Hank wraps up the Crash Course on ecology by taking a look at the growing fields of conservation biology and restoration ecology, which use all the kung fu moves we've learned about in the past eleven weeks and apply them to protecting...

In Greek mythology, King Midas is known as a rogue ruler whose antics bemused his people and irritated the Gods. Many know the classic story of Midas's golden touch, but the foolish king was also known for his unusual pair of ears....

In this video Paul Andersen explains how water quality can be degraded by pollutants. Wastewater is the main source of water pollution and can be measure using the BOD (biochemical oxygen demand). Dead zones, cultural eutrophication,...

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 (__), it's your shuxiang, meaning the animal assigned to your birth year. And of the...

In this video Paul Andersen explains how water is unequally distributed around the globe through the hydrologic cycles. Seawater is everywhere but is not useful without costly desalination. Freshwater is divided between surface water...

In the mid-19th century, suspension bridges were collapsing all across Europe. Their industrial cables frayed and snapped under the weight of their decks. So when German American engineer John Roebling proposed building the largest and...

Rivers are one of nature's most powerful forces -- they bulldoze mountains and carve up the earth, and their courses are constantly moving. Understanding how they form and how they'll change is important for those that call their banks...

Waddling along the parched Australian earth, a female platypus is searching for fresh water. Over the past year, a severe drought turned rivers and streams to mere trickles. She barely survived and was unable to reproduce. Could the next...

The marriage of Orpheus, the greatest of all poets and musicians, to Eurydice, a wood nymph, was heralded as the perfect union. Anyone could tell the couple was deeply in love. So when their wedding ceremony ended in Eurydice's untimely...

History's first empire rose out of a hot, dry landscape, without rainfall to nourish crops, without trees or stones for building. In spite of all this, its inhabitants built the world's first cities, with monumental architecture and...

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...

What happens to a single ecosystem when the amount of freshwater available in it changes? Not really much good. In this episode of Crash Course Kids, Sabrina talks about ecosystems and how one small change can lead to a cascade effect in...

Join Jessi and create your own mini landscape, to see how water can cause erosion, and change a landscape into something different! #sciencegoals

We've already talked about how the Earth is divided into four spheres (The Hydrosphere, the Biosphere, the Geosphere, and the Atmosphere). But, how do these different sphere interact with each other? In this episode of Crash Course Kids,...

New ReviewVisit Fredericksburg, Virginia and see where the Civil War battle of Fredericksburg took place and Fredericksburg and Spotsylvania national military park

New ReviewTravel to Selma, Alabama and the Edmund Pettis Bridge to learn about Bloody Sunday and how the Selma to Montgomery March was a turning point in Civil Rights history

New ReviewVisit Washington Crossing Historic Park in Pennsylvania to learn how George Washington and the Continental Army won the Battle of Trenton.

New ReviewHarriet Tubman plays a vital role in the Civil War, contributing to the Union Army and the Underground Railroad. She serves as a spy, scout, cook, and nurse, using her knowledge of the South to gather intelligence and assist Union...

This video is answering the question of where is lake Baikal.

This video is answering the question of what's the longest river in North America.

This video is answering the question of how was the Nile help tell the time.

This video is answering the question of how is the Nile important to Egypt.

This video is answering the question of how did the Nile help farms.

This video is answering the question of how did ancient Egyptians travel the river.