HEALTH

Why Does Salt Make Everything Taste Better?

Salted french fries
Credit: A. C./Unsplash.com
Kathryn Whitbourne
Author
Kathryn Whitbourne is a freelance writer and copy editor at the Atlanta Journal-Constitution. Her work has appeared in HowStuffWorks, WebMD, Success.com and other websites. She is originally from Jamaica.

“Needs more salt.” Ever thought that when you tasted something? But salt doesn’t just make meat or soup taste better. It can also improve the taste of foods such as coffee, chocolate, or oatmeal. So, how does salt get this superpower?

Worth Its Salt

Diagram of human tongue
Credit: Encyclopædia Britannica, Inc.

Salt is a chemical compound made up of two different elements: sodium and chloride. Sodium is mostly responsible for the salty taste, thanks to some special cells on your tongue. Your tongue is covered with tiny bumps called papillae. Inside those papillae are taste buds, tiny cells that inform how things taste. 

Your taste buds can detect five basic tastes: sweet, sour, salty, bitter, and umami. (Umami is a savory flavor often found in meats and other foods.) Your taste buds can detect these flavors on any part of your tongue, but certain areas of your tongue are more sensitive to certain flavors. The front and side of the tongue are the most sensitive to salt.

When your taste buds detect an increase in sodium, signals are sent to your brain that what you’re eating is salty. Just a few compounds are interpreted by your taste buds as “salty.” Typical table salt is sodium chloride, while other types of sodium register as salty and bitter, or just bitter. The added bitterness is why salt substitutes often don’t measure up to the real thing.

Salt crystals
Credit: Behnam Norouzi/Unsplash.com

This is simple science — basic chemistry and biology working together. As for why many people often react favorably to that salty sensation, however, that isn’t as certain. One theory is that in addition to salt affecting specific taste receptors on our tongue, the presence of salt in a meal also creates a more pleasurable mouthfeel.

It’s also possible that salt improves the taste of food by blocking the receptors on your tongue that register bitterness. (Bitterness is often seen as a negative trait in food, possibly because we’ve evolved to avoid the taste of harmful and poisonous plants). 

This allows salt to improve the flavor of foods that are naturally bitter, such as black coffee. By dialing down bitterness, salt also helps make other foods, such as dark chocolate, seem sweeter.

Salted meat
Credit: Pablo Merchán Montes/Unsplash.com

Salt also attracts H2O molecules, which is why it helps absorb moisture and water (as anyone who likes to dry rub a steak or grill an eggplant can tell you). By decreasing the amount of “unbound water” (water not bonded to other components) in food, flavors concentrate and can taste stronger. Absorbing water also makes it easier for these flavor components to escape into the air, creating a nice aroma that can make food seem to taste more flavorful. 

But salt improves food only to a point (called the “bliss point”). After that, too much salt in food can make it unpalatable. That’s why a glass of seawater isn’t as tasty as water from the tap. However, people have different bliss points — some prefer more salt in their food than others. 

Studies have shown that, over time, people can learn to like food with less sodium, even though they find it bland at first. That’s good, because a diet with too much sodium can raise your blood pressure and cause other health problems. 

So the next time you find yourself asking if something needs more salt, consider whether or not you’d just like more salt.

Short Answer

Your tongue has cells that register salty and bitter flavors, so the more salt in a food, the less bitter something tastes. For the same reason, salt can make bitter foods taste sweeter. Salt crystals also physically affect mouthfeel and absorb excess water in foods, which both concentrates flavor and makes it easier to escape into the air and create a stronger aroma.

CULTURE

Why Do Songs Get Stuck in Your Head?

Person listening to music in a field
Credit: Joshua Earle/Unsplash.com
Sarah Gleim
Author
Sarah Gleim is an Atlanta-based freelancer with more than 25 years of experience writing and producing explainers and features about history, science, food, and health for media outlets such as AARP, WebMD, The Conversation, History.com, HowStuffWorks, CNN, and others. She's also the editor of several cookbooks for Southern Living and Cooking Light.

It can happen without warning: A song starts replaying in your head as if there’s a band in your brain singing the chorus over and over. Maybe it’s the Archies’ chart-topper “Sugar, Sugar” (“Sugar … ah, honey, honey”) or the excruciatingly relentless “1-877-KARS-4-KIDS” jingle.

It’s usually just a short part of the song, about 15 to 30 seconds, and whatever the melody, it’s impossible to shake. Why does this happen, and more importantly, how do you make it stop?

Sticky Tunes

Person listening to music
Credit: Brock Wegner/Unsplash.com

There’s a scientific name for this pesky phenomenon: involuntary musical imagery, colloquially known as an earworm. But don’t worry: There are no actual creepy crawlers inside your head.

Researchers estimate that more than 90% of people get tunes stuck in their heads at least once a week. And while these earworms can definitely be irritating, they’re typically harmless.

One reason songs get stuck in your head is because your brain is wired for it. Your brain uses many systems at the same time when you listen to music, including one known as phonological loop. It’s the part of your working memory that temporarily stores and replays sounds, such as lyrics to a song — think of it as the brain’s mental notepad. 

