Building a perfect igloo takes cool science!

This is the first-ever video of what we’re calling the "hermit crab caterpillar"! We’re pretty sure this strange caterpillar is a NEW SPECIES. We went to the Peruvian Amazon to see amazing things, but we never expected this :) But that makes me wonder: What *is* a species anyway? And how do you know if you’ve found a new species?

How do we protect what we don’t know exists?

As we get ready to watch that big football game that my lawyers tell me I’m not allowed to say the name of, let’s celebrate a champion of the bird world: Stealthy and silent owls! Learn how owls fly so silently, how they see in the dark, and how owls’ incredible hearing makes them such superb aerial hunters.

Relationship Advice From the Animal Kingdom Ever find yourself wishing for relationship advice and have no one to turn to? Looking for the secrets to a long and happy relationship but can’t find the answers? Maybe you just want to know how to tell that certain someone that you like them, but don’t know how to make the first move? Have no fear, Mother Nature is here! Other animals have millennia worth of mating experience, maybe they can teach us a thing or two?

We’re proud to collaborate with Bill and Melinda Gates for this week’s video! It may sometimes seem like things are getting worse, but there’s lots of reasons to be optimistic about the future. More people have access to toilets and sanitation than ever before. Thanks to public health improvements like this, since 1990, 122 million children’s lives have been saved. Diseases like polio are nearing eradication. Women have more access to health care and education than ever before.

How the Meter Became the Meter The meter is the world’s ultimate measure, but how did it become “the” meter? What is this measurement based on? The story of this revolution in measurement traces its roots to the French Revolution. Scientists decided that an equal and united people should have equal and united measures. So they sent a pair of young astronomers out to measure the world, and invent the meter. Little did they know they’d find nothing but war, deception, and strife along the way. As a result of this ill-fated mission, the meter carries an error that still persists today. Still think the metric system is so perfect?

Solving the Puzzle of Plate Tectonics But did thee feel the Earth move? Why do Africa and South America fit together? Anyone who’s ever looked at a map can see that Earth’s continents are kind of like a jigsaw puzzle. The idea that continents are constantly moving and weren’t always in their current spots is a pretty obvious idea, right? You might be surprised to learn that geologists only accepted that idea recently in the past few decades, and it figuring out how plate tectonics and continental drift work required some pretty strange evidence.

Is luck real? It might feel like a mystical force tugging us toward good or bad fortune, but it turns out luck is really where probability runs into the human mind. That’s right, there’s a scientific side to luck, and if you study a few principles of math and psychology, you might even be able to create your own good fortune.

Illuminating the Universe: The History of Light Beyond what we can touch, taste, smell, and hear, we experience the universe through light. But how did we come to discover light, and how did we learn light’s true nature, as the fastest thing in the universe, an electromagnetic spectrum, a wave and particle capable of the most amazing things? Here is the history of light, according to physics.

What can you do to make the oceans plastic-free?

Dogs and Humans: A 30,000-Year Friendship Of all the species that humans have domesticated, dogs are our oldest animal friends. But how did a group of wolves become the furry pup at the end of the bed? New research is finally unlocking the paw-in-hand evolution of dogs and humans. In this episode we’re answering one big question: Did we domesticate dogs, or did dogs domesticate us?

Ready to untangle the branches of the human family tree?

In part 2 of our special series on human ancestry, we ask why we are the only surviving branch on the human evolutionary tree. Just 50,000-100,000 years ago, Earth was home to three or four separate human species, including our most famous cousins: the Neanderthals. New research has shown that Neanderthals were not the brutish, unintelligent cavemen that cartoons make them out to be. They were creative, smart, social, and perhaps even had complex language. So why did they go extinct as soon as Homo sapiens moved into their territory? Does any trace of them live on today? Why don’t we have Neanderthal neighbors?

Much A-Do About Hair All mammals have hair at some point in their lives, but none of them wear it quite like humans. Why does our hair grow where it does, and not grow where it doesn’t? How does our hair get its color? And why does it go gray and often fall out when we get older and go bald? Learn all about the science of human hair in this week’s video!

In part 3 of our special series on human ancestry, we investigate how closely related we all really are. Basic math tells us that all humans share ancestors. But you’ll be amazed at how recently those shared ancestors lived. Thanks to genetic data in the 21st century, we’re even discovering that we really are all descended from one mother.

De-Extinction: A Mammoth Undertaking De-extinction, or using the power of modern biotechnology to bring back extinct species like mammoths and dinosaurs, would be cool. But is it really as easy as the movies make it look? Or do the cruel hands of time make it impossible? This weel we look at the technical and ethical hurdles behind the science of de-extinction and reverse engineering species that are no longer around.

Who built the pyramids? The colossal geometric monuments found at Giza and elsewhere in Egypt are some of Earth’s most impressive constructions. Pyramids are truly wonders of the ancient and modern world. But when the pyramids were built, the ancient Egyptians hadn’t invented the wheel, developed bronze tools, or discovered pi. How were they able to stack two million stone blocks, each weighing more than two tons, into precise geometric alignments that would survive more than 4,000 years and capture the imaginations of explorers throughout history? They did it the same way we always have: by trial and error. The true history of the pyramids is one of experimentation and science, not magic… or aliens.

Are humans nature’s greatest architects? When we look elsewhere in nature, we find some pretty amazing animal architects. Species like ants, termites, prairie dogs, birds, and more have engineered some incredible structures. This week we look at how a few of these species have mastered physics to install air conditioning in their homes!

