandfish (Scincus scincus), a lizard known for burrowing into the Sahara Desert and literally swimming through its sand like a fish. It’s one of the animal kingdom’s strangest methods of propulsion, but it may help shape the future of Mars exploration.

A video of the rover, released this week by the University of Würzburg, shows a mini-fridge-sized, silver rover making its way through a sandy, Martian-mimicking test floor. Rather than rolling forward, each of its four wheels cuts through the sand in what looks like a figure-eight motion. The rover pushes on several yards and then cuts a corner and returns to where it started.

“The wheels mimic the animal’s [sandfish’s]characteristic interaction with the ground, generating both longitudinal and lateral forces,” University of Würzburg researcher Amenosis Lopez said in a statement. “The rover leaves sinusoidal tracks in the sand.” 

The sandfish: nature’s cute solution to slippery sand 

Though most people likely associate space rovers with round wheels or tracks reminiscent of those on WALL-E, neither design is ideal for dealing with Mars’s uniquely harsh and sandy environment. Sand is unique because it’s a material with both solid and liquid-like qualities. On top of sand’s mixed texture, rovers roaming on the Red Planet have to deal with steep slopes and uneven terrain, where varying levels of slipperiness can cause imbalance. Patches of softer sand are also a nightmare for wheels, making the prospect of a rover getting stuck never far from mind

But nature figured out a solution to this issue millions of years ago, and it’s called the sandfish. Contrary to its name, the Sahara Desert native is a lizard in the skink family. Above ground, the sandfish uses its tiny legs to scrabble around much the same as any lizard. Things get more interesting when it burrows down into the sand. X-ray imaging shows  the sandfish propelling itself forward under the sand, using a powerful waving motion to generate thrust and overcome drag. The result looks like an animal swimming through the sand, remarkably similarly to how a fish would oscillate its body to move through water

Engineers at Georgia Tech took those observations and used them to create their own sandfish robot in 2011. Testing with their robots showed that the little lizard’s oddly wedged shaped head may also help it generate lift forces and more easily swim through sand. 

Sink or swim: new rover did both 

Researchers working on the sandfish-inspired robot said it outperformed a wheeled version when navigating through a sandy test track. Where the round wheels would wobble and weave, the oscillating wheels stayed relatively stable. That’s not to say the new approach worked right out of the gate. Early models of the design were reportedly so heavy that the  rover literally sank into the sand. The team went back to the drawing board and made a second version, this time increasing each wheel’s width and reducing overall mass

It’s unlikely these oddball new wheels will become the main chassis system for NASA rovers, at least not in the immediate future. More work still needs to be done to increase their overall controllability and account for slippage that can occur in complicated, real-world environments. There are also the added variables of accounting for scientific instruments and other cargo a rover might have to carry. 

More than anything, the wheel design is a testament to the sandfish’s innate ingenuity and evolutionary gifts. Many scientists only recently began to truly appreciate these traits and what other technology they could inspire. 

The post New Mars rover could swim through sand like a desert lizard appeared first on Popular Science.

XAI AI data center economics are even better when you can start a project and finish it in 12 months and get it rented and paid off while competitors are still building. An active AI Gigawatt of data center in the hand is worth $20 billion per year while an under construction Gigawatt data center ...

Read more

XAI Colossus 1 and part of 2 is leasing to Anthropic for $15 billion per year. This will mean SpaceXAI will be able to have more deals to build faster with huge profits. They can be renting ½ of the new capacity to scale the earth based data centers to 100B+/year high-margin rental business by ...

Read more

For over ten millennia of the farming era, most folks saw themselves as tightly tied to small groups that lived in a largely alien and hostile world, under the thumb of empires and elites selected by tradition and power, elites not embarrassed by their privilege, interested in the general welfare, nor open to persuasion by argument. Few saw grand arcs of history as the sorts of things that they could or should much influence.

