Featured Image Credit: Shutterstock.

Sea otter

Scientists counted the hair on sea otters and found that they can have up to 140,000 hairs in a single square centimeter. That’s denser than any other mammal we’ve ever studied. In fact, a sea otter’s underhairs are so fine at 7.6 to 11.9 microns across that water can’t touch their skin.  One micron is around 0.00003937 inches, so those hairs are rather small.

Platypus

Yes, a platypus looks odd, but its coat is rather impressive. Each square millimeter carries 600 to 900 hairs & traps a layer of air that keeps it warm while it dives. That’s roughly 60,000 to 90,000 hairs per square centimeter. It’s quite important, as they need to stay underwater for long periods without losing body heat.

Vicuña

You probably haven’t heard of the vicuña. It’s a wild relative of the llama & it has fibers so fine they average only 12 to 13 microns wide. Interestingly, research has shown that these animals have incredible uniformity across herds in Peru & Chile, with each staple of fleece being about 31 mm long. This gives their fiber its smooth, almost silk-like look.

Musk ox

Beneath a musk ox’s shaggy coat, they have something called a qiviut, which is an underwool that insulates the animal against Arctic winters. Qiviut fibers are only 17.5–18.2 microns thick on average & researchers discovered that females usually have slightly finer samples than males. That’s quite different from their coarse guard hairs, which can be ten times as thick.

Angora rabbit

Breeders & textile researchers measured the fibers of the Angora rabbit and found that it’s usually between 12.4 and 14.1 microns. So what’s the secret to their softness? Well, the size is just as important as the structure because the down fibers have little to no medulla, which is the central core in hair. This makes the fur flexible & springy.

Cashmere goat

Cashmere goats produce an undercoat that’s between 15.6 and 19.5 microns in diameter. However, some breeds, especially in Inner Mongolia, can go as low as 13.8 microns. The sex & age can affect the hair’s diameter, and so can the climate. But the cashmere itself is hidden under a rougher outer coat. These animals shed it naturally each spring.

Common eider

In northern communities, eider ducks are famous for their down because it behaves differently from goose or duck down. Each barbule has tiny prongs that hook together & form clusters that cling without stitching. In fact, these clusters spring back into shape and insulate the eider evenly, so it’s no surprise it’s known as one of nature’s strongest soft materials.

The following sources were consulted in the preparation of this article:

1. An Analysis of California Sea Otter (ENHYDRA LUTRIS) Pelage and Integument
2. The sensory world of the platypus
3. Fibre characteristics of vicuña (Vicugna vicugna mensalis)
4. Fiber characteristics of qiviut and guard hair from wild muskoxen (Ovibos moschatus)
5. Characteristics of Angora rabbit fiber using optical fiber diameter analyzer 
6. Effect of sex and rearing system on the quality and mineral content of fiber from raeini cashmere goats
7. Contributions of feather microstructure to eider down insulation properties

Featured Image Credit: Shutterstock.

Cattle see two cone colors, not a true red

Bulls’ eyes are wired differently from humans, and instead of three color sensors like us, they only have two. Neither one of these is tuned to red. As such, when they look at that famous cape, it’s essentially just another shade of dull grayish-green, and there’s no red alert going on in their brains.

Red versus green

When light levels are balanced, cattle also have a hard time telling one hue from another because their eyes rely more on brightness differences than subtle color shifts. They’re unable to pick red over green unless the lighting’s uneven. When both of them look equally bright, it’s more of a guessing game when they’re trying to spot the difference.

The importance of movement

So what’s going on? When the cape’s completely still, the bull normally does nothing & just stands completely still. But the second that thing swishes, the animal snaps to attention. This is because bulls rely on motion to decide whether something’s a threat. The color itself is background noise for a bull, compared to a sudden flick or wave.

Fighting cattle show no pull to red

Spanish fighting bulls don’t care more about red than any other color. In fact, most bulls simply react to whatever is in front of them when it moves, and a bright blue tarp would do the trick just as well as a red one. However, most shows use red because it’s easier for humans to see, not the bulls.

Two capes, two colors

Usually, bullfighters use two capes. The first one is often magenta & gold, which the bulls charge at just fine, while the red one is used later mostly for tradition. It also masks the animals’ blood stains. However, in practice, both colors get equal attention from the bull because it’s the waving motion that sets them off instead of the shade.

Red became the usual choice in the 1800s

Matadors didn’t use to have a strict color rule. In the early days, the fighters waved white or yellow cloth, sometimes blue, as red wasn’t the most popular option. It took until the 1800s for it to become the standard. Bullrings across Spain began using the red muleta, and by the late 19th century, it was practically the only option.

