TED-Ed Kahoots

In ancient Egypt, there was a spell that declared, “Be far from me, O vile cockroach.” Thousands of years later, we’re still trying to oust these insects. But from poison traps to brandished slippers, cockroaches seem to weather just about everything we throw at them. So, what makes cockroaches so hard to kill? Ameya Gondhalekar digs into the genetic wonders of this troublingly tenacious creature.

Watching a kitten fumbling around, it might feel as if you’ve never encountered anything so devastatingly adorable in your mortal life. You may want to pet its soft fur and kiss its tiny head. But you may also feel the conflicting urge… to squeeze or smush the kitten, maybe even stuff it in your mouth. What is this peculiar phenomenon? Joshua Paul Dale explores the urge known as cute aggression.

Aphids can reproduce incredibly fast: they can make 20 new generations within a single season. And that means lots of poop. Some aphid populations can produce hundreds of kilograms of poop per acre— making them some of the most prolific poopers on the planet. We know this poop as the sweet, syrupy liquid called honeydew. George Zaidan explores the wonderfully weird life of an aphid.

They’re cute, they’re lovable, and judging by the 26 billion views on over 2 million YouTube videos of them, one thing is certain: cats are very entertaining. But their strange feline behaviors, both amusing and baffling, leave many of us asking: Why do cats do that? Tony Buffington explains the science behind some of your cat’s strangest behaviors.

Without water, a human can only survive for about 100 hours. But there’s a creature so resilient that it can go without it for decades. This 1-millimeter animal can survive both the hottest and coldest environments on earth, and can even withstand high levels of radiation. Thomas Boothby introduces us to the tardigrade, one of the toughest creatures on Earth.

Zebras belong to the same equine family as horses and donkeys. After their lineage entered Africa, they evolved into three zebra species, lived in social herds, grazed on grasses, and evaded fierce predators. One mystery that has perplexed prominent scientists for decades is the matter of their coats: why are they striped? Cella Wright digs into the common theories about the unique patterning.

More than 500 years after its creation, Leonardo da Vinci’s “Mona Lisa” is arguably the world’s most famous painting. Many scholars consider it an outstanding work of Renaissance art— but history is full of great paintings. So, how did this particular portrait skyrocket to unprecedented fame? Noah Charney explores the factors that helped create a worldwide sensation.

An undulating sky melds into the landscape, two silhouettes move along a balustraded walkway, and a ghostly figure’s features extend in agony. Since Norwegian artist Edvard Munch created "The Scream" in 1893, it’s become one of the world’s most famous artworks. But why has its cry traveled so far and endured so long? Noah Charney shares the inspiration behind the dramatic and haunting masterpiece.

What’s your sign? In Western astrology, it’s a constellation determined by when your birthday falls in the calendar. But according to the Chinese zodiac (生肖), it’s your shuxiang, meaning the animal assigned to your birth year. And of the many myths explaining these animal signs and their arrangement, the most enduring one is that of The Great Race. Megan Campisi and Pen-Pen Chen recount this classic myth.

Today, surfing is a multi-billion-dollar global industry, with tens of millions of enthusiasts worldwide. For some it’s a serious sport; for others, just a way to let loose. But despite its casual association with fun and sun, surfing has a richer and deeper history than many realize. Scott Laderman shares the hidden history of surfing.

Rice contributes over 20% of the calories consumed by humans each year. Korean bibimbap, Nigerian jollof, Indian biryani, Spanish paella, and countless other culinary masterpieces all begin with rice. So how did this humble grain end up in so many cuisines? Carolyn Beans investigates the global expansion of this beloved crop and the unintended consequences of its popularity.

Mansa Musa, the 14th century African king of the Mali Empire, is said to have amassed a fortune that possibly made him one of the wealthiest people who ever lived. Jessica Smith tells the story of how Mansa Musa literally put his empire – and himself – on the map.

Like Beat writers who composed their work by shredding and reassembling scraps of writing, artist Jean-Michel Basquiat used similar techniques to remix his materials. Pulling in splintered anatomy, reimagined historical scenes and skulls, he repurposed present day experiences and art history into an inventive visual language. Jordana Moore Saggese explores the chaotic and prolific art of Basquiat.