Today, in contrast, most people and especially elites see themselves as part of a single big world, with elites selected more by merit, embarrassed by unmerited privilege, interested in general welfare, and especially smart and open to persuasion. So we see world arcs and problems as things to be dealt with by smart elites talking stuff out until they agree, and most everyone is eager to join in such talk to seem like elites.

How did this change? In 2010, I started to explore this explanation: modern values are mainly a reversion to forager values.

[Forager] individuals who otherwise would be subordinated are clever enough to form a large and united political coalition. … the weak combine forces to actively dominate the strong. … They must continue such domination if they are to remain autonomous and equal, and prehistorically we shall see that they appear to have done so very predictably as long as hunting bands remained mobile. … Before twelve thousand years ago, humans basically were egalitarian. They lived in what might be called societies of equals, with minimal political centralization and no social classes. Everyone participated in group decisions, and outside the family there were no dominators. For more than five millennia now, the human trend has been toward hierarchy rather than equality. But the past several centuries have witnessed sporadic but highly successful attempts to reverse this trend. (More)

A lot of today’s political disputes come down to a conflict between farmer and forager ways, with forager ways slowly and steadily winning out since the industrial revolution. It seems we acted like farmers when farming required that, but when richer we feel we can afford to revert to more natural-feeling forager ways. (More)

In the absence of [big] threats, the talky collective was the main arena that mattered. Everyone worked hard to look good by the far-view idealistic and empathy-based norms usually favored in collective views. … When they felt on good terms with the group, people could relax and feel safe. They then become more playful, and acted like animals generally do when playful. Within a bounded safe space, behavior becomes more varied, stylized, artistic, humorous, teasing, self-indulgent, and emotionally expressive. For example, there is more, and more varied, music and dance. New possibilities are explored. (More)

We [today] … have a strong world culture of regulators, driven by a stronger world culture of elites. Elites all over the world talk, and then form a consensus, and then authorities everywhere are pressured into following that consensus. … This looks a lot like the ancient forager system of conflict resolution within bands. Forager bands would gossip about a problem, come to a consensus about what to do, and then everyone would just do that. … This world system [is] new … this looks like another way in which our world has become more forager-like over the last few centuries, as we’ve felt more rich and safe. (More)

Weak cultural selection pressures have allowed a drift back to forager habits and attitudes, which DNA makes still more natural than farmer alternatives. Our increased wealth, health, and peace now makes us unusually willing and able to indulge forager-style moral preferences. The usual forager view is this: we must coordinate via norms and governance to prevent dangerous competition from undermining our precious stable shared human values. (More)

I don’t claim to be totally original here. Let me credit sources who explored related ideas: Joshua Meyrowitz (1986) No Sense of Place, Friedrich Hayek (1988) The Fatal Conceit, Ernest Gellner (1994) Conditions of Liberty; Christopher Boehm (1999) Hierarchy in the Forest; Ronald Inglehart, Christian Welzel (2005) Modernization, Cultural Change, and Democracy; Peter Turchin (2105) Ultrasociety; Ian Morris (2015) Foragers, Farmers, and Fossil Fuels; James Suzman (2020) Work.

To test this basic idea, I asked 3 LLMs to find 100 cultural changes in the West in each of the periods 1400-1726, 1726-1826, 1826-1926, and 1926-2026, and then to score each change as more toward a forager style, more toward a farmer style, or hard to classify and thus neither. Here are their results:

For the last century, we see a strong correlation: averaging over LLMs, 89% of culture trends that can be classified are toward-forager. Making this return-to-forager-styles theory quite explanatory for that period. However, over the prior two centuries the correlation seems real but weaker, with 59% and then 65% of trends being toward-forager. For the earliest period of 1400-1726, the tendency was the opposite, with only 37% of trends were toward-forager.

