Tropical rainforests are known for being super biologically diverse _ they're full of different species, from colorful birds and insects to plants and fungi. We haven't even come close to cataloguing everything that's there.

Poop Transplants!

In 1884, an unlucky patient who had a rapidly growing cancer in his neck came down with an unrelated bacterial skin infection. As he recovered from the infection, the cancer surprisingly began to recede. The infection had stimulated the...

Paul Andersen explains how asking questions is the first step in both science and engineering. Questions allow scientists to direct inquiry with a goal of understanding the phenomena in the Universe. Questions allow engineers to define...

Hank addresses recent news items that point toward a so-called "zombie apocalypse," and introduces us to some new additions to the periodic table.

In this video Paul Andersen explains how biodiversity can be measured through genetic, species, or ecosystem variety on the planet. Species diversity is increased through speciation and decrease through extinction. The mechanism for...

Snowflakes are infinitely beautiful, but are they infinitely unique? Here's all the science behind Earth's favorite cold crystal

Paul Andersen explains how eukaryotic cells were formed through a process of endosymbiosis. He describes how aerobic bacteria became mitochondria and cyanobacteria became chloroplasts. He mentions an example of symbiosis that occurs...

Physicist Lee Smolin talks about how the scientific community works: as he puts it, "we fight and argue as hard as we can," but everyone accepts that the next generation of scientists will decide who's right. And, he says, that's how...

Zombies are EVERYWHERE!! Wait, don't panic- we mean in pop culture, not outside your window. But why is that? Bad guys and monsters seem to go through phases: one decade there's a dozen movies about aliens, ten years later it's vampires....

You might have a roommate who rolls their eyes a lot and leaves sassy sticky notes all over the place, but no matter how frustrating it is, it’s probably not a personality disorder.

In which John Green teaches you about the Crusades embarked upon by European Christians in the 12th and 13th centuries. Our traditional perception of the Crusades as European Colonization thinly veiled in religion isn't quite right. John...

In this video Paul Andersen explains how engineers optimize the design solution. After a number of solutions have been identified engineers will test each of them against a given set of criteria. They will trade-off different...

Researchers have found that the expression of gratitude gives positive effects on our both mental and physical health.

Math is invisible. Unlike physics, chemistry, and biology we can't see it, smell it, or even directly observe it in the universe. And so that has made a lot of really smart people ask, does it actually even EXIST?!?!

How would you measure a personality? What, exactly, is the self? Well, as you've come to expect, it's not that easy to nail down an answer for those questions. Whether you're into blood, bile, earth, wind, fire, or those Buzzfeed...

Consider the following sentence: "This statement is false." Is that true? If so, that would make the statement false. But if it's false, then the statement is true. This sentence creates an unsolvable paradox; if it's not true and it's...

Social media has become our new home. Can we build it better? Taking design cues from urban planners and social scientists, technologist Eli Pariser shows how the problems we're encountering on digital platforms aren't all that new --...

In this video Paul Andersen explains in more detail the history of the Earth. He shows how the history of the Earth is written in the rocks that are built up over time. Fossils allow us to compare different rock layers relative to one...

This video is a collaboration with Aatish Bhatia about how to see the COVID-19 tipping point - we present a better way to graph COVID-19 coronavirus cases using a logarithmic scale in "phase space" - plotting the growth rate against the...

In which John Green continues to teach you about Slaughterhouse-Five by Kurt Vonnegut. (WARNING: When Slaughterhouse-Five was published, some of the crude language in the book caused controversy. We quote one mildly controversial line in...

What is globalization? Is globalization a good thing or not. Well, I have an answer that may not surprise you: It's complicated. This week, Jacob and Adriene will argue that globalization is, in aggregate, good. Free trade and...

Today's Crash Course Chemistry takes a historical perspective on the creation of the science, which didn't really exist until a super-smart, super-wealthy Frenchman put the puzzle pieces together - Hank tells the story of how we...

The best way to make sure you're making the most of the time you have is to start off well organized. This week we're talking about planning and organizational systems and how to set yourself up for success.