Since the days of Ancient Greece, philosophers and scientists have been wondering: What is space? Is the absence of things… a thing? These questions continued to fascinate physicists in the modern era, leading Isaac Newton, Ernst Mach, and Albert Einstein to wonder about the true nature of the fabric of the cosmos. The search for an answer led them to some of the greatest theories in physics. This week, we ask if space and time are really real, and how they come together to make “spacetime”!

You asked for it, so here’s the follow-up! Just because something is difficult doesn’t mean it’s impossible. Over the past centuries, archaeologists, historians, and engineers have reconstructed a great deal of the technology and science used to build the Egyptian pyramids. This week we look at ancient Egyptian mathematics, building techniques, tools, and culture to reconstruct the Great Pyramid’s construction.

Nearly all life on Earth is ultimately powered by light. But many creatures have learned how to make their own. This week we investigate the beautiful phenomenon of bioluminescence. From blinking fireflies on summer nights to glowing deep sea monsters, prepare to learn about the chemistry of living light.

This video is perfect for adults orchids. Many creatures wear disguises in order to keep safe from predators, but there are some that dress to kill. Orchid mantises are one of nature’s most awesome examples of aggressive mimicry. These killer insects are almost indistinguishable from orchids! Scientists recently learned that their disguise doesn’t work quite how we thought it did.

Beavers have done more to shape North American landscapes than any animal beside humans. We don’t notice them much today because there aren’t many left, but before colonization, North America was home to hundreds of millions of these furry engineers. This week, we show you why Earth’s second largest rodent is more amazing than you ever knew, and why they’re the smartest thing in fur pants.

Glacier ice is weird. It’s solid. Solid things aren’t supposed to flow. But glacier ice flows like a liquid, and it does that without melting! How is this possible? I traveled to Mendenhall Glacier in Juneau, Alaska to find out.

From spirals to spots to fractals, nature is full of interesting patterns. Many of these patterns even resemble geometric shapes. One of the most common? Hexagons. Why do we see this six-sided shape occur so many times in nature? This week we explore why hexagons are so common in the natural world, from honeycomb to bubbles to rocks, and what their mathematics, physics, and biology may have in common.

News about climate change is often full of doom, guilt, and anxiety. This can make many people reluctant to pay attention to or discuss it. We asked former Vice President Al Gore to help us find a different way to talk about climate change.

Earth has seasons, but what about the rest of the planets in the solar system? Let’s take a tour from Mercury to Pluto and see what seasons would be like on all our planetary neighbors. Bring a sweater!

Waste not, want not… right? Poop, in all of its various forms throughout nature, shapes the world in ways you might not imagine. One creature’s waste is another’s fuel, and all over nature these leftovers help new life spring up. Here’s how whales, birds, worms, bats, and more help the world breathe clean, thanks to their poop.

Biology textbooks are full of drawings of DNA, but none of those show what DNA actually looks like. Sure, they’re good models for understanding how DNA works, but inside of real cells, it’s a whole lot more interesting. Learn why we can’t look directly at DNA, and find out how DNA is actually packed inside cells.

Replace Harvey with Irma… still true.

Are you a left-brained person or a right-brained person? Spoiler: You’re neither. Each of us uses both sides of our brain for most of what we do. But still, there are a number of brain functions that do show lateralization, where they are localized to one side or another. Why is this? And how does it influence our definition of consciousness? People with “split brains” can help us figure it out.

Why is the universe organized the way it is? And why is it so empty? From planets and stars to superclusters and galactic filaments, the universe’s largest structures formed because of its smallest. In this special collaboration with PHD Comics, we’ll learn how the earliest, quantumest blips seeded the structure of everything everywhere.

How did we come up with our system of telling time? Why do we divide the day into 24 hours of 60 minutes each, and put 60 seconds in each minute? Where does the definition of a second come from? And who decides what clock shows the correct time? There’s clearly a lot of questions when it comes to time.

Ever notice how cereal clumps up in your bowl, or how cereal sticks to the edges of the bowl? Bubbles in beverages do the same thing.You've probably seen this surface tension and buoyancy at work, but did you know there's some mind-blowing science behind it? What we learn in our cereal bowl even connects to the lives of tiny insects that walk on water.

An intermittent fasting diet is one of the hippest new nutrition and fitness philosophies, based around the idea that going hungry can be good for your health. Some think it’s a weight loss secret that calls upon our ancient evolutionary programming. We look at the science behind intermittent fasting.

Asteroid mining sounds like something out of a bad space movie, but harvesting materials from space rocks might be our ticket to building space colonies or living on Mars. Most of Earth’s precious and rare metals are locked too far in the crust for us to get at them, and launching them to space is too expensive for us to supply large colonies off Earth or explore far off worlds. How do we get our hands on the planetary resources inside asteroids? Let’s find out!

Organisms of all shapes and sizes synchronize their behaviors using biological clocks. Some keep pace with the daily rising and setting sun using circadian rhythms. Others use annual cycles or the changing seasons as their cue. But many animals use moonlight and Earth’s lunar cycle to run their biological clock. Do humans do the same thing, with things like menstrual cycles? This week we take a look at living by moonlight.

Where do glaciers and icebergs get their beautiful blue color? This unique blue might be nature’s most brilliant, and the color arises in a very special way thanks to some surprising interactions between light and water molecules. Who knew physics could be so breathtaking?

You’ll never look at spiders the same way again!

Why do we love people we’re related to? Compared to strangers, why do we feel such a deep sense of connection with our family members? Sure, they’re nice to us, we take care of each other, and we often live with them, but there has to be a deeper biological reason. That reason, unsurprisingly is evolution. In this video, I explain why taking care of our family, or even dying for them, makes sense in the eyes of evolution.