To explain recent trends even better, let’s add in two more key changes: the world got both better connected and more educated. Increasing talk, travel, and trade made us intuitively feel part of much larger communities. So when our elites try to act like forager sitting around the campfire pontificating on their band’s problems, they see much larger social units as their “band”, often the whole world. And being better educated, elites now use much higher levels of abstraction and other mental tools of the educated when pontificating on big arcs and problems. Also, putting our young elites together in school has created strong youth cultures, which have for the last century driven rapid change in core cultural values.

This return to forager styles has created the intellectual world that I have known and loved all my life. The world in which I love to read, listen, write, and speak. And which sits adjacent to the songs, movies, art, etc. that I love. A world where, at its best, smart young people talk abstractly and idealistically about big issues and problems, and then greatly influence policy and culture. In the last few decades I’ve been associated with new groups like rationalists and effective altruists who have arisen in this mold.

Alas, I recently learned that forager-style elite talky collectives seem to be contributing to our civilization’s key problem of decline due to insufficient evolutionary pressures for dimensions of behavior not greatly under the control of capitalism, but instead subject to strong individual conformity pressures. Not only have youth movements been rapidly changing key cultural values with little regard to their adaptiveness, but our forager elite intellectuals have been overconfidently inducing over-regulation, severely limiting the scope of strong evolutionary pressures.

You see, ancient forager elites didn’t just consider in general how to promote their groups, they instead focused mostly on the possibility that some of group members might gain and use dangerous powers. Since then, people thinking like foragers have similarly focused on identifying and reigning in what they see as the dangerous potentially-ineqalitarian powers of their world. In the last few centuries, such dangers have included alien ideologies and militaries, capitalist owners and firms, and technologies like nuclear, genetic engineering, and AI. A lifetime of detailed examination of such things allows me to say with some confidence: we have consistently greatly over-regulated such things.

It is likely that our civilization will fall, to be replaced by much less forager-like versions. Like civs built by descendants of today’s Amish and Haredim. But I see a chance to save a lot, a chance I want to explore. Yes, this would require substantial compromise; we just can’t keep on relying on simple forager intuitions as naively as we have. But I do see a potential way out.

First, we’d need to adopt far more effective and accountable institutions for creating consensus on claims about the concrete consequences of policies. Institutions like policy decision markets or academic prestige futures. These could cut much of the bias in our policy choices, relative to our values. Second we’d need to either directly or indirectly show far more respect for adaptiveness when expressing our deep values. Either have big polities hold to sacred goals inconsistent with civ collapse, or smaller polities hold directly to their long term adaptiveness, both via rather competent governance institutions. Big asks, I know, but at least I see a chance here.

2034 Earth–Venus–Mars opportunity looks promising. 10–15 on-orbit refueling operations may be needed to make a crewed ship full. (A version 4 Starship could refuel with five tanker launches. Most refueling can be done at an altitude of 180–200 km, made possible by Starship’s size. The final refueling may be performed at a higher altitude of ...

Read more

Freda Duan estimates XAI Colossus 1 has ~$6B annual rent. Colossus 2 is leasing roughly one-third of its total compute capacity to $Anthropic. I am extending the analysis to renting out one third to one half of the new construction. This does not included distributed compute from Tesla cars, Tesla bots, new servers with Tesla ...

Read more

The twelfth flight test of Starship is preparing to launch Friday, May 22. The 90-minute launch window will open at 5:30 p.m. CT. Yesterdays, attempt was cancelled because the launch tower had a pin that did not retract. A live webcast of the flight test will begin about 45 minutes before liftoff, which you can ...

Read more

Cows are not necessarily known for their intelligence, but that less-than-stellar reputation is beginning to change. A 13-year-old pet cow in Austria named Veronika uses brooms to scratch her back, which qualifies as a form of tool use. Tool use is considered a general marker for intelligence in animals. The domestic cow species that live in close contact with humans are also highly social animals, another sign of intelligence. 

New research finds that one domestic species of cow (Bos taurus taurus) can recognize humans and distinguish between them. The cows show a visual preference for new human faces and can match a known handler’s voice to their face. The findings are detailed in a small study published today in the journal PLOS One.

