S2019 E1 • Is There Life on Earth?

If we lived light years from Earth, how would we know there’s life here? Let’s take a look at the search for extraterrestrial life on habitable exoplanets, and discover what biosignatures would show someone else that we’re here.

Première diffusion : 7 février 2019

S2019 E2 • The Impossible Hugeness of Deep Time

Humans have a hard time with really big numbers, especially when it comes to DEEP TIME. The history of the Earth took a lot longer than you think, trust me. But I’m here to help you put it in perspective. With some string.

Première diffusion : 12