The Great Wall of China is a 13,000-mile dragon of earth and stone that winds its way through the countryside of China. As it turns out, the wall's history is almost as long and serpentine as its structure. Megan Campisi and Pen-Pen Chen detail the building and subsequent decay of this massive, impressive wall. [Directed by Steff Lee, narrated b...

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 Ra...

Your favorite athlete closes in for a win; the crowd holds its breath, and at the crucial moment ... she misses the shot. That competitor just experienced the phenomenon known as "choking," where despite months, even years, of practice, a person fails right when it matters most. Why does this happen, and what can we do to avoid it? Noa Kageyama ...

You may have heard the expression that dogs 'see with their noses.' But these creature's amazing nasal architecture actually reveals a whole world beyond what we can see. Alexandra Horowitz illustrates how the dog's nose can smell the past, the future and even things that can't be seen at all. [Directed by Província Studio, narrated by Pen-Pen C...

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. [Directed by Sandro Katamashvili, narrated by Pen-Pen Chen].

To human eyes, the world at night is a formless canvas of grey. Many nocturnal animals, on the other hand, experience a rich and varied world, bursting with details, shapes, and colors. What is it, then, that separates moths from men? Anna Stöckl uncovers the science behind night vision. [Directed by Jeremiah Dickey, narrated by Pen-Pen Chen].

Nestled in the tissues of your neck is a small, unassuming organ that wields enormous power over your body: the thyroid. Emma Bryce explains how the thyroid, like the operations manager in a company, is tasked with making sure that all the cells in your body are working properly. [Directed by Tremendousness, narrated by Pen-Pen Chen].

We’ve all had the experience: you’re walking across a soft carpet, you reach for the doorknob and … ZAP. But what causes this trademark jolt of static electricity? Anuradha Bhagwat sheds light on the phenomenon by examining the nature of matter. [Directed by Outis, narrated by Pen-Pen Chen, music by Cem Misirlioglu].

When most people think of fishing, we imagine relaxing in a boat and patiently reeling in the day's catch. But modern industrial fishing -- the kind that stocks our grocery shelves -- looks more like warfare. Ayana Elizabeth Johnson and Jennifer Jacquet explain overfishing and its effects on ecosystems, food security, jobs, economies, and coasta...

Obesity is an escalating global epidemic. It substantially raises the probability of diseases like diabetes, heart disease, stroke, high blood pressure, and cancer. But what is the distinction between being overweight and being obese? And how does a person become obese? Mia Nacamulli explores obesity. [Directed by Kozmonot Animation Studio, narr...

Human bodies aren't built for extreme aging: our capacity is set at about 90 years. But what does aging really mean, and how does it counteract the body's efforts to stay alive? Monica Menesini details the nine physiological traits that play a central role in aging. [Directed by Cinematic, narrated by Pen-Pen Chen].

Sometimes, against a uniform, bright background such as a clear sky or a blank computer screen, you might see things floating across your field of vision. What are these moving objects, and how are you seeing them? Michael Mauser explains the visual phenomenon that is floaters. [Directed by Reflective Films, narrated by Pen-Pen Chen].

Think back to a really vivid memory. Got it? Now try to remember what you had for lunch three weeks ago. That second memory probably isn't as strong— but why not? Why do we remember some things, and not others? And why do memories eventually fade? Catharine Young gives the basics on memory and memory loss. [Directed by Patrick Smith, narrated by...

Tea is the second most consumed beverage in the world after water –– and from sugary Turkish Rize tea to salty Tibetan butter tea, there are almost as many ways of preparing the beverage as there are cultures on the globe. Where did this beverage originate, and how did it become so popular? Shunan Teng details tea's long history. [Directed by St...

In August 1968, factory workers overheard news of a mandatory meeting. Whispered rumors described shipments of a gift from the country's Communist leader, Chairman Mao Zedong. And sure enough, managers soon distributed a gift to every factory worker– a glass box encasing a golden wax replica of a mango. What was the meaning behind this unusual o...