To see whether cows can discriminate between familiar and unfamiliar faces, the team collected data from 32 Prim’Holstein cows. This breed originated in Holland and is the most common dairy cow breed in France. In one single lactation, they can generate about 22,000 pounds of milk. 

The team played videos of familiar and unfamiliar male faces with the sound off for the cows, and measured how long the animals looked at the video. Specifically, the team was looking for cross-modal recognition, or the cognitive ability to recognize objects presented in two different sensory settings. 

They also played videos of both familiar and unfamiliar human faces, while broadcasting audio corresponding to one of the two men. Each man also said the same sentence. The team measured the animals’ heart rates as they watched the videos, to see if the bovines responded to the videos emotionally. 

Experimental setup for visual preference and cross-modal tests. The cow was positioned centrally between two screens. Each screen showed a video of a person’s face: one familiar and one unfamiliar to the cow. During cross-modal tests, a speaker placed between the screens played the voice of one of the two individuals. Cameras recorded the cow’s behavioral responses throughout the test. Image: Amichaud et al., 2026, PLOS One, CC-BY 4.0

The cows were not afraid of the videos without sound and stared at the unfamiliar faces longer. According to the team, the staring shows that the animals can distinguish between an unknown and known face. 

When researchers paired the videos with sound, the cows spent more time staring at the video when the voice matched the face. This shows that the cows can pair a face with the voice that they know. Captive big cats can also do this with their handlers. 

Based on their heart rate, neither the familiar or unfamiliar voices appeared to affect the cows’ emotional response. 

The team notes that a video and sound recording are not a full interaction with a human, but these results indicate that cows can tell the difference between familiar and unfamiliar people, and they can tell humans apart by face and voice. To better understand the animals and their welfare, future studies could examine how cows interact with specific people.

The post Cows can tell humans apart, new study finds appeared first on Popular Science.

NASA’s Psyche spacecraft is currently en route to a small, metal-rich asteroid near Jupiter. However, the barely 3,600-pound probe recently required a little help from Mars to complete its lengthy 2.2-billion-mile mission. Despite its complex gravity assist earlier this month, the groundbreaking spacecraft still found time to snap some travel photos showcasing its Red Planet flyby. NASA released the latest image from Psyche’s trip on May 20, which offers a gorgeous view of Mars just hours before Earth’s neighbor temporarily eclipsed the cosmic traveller.

According to NASA, the image was taken on May 15 at about 8:03 a.m. EDT by the spacecraft’s multispectral imager instrument. The thin crescent view of Mars is due to the spacecraft’s approach at what’s known as a high phase angle. The fingernail slice of Red Planet actually looks brighter and wider than mission specialists anticipated, thanks to a large level of sunlight scattering through the dusty Martian atmosphere. Interestingly, the instrument’s original unfiltered image wouldn’t look very discernible to the human eye. Instead, scientists processed the photo into a natural-color palette using the probe’s red, blue, and green imager filter data.

Launched in October 2023, Psyche is destined for 16 Psyche, a 140-mile-wide rock that astronomers theorize may be the remnant of an ancient planetary core. Once there, the spacecraft will study its iron magnetic properties, as well as use its imagers and spectrometers to analyze the asteroid’s chemical and elemental compositions. 

Thanks to the Martian gravity assist, Psyche is scheduled to reach its destination in 2029. At its closest pass, Psyche swung around the Red Planet barely 2,800 miles above the surface at a speed of around 12,333 miles per hour.

The post Mars shines in ethereal photo from Psyche space probe appeared first on Popular Science.

What’s the weirdest thing you learned this week? Well, whatever it is, we promise you’ll have an even weirder answer if you listen to Popular Science’s hit podcast. The Weirdest Thing I Learned This Week hits Spotify, YouTube, Apple, and everywhere else you listen to podcasts every-other Wednesday morning. It’s your new favorite source for the strangest science-adjacent facts, figures, and Wikipedia spirals the editors of Popular Science can muster. If you like the stories in this post, we guarantee you’ll love the show.