Because your brain recognizes and repeats patterns, catchy songs can get “looped” in this part of your memory. The phonological loop also tends to get hung up on unfinished sequences because your brain wants to complete them. This could explain why you need to hear only a short snippet of a song for it to get stuck in your head.

Person covering their face while listening to music
Credit: Valeriia Miller/Unsplash.com

Many pop songs are also written to linger in this way. Studies have found that most earworms tend to have simple melodies, upbeat tempos, and musical patterns that are easy to remember. Pop songs with repetitive choruses (“Sugar, Sugar,” for instance) often fit this formula perfectly.

Memory plays a major role, too. Psychologists suggest that even if you hear just a short part of a song — the first “Sugar,” for instance — it can trigger your brain’s memory networks to replay the rest of the song. Emotional memories, such as seeing a particular person or visiting a special place, can also prompt song recall.

Your mood can matter as well. If you’re stressed or bored or doing things that don’t take much mental effort, your mind may wander and start singing that familiar song.

Make It Stop!

If you just can’t take that song on loop anymore, there are a few tricks that might help make it stop. Cleveland Clinic suggests you listen to the entire song — this might satisfy your brain’s need to “complete the loop.” 

If that doesn’t work, listen to another song, or try to refocus your brain by taking a walk or solving a puzzle. Some studies have even found that chewing gum helps. Whatever works, right?

Short Answer

Songs get stuck in your head because they have patterns, associations, and repetition — everything your brain needs to reinforce memory. That’s why catchy melodies with simple, repetitive tunes, or songs that trigger strong memories or emotions, tend to be the ones that end up on repeat in your head.

TECHNOLOGY

Could You Tell if Your Burger Was Grown in a Lab?

Cube of lab-grown meat
Credit: anaumenko/stock.adobe.com
Juliet Bennett Rylah
Author
Juliet Bennett Rylah is a Los Angeles-based journalist whose bylines include Atlas Obscura, The Hollywood Reporter, Vice, and many more. In her free time, she likes to karaoke and record spooky podcasts.

Some people avoid meat for health reasons, while other vegetarians do so because they’re not comfortable with the idea that animals are raised and slain for food. For the latter, cultivated meat offers an ethical solution: You can enjoy a juicy burger knowing the cow it came from is still grazing on a farm.

This may sound impossible, but several startups are already producing lab-grown chicken nuggets, meatballs, tuna, and even foie gras. And unlike plant-based alternatives made from soy, beans, and other proteins, cultivated meat is actually meat, right down to the DNA. Because of this, it’s not entirely accurate to call it “synthetic,” though many refer to it this way.

Even those abstaining from red meat for dietary reasons may benefit from meat grown in a lab. Here’s why.

How the Sausage Is Grown

Packaged cultivated meat
Credit: Firn/stock.adobe.com

Lab meat isn’t made — it’s grown. Rather than thinking of it as a plant or crop, though, it grows much like an animal does, cell by cell. However, the entire animal isn’t cloned (that would defeat the purpose) — just the parts we eat.

First, stem cells are harvested from an animal, often in a process similar to a biopsy or blood draw. Stem cells are used specifically because they can develop into other kinds of specialized cells, such as blood or muscle. Manufacturers place the cells in a stainless steel tank, called a bioreactor or cultivator, in a liquid rich with proteins, vitamins, sugars, and other nutrients.

Adjusting the nutrients in the liquid encourages cells to mature into muscle, fat, or connective tissue, which can be separated and arranged into different forms, such as ground beef or steaks. This is done by growing the cells on a three-dimensional scaffold, such as collagen or edible plant-based materials standing in for skeletal structure.

No macroscopic parts of the cow are ever made outside of the specific parts we like to cook and eat. If, for example, we were growing synthetic two-by-four lumber in a lab, only wood fibers would ever be grown. There’d never be an oak tree or seedlings, or even parts such as leaves or roots. Just the fibers.


For food made from lab-grown muscle fibers, the entire process takes two to eight weeks, depending on the type of meat. Products with less structure, such as ground beef, are easier to create than steaks.

Why Lab-Grown Meat?

Chart showing agricultural land use
Credit: How Everything Works

Proponents of lab meat tout the most obvious benefit: No animals are slaughtered (though some methods culture cells from already-slaughtered livestock). But it’s also good for the environment. Traditional livestock production uses a whopping 80% of agricultural land when accounting for grazing pastures and crops grown for animal feed. Farms also account for about 10% of U.S. greenhouse gas emissions, half of which come from cattle.

Lab meat requires far fewer animals. Mark Post, the pharmacologist who developed the first lab-grown burger in 2013,, estimates that 175 million burgers could be produced using cells from a single cow.


Cultivated meat is also made in a highly controlled environment, potentially decreasing the risk of bacterial contamination — which can pose a serious health threat when slaughterhouses and farms don’t uphold the best hygienic practices.