Why do we dance? African-American social dances started as a way for enslaved Africans to keep cultural traditions alive and retain a sense of inner freedom. They remain an affirmation of identity and independence. In this electric demonstration, packed with live performances, choreographer, educator and TED Fellow Camille A. Brown explores what happens when communities let loose and express themselves by dancing together.

Imagine something small enough to float on a particle of dust that holds the keys to understanding cancer, virology, and genetics. Luckily for us, such a thing exists in the form of trillions upon trillions of human, lab-grown cells called HeLa. But where did we get these cells? Robin Bulleri tells the story of Henrietta Lacks, a woman whose DNA led to countless cures, patents, and discoveries.

Born in 1731 to freed slaves on a farm in Baltimore, Benjamin Banneker was obsessed with math and science. And his appetite for knowledge only grew as he taught himself astronomy, mathematics, engineering, and the study of the natural world. Rose-Margaret Ekeng-Itua details the numerous accomplishments of Benjamin Banneker.

Straddling Virginia and North Carolina is an area that was once described as the “most repulsive of American possessions.” By 1728, it was known as the Great Dismal Swamp. But while many deemed it uninhabitable, recent findings suggest that a hidden society persisted in the Swamp until the mid-1800’s. So, who lived there? And what happened to them? Dan Sayers uncovers a lost civilization.

At the end of the Civil War, though slavery was technically illegal in all states, it still persisted in the last bastions of the Confederacy. This was the case when Union General Gordon Granger marched his troops into Galveston, Texas on June 19th and announced that all enslaved people there were officially free. Karlos K. Hill and Soraya Field Fiorio dig into the history of Juneteenth.

Escaping slavery; risking everything to save her family; leading a military raid; championing the cause of women’s suffrage; these are just a handful of the accomplishments of one of America’s most courageous heroes. Janell Hobson details Harriet Tubman's many fights for freedom.

On March 3, 1913, after months of strategic planning and controversy, thousands of women gathered in Washington D.C. for the Women’s Suffrage Parade -- the first mass protest for a woman’s right to vote. Michelle Mehrtens details how the march rejuvenated the fight for the 19th amendment.

Before empires and royalty, before pottery and writing, before metal tools and weapons – there was cheese. As early as 8000 BCE, Neolithic farmers began a legacy of cheesemaking almost as old as civilization. Today, the world produces roughly 22 billion kilograms of cheese a year, shipped and consumed around the globe. Paul Kindstedt shares the history of one of our oldest and most beloved foods.

Soft percussion and a toasty scent mark the violent transformation of tough seeds into cloud-like puffs. This is the almost magical process of popcorn-making. Dozens of kinds of popcorn are now grown in the US, with different strains assuming distinctive shapes when their kernels explode. So, how did we actually end up with this whimsical food? Andrew Smith traces the history of popcorn.

Water is essentially everywhere in our world, and the average human is composed of between 55 and 60% water. So what role does water play in our bodies, and how much do we actually need to drink to stay healthy? Mia Nacamulli details the health benefits of hydration.

When you take a bite of a hot pepper, your body reacts as if your mouth is on fire -- because that's essentially what you've told your brain! Rose Eveleth details the science and history behind spicy foods, giving insights into why some people continue to pay the painful price for a little spice.

Baked or fried, boiled or roasted, as chips or fries; at some point in your life you’ve probably eaten a potato. But potatoes have played a much more significant role in our history than just that of the dietary staple we have come to know and love today. Leo Bear-McGuinness shares how without the potato, our modern civilization might not exist at all.

Countries around the world waste huge amounts of food every year: roughly a fifth of food items in the US are tossed because consumers aren’t sure how to interpret expiration labels. But most groceries are still perfectly safe to eat past their expiration dates. If the dates on our food don’t tell us that something’s gone bad, what do they tell us? Carolyn Beans shares how to prevent food waste.

If you can’t imagine life without chocolate, you’re lucky you weren’t born before the 16th century. Until then, chocolate only existed as a bitter, foamy drink in Mesoamerica. So how did we get from a bitter beverage to the chocolate bars of today? Deanna Pucciarelli traces the fascinating and often cruel history of chocolate.

Photosynthesis is an essential part of the exchange between humans and plants. Amanda Ooten walks us through the process of photosynthesis, also discussing the relationship between photosynthesis and carbohydrates, starch, and fiber -- and how the air we breathe is related to the food we ingest.