FACT: There’s more than one way to sterilize a hippo, but there’s no easy way to sterilize a hippo

By Rachel Feltman

If you’re a longtime fan of Pablo Escobar’s hippos, you may have heard that their time is running out. After years of trying to deal with these feral hippos conservatively, the Colombian government recently announced that they’ll have to cull some of them to curb their rampant population growth. An Indian billionaire did recently make a last-minute offer to save the hippos at any cost, but transporting a grown hippo—an incredibly deadly animal that weighs literal tons—is no easy feat, so it’s likely that some, if not all, of the planned culling will still take place.

This is not for lack of trying. Like, seriously: The government really, really tried to avoid killing any hippos. But the years-long effort to sterilize these animals has largely failed, and researchers say we’re running out of time to avoid a population too large to deal with. That got me wondering… what makes it so difficult to sterilize a hippo?

As you’ll learn in this week’s episode, sterilizing a hippo surgically is a difficult, dangerous, and expensive endeavor. And while chemical castration (AKA shooting hippos with birth control darts) might sound simpler, it’s… still difficult, dangerous, and expensive. 

For a hippo palate cleanser, I also dive into the herculean effort made to save Fiona the hippo a few years back, which required milking a hippo (a feat never before attempted!) and replicating hippo milk.    

FACT: John Steinbeck took part in a failed deep-sea drilling expedition

Featuring Ben Lillie (the co-founder of Caveat, our favorite venue in NYC!)

This week’s episode features special guest Ben Lillie, otherwise known as the keeper of our favorite place to do Weirdest Thing live shows! He spun a yarn about Project Mohole, a failed deep-sea drilling expedition that took place back in the 1960s. The expedition featured a surprising crew member: John Steinbeck, who covered the endeavor for LIFE Magazine in… very Steinbeck-ian fashion. 

Ben came across this story while working on a live show all about jargon. You can catch that show live and in-person at Caveat on Wednesday, May 27. 

FACT: Joseph Pilates didn’t mean for his workout to get so bougie

By Sara Kiley Watson

Pilates is a super trendy workout modality right now, and it’s gotten a reputation for being pretty elitist. But Joseph Pilates—yes, he was a real guy, and his name was Pilates—didn’t set out to create a workout that looked good on the ‘gram. He didn’t even set out to create a workout that people would spend loads of money on. The former circus performer actually dreamed up the exercises that would become pilates while interned in a prison camp. You can learn more about the reformer’s journey from janky hospital bed to sleek boutique workout equipment in this week’s episode, or by checking out this article I wrote about the history of Pilates. 

The post There’s more than one way to sterilize a cocaine hippo. Unfortunately, both ways suck.  appeared first on Popular Science.

Long before humans smacked “delete” to obliterate typos, we fixed mistakes and revised written language the old-fashioned way: by rubbing errors clean off the page.

The quintessential pink eraser is now a mainstay in household junk drawers, classrooms, and office supply cabinets, but how exactly do these ingenious little pieces of technology work? How do erasers erase?

The history of erasers

Humans have marked stuff with graphite for thousands of years. However, modern pencils—which encase graphite, or a mixture of graphite and clay, in wood—date back to the 17th century. 

Contemporary erasers, meanwhile, came fashionably late. Their precursors include balled-up stale bread and wax. Then, in the 18th century, natural rubber was used as an eraser. Later, in the 19th century, raw rubber erasers were toughened up with heat and sulphur. And, finally plastic erasers debuted in the 20th century. Whether erasers were snackable, heat-treated, or even electrified, the fundamentals of erasing remain. Pencils and erasers work together through the forces of attraction—and friction.

