In which John Green teaches you about water! So, we talk about resources a lot on Crash Course, and today is no exception. It turns out people can't live without water, which means it's absolutely necessary for civilization. Today John...

It’s nice to think that every rover we land on Mars is totally unique, but isn’t it even nicer to know that they’ve got a twin or even a triplet here on Earth making sure they’re up for the job ahead?

If the human body could be distilled down into one molecule, what would our chemical formula be? And WHY is it that way? There’s a whole lot of elements on the periodic table, but life depends on relatively few of them in order to...

If you take a look at a map of Scotland, you'll notice an eerily straight line running through the highlands, this is the Great Glen Fault the product of half a billion years of time and geology.

We’re beginning our engineering journey with a tour through the major branches. Today Shini explains the facets of civil engineering, including structural and construction engineering, city planning, transportation, and sanitation.

Before every launch, there's a crawl.

In the early 20th century, the US had expanded from coast to coast, but many cities in the southwest still lacked reliable water sources. The Colorado River's erratic flow and frequent floods made it unreliable for agriculture, and the...

Significant pieces of the globe are literally not on the map: they're missing from the most widely used mapping platforms, like Google Street View, leaving communities neglected of vital services and humanitarian aid. In this...

The scene of the three wise men offering gifts to a newborn Jesus was widely painted during the Renaissance era, so how did painter Sandro Botticelli create a version that's still well known today? James Earle describes who and what set...

We need to change how we prescribe drugs, says physician Daniel Kraft: too often, medications are dosed incorrectly, cause toxic side effects or just don't work. In a talk and concept demo, Kraft shares his vision for a future of...

What if an advanced civilization ran out of room to grow on their home planet? Their best bet might be to build settlements in space, so they could capture more of their star's energy.

The Hubble Space Telescope has been sending home images of the universe for more than thirty years, but none of its work would have been possible without the many servicing missions that kept it up to date.

I took a trip to Washington D.C. to check out some of our nation's most famous monuments. Where do they come from? From the depths of the Earth to the distant reaches of the cosmos, you'll never look at history the same way again

A hearty bowl of cereal gives you the energy to start your day, but how exactly did that energy make its way into your bowl? It all begins with photosynthesis, the process that converts the air we breathe into energizing glucose. Cathy...

If walls could talk, Turkey's Hagia Sophia would have an abundance of stories to tell. Once a church, then a mosque, and now a museum, this world marvel has stood the test of time and war, surviving centuries of conquest by some of...

Hank is back in the studio and is very excited to be able again to share news of the universe with you, including his encounter with a giant squid, an English king discovered under a parking lot, new pyramids discovered in Africa, and...

TED Fellow and astronomer Erika Hamden leads the team building FIREBall, a telescope that hangs from a giant balloon at the very edge of space and looks for clues about how stars are created. She takes us inside the roller-coaster,...

This is episode 10 of our animated series "Think Like A Coder." This 10-episode narrative follows a girl, Ethic, and her robot companion, Hedge, as they attempt to save the world. The two embark on a quest to collect three artifacts and...

In this short, provocative talk, architect Alison Killing looks at buildings where death and dying happen -- cemeteries, hospitals, homes. The way we die is changing, and the way we build for dying ... well, maybe that should too. It's a...

From something as familiar as our bodies to things vast as the formation of galaxies, we can observe the process of self-assembly, or when unordered parts come together in an organized structure. Skylar Tibbits explains how we see...

Stretching 227 meters tall, two towers were assembled to support California's Golden Gate Bridge. They were just one of the challenges facing engineers Charles Ellis and Joseph Strauss. Even before construction began, many thought the...

Sitting down for brief periods can help us recover from stress or recuperate from exercise. But nowadays, our lifestyles make us sit much more than we move around. Are our bodies built for such a sedentary existence? Murat Dalkilin�c...

Author Sam Martin shares photos of a quirky world hobby that's trending with the XY set: "manspaces." (They're custom-built hangouts where a man can claim a bit of his own territory to work, relax, be himself.) Grab a cold one and enjoy.

The human body has a few built-in methods for getting rid of toxins. Sweating seems like it should be one of them, but it isn't doing as much as you think.