Rice contributes over 20% of the calories consumed by humans each year. Korean bibimbap, Nigerian jollof, Indian biryani, Spanish paella, and countless other culinary masterpieces all begin with rice. So how did this humble grain end up in so many cuisines? Carolyn Beans investigates the global expansion of this beloved crop and the unintended consequences of its popularity.

One day around 850 CE, a goatherd observed that his goats started acting abnormally after nibbling on some berries. The herder tried them himself, and soon enough, he was just as hyper. As the story goes, this was humanity’s first run-in with coffee. So, how did coffee go from humble plant to one of the world's most consumed beverages? Jonathan Morris traces the history of this energizing elixir.

In the mid-18th century, England was crazy for ketchup. The sauce was a staple, but this ketchup wasn’t the ubiquitous red goop you’re familiar with today. In fact, it was a sweet and savory brown sauce that didn’t even have tomatoes in it. So where did this early ketchup come from, and how did it become the dip we know and love? Dan Kwartler traces the condiment's history.

Beginning in the third century BCE, the Romans conquered the Iberian peninsula. This period gave rise to several regional languages in the area that’s now Spain, including Castilian, Catalan, and Galician. One of these would become Spanish— but not for another 1,500 years. Those years tell the origin story of what’s become a global modern language. Ilan Stavans traces the evolution of Spanish.

If you can’t imagine life without chocolate, you’re lucky you weren’t born before the 16th century. Until then, chocolate only existed as a bitter, foamy drink in Mesoamerica. So how did we get from a bitter beverage to the chocolate bars of today? Deanna Pucciarelli traces the fascinating and often cruel history of chocolate.

The sun god was in love with the moon goddess, Ix Chel. But the goddess’ grandfather was very possessive, and would not let the sun god anywhere near his beloved granddaughter. Desperate to be together, they escaped and were ready to light up the sky with their powerful rays. Unfortunately, their love story doesn’t end happily ever after. Cynthia Fay Davis details the Maya myth of Ix Chel.

When you take a bite of a hot pepper, your body reacts as if your mouth is on fire -- because that's essentially what you've told your brain! Rose Eveleth details the science and history behind spicy foods, giving insights into why some people continue to pay the painful price for a little spice.

Baked or fried, boiled or roasted, as chips or fries; at some point in your life you’ve probably eaten a potato. But potatoes have played a much more significant role in our history than just that of the dietary staple we have come to know and love today. Leo Bear-McGuinness shares how without the potato, our modern civilization might not exist at all.

Late one night in 1871, a group of riders descended on a sleeping army camp, stole about 70 horses, and disappeared. Led by a young chief named Quanah Parker, the raid was the latest in a long series of altercations along the Texas frontier between Indigenous people and United States forces. Who was this brave warrior? Dustin Tahmahkera details the life of the last chief of the Comanches.

In 1776, a powerful empire was born in North America. The Lakotas had reached the Black Hills, the most sacred place and most coveted buffalo hunting grounds in the western plains. Located in what is now South Dakota, control of the Black Hills, or Paha Sapa, marked the tribe as the dominant power in the American West. Pekka Hämäläinen explores the rise and fall of the Lakota Empire.

Between 1927 and 1941, workers blasted 450,000 tons of rock from a mountainside using chisels, jackhammers, and dynamite. Gradually, they carved out Mount Rushmore. Today, the monument draws nearly 3 million people to South Dakota’s Black Hills every year. But its façade belies a dark history. Ned Blackhawk and Jeffrey D. Means explore the destruction of the sacred Six Grandfathers Mountain.

Today, surfing is a multi-billion-dollar global industry, with tens of millions of enthusiasts worldwide. For some it’s a serious sport; for others, just a way to let loose. But despite its casual association with fun and sun, surfing has a richer and deeper history than many realize. Scott Laderman shares the hidden history of surfing.

For most humans, farts are a welcome relief, an embarrassing incident, or an opportunity for a gas-based gag. But for many other creatures, farts are no laughing matter. Deep in the bowels of the animal kingdom, farts can serve as tools of intimidation, acts of self-defense, and weapons of malodorous murder. Nick Caruso and Dani Rabaiotti dig into the funky and foul world of animal flatulence.