A late 19th century postcard shows people harvesting natural rubber from rubber trees. Early erasers were made using natural rubber. Image: Contributor / Getty Images / Sepia Times

“When you run a pencil over paper, tiny little pieces of carbon flake off and stay on the paper, and that’s what leaves the pencil mark,” Dr. Joseph A. Schwarcz, a chemistry professor who directs the Office for Science and Society at McGill University, tells Popular Science. The pencil’s “lead”—a misnomer, as it’s not actually lead—isn’t just lodged between the fibers in paper; as graphite particles shear off, they also sit atop the page and remain there due to “a very small attraction between molecules,” Schwarcz explains. 

That’s where the eraser comes in, Schwarcz says. “There’s a greater adhesion of those little [graphite] particles to rubber than to the paper, so when you rub the rubber over the paper, it removes them.”

Several thousand years before colonizers commercialized rubber, Mesoamericans developed tools and recreational items with natural latex by tapping and processing the fluid in native rubber trees. While synthetic erasers, composed of substances such as polyvinyl chloride, are now more popular than natural rubber in some parts of the world, all erasers generally work the same way: “The graphite particles are attracted more to the eraser than they are to the paper,” says Schwarcz. 

“There’s also a slight abrasion effect, where you’re dislodging the graphite particles by friction,” Schwarcz adds. This process erodes some of the paper, which helps explain why so many different varieties of erasers exist; softer erasers tend to be gentler on the page, while firmer erasers are generally more durable and precise. 

The science behind the attraction

The chemical attractions Schwarcz describes are called van der Waals forces. “Molecules have tiny little charges distributed over the atoms, and the positive charges will attract the negative charges. So paper will have some molecules with negative charges that are attracted to the positive surfaces of the graphite,” Schwarcz says. Basically, when you write with a pencil, the graphite stays on the page thanks to forces of attraction.

But the attraction between graphite and paper is pretty weak. So when you rub an eraser on a piece of paper, friction basically disrupts the attraction between the graphite and the page, and the graphite that was once on the paper ends up sticking to the eraser.

On a molecular level, graphite is made up of many two-dimensional sheets of carbon, known as graphene, stacked one upon another and held together by van der Waals forces. 

“There’s this cloud of electrons on one layer of graphene, and another cloud of electrons on another layer of graphene,” Dr. Justin Caram, an associate professor of chemistry at the University of California, Los Angeles, tells Popular Science. The electrons on these sheets can “randomly fluctuate” to make one side a little positively charged, and the other a little negatively charged. 

“Because positive and negative charges interact with each other, that binds things together,” Caram says. In other words, we have van der Waals forces to thank for why graphite sticks together on a page.

Although individual sheets of graphene are “completely neutral and have no intrinsic dipole”—or inherently positive and negative side—“they still interact with each other because of these random fluctuations.” Caram adds, “That’s what a van der Waals force is. It’s basically a force between any two things where the electrons can move around and compensate for one another,” keeping things together—if somewhat weakly.

Related 'Ask Us Anything' Stories

Color doesn’t exist—at least not how you think

Chess or video games—which actually makes you smarter? The answer may surprise you.

Why our ancestors had straight teeth without braces

Are induction stoves better? These chefs think so.

How do airplane toilets work?

What really happens to your bag after you check it in?

What about erasable markers and inks?

Whiteboard markers and dry erasers function similarly to pencil erasers but with added complexity, incorporating a slick writing surface to prevent ink absorption and an oily release agent to suspend ink over the board. A quick swipe of a dry eraser easily disrupts the bond between the oily agent and the whiteboard.

However, some erasable inks work differently. Penmakers such as Pilot use thermochromic ink that responds to temperature changes (sort of like a mood ring), becoming clear when exposed to heat. 

So as you rub an eraser against the page, this friction boosts temperatures above 140 degrees Fahrenheit, triggering a regulator in the ink. This temporarily breaks “the bond between the color former and the color developer,” writes Pilot, “effectively erasing your writing.” 

