Hank introduces us to the most beautiful numbers in nature - the Fibonacci sequence.

People have been migrating and transplanting since before recorded history, and understanding the reasons why people migrate can help explain some of the cultural, economic, and political patterns we see around the world. Today, we’re...

The thing about European History is that it tends to leak out of Europe. Europeans haven't been great at staying put in Europe. As human beings do, the people of Europe were very busy traveling around to trade, to spread religion, and in...

In which John Green teaches you about the Mughal Empire, which ruled large swaths of the Indian Sub-Continent from 1526 to (technically) 1857. While John teaches you about this long-lived Muslim empire, he'll also look at the idea of...

Ancient Sanskrit theater is one of the oldest theater traditions, and thanks to Bharata Muni and his treatise on theater, the Natyashastra, we can tell you quite a bit about it, all the way down to eyebrow and nostril poses. This week...

Many people in the United States and Latin America have grown up celebrating the anniversary of Christopher Columbus's voyage. But was he an intrepid explorer who brought two worlds together or a ruthless exploiter who brought...

In which John Green teaches you about Sub-Saharan Africa! So, what exactly was going on there? It turns out, it was a lot of trade, converting to Islam, visits from Ibn Battuta, trade, beautiful women, trade, some impressive...

No one thinks twice about a woman wearing blue jeans in New York City -- but when Nobel laureate Malala wears them, it's a political act. Around the globe, individuality can be a crime, and clothing can be a form of protest. In a talk...

Consider the classic white t-shirt. Annually, we sell and buy 2 billion t-shirts globally, making it one of the most common garments in the world. But how and where is the average t-shirt made, and what's its environmental impact? Angel...

The Hindu Kush Himalaya region is the world's third-largest repository of ice, after the North and South Poles -- and if current melting rates continue, two-thirds of its glaciers could be gone by the end of this century. What will...

Shopping is about more than just what you buy: it's a treasure hunt to discover something new, a negotiation to get a great deal, a time to catch up with friends and family. But for many, online shopping has turned the experience into an...

There's no greater freedom than finding your purpose, says education advocate Ashweetha Shetty. Born to a poor family in rural India, Shetty didn't let the social norms of her community stifle her dreams and silence her voice. In this...

How do different societies establish a social hierarchy? Today we’re starting our unit on social stratification, starting with four basic principles of a sociological understanding of stratification. We’ll explain open and closed systems...

The gharial and king cobra are two of India's most iconic reptiles, and they're endangered because of polluted waterways. Conservationist Romulus Whitaker shows rare footage of these magnificent animals and urges us to save the rivers...

Forests don't have to be far-flung nature reserves, isolated from human life. Instead, we can grow them right where we are -- even in cities. eco-entrepreneur and TED Fellow Shubhendu Sharma grows ultra-dense, biodiverse mini-forests of...

In which John relates a condensed history of India, post-Indus Valley Civilization. John explores Hinduism and the origins of Buddhism. He also gets into the reign of Ashoka, the Buddhist emperor who, in spite of Buddhism's structural...

In 1947, the British viceroy announced that after 200 years of British rule, India would gain independence and be partitioned into Hindu India and Muslim Pakistan. What followed was one of the largest and bloodiest forced migrations in...

Rajesh Rao is fascinated by "the mother of all crossword puzzles": how to decipher the 4000-year-old Indus script. He's enlisting modern computation to try to read this lost language, the key to understanding this ancient civilization.

In this video Paul Andersen explains how the world population has undergone exponential growth since the industrial revolution. Predicting the future world population is difficult because each country will grow at different rates. ...

There are many different approaches to modern yoga— though most forms have three core elements: physical postures, breathing exercises, and spiritual contemplation.This blend of physical and mental exercise is widely believed to have a...

It's perfectly human to grapple with questions, like 'Where do we come from?' and 'How do I live a life of meaning?' These existential questions are central to the five major world religions -- and that's not all that connects these...

Artist Raghava KK demos his new children's book for iPad with a fun feature: when you shake it, the story -- and your perspective -- changes. In this charming short talk, he invites all of us to shake up our perspective a little bit.

New ReviewRikki faces Nagaina for the final time to save Teddy, his family and the garden from the evil cobras.

New ReviewRikki meets Chuchundra the muskrat, saves Teddy's family from Nag and finds the cobras' eggs.