The following sources were consulted in the preparation of this article:

1. Photopigment basis for dichromatic color vision in cows, goats, and sheep
2. Behavioral Principles of Livestock Handling
3. The Perception of Color by Cattle and its Influence on Behavior
4. Colour perception in fighting cattle

Featured Image Credit: Shutterstock.

The Moon’s core is shaped like Earth’s, but much smaller

To start with, the Moon isn’t simply a solid hunk of rock. It has a tiny inner core that’s made of dense iron-like material. It’s only a few hundred miles wide & is wrapped in a liquid layer. Essentially, you can think about it as being like Earth’s core. But it’s shrunk down by quite a bit. How cool is that?

Some lunar spots are colder than Pluto

Most people know that Pluto’s freezing. But it turns out that parts of the Moon are even colder, as the bottoms of certain lunar craters barely creep above minus 390°F. That’s colder than some parts of deep space. These holes trap ice, and they don’t get a single ray of sunlight. Ever.

The Moon has a 500,000-mile-long sodium tail

The Moon has its own faint orange tail made of sodium atoms, which stretches about half a million miles into space. We can’t see it with our eyes. However, astronomers have cameras that catch the glow around the same time of the new moon. It’s a pretty incredible sight to behold.

Moonquakes can last nearly an hour

You probably know that the Moon doesn’t have earthquakes because, well, it’s not Earth. It has moonquakes instead. The seismometers on Apollo spacecraft have measured these quakes, and some of have gone on for almost an hour. This is because the Moon’s dry crust doesn’t dampen vibrations like Earth’s. As such, the tremors just bounce around for a long time.

Gravity on the Moon is lumpy and weird

Gravity works differently on different parts of the Moon. That means that spacecraft flying over certain spots will be tugged down harder than expected, and those spots are called “mascons.” This is short for mass concentrations. Essentially, they’re hidden gravity potholes & they came from giant asteroid impacts. These left behind heavy, dense layers underground.

The far side is built like a fortress

The far side of the Moon is the one we never see from Earth. It has a crust that’s much thicker than the side we know, and the difference between the two is like the difference between a paper plate & a brick wall. This is one of the main reasons why that side has a lot of rugged mountains, instead of smooth lava plains.

Lava erupted just two billion years ago

Not all Moon lava is as ancient as you might think. In 2020, China’s Chang’e-5 mission scooped up volcanic rock that turned out to be only 1.96 billion years old. That’s practically yesterday from a geologic timeframe. Somehow, the Moon was spewing out lava while dinosaurs were just starting to stir on Earth. That really puts stuff into perspective, doesn’t it?

The Moon once had a magnetic field stronger than Earth’s

The Moon’s surface is relatively quiet today. But long ago, the Moon had a magnetic field that was even stronger than Earth’s. Rocks brought back from Apollo missions show that the field may have been twice as strong as Earth’s. That field lasted for billions of years. It’s quite surprising, given how small the Moon is.

We actually see 59% of the surface

The idea that we only ever see half the Moon isn’t strictly true. The Moon wobbles a little as it orbits, meaning that we get sneak peeks around the edges. Eventually, we see around 59% of the whole lunar surface. It’s not a lot more than half. But it’s enough.

The Moon is slowly moving away from Earth

Scientists have conducted numerous experiments & found out that the Moon isn’t staying put. It drifts a tiny bit farther from Earth each year. It’s not a lot, just over an inch, but it confirms that our lunar neighbor is slowly slipping out of reach. Astronauts left mirrors up on the Moon. On Earth, we bounce lasers off them to measure the distance.

The following sources were consulted in the preparation of this article:

1. The lunar solid inner core and the mantle overturn
2. Diviner Lunar Radiometer Observations of Cold Traps in the Moon’s South Polar Region
3. Long-Term Observations and Physical Processes in the Moon’s Extended Sodium Tail
4. Effects of Lunar Near-Surface Geology on Moonquakes Ground Motion Amplification
5. 3-D Density Structure of the Lunar Mascon Basins Revealed by a High-Efficient Gravity Inversion of the GRAIL Data
6. The crust of the Moon as seen by GRAIL
7. Age and composition of young basalts on the Moon, measured from samples returned by Chang’e-5
8. Assessing lunar paleointensity variability during the 3.9 – 3.5 Ga high field epoch
9. A two-billion-year history for the lunar dynamo
10. The Lunar Laser Ranging Experiment: Accurate ranges have given a large improvement in the lunar orbit and new selenophysical information

Featured Image Credit: Shutterstock.