The word “effectively” is doing a whole lot of work in this sentence, because whatever you’ve written is still technically there—absorbed into the paper. Pilot explains: “With enough cooling, (like placing the paper in a freezer), at approximately [negative four degrees Fahrenheit], the components would combine again, and your writing could reappear!”

To err(ase) is human

Ink isn’t usually reactive to temperature like erasable inks, making it tricky or impossible to “erase” errors without marring writing surfaces like paper. “Ink is carried by liquid into the fibers [ of a piece of paper], and when the liquid dries the ink stays behind,” says Caram. Compared to graphite, “it’s much more embedded in the actual molecular network that makes up the paper.”

Mass-produced correction fluids, pens, and tapes (think: Wite-Out, Tipp-Ex, and Liquid Paper) took off in the mid-20th century to conceal inky, typewritten mistakes. Yet, the underlying concept of covering up errors by effectively painting over them is much older. 

Ancient artisans in Egypt used white paint to cover up errors on papyrus, including to narrow the gut of a jackal in an illustration from the Book of the Dead, researchers at Cambridge’s Fitzwilliam Museum said in March.

A secretary uses an eraser to fix a mistake on a page in her Underwood typewriter in a photograph taken around 1945. Image: Stringer / Getty Images / Herbert

Many pencils now feature built-in erasers, an innovation that was first patented in Philadelphia in 1868. Yet, as inseparable as they now seem, modern pencils and erasers didn’t wed right away. 

Japanese pencil and stationery maker Tombow, for example, released its first pencil in 1913; the company tells Popular Science that it developed its first eraser, the Iron Helmet Eraser (“Tetsu-kabuto Jikeshi”), 26 years later. 

Due to “wartime economic blockades,” Tombow said its initial eraser was “manufactured using oils and fats instead of natural rubber.” Material shortages later drove the development of plastic erasers. 

Now, even as screen time defines much of modern life, the modern pencil and eraser live on, as students, artists, and office workers snap them up by the billions each year. 

With pencil and pen sales projected to rise (and autocorrect now ever present in written communication), errors and revisions haven’t really gone anywhere; some tools just make them more (or less) obvious to others. 

Whether you’re a scribe touching up a sacred text or a student erasing doodles in the margins, mistakes are only human. And one way or another, covering them up is, too.

In Ask Us Anything, Popular Science answers your most outlandish, mind-burning questions, from the everyday things you’ve always wondered to the bizarre things you never thought to ask. Have something you’ve always wanted to know? Ask us.

The post How do erasers actually work? It’s surprisingly complicated. appeared first on Popular Science.

Tyrannosaurus rex is iconic for its ferocity and big teeth, as well as those teeny-tiny arms. The Cretaceous Period apex predator wasn’t the only carnivore with underdeveloped forelimbs, however. At least five groups of two-legged, mostly meat-eating theropod dinosaurs experienced a shortening of the upper arms over the course of their evolutionary journey. But why did they have such comically small claws? One team of researchers believes the answer is simple.

“It’s a case of ‘use it or lose it,’” University College London paleontologist Charlie Scherer said in a statement.

Scherer and his colleagues recently examined the data for 82 theropod species, including those in T. rex’s tyrannosaurid family. Their study published today in the Proceedings of the Royal Society B Biological Sciences argues a combination of massive skulls and crushing jaws—coupled with increasingly large prey—had many theropods relying increasingly less on their forearms.

“We sought to understand what was driving this change and found a strong relationship between short arms and large, powerfully built heads,” explained Scherer. “The head took over from the arms as the method of attack.”

The team based their conclusions on a new system of assessing dinosaur skull strength based on attributes like overall dimensions, how tightly bones were joined in the head, and bite force. Unsurprisingly, T. rex came in first place for bite force, followed by the Tyrannotitan. Almost as large as a T. rex, the Tyrannotitan lived in present-day Argentina during the Early Cretaceous over 30 million years before its famous descendent. In each example, the reason for short arms likely coincided with hunting larger and larger dinner targets.