The universe is bustling with matter and energy. Even in the vast, apparent emptiness of intergalactic space, there’s one hydrogen atom per cubic meter. But is there such thing as a total absence of everything? Is it possible to make a completely empty space? Rolf Landua and Anais Rassat explain the science behind vacuums. [Directed by Ricky Ear...

Deep inside Yale's Beinecke Rare Book and Manuscript Library lies a 240 page tome. Recently carbon dated to around 1420, its pages feature looping handwriting and hand drawn images seemingly stolen from a dream. It is called the Voynich manuscript, and it's one of history's biggest unsolved mysteries. The reason why? No one can figure out what i...

Often people make decisions that are not "rational" from a purely economical point of view — meaning that they don't necessarily lead to the best result. Why is that? Are we just bad at dealing with numbers and odds? Or is there a psychological mechanism behind it? Sara Garofalo explains heuristics, problem-solving approaches based on previous e...

For over 200 years, potatoes thrived in Ireland; roughly half the country’s residents lived almost entirely on potatoes. But when harvesting began in 1845, farmers found their potatoes blackened and shriveled. While this failed harvest created a crisis, the government’s response turned it into a national catastrophe. Stephanie Honchell Smith dig...

Some swear they're cursed to be hunted by mosquitos while their close-by companions are regularly left unscathed. Are mosquitos really attracted to some people more than others? And if so, is there anything we can do about it? Maria Elena De Obaldia digs into what factors make people tasty targets for these pesky insects. [Directed by Anton Boga...

In 2010, 30 billion dollars worth of fruits and vegetables were wasted by American retailers and shoppers, in part because of cosmetic problems and perceived spoilage. But what are these spots, anyway, and are they okay to eat? Elizabeth Brauer explains why you may not need to be afraid of picking up your grocery store’s funky-looking fruit. [Di...

It's obvious that knowing more than one language can make certain things easier -- like traveling or watching movies without subtitles. But are there other advantages to having a bilingual (or multilingual) brain? Educator Mia Nacamulli details the three types of bilingual brains and shows how knowing more than one language keeps your brain heal...

Within the periodic table loom many potential hazardous elements. Some elements are dangerous due to their toxicity. Others are dangerous because of how they respond, react, or even explode in the outside environment. And perhaps the most threatening elements are those that silently emit energy. So, which substances on the periodic table are the...

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 c...

Our early ancestors relied on lightning to cause forest fires, from which they could collect coals and burning sticks to help them cook food and clear land. Yet, it wasn’t just humans who benefited from these natural phenomena. Even as they destroyed trees, fires also helped the forests themselves. Jim Schulz outlines the benefits of wildfire. [...

Elementary particles are the smallest known building blocks in the universe—and the neutrino is one of the smallest of the small. These tiny neutrinos can tell us about the furthest reaches and most extreme environments of the universe ... but only if we can catch them. Sílvia Bravo Gallart details how the IceCube telescope in Antarctica is work...

As archaeologists pored over ancient tombs in western China, they discovered some surprisingly well-preserved and familiar relics. Though hardened over 1,000 years, there sat little crescent-shaped dumplings. So who invented these plump pockets of perfection, and how did they spread across the world? Miranda Brown traces the tangled, mysterious ...

When they're used well, graphs can help us intuitively grasp complex data. But as visual software has enabled more usage of graphs throughout all media, it has also made them easier to use in a careless or dishonest way — and as it turns out, there are plenty of ways graphs can mislead and outright manipulate. Lea Gaslowitz shares some things to...

In 1960, composer John Cage went on television to share his latest work. But rather than using traditional instruments, Cage appeared surrounded by household clutter, including a bathtub, ice cubes, a toy fish, a rubber duck, several radios, and performed "Water Walk." Most people watching had the same question: is this even music? Hanako Sawada...

Industrial manufacturers spend a huge amount of energy generating heat to make everyday materials and objects, like cement, steel, and paper. And since most companies use fossil fuels to reach these high temperatures, industrial heat accounts for 20% of our annual global carbon pollution. Thankfully, this is where a century-old technology comes ...