Electrical stimulation in the temporal lobe can trigger déjà vu

Doctors discovered in neurosurgery labs that zapping certain parts of the brain can set off instant déjà vu. Patients reported feeling as though they were somewhere familiar or even that they had dream-like memories when the electrodes hit the temporal lobe. This is also true in epilepsy cases. Some people feel a sense of déjà vu right before a seizure.

People experience less déjà vu when they’re older

Questionnaires & surveys show déjà vu changes as you age. Teenagers & young adults say they get it a lot, but older adults report it far less, which could be due to stress and fatigue. In fact, one study estimated that around 60% of people have experienced déjà vu at least once. But how often that happens depends quite a lot on your age.

Your brain’s right-side experiences it more

Neurologists compared left vs. right brain stimulation and found something interesting. Déjà vu shows up a lot more often on the right. Patients with epilepsy had electrodes placed in both sides of the temporal lobe, and they reported stronger déjà vu when the right side was activated. That makes sense, since it’s where your hippocampus & rhinal cortex work together.

Some people suffer from “déjà vécu”

Experiencing déjà vu just once can be strange. Now imagine feeling it all the time. For some people, that’s a reality. They feel as though every single thing they do has already happened before. It happened to at least two dementia patients in an experiment, as well as someone with anxiety. Doctors called this “déjà vécu.” It means “already lived.”

Hypnosis can create déjà vu

In 2009, a group of researchers used hypnosis to see how it would affect people’s sense of déjà vu. Participants were told under hypnosis that certain new words would feel familiar later on. When those words actually appeared, the volunteers swore they’d seen them before. But they hadn’t. Clearly, hypnosis can make your brain play all sorts of tricks on you.

Some amnesia patients still experience déjà vu

Even memory loss can’t block déjà vu completely. In one case study, patients with serious amnesia (aka people who couldn’t recall events from just minutes before) still claimed to have feelings of déjà vu. The research found this could be connected to damage in the temporal lobe.

The following sources were consulted in the preparation of this article:

1. The dreamy state: hallucinations of autobiographic memory evoked by temporal lobe stimulations and seizures
2. Validation Study of Italian Version of Inventory for Déjà Vu Experiences Assessment (I-IDEA): A Screening Tool to Detect Déjà Vu Phenomenon in Italian Healthy Individuals
3. Memory scrutinized through electrical brain stimulation: A review of 80 years of experiential phenomena
4. Disordered memory awareness: recollective confabulation in two cases of persistent déjà vecu
5. Déjà Vu in the Laboratory: A Behavioral and Experiential Comparison of Posthypnotic Amnesia and Posthypnotic Familiarity
6. Déjà Experiences in Temporal Lobe Epilepsy

These burgers, fries, and chicken changed our childhoods and fueled our road trips, all while becoming some of the most successful food items in history. Without further ado, here are the 10 best-selling fast-food items of all time.

McDonald’s French Fries

McDonald’s fries are by far the king of fast food dishes. Many people visit McDonald’s just to eat their world-famous fries. Once McDonald’s made the switch to frozen, shoestring fries in the 1960’s, sales skyrocketed because every fry was guaranteed to taste the exact same.

Today, the restaurant serves approximately 9 million pounds of fries PER DAY. Because fries are included in almost every value meal, they are considered to be the most purchased fast-food item of all time. No other snack has come close to selling more than McDonald’s fries.

McDonald’s Big Mac

Did you know you can measure how expensive it is to live in foreign countries by using McDonald’s burgers? The Big Mac is so popular and ubiquitous that economists actually track the price of them around the world using something called the “Big Mac Index”.

In 1967, a Pennsylvania franchise owner invented the signature McDonald’s burger. Featuring two patties and “special sauce”, the burger became a national sensation by 1968. Americans alone eat approximately 550 million Big Macs per year. That comes out to about 17 burgers per second.

Burger King Whopper

If the Big Mac is the king of popularity, the Whopper has been the king when it comes to burger customization. Burger King actually beat McDonald’s to the punch by 10 years, introducing the hamburger in 1957.

The secret to its success is the burger’s famous “flame-grilled” flavor, which has given Burger King a noticeable barbecue taste that stands out from regular fried burgers.

Burger King sells over 2 billion Whoppers worldwide every year. Its signature “Have It Your Way” slogan made it a phenomenon because it allowed customers to adjust the ingredients to their liking.