The placebo effect is an unexplained phenomenon wherein drugs, treatments, and therapies that aren’t supposed to have an effect — and are often fake — miraculously make people feel better. What’s going on? Emma Bryce dives into the mystery of placebos’ bizarre benefits.

In the 1980s, the world faced a huge problem: there was a rapidly expanding hole in the ozone layer. If it continued to grow, rates of skin cancer could skyrocket, photosynthesis would be impaired, agricultural production would plummet, and entire ecosystems would collapse. So, what happened? Stephanie Honchell Smith shares how decisive global cooperation helped restore the ozone layer.

When radium was first discovered, its luminous green color inspired people to add it into beauty products and jewelry. It wasn’t until much later that we realized that radium’s harmful effects outweighed its visual benefits. Unfortunately, radium isn’t the only pigment that historically seemed harmless or useful but turned out to be deadly. J. V. Maranto details history’s deadliest colors.

The year is 1656. Your body is wracked by violent chills. Your head pounds and you're too weak to sit up. In your feverish state, you see a strange-looking man wearing a beak-like mask, his body covered from head to toe. Without seeing his face, you know: you have the plague. So, where did these iconic outfits come from? Stephanie Honchell Smith explores the history of plague doctors.

You’re on an airplane when you feel a sudden jolt. Outside your window nothing seems to be happening, yet the plane continues to rattle you and your fellow passengers as it passes through turbulent air in the atmosphere. What exactly is turbulence, and why does it happen? Tomás Chor dives into one of the prevailing mysteries of physics: the complex phenomenon of turbulence.  

We’ve all been told that we should recycle plastic bottles and containers. But what actually happens to the plastic if we just throw it away? Emma Bryce traces the life cycles of three different plastic bottles, shedding light on the dangers these disposables present to our world.

If you’ve ever looked at the bottom of a disposable bottle or cup, you’ve probably noticed a recycling symbol. Seeing this, many people assume the item should be put in a recycling bin. Yet many plastics are incapable of being recycled at most centers. In fact, only 9% is recycled each year. So why are so few plastics recycled? And what do these symbols actually mean? Shannon Odell investigates.

Almost all batteries, even single-use batteries, are theoretically rechargeable. That’s because the metals and other chemicals are still there in the battery. So chemically speaking, a dead battery is actually not that different from a fresh one. Then why do batteries die in the first place? And what should you do with them once they’re spent? George Zaidan digs into the science of batteries.

In 2010, NASA announced the discovery of a never-before-seen galactic object: two gigantic gaseous bubbles, each emanating an impressive 25,000 light years from the center of the Milky Way. Astronomers were perplexed: what created these structures? And could this mean that the black hole at the center of our galaxy was waking up? Ashkbiz Danehkar explores the possible origins of the Fermi bubbles.

Without water, a human can only survive for about 100 hours. But there’s a creature so resilient that it can go without it for decades. This 1-millimeter animal can survive both the hottest and coldest environments on earth, and can even withstand high levels of radiation. Thomas Boothby introduces us to the tardigrade, one of the toughest creatures on Earth.

Love is often described as heartwarming, heart-wrenching, or even heartbreaking— and your brain is responsible for all these feelings. The journey from first spark to the last tear is guided by a symphony of neurochemicals and brain systems. Shannon Odell explores what happens in your brain when you fall in love, how it responds to a relationship, and how it reacts to a breakup.

How did the periodic table of elements revolutionize our understanding of the world? What scientists contributed to the table we have today? Eric Rosado discusses the key people and discoveries that have molded our understanding of chemistry today.

Photosynthesis is an essential part of the exchange between humans and plants. Amanda Ooten walks us through the process of photosynthesis, also discussing the relationship between photosynthesis and carbohydrates, starch, and fiber -- and how the air we breathe is related to the food we ingest.

In 2010, South Korea experienced a particularly cold winter. People couldn’t activate their smartphones while wearing gloves, so they began wielding snack sausages— causing one company to see a 40% rise in sausage sales. So, what could sausages do that gloves couldn’t? In other words, how do touchscreens actually work? Charles Wallace and Sajan Saini dig into the science of touchscreens.