“Trying to pull and grab at a 100–foot–long sauropod with your claws is not ideal. Attacking and holding on with the jaws might have been more effective,” added Scherer.

Overall, the team identified a bigger correlation between skull strength and smaller arms than with either skull or body size. This conclusion is further supported by some theropod dinosaurs with strong heads, tiny forelimbs, and a relatively small stature. For example, Majungasaurus roamed present-day Madagascar 70 million years ago while weighing about 1.75 tons—around a fifth the size of T. rex.

Not every dinosaur’s limbs shrank in the same way, either. Abelisaurids like Majungasaurus exhibited smaller arms past their elbows as well as their hands, while tyrannosaurid arms reduced proportionally. In each case, it seems that the theropods initially had far more success latching onto prey with their powerful jaws, then evolution did the rest of the work.

As to which dinosaur had the teeniest forearms, the answer according to Scherer is clear.

“The Carnotaurus had ridiculously tiny arms, smaller than the T. rex,” he said.

The post Why were T. rex’s arms so tiny? Paleontologists finally find an answer. appeared first on Popular Science.

The happy-face spider (Theridion grallator) is famous for the particularly cheery looking patterns on top of its abdomen. Ecologists in Hawaii first described the tiny, vibrantly green arachnids in 1900, and have long assumed them to be unique to the islands. However, an unexpected encounter thousands of miles away recently surprised researchers combing through the forested slopes of the Himalayan mountains.

According to their study published in the journal Evolutionary Systematics, there is at least one more smiley spider species in the world. Of course, such a discovery deserves an equally appropriate name. Without further ado, it’s time to meet the Himalayan happy-face spider (Theridion himalayana).

Mature male (left) and female (right) of Theridion himalayana sp. nov. Credit: Devi Priyadarshini and Ashirwad Tripathy.

The meetup began in 2023 during an expedition in the northern state of Uttarakhand, a region home to many animals that remain unknown to science. Researchers from India’s Forest Research Institute and the Regional Museum of Natural History intended to catalogue ant biodiversity at the foot of the Himalayan mountains, but they kept getting distracted by the insects’ eight-legged neighbors.

“My co-author [Ashirwad Tripathy] kept sending me spiders from high altitude regions for identification,” Regional Museum of Natural History biologist Devi Priyadarshini said in a statement.

Priyadarshini recalled on “one fine day,” her colleague sent a photo of an arachnid clinging to a Daphniphyllum leaf. That was when she “froze in shock.”

“I had seen the Hawaiian spider during my master’s program…I knew instantly we had a jackpot because of its striking resemblance,” explained Priyadarshini.

Over the next few months, Tripathy continued to document every similar spider he saw during his survey. While each of the 32 examples clearly belonged to the same species, they all showcased an array of smiley dot-and-stripe coloration patterns (known as morphs) on their bodies. Once in the lab, the team conducted a DNA analysis of their specimens and discovered about an 8.5 percent genetic variation from the Hawaiian happy-face spider. This confirmed it evolved completely independent of the almost identical island spiders, thus earning the name Theridion himalayana.

“The name [Theridion] Himalayana was decided as the species name because we both wanted to pay our respects to the mighty Himalaya mountain ranges, which have been standing tall not just guarding our country but also holding a plethora of biodiversity within them,” added Tripathy.

Although the green coloration obviously helps both spiders blend into the surrounding vegetation, the exact reason for their back patterns remains unclear. Priyadarshini said this question is “definitely indicative of a deeper genetic mystery” that deserves further investigation. However, another shared trait is even stranger. Both species have a fondness for ginger plants, even though ginger isn’t native to Hawaii.

“How did the [Hawaiian] spiders choose an invasive species and ginger exactly?” wondered Priyadarshini, who theorized T. himalayan may be an “elder cousin” of T. grallator.“Although this sounds like a tall claim now, it will be our further scope of work to establish any missing links,” she said.

The post Newly discovered spider has smiley face on its back appeared first on Popular Science.