Plus, the specific fat content of lab-grown meat can be dictated from the start. Want extra gristle for the taste? It can be done. More importantly, meat can be manipulated to contain less saturated fat or even more nutrients and vitamins. This means that cultivated meat may actually be a healthier choice. Considering it’s real meat made from real animal muscle, the easiest way to distinguish the two may be just how nutritionally optimized lab meat is.

European farm with livestock
Credit: Illiya Vjestica/Unsplash.com

If that’s the case, why aren’t synthetic nuggets lining the freezer aisle? For one thing, startups have struggled to produce cultivated meat at scale, so it isn’t an affordable replacement yet. Meanwhile, agricultural lobbyists, traditional farmers, and some lawmakers have pushed back on the technology. Italy banned lab-grown meat in 2023, citing the need to protect the country’s heritage. Hungary imposed a similar ban in 2025. 

It’s also unclear how popular, and thus profitable, lab meat would be with consumers. Those who’ve sampled it say it feels and tastes pretty close to the real thing. In a blind taste test, you might not be able to notice a difference. (But the cow that was spared will.)

Short Answer

Lab-grown meat, also called synthetic or cultivated meat, is made by using stem cells from an animal to grow muscle, fat, and other components in a bioreactor. These cells grow around collagen or other structures to form steaks, nuggets, ground meat, and other forms. No organs or other animal parts are cultivated — just what’s made to be eaten. Nutrient and fat content can be customized to an extent as cultivated meat is grown.

NATURE

Do Vegetables Actually Exist?

Produce section of a grocery store
Credit: nrd/Unsplash.com
Erin Scottberg
Author
Erin Scottberg is a Brooklyn-based writer, garden designer, and houseplant expert — and the founder of Full Sun Studio (fullsun.studio), a garden design and plant consulting studio in New York City. She holds an Urban Horticulture Certificate from Brooklyn Botanic Garden, an NYC Street Tree Pruner License, and an NYC Master Composter Certification, and spent three years as Head of Content and Education at The Sill. When she's not working, you can find her creating in her textile studio, running craft nights in her neighborhood, or hanging with her rescue pup, Sunny. She's an ambitious DIYer, avid composter, and has never been able to walk by a thrift store without taking a look.

There’s a joke that’s common in horticultural circles. It goes like this: “If a tomato is a fruit, does that make ketchup a smoothie?” It’s often delivered to a chorus of groans, but it brings up some interesting questions. In the produce section, tomatoes are typically found among other vegetables, such as carrots and potatoes, rather than apples and berries. 

It’s not just tomatoes that blur the lines. And in fact, there really aren’t any lines. Unlike fruits, which are scientifically defined as the seed-bearing structures produced by a plant, vegetables have no specific scientific classification. It leaves you wondering: If tomatoes are fruits because they have seeds, what about eggplants? What about peppers or green beans?

So what makes a vegetable a vegetable? The question can be answered, but it takes a bit of digging (pun intended).

‘Vegetable’ Covers a Lot of Ground

Green tomatoes and tomato flowers
Credit: Rens D/Unsplash.com

Conventional wisdom is that a vegetable is the edible part of an herbaceous (non-woody) plant. And that definition works fine at the dinner table, but it falls apart the moment you ask a botanist. 

Scientifically, a fruit is the part of a plant that develops from the flower’s ovary and carries the seeds. Sweetness, time of day in which it’s consumed, and the kinds of recipes it’s found in have nothing to do with its identity. This is why tomatoes, squash, cucumbers, peppers, and other “vegetables” borne from flowers are technically fruits.

“Vegetable” is really just a culinary catch-all for edible plant parts that aren’t sweet — and those parts come from all over the plant. Carrots and beets are root vegetables. Lettuce and spinach are leafy greens. Celery and asparagus are stems and stalks. Broccoli and cauliflower are immature flower buds that are harvested before they get the chance to bloom.

Diagram of major types of vegetables
Credit: stock.adobe.com; Illustration How Everything Works

If that’s not confusing enough, there are also certain plant parts that are considered veggies for one species but something else for another. For example, look at legumes — peas, beans, and peanuts, to name a few — which are the seeds of plants in the Fabaceae (bean) family. 

The USDA hedges that sometimes, beans and peas can also be filed as a protein, depending on the plate. Peas are definitely considered a vegetable, but peanuts? Not so much, despite being the same part of a legume. (Note how the idea of what kind of meal the edible plant shows up in affects its “vegetable” status.)

And let’s not forget alliums, which are vegetables that come from plant bulbs. These include onions, leeks, garlic, and chives. But don’t think too hard about that last one, as chives are usually used as an herb and classified as such. (Yet another instance showing that how the edible part of the plant is used determines how it’s categorized.)

So, Does That Ketchup Joke Work?

Rhubarb
Credit: kaori nohara/Unsplash.com

Just as some fruits, such as tomatoes, are commonly described as vegetables, the reverse can also be true. Rhubarb is a leaf stalk, not the fruit of a plant. But, because it’s used mostly in sweet dishes such as pie, most people call it a fruit. Nothing about the plant changed. The plate did.