McDonald’s Happy Meal

Arguably the most genius fast-food idea of all-time. Happy Meals were invented with children in mind, combining food with a toy. Introduced in 1979, the circus-wagon themed boxes were the first “child-friendly” meals to offer toys built right into them.

This ensures that once kids learn how to talk, McDonald’s will be the first place they demand to eat. Selling over 1 billion meals per year, the Happy Meal has actually made McDonald’s the largest toy distributor in history, outselling even places like Hasbro or Mattel.

KFC Original Recipe Bucket

When Colonel Sanders began selling food, he marketed his product as a “Sunday Dinner” you could get in a bucket. The idea of a “bucket” of chicken changed fast food history because customers were no longer just buying lunch for themselves on the go, but an entire family’s worth of food to eat at home.

The secret “11 herbs and spices” was the most famous secret recipe in world history all throughout the century. KFC was also one of the first fast food chains to successfully expand all over the world.

Wendy’s Frosty

Dave Thomas started Wendy’s with only 5 things on the menu, and Frosty was one of them. At the time, Frosty was unique because it wasn’t a milkshake. It also wasn’t soft-serve ice cream. It was thick enough that you could eat it with a spoon, but soft enough to dip your French fry in.

Throughout the 80s and 90s, Frostys were some of the highest-selling desserts in the world. It’s historical because it hasn’t changed at all in decades, while competitors were changing their recipes yearly.

Dairy Queen Blizzard

When the Blizzard was introduced to the world in the mid-80s, it was a cultural phenomenon. Never before had someone successfully “mixed” candy and cookies into soft serve.

In year one alone, Dairy Queen sold over 175 million Blizzards. The bandana that came with every Blizzard covered the cup so you couldn’t see how thick it was inside. Servers then flipped the cup upside down at your table to showcase the inventor’s insanity and creativity.

Taco Bell Crunchy Taco

When Taco Bell started, Americans didn’t know what tacos were. Glen Bell took the traditional taco and squared it off like a hamburger. Taco Bell fried their shells so they would stay crunchy without softening, allowing the restaurant to crank out tacos as quickly as burgers.

For decades, you could get a taco shell and filler for 19 cents (later 59 cents). They became the gold-standard of budget meals.

Pizza Hut Original Pan Pizza

Pizza Hut revolutionized pizza during the ‘80s when it created the “Pan Pizza.” Before this era, the majority of pizzas you could get were thin-crust.

Pizza Hut figured that if they fried their dough in the pan before adding sauce, it would create a texture more similar to a “sit-down pizza.” Pizza Hut was the largest pizza chain during the 90s because of this crave-able crust.

McDonald’s Chicken McNuggets

Chicken McNuggets may be the single-handed greatest invention in fast food. Before McNuggets, if you wanted chicken at fast food, you ate it on the bone, just like KFC.

However, McDonald’s hired a scientist to create the perfect “boneless” nugget you could dip in sauce and eat with your hands. By the end of the decade, McNuggets were so wildly popular that they changed how the world butchered chickens and ate chicken.

Arby’s Classic Roast Beef

Arby’s was founded on the idea that Americans were getting tired of hamburgers. He decided that his restaurant would serve something that felt a little “classier” than a solid burger.

For as long as it was on the menu, Arby’s roast beef sandwich sold extremely well. The thinly sliced roast beef on a sesame seed bun was a hit because of how different it was. They discovered a massive niche of customers who wanted “fast” food that wasn’t tacos or hamburgers.

The following sources were consulted in the preparation of this article:

1. Most Iconic Fast Food Items in History
2. McDonald’s History
3. The World’s Bestselling Fast-Food Items – Interesting Facts

It’s these enigmas that inspire us to be curious about the world around us and to remember that we still have so much to learn. So here are 10 nature mysteries that science hasn’t been yet able to explain.

Ball lightning

When you hear the word lightning, you probably picture a quick flash of electricity. Ball lightning is different because it is spherical and can hover around for up to thirty seconds before disappearing with a “pop.”

Some scientists believe that when lightning hits the ground, it superheats mineral silicon in the soil and creates a vapor that ignites and glows as it burns in air. Others believe ball lightning is merely electrical activity causing a hallucination in the brain. But it has been photographed too many times to be written off as such.

The Taos hum

To the few residents of Taos, New Mexico who hear it, the Taos Hum sounds like a large truck idling at the end of your street. It never stops, you can hear it anytime, and it often seems louder inside your house than outside.

But when authorities bring super-accurate microphones to Taos to find the noise, they never pick it up. It could be infrasound (sounds so low we sense them through our body than our ears) coming from oceans or shifting tectonic plates.