Almost all batteries, even single-use batteries, are theoretically rechargeable. That’s because the metals and other chemicals are still there in the battery. So chemically speaking, a dead battery is actually not that different from a fresh one. Then why do batteries die in the first place? And what should you do with them once they’re spent? George Zaidan digs into the science of batteries.

In 1815, Mount Tambora erupted and its emissions spread across the globe, blotting out the sun for almost an entire year. This wreaked havoc on agriculture, leading to famines all across the Northern hemisphere. It was the year without summer— one of the darkest periods in human history. So why are some modern researchers considering repeating it? David Biello digs into geoengineering.

During the Victorian Age, women were unlikely to become great explorers, but a few intelligent, gritty and brave women made major contributions to the study of previously little-understood territory. Courtney Stephens examines three women -- Marianne North, Mary Kingsley and Alexandra David-Néel -- who wouldn’t take no for an answer (and shows why we should be grateful that they didn’t).

On March 3, 1913, after months of strategic planning and controversy, thousands of women gathered in Washington D.C. for the Women’s Suffrage Parade -- the first mass protest for a woman’s right to vote. Michelle Mehrtens details how the march rejuvenated the fight for the 19th amendment.

Escaping slavery; risking everything to save her family; leading a military raid; championing the cause of women’s suffrage; these are just a handful of the accomplishments of one of America’s most courageous heroes. Janell Hobson details Harriet Tubman's many fights for freedom.

Marie Skłodowska Curie’s revolutionary research laid the groundwork for our understanding of physics and chemistry, blazing trails in oncology, technology, medicine, and nuclear physics, to name a few. But what did she actually do? Shohini Ghose expounds on some of Marie Skłodowska Curie’s most revolutionary discoveries.

In 1958, after receiving a letter describing the deaths of songbirds due to the pesticide known as DDT, Rachel Carson began an investigation into the misuse of chemicals and their toll on nature. In 1962, she published her findings in “Silent Spring,” which immediately drew both applause and impassioned dissent. How did this biologist and writer ignite such controversy? Mark Lytle investigates.

Imagine something small enough to float on a particle of dust that holds the keys to understanding cancer, virology, and genetics. Luckily for us, such a thing exists in the form of trillions upon trillions of human, lab-grown cells called HeLa. But where did we get these cells? Robin Bulleri tells the story of Henrietta Lacks, a woman whose DNA led to countless cures, patents, and discoveries.

By 1973, Harvey Milk had already been many things: naval officer, high school teacher, bit-part actor and wandering hippie. Starting fresh in San Francisco, his belief in a more personal approach to local government led him to run for office in the heart of American gay culture, the Castro. Lillian Faderman details the tenacity and courage of California's first openly gay public official.

The attacking infantry advances, their elephants already having broken the defensive line. The king tries to retreat, but the enemy flanks him from the rear. Escape is impossible. This isn’t a real war— nor is it just a game. Over the 1,500 years of its existence, chess has been known as a military strategy tool, a metaphor for human affairs and a measure of genius. Alex Gendler shares its history.

Over a hundred years after his creator was laid to rest, Dracula lives on as the most famous vampire in history. But this Transylvanian noble – neither the first fictional vampire, nor the most popular of his time – may have remained buried in obscurity if not for a twist of fate. Stanley Stepanic explains how a critical copyright battle catapulted Bram Stoker’s character into literary renown.

The sight of mistletoe may either send you scurrying or, if you have your eye on someone, awaiting an opportunity beneath its snow-white berries. But how did the festive tradition of kissing under mistletoe come about? Carlos Reif explains how this long-lived custom intertwines the mythology and biology of this intriguing plant.

For centuries, scholars puzzled over the hieroglyphs they found carved onto ancient Egyptian ruins, tablets, and papyri. But in 1799, a unique discovery would finally help unlock their meaning. It was a stone inscribed with three different texts: Egyptian Hieroglyphs, Demotic Egyptian, and Ancient Greek. Franziska Naether shares how scholars decoded the ancient message of the Rosetta Stone.

They say the pen is mightier than the sword, and authorities have often agreed. From outlawed religious tracts and revolutionary manifestos to censored and burned books, we know the potential power of words to overturn the social order. But as strange as it may seem, some numbers have also been considered dangerous enough to ban. Alessandra King details the history behind illegal numbers.