Back to that groan-inducing joke: Is ketchup a fruit smoothie? Tomatoes are fruit, so the premise holds — but once they’ve been cooked down and cut with vinegar and sugar, “smoothie” is a generous, at best, word for it. And this is the whole point. Botany can tell you what a plant is, but the kitchen holds the power to decide what we call it.

Short Answer

Botanically, “vegetable” isn’t a real category. It’s a culinary label for the edible parts of plants we eat at meals — whether that’s a root (carrots), a leaf (spinach), a stem (celery), or a flower (broccoli). “Fruit,” by contrast, is a true scientific term for the seed-bearing part that grows from a plant’s flower, which is why tomatoes and cucumbers are technically fruits. What makes something a vegetable is mostly how we perceive it and use it in the kitchen, not its biology.

HEALTH

Why Do You Feel Someone Staring at You?

A person looking behind him
Credit: Shotprime Studio/stock.adobe.com
Juliet Bennett Rylah
Author
Juliet Bennett Rylah is a Los Angeles-based journalist whose bylines include Atlas Obscura, The Hollywood Reporter, Vice, and many more. In her free time, she likes to karaoke and record spooky podcasts.

Chances are, at one time or another, you’ve had the feeling that someone is staring at you, as though another person’s gaze is a tangible beam. You may even look and find that to be the case. Or perhaps you’re the one doing the staring, and avoid doing it for too long for fear the object of your attention will whip around and catch you.

This phenomenon is known as scopaesthesia, or the psychic staring effect, defined as the ability to tell when someone is looking at us. But is it real?

Sixth Sense or Nixed Sense?

A person feeling the back of their neck
Credit: Frank Flores/Unsplash.com

That question of how this “sixth sense” works, or if we even have one at all, remains a subject of dispute between parapsychologists (who study psychic phenomena such as telekinesis and clairvoyance) and skeptics. There are studies on the topic dating back to the late 19th century, but none have been accepted by mainstream science.

In 1898, psychologist Edward B. Titchener wrote that his students described the sensation as a stiffness at the base of their neck, “sometimes accompanied by a tingling.” He never fully detailed the experiments he ran at Cornell University, but wrote that he found no evidence of psychic abilities. He posited that people turning to see if someone’s staring is what attracts the other person’s attention in the first place, creating the illusion that they’d been caught looking. 

Close-up of a person's eyes
Credit: Victor Muzza/Unsplash.com

Later studies found that the accuracy of subjects who could identify when they were being looked at was no better than chance, while other studies reported small but statistically significant accuracy. In 1993, researchers suggested in the Journal of Parapsychology that experiments shouldn’t ask subjects to guess if they’re being watched, but should instead monitor an involuntary physical response, such as electrodermal activity (changes in the skin’s ability to conduct electricity).

Studying the staring effect this way has led to mixed results. Researchers from the University of Freiburg and University of Northampton found that subjects showed significantly higher skin activity when they were stared at, despite not knowing when this was occurring during the experiment. 

Other researchers have concluded that studies concerning the staring effect are influenced by experimenter bias. One study published in the Journal of Parapsychology found that proponents of parapsychology unconsciously influence subjects’ responses through subtle cues and interactions, whereas skeptics conducting the same tests with the same subjects yielded different results.

Yet if scopaesthesia isn’t real, what explains this sensation that so many people claim to have experienced?

Looking for Cues

Person looking at another person
Credit: Lia Bekyan/Unsplash.com

For starters, it’s possible we only remember when we’ve turned around and someone was staring at us (versus when we’ve turned around and nothing was there), reinforcing the belief we have the ability to tell. Professor Colin Clifford at the University of Sydney has another theory, published in Current Biology: that we think people are staring even when they’re not. 

His team’s study concluded that human brains are wired to believe we’re being watched, even (and especially) when we lack the data to confirm it — for instance, when it’s dark or someone’s wearing sunglasses.

This would make sense, evolutionarily speaking. By being able to sense subtle cues — such as someone in our peripheral vision, a reflection, or a change in the direction of sound they’re making — we can better protect ourselves from attack. This may not be particularly useful when you’re riding an elevator, but it would be very helpful to early humans traversing dark jungles filled with predators. 

Over time, evolution may have wired our brains to “look without looking” — a defensive mechanism that in our modern society can misinterpret external cues and make us a bit paranoid that danger lurks just out of view.

Then again, we may have evolved it for a very different reason: to communicate and understand one another better. By having a honed sense of where someone else was looking and picking up on other subtle signals, early humans could better coordinate hunting and defense, as well as teach skills and share other social cues. 

The fact that human eyes have more contrast between the white sclera and black pupils may even make it easier for us to notice slight changes in visual attention, even in the far periphery. This skill may be why you can sense someone barely in your line of sight turning their gaze toward you.

Then again, they might not be looking at you at all. Maybe the staring effect is just us wanting to feel like the main character sometimes.

Short Answer

Scopaesthesia, or the psychic staring effect, is defined as the ability to tell when someone is looking at us. Parapsychologists believe it’s a real psychic phenomenon, but mainstream science points to evolution. Our brains may be wired to perceive cues and changes in our surroundings, including things in our peripheral vision, to better detect predators. This ancient defense mechanism may still kick in when someone in our periphery is looking at us, or even just in our general direction, whether intentionally or not.