It could also be that only certain people’s ears can translate radio waves or electromagnetic signals from electrical equipment.

Star jelly

For centuries, people have been finding blobs of translucent Jell-O like substance on their lawns after meteor showers. Scientists cannot prove it’s from space because by the time the gooey substance is collected and analyzed, it has mysteriously dissolved or evaporated.

It could be frog eggs regurgitated by birds. It might be certain types of algae that swell up when wet. But the reason it seems to appear right after shooting stars remains a strange coincidence that hasn’t been fully linked.

Earthquake lights

Before some earthquakes, people have spotted multicolored clouds or blue flames shooting out of the ground. Scientists thought these were hallucinations until witnesses took video that proved the lights were real.

Experts think that similar to a clicker-lighter, squeezing certain crystals together creates a spark. It seems that pressure squeezing crystals inside mountains causes them to spark, like when you crank a clicker-lighter.

Researchers think miles of squeezed rock generate electricity that travels to the surface where the sparks ignite in the air.

Singing sand dunes

Sliding down sand dunes in certain deserts will create not only a sand crunching sound, but an orchestral booming note. The noise can sound like a cello being played backward or a plane engine. Scientists have discovered that not all sand makes this sound.

To create this music, you need specific-sized sand particles and just the right amount of moisture. Similar to rubbing a violin string, when two layers of sand slide over each other, it creates vibration. But we still don’t know why millions of tiny grains of sand synchronize to vibrate at the exact same frequency to create one audible note.

Catatumbo lightning

One tiny spot on Earth has more lightning than any other place. Every night, without fail, billions of bolts crackle over Lake Maracaibo in Venezuela for hours at a time. Lightning storms come and go, but this storm has raged in the same spot for hundreds of years.

Scientists think geography is the cause: a cliff where cold air from the mountain blasts into warm air cascading off a lake. Others speculate that methane gas evaporating from marshes lubricates the storm, making it easier for lightning to jump.

The Placebo effect

If a doctor gives you a “medicine” that is actually just a sugar pill, but you truly believe it is real, your body can sometimes actually heal itself. Tiny electric currents in your brain can convince your body to release hormones that decrease swelling, reduce blood pressure, or dim the volume on pain receptors.

Your brain tricks itself into secreting natural painkillers called endorphins when you believe you are taking medicine. We have proven it happens, but we haven’t found the “missing link” that tells your body to heal itself just because you think so.

Hessdalen lights

Every few months, weird glowing orbs that look like flying cars soar through the night sky in Norway. When they appear, they can shoot across the sky at impossible speeds for scientists to catch on film. Most people don’t travel through the valley where they appear often.

Scientists think it might have something to do with the valley’s unique river; one side of the riverbed is covered in copper ore and the other in zinc. The two metals combined create a sort of battery, and researchers think when acidic gases are released from the water and rise into the air, they can combust and create the floating lanterns. We haven’t discovered what ignites them though.

Dark matter & dark energy

When you look at a galaxy, there isn’t enough gravity from all the stars to hold it together. It should blast apart like water shooting off a tire that is spinning too fast. Therefore, we know there is an “invisible” substance with gravity holding galaxies together.

We also know there is another invisible force acting like fuel to cause the universe to expand. We cannot see, touch, or smell this “dark” stuff, and we only know it exists because we see its gravity pulling on the stars we can see. It’s probably a particle that we haven’t discovered with our technology in 2026.

The Wow! signal

On August 15, 1977, a radio telescope picked up the strongest pulse of radio waves it had ever recorded. Not only was it powerful, but the 72-second broadcast was coming from the direction of the Sagittarius constellation.

Normally scientists can write off mysterious space noises as pulsars or dying stars, but this one was concentrated and powerful. The astronomer who discovered it was so excited when he saw the reading, he circled it on his computer printout and wrote “Wow!” in the margin.

It has never been heard since, and scientists in 2026 still don’t know exactly what it was. Most chalk it up to a passing comet or solar flare, but none of those theories can explain how it was strongest in one direction and looked so deliberate.

The following sources were consulted in the preparation of this article:

1. Ball Lightning: Weird, Mysterious, Perplexing, And Deadly
2. What Is The Taos Hum?
3. Star Jelly
4. Singing Sand Dunes: The Mystery Of Desert Music
5. Catatumbo Lightning
6. The Placebo Effect: What Is It?
7. Hessdalen Lights
8. Wow! Signal

Here are ten intriguing facts about Cleopatra. Which one surprised you the most?

She spoke many regional languages

Writers from Cleopatra’s time said that she very rarely required an interpreter. Instead, she was able to switch between various languages with ease, sometimes even speaking to visitors directly herself.

It was quite unusual for a Ptolemaic ruler at that time. Her native language was Greek, and she could also speak Egyptian & supposedly seven other languages, too.

She was a technical author

You might not think of Cleopatra as a scientist or author. But technically, she was. Cleopatra wrote & produced a lot of specialized material that suggests she had a good knowledge of medicinal formulas and magical practices of the time.

She also knew some early ideas of alchemy. Not bad for someone who was “just” a queen.

She tested poisons on condemned prisoners

One of the not-so-nice facts about Cleopatra is that she supposedly tested poisons on prisoners.

Plutarch & later writers claim that the queen wanted to see how different toxins work, including snake venoms and plant-based poisons. She also wanted to see how fast they acted and people’s symptoms once they took them.

She tied her public image to the goddess Isis

A lot of Cleopatra’s public image was connected to the Egyptian goddess, Isis. Many of her symbolic decorations & inscriptions were meant to mirror the goddess of fertility, due to Cleopatra’s status as royal mother.

In fact, Roman accounts claim there was a golden statue of Cleopatra. It was apparently in Caesar’s Temple of Venus Genetrix.

She followed the Ptolemaic habit of marrying her brothers

Cleopatra grew up in a royal family that had a long history of marrying their siblings. She was no different. Cleopatra first ruled & married her brother Ptolemy XIII until their relationship broke down, leading to a civil war.

She then married her younger brother, Ptolemy XIV, before he died. Rumor has it that Cleopatra poisoned him so that their son, Caesarion, could rule Egypt.

She had a signature perfume tied to a real workshop site

Cleopatra really enjoyed strong & warm perfumes, and Mendesian was one of her most famous ones. The perfume’s creation was connected to a real production site at Tell Timai.

It was a mix of myrrh, cinnamon & oil from the Nile Delta. It’s probably one of the reasons why people thought Cleopatra was so glamorous. 

A single Greek word may be the only bit of her handwriting

Sadly, we only have one surviving example of what could be Cleopatra’s own handwriting. It’s incredibly short.

There’s a tax-related decree that has the Greek word ginesthoi written at the bottom. It essentially means “let it be done.” While it may be rather small, historians believe it’s the most likely example of her writing that we still have today.

She may have hosted scientific demonstrations with live animals

Writers from Cleopatra’s time mentioned that the queen had gatherings that involved many scholars. They would do demonstrations for the court.

One of these gatherings included her watching people test weight & movement using animals as props. However, these weren’t exactly formal lessons. These were displays for court thinkers to show off Greek physics. 

She supposedly won a huge bet by drinking a dissolved pearl

Cleopatra was apparently a rather competitive person. So much so that, according to legend, she showed up to a dinner with Antony & wore enormous pearl earrings. She dropped one into strong vinegar until the pearl softened.

Later, the story says that Cleopatra drank the dissolved pearl. Why? Because she wanted to settle a bet about hosting the most expensive banquet.

Ancient accounts give conflicting explanations for her death

One of the most intriguing details about Cleopatra is that we don’t actually know how she died. One writer, Strabo, claims that she killed herself through the bite of an asp, or a prepared ointment.

However, Plutarch claims she committed suicide with a secret device, like a hollow hairpin. Cassius Dio wrote about tiny wounds. Who knows what really happened?

The following sources were consulted in the preparation of this article:

1. Cleopatra’s Languages
2. Cleopatra VII: Scholar, Patron, Queen
3. Toxicology and snakes in ptolemaic Egyptian dynasty: The suicide of Cleopatra
4. Cleopatra the Great: Last Power of the Ptolemaic Dynasty
5. The expulsion of Cleopatra VII: context, causes, and chronology
6. Eau de Cleopatra: Mendesian Perfume and Tell Timai
7. Make It So! Sayeth Cleopatra
8. Three Ways Cleopatra Contributed to Science and Medicine
9. Cleopatra’s Cocktail

Here are seven interesting facts about swimming pools. Which one surprised you the most?

Urine really does react with chlorine

Pool smell doesn’t come solely from chlorine. It’s actually from when urine mixes with chlorine to create gases like cyanogen chloride & trichloramine, both of which irritate your eyes and nose.

Tiny amounts of uric acid trigger this chemical reaction. So yes, your eyes stinging after swimming is caused by chemistry, rather than cleanliness.