SCIENCE

Are You Safe if Lightning Hits Your Car?

Lightning strike over a highway
Credit: carmen dominguez/Unsplash.com
Darren Orf
Author
Darren Orf is a writer and editor living in Portland, Oregon, who covers science and the natural world for places like Popular Mechanics, National Geographic, and Smithsonian Magazine, among others.

Earth experiences roughly 8.6 million lightning strikes every day. And every day, at least 1.5 billion cars snake along the various highways and byways that crisscross the planet. You don’t need a calculator to do the math: It’s only a matter of time before the two collide in an incredible display of electromagnetism.

Conventional wisdom is that if you happen to be inside a car when it’s struck by lightning, you’re inherently safe thanks to the vehicle’s rubber tires. That’s not entirely the case, though, as rubber only acts as an electrical insulator for low voltages, and lightning is anything but. A typical lightning strike delivers roughly 300 million volts (a standard electrical outlet, by comparison, delivers 120 volts). 

With such high voltages, tires alone won’t protect you in a lightning strike — they likely won’t even survive themselves. Lightning can raise the temperature of surrounding air by as much as 50,000 degrees Fahrenheit — more than five times as hot as the surface of the sun — sometimes causing car tires to explode

But even if that happens, you may be just fine sitting inside your vehicle. Here’s why.

A Metal Shield

Illustration of what happens when lightning strikes a vehicle
Credit: nerthuz/stock.adobe.com; Illustration How Everything Works

Because lightning is attracted to the tallest metal objects in the vicinity, cars are basically big fat lightning rods, so it wouldn’t be a total shock if a vehicle was struck. (Well, it would in one sense.) But cars are also sort of like a Faraday cage on wheels — and this offers some protection. 

Named after English physicist Michael Faraday in the early 1800s, a Faraday cage is a fully enclosed box made from an electrically conductive material. This material allows a Faraday cage to isolate what’s inside from electromagnetic radiation outside of it. You may carry a small Faraday cage in your pocket — it’s how anti-theft sleeves block thieves from remotely scanning your credit cards or cloning your key fob. Free electrons in the outer shell of a Faraday cage create an electromagnetic field that essentially cancels out other fields.

So when lightning strikes a vehicle, it’s the metal chassis of the car — not its rubber tires — that funnels the energy away from the cabin to the ground, protecting the passengers inside. (Technically, a car is only similar to a Faraday cage because it still has openings in the metal chassis, such as the windows, which allow other forms of electromagnetic radiation inside. That’s why your phone still gets a signal even when you’re driving inside a metal box.)

This effect provides some protection, but it certainly doesn’t mean you should go barreling into severe lightning storms on a whim. While the people inside the car may not get electrocuted, a lightning strike can still fry onboard electronics. The antenna may melt, the windows may shatter, and fires can break out. And there’s also the whole exploding tires problem. 

And of course, this chassis-based shield only applies to fully enclosed vehicles — meaning motorcycles, bikes, or convertibles do not share the same level of safety. That’s why it’s really important to remember that having rubber tires does not make your vehicle immune to lightning.

Short Answer

The metal chassis of a typical automobile creates a partial Faraday cage, meaning electricity from a lightning strike is directed around the body of the car and into the ground. While rubber tires are insulators for lower voltages, lightning, which produces voltages in the hundreds of millions, can explode tires and cause other damage to the vehicle, so you should take thunderstorms very seriously even when inside a car.

ENGINEERING

Why Don’t You Ever See Cranes on the Road?

A construction crane
Credit: Valentyn Chernetskyi/Unsplash.com
Erin Scottberg
Author
Erin Scottberg is a Brooklyn-based writer, garden designer, and houseplant expert — and the founder of Full Sun Studio (fullsun.studio), a garden design and plant consulting studio in New York City. She holds an Urban Horticulture Certificate from Brooklyn Botanic Garden, an NYC Street Tree Pruner License, and an NYC Master Composter Certification, and spent three years as Head of Content and Education at The Sill. When she's not working, you can find her creating in her textile studio, running craft nights in her neighborhood, or hanging with her rescue pup, Sunny. She's an ambitious DIYer, avid composter, and has never been able to walk by a thrift store without taking a look.

The image of massive construction cranes rising above steel columns and half-completed buildings is a classic urban landscape. But try to remember the last time you saw one of those giant beasts rumbling down the highway to get there. You probably can’t, and that’s for good reason. 

The large, erector-set-looking cranes that loom over construction sites weigh multiple tons and stretch hundreds of feet into the air. Getting one to a work site isn’t as simple as, say, driving a cement truck up to the job and putting it in park. It’s actually a two-part feat: first the trip, then the climb.

The Trip

A construction crane being transported
Credit: HENADZY/stock.adobe.com

The reason you never see a finished crane cruising down the road is that, for most of the journey, it isn’t one yet. A large tower crane — the most common type of crane — travels in pieces, kind of like flat-pack furniture that needs to be assembled at home. That’s because as a single machine a crane isn’t just large but also very heavy. 

It needs that weight to keep stable and firmly stay on the ground as it lifts heavy construction materials. Tower cranes are bolted to concrete bases that weigh up to 200 tons (400,000 pounds), but the machine itself can still weigh tens of tons. (That’s also about as much as they’re typically allowed to lift at once, though some can lift much more.)

There are a few major components to these cranes: the mast (the part that goes straight up), the jib (its long horizontal arm), and the counterweights to keep the load balanced. These parts all arrive in pieces, usually on flatbed trucks. The crane is bolted back together once all the pieces arrive on site. Funny enough, it usually takes the help of a smaller crane to put the big ones together. 

Even in pieces, a crane is an awkward thing to haul. Loads that are especially tall or wide require special permits and often need a pilot-car escort (that’s what those vehicles advertising “oversized load” are called). Cranes also typically need a route mapped out in advance, making sure to dodge low bridges and tight turns. 

Many places only allow these oversize loads to travel during certain hours when traffic is expected to be light, which is part of why the delivery tends to happen when you’re not around to see it. That said, the smaller, mobile cranes mentioned earlier can drive themselves short distances on their own wheels, and you may spot those in traffic.

The Climb

Construction crane on site
Credit: Jarama/stock.adobe.com

Once assembled, a tower crane needs to live up to its name and get tall. A crane anchored only to the ground can only rise so high — generally not much more than 265 feet, or roughly 25 stories — before stability becomes a problem. To go taller, the crane basically “grows” alongside the building it’s helping to build, rising floor by floor and leaning on that same structure for support. Which is to say: The crane helps build the very thing that holds it up.

One way it does this is via a method called “external climbing.” The crane stands beside the building and uses a hydraulic climbing frame to hoist itself up, adding a new tower section into place each time. All the while, steel collars tie it to the finished structure for support. Gardeners can think of it like attaching a tomato plant to a wooden support as it grows. 

The other method is “internal climbing,” in which the crane sits inside the building’s core — in, say, a future elevator shaft — and leapfrogs upward floor by floor as new levels are poured beneath it. 

Either way, the crane is never lifted to the top — it climbs there, one section at a time. To leave the site after construction is complete, a “Russian doll” method is usually implemented: A small crane dismantles the big one, then an even smaller crane is hauled up to take apart that one, and so on.

So the next time you pass a construction site, remember that one of the first things that needed to be built was the crane itself, after traveling there in pieces. It then gradually rose higher with the building it’s helping assemble — giving a whole new meaning to “climbing the corporate ladder.”

Short Answer

The giant cranes we see at construction sites are too big to travel as one piece, so they arrive disassembled on flatbed trucks. Those trucks often need oversized-load escorts and travel at odd hours when traffic is lighter. The crane is then put together on site. It rises higher with the structure being built, using the building itself for support to remain stable.

HEALTH

Why Are Some People Left-Handed?

Person writing with left hand
Credit: Kelly Sikkema/Unsplash.com
Sarah Gleim
Author
Sarah Gleim is an Atlanta-based freelancer with more than 25 years of experience writing and producing explainers and features about history, science, food, and health for media outlets such as AARP, WebMD, The Conversation, History.com, HowStuffWorks, CNN, and others. She's also the editor of several cookbooks for Southern Living and Cooking Light.

Whether they’re writing their grocery lists or using a pair of scissors, about 90% of folks favor their right hand. Across cultures, continents, and historical eras, lefties have always been in the minority.

But despite decades of research, scientists still haven’t found a specific reason why roughly one in 10 people are naturally left-handed. Instead, evidence suggests handedness — or your preference to use one hand over the other — is shaped by multiple factors.

Genetics plays a role, but it’s not as simple as being born with a single, specific “southpaw gene” — it doesn’t exist. So let’s get right (or left) to business and dig into what gives you your handedness.

Is Left-Handedness Genetic?

Twins taking a selfie
Credit: Getty Images/Unsplash.com

Somewhat confusingly, the left and right hemispheres of your brain control your motor skills on the opposite sides of your body, meaning the right side of your brain is responsible for your left arm and hand. But because they rarely control behaviors equally, you typically prefer one hand over the other. This is called cerebral lateralization.

For right-handed folks, motor control over their hand is better developed in the left side of the brain, while the opposite is true for lefties. Language, on the other hand, is dominated by the left hemisphere for most people, regardless of how they write. 

That means, in the brains of most right-handed people, hand control (writing) and language are more closely connected, neurologically speaking. This could explain why most humans prefer to write with their right hands.

You could even have a preference for your left hand before you’re born. Studies have shown fetuses will suck one thumb more than the other as early as 15 weeks.

Diagram of brain regions
Credit: jonsen/stock.adobe.com

Research shows that your genes play a big role in whether you’ll be right- or left-handed. We’ve known for decades that left-handedness tends to run in families: Studies show that when both of your parents are left-handed, you’re much more likely to be, too. 

If your parents are right-handed, meanwhile, you’re very unlikely to be left-handed. This suggests that handedness could be passed on from parents to their children, but no “left-handed gene” has been discovered. Instead, like many human traits, it’s believed to be a combination of dozens of different genes, as well as which ones are turned “on” or “off.” 

Plus, if handedness was purely genetic, then identical twins — who usually share 100% of their DNA — would always be both right-handed or left-handed. However, that’s not the case, as one twin may be a lefty and the other a righty. 

That said, a recent meta-analysis of twin studies found that identical twins are more likely to use the same hand compared to fraternal twins (who share just 50% of their DNA). This suggests genetics still plays a significant role in the development of handedness.

Nature vs. Nurture

Child writing with left hand
Credit: DanitzaPulgarM/stock.adobe.com

While genetics plays a role, so does epigenetics — which is the way your environment and habits can physically alter the way your genes work. That’s why genetically identical twins can look pretty different as they age, as different genes are turned on and off based on external factors. 

Epigenetics may also play a role in handedness, especially since lefties live in a world dominated by righties and often have no choice but to use tools and equipment designed for right-handedness — everything from scissors and gear shifts to musical instruments and sports equipment.

But given a plethora of left-handed products are more easily available to purchase these days, shopping opti, this is less likely to be a factor in modern developed societies.

Using your right hand out of convenience is one thing, but many lefties have been forced to do it. In many cultures, left-handedness was a social stigma, and children who showed signs of being left-handed were often made to write with their right hand instead. Many righties are actually lefties in disguise. At least two U.S. presidents — Ronald Reagan and Harry Truman — were lefties forced to write with their right hand. 

Studies show that as the rate of “enforced right-handedness,” which varies between cultures, has declined in recent decades, left-handedness in those populations has increased. 

Still, a “southpaw revolution” is unlikely to occur anytime soon, as natural left-handedness remains relatively rare. So you can safely assume that the pair of scissors you’re buying off the shelf is designed to be used with your right hand.

Short Answer

The left side of the brain controls the motor functions of the right side of the brain and vice versa. For around 10% of the population, motor functions are more developed in the brain’s right hemisphere, making it easier to write with the left hand. Right-handedness may be more common because language is usually controlled by the left brain, which also controls writing with your right hand.

Whether you’re left-handed or right-handed is largely determined before you’re born based on genetics, though no single gene is responsible for it. Environmental factors may also affect the complex relationship of genetics and brain development.

NATURE

Is Spider Silk Really Stronger Than Steel?

Spider web with dew
Credit: PRASERT/stock.adobe.com
Melissa Petruzzello
Author
Melissa Petruzzello (she/her) is an Assistant Managing Editor at Encyclopaedia Britannica and covers a range of content including plants, algae, and fungi; insects and spiders; and renewable energy and environmental engineering. She also handles certain topics in Christianity, notably Protestant history and churches.

Spider silk doesn’t look particularly impressive. It’s thinner than a human hair, light enough to drift on the breeze, and fragile enough to disappear in a single swipe of a broom. 

Yet pound for pound, some spider silks are stronger than steel and tougher than Kevlar — the material used in bulletproof vests. So how can something so delicate outperform some of the toughest materials humans have ever invented?

Small Thread, Big Performance

Flexible spider silk
Credit: GG/Unsplash.com

First, comparing spider silk to steel and Kevlar needs a little unpacking (unspooling?). A steel wire of the same thickness is generally stronger than spider silk in absolute terms. What makes spider silk remarkable is that it’s incredibly strong for its weight while also being unusually stretchy. 

Similarly, Kevlar can withstand greater pulling forces than spider silk before breaking, but spider silk stretches even farther before it snaps. Spider silks can stretch anywhere from 30-200% of its size, depending on the type. This rare combination of strength and flexibility is known as toughness (yep, that really is the scientific term for it) and allows it to absorb enormous amounts of energy before breaking. 

The secret to this lies in the chemical composition and physical structure of the silk. Spider silk begins as a liquid made almost entirely of proteins called spidroins. As the liquid is pulled through the spider’s spinnerets, the proteins line up and harden into a fiber. 

At the microscopic level, the fiber is built from tiny, tightly packed crystalline regions that provide strength, connected by softer, elastic regions that let the silk stretch. Think of it as a natural composite material that combines rigid reinforcements with flexible springs.

Spider web
Credit: Matt Busse/Unsplash.com

Not all spider silk is the same. Most spiders spin several different kinds, each specialized for a particular task. Dragline silk — used as a lifeline and to form the framework of a web — is among the strongest natural fibers in the world. 

Sticky capture silk is much stretchier, keeping it from snapping as it absorbs the impact of a flying insect (or your face when you unwittingly walk into one). Other silks are used to wrap prey, protect eggs, or build shelters.

These remarkable properties have made spider silk a favorite of materials scientists, who look to use synthetic versions in everything from surgical sutures and artificial ligaments to biodegradable textiles and lightweight protective gear. 

Reproducing natural spider silk, however, has proven difficult — not least because many spiders are territorial, cannibalistic, and decidedly uninterested in being farmed.