Scientists measured how much urine is actually in pools

Speaking of urine, scientists performed tests to see how much urine is in pool water. They checked for a sugar substitute known as acesulfame-K, which passes through the body unchanged. What did they find?

It was in every pool they tested. The scientists compared levels & found out that a public pool likely has around 30 to 75 liters of urine. How delightful.

Swimmers add sweat

Most people have no clue about how much they’re actually “contributing” to pool water. Each swimmer adds sweat & plenty of other organic material to the swimming pool, even when they don’t leave the lane.

The average person releases around 0.1 to 0.8 liters of sweat every hour. That’s not including other compounds like nitrogen & carbon. These all mix together in the pool, making for a shared experience in the worst way.

The water looks blue because red light gets absorbed

Physics is the reason why pools look blue, not dye or tiles. Water naturally absorbs red light better than blue. The light that bounces back to your eyes looks sky blue, and the deeper the pool, the more blue it appears to your eyes.

It’s the same reason a glass of water looks clearer than an Olympic pool.

Green hair from pools comes from copper, not chlorine

That’s not all for colors. Most people assume that when their hair goes green after swimming, it must mean there’s a high concentration of chlorine in the pool. But the real cause is copper.

Copper leaches from pipes & algaecides, then grabs onto your hair protein. The effect is especially noticeable with blond or color-treated hair.

Thankfully, you can avoid the effect by rinsing your hair first or using special shampoos to take the metal out.

Olympic pools are kept colder on purpose

Olympic swimming pools are cooler than you might expect. Officials keep the temperature around 77 to 82°F. Why?

Because it’s the perfect temperature for when you’re trying to move quickly, as cooler water helps your muscles work longer. The lower temperature also keeps your body temperature steady when you’re doing intense laps.

The world’s deepest pool could swallow a building

Poland is home to the world’s deepest swimming pool. It’s called Deepspot & it has a drop of approximately 148 feet. That’s rather impressive when you remember that the average building is only around 20 to 26 feet, including the roof.

Deepspot also holds a million gallons of water. But the pool isn’t made for a casual swim. It’s only for divers & film crews, as well as those who are training to deal with pressure under deep water.

The following sources were consulted in the preparation of this article:

1. Volatile disinfection byproducts resulting from chlorination of uric acid: implications for swimming pools
2. Quantification of continual anthropogenic pollutants released in swimming pools
3. Absorption spectrum (340–640 nm) of pure water. I. Photothermal measurements
4. Sweetened Swimming Pools and Hot Tubs
5. Pseudo Green Hair
6. Deepspot – a pool of extraordinary transparency
7. FINA facilities rules 2021 – 2025

Featured Image Credit: Shutterstock.

The world hit 8 billion on November 15, 2022

Tuesday, November 15th, 2022, was a special date. It was when the UN’s official estimate finally reached over 8 billion people, although they didn’t count heads one by one. This number came from decades of birth & death records blended with census data. It’s more of a symbolic date than a “true” count. But it was still an important moment in history.

India is the most populous country

China had the most people for many years. But in 2023, India pulled ahead, with a gap of around two million people, which sounds small, but it was enough for the UN to call it. India had about 1.428 billion & China slightly less at 1.426 billion. It was a real passing of the crown. And it’s all thanks to the slowing birth rates in China and steady growth in India.

Global births peaked in 2012

More babies were born in 2012 than in any other year so far, at roughly 146 million. That number has decreased slightly since then. Demographers have tracked this figure with fertility rates, but the big picture is that the world’s “baby boom” year already came & went. Who knows when the next one will happen?

The growth rate fell below 1%

2020 sure was a record-breaking year. It was the first time since the 1950s that the global growth rate slipped under 1% a year. The headcount did rise afterwards, but it’s climbing more slowly than before. Fewer than one extra person per hundred has been added each year worldwide.

Eight countries drive over half of growth

Population growth isn’t spread evenly. According to the UN, just eight countries will account for more than half the world’s increase through 2050. These are Congo (DRC), Egypt, Ethiopia, India, Nigeria, Pakistan, the Philippines & Tanzania. The majority of other countries? They’re suffering from low birth rates.

Urban living will reach about 68% by 2050

Anyone who lives in a city will know how packed they feel now. But try imagining nearly 7 out of 10 people worldwide living in one. That’s the UN’s forecast for 2050, and in 2018, the number was closer to 55%. They used data from tracking settlements & standardizing to create this figure. Let’s hope it doesn’t get that bad.

Older adults surpassed under-fives in 2018

In 2018, the worldwide demographic flipped. The number of people aged 65+ outnumbered kids under five for the very first time in history. Looking forward, the UN projects that about one in six people will be 65 or older by 2050. This figure means that the age pyramid will look more like a rectangle in the future.

Japan has the highest share of people over 65

Almost three out of every ten people are now over 65 in Japan. That’s roughly 29% of the population in 2023. It’s a higher figure than anywhere else in the world, even in countries like Italy & Finland. These also have large older populations. But Japan has a high number of older people, yet also a low number of young people.

38% of people live close to coasts

A huge chunk of the world prefers to stay near the water. One 2018 study showed that about 38% of people live within 100 kilometers of a coast, for one reason or another. That’s nearly four out of every ten humans choosing spots that aren’t far from shorelines. It makes sense, though. Coastal zones often mean easier access to trade, food & transportation.

The world will have 43 megacities by 2030

A megacity is defined as 10 million people or more. And the UN expects there will be 43 of them by 2030, although back in 2018, there were only 33. The biggest growth is happening in Asia & Africa. Urban areas are expanding there faster than anywhere else, with cities like Lagos & Kinshasa being on track to join or climb higher on the list.

The following sources were consulted in the preparation of this article:

1. World Population Prospects 2022
2. India to overtake China as world’s most populous country in April 2023, United Nations projects
3. World Urbanization Prospects 2018
4. World Population Prospects 2024
5. World population to reach 8 billion on 15 November 2022
6. World Urbanization Prospects: The 2018 Revision
7. Older People Projected to Outnumber Children for First Time in U.S. History
8. Population aging in Japan
9. 2018 Revision of World Urbanization Prospects
10. Accelerating growth of human coastal populations at the global and continent levels: 2000–2018

Featured Image Credit: Shutterstock.

The pistol shrimp cavitation snap

A pistol shrimp is able to slam its claw shut, and it’s loud. Pretty loud. In fact, it blasts out a jet of water so fast that it makes a bubble collapse with a bang. That brief implosion is hotter than the surface of the sun & it also gives off a flash of light. It all comes from a shrimp under two inches long.

The peacock mantis shrimp’s punch

The peacock mantis shrimp uses more than simple muscles to punch. It has a biological “spring-loaded hammer,” which is a kind of joint that stores energy. The mantis then lets the punch fly in a move that’s faster than most bullets in water. In fact, high-speed cameras have clocked the strike at over 50 mph. That’s enough to crack crab shells & even aquarium glass.

The electric eel’s shock

An electric eel is essentially an eel with built-in tasers. It fires off rapid electrical pulses that are able to make the fish’s muscles contract without the fish needing to move. The shock freezes prey in place, leaving it utterly helpless, and the eel can use this ability when it’s threatened. The fish can leap up & deliver the jolt straight to whatever’s touching it.

The bombardier beetle’s boiling spray

This beetle has chemistry labs inside its body, and when threatened, it mixes stored chemicals. These instantly react & heat to boiling. The result? A scalding spray that comes out in bursts, almost like a tiny machine gun, with a temperature that reaches near 212°F. The beetle can swivel its nozzle to aim with surprising accuracy.

The wood frog’s deep freeze survival

Wood frogs do what sounds impossible every winter. They literally freeze. Their hearts stop & ice fills much of their bodies, but they aren’t dead. This is because of the amount of glucose & urea that they pump into their cells. It acts like natural antifreeze. Once the warmth of spring arrives, they thaw out and hop off as if nothing happened.

The hagfish’s rapid fiber-gel

The hagfish is a fish that defends itself with instant slime. Yes, really. It releases threads & mucus that mix with seawater to form a gooey net in seconds. The creature expands so much that it can choke the gills of predators trying to bite it, although that’s not the weirdest part. It’s the fact that it takes very little raw material to make gallons of the stuff.

The immortal jellyfish’s lifespan

Scientists found that Turritopsis dohrnii doesn’t age like other animals. Anytime something bad happens, like injury or stress, these jellyfish can literally de-age themselves. They roll back into their polyp stage. Essentially, they start fresh instead of breaking down with age, and they can do it again & again.

The following sources were consulted in the preparation of this article:

1. Snapping shrimp make flashing bubbles
2. Biomechanics: deadly strike mechanism of a mantis shrimp
3. Electric Eels Concentrate Their Electric Field to Induce Involuntary Fatigue in Struggling Prey
4. Biochemistry at 100°C: Explosive Secretory Discharge of Bombardier Beetles (Brachinus)
5. Molecular Physiology of Freeze Tolerance in Vertebrates
6. Composition, morphology and mechanics of hagfish slime