Short Answer

Pound for pound, spider silk is tougher than steel and Kevlar because its proteins are arranged into microscopic crystalline regions linked by flexible chains. This unique structure gives silk an exceptional combination of strength, elasticity, and energy absorption that few human-made materials can match.

HEALTH

Why Do Dreams Make Sense Until You Wake Up?

Surreal dream imagery of a ladder connecting a boat to a cloud
Credit: Behnam Mohsenzadeh/Unsplash.com
Bess Lovejoy
Author
Bess Lovejoy is a writer and editor who lives in Seattle. She is the author of the book Rest in Pieces: The Curious Fates of Famous Corpses, and her writing has also appeared in The New York Times, The Boston Globe, The Wall Street Journal, Time, Lapham’s Quarterly, The Public Domain Review, Atlas Obscura, and elsewhere. She was formerly an editor at Mental Floss and SmithsonianMag.com, and currently teaches classes on research.

One moment, you’re late for an exam for a class you forgot you signed up for. Then your old high school turns into an aquarium; a giant octopus is somehow giving the test. You forgot to wear pants. As anxiety-inducing as all this is, none of it seems particularly strange while you’re experiencing it.

Then you wake up, and within seconds, the entire dream collapses under the weight of its own absurdity. You wipe your brow, wondering how you could possibly have been worried about any of it.

Sometimes it seems like your sleeping brain has lost the plot. But it turns out it’s just operating under a different set of rules. While you dream, the brain is remarkably good at creating vivid worlds, telling stories, and generating emotions. 

What it isn’t so good at is stopping to ask, “Hang on… does any of this actually make sense?” Here’s why.

When Logic Falls Asleep

Diagram of major brain regions
Credit: jonsen/stock.adobe.com

Credit: jonsen/stock.adobe.com

Scientists once believed that dreams were simply random imagery generated during REM (rapid eye movement) sleep. Today, they think the answer is more complicated. 

For one thing, dreams can occur outside of REM sleep, during other stages of sleep. Although researchers are still debating exactly why we dream, there’s a growing consensus around what makes dreams feel so convincing while they’re happening.

One key difference between dreaming and waking states is what’s happening in your prefrontal cortex. This is the region of your brain that helps with planning, logical reasoning, self-reflection, and reality checking. During REM sleep, the activity in parts of this region — particularly the dorsolateral prefrontal cortex — decreases. 

That means your brain is literally making less of an effort to make sense of things, which is understandable, given it’s trying to give you a good night’s rest. Meanwhile, brain regions involved in visual imagery, emotion, and memory remain highly active. 

It’s a bit like watching a really engaging movie — one that’s so engaging it allows you to suspend your sense of disbelief. If the film is engrossing enough, you let plot holes, obvious in retrospect, slip by because you’re so wrapped up in the story. Similarly, your brain’s movie is immersive, the scenery is vivid, the emotions are intense, and the plot barrels confidently forward. 

The setting and even the “characters” in your dream can completely change at a moment’s notice. What’s missing is the little voice that might whisper, “Wait a second, your childhood home can’t also be a submarine.” 

Neuroscientists call this reduced reality monitoring. In waking life, your brain constantly compares what you’re experiencing against your memories and knowledge of how the world works. During dreams, that monitoring system is less active, making it much easier to accept contradictions. Flying feels perfectly ordinary. Your childhood dog starts speaking flawless French. Then he becomes your dentist.

The moon's surface right outside a window
Credit: NASA/Getty Images/Unsplash.com

The way your sleeping brain handles memory also affects how you interpret your dreams. Dreams rarely replay real events exactly as they happened. Instead, they pull fragments from different memories and stitch them together into entirely new combinations. A coworker might wear your grandmother’s face. Your childhood bedroom might open directly onto the moon.

Researchers call this tendency hyperassociativity — the brain forms looser, more creative connections between ideas than it usually does while awake. This also explains why dreams often feel emotionally true even when they’re factually impossible. 

The emotions are coming from real concerns — anxiety about work, excitement about an upcoming trip, grief over someone you miss. But the brain expresses them through imaginative, often bizarre scenarios. A stressful presentation at work might become a dream about trying to conduct an orchestra while riding a giraffe through a car dealership. The details are nonsense, but the feeling is genuine.

When you wake up, your brain’s executive systems quickly come back online, getting ready to interact with the real world. If the memory of your dream still lingers, your prefrontal cortex compares the dream against reality. Contradictions that passed unnoticed seconds earlier suddenly become obvious. Your knowledge of yourself and of how the world works returns, and your inner fact-checker starts filing objections. 

The dream itself, or your memory of it, hasn’t changed. Your brain has simply regained its ability to notice just how bizarre it was.

Short Answer

While you’re asleep, the parts of your brain that normally detect contradictions and help with logical reasoning become less active. Meanwhile, the brain regions responsible for vivid imagery, emotion, and storytelling remain active. You’re dreaming, but have lost the ability to fact-check reality or even question it. When you wake up, those logic systems switch back on, making even your most convincing dream suddenly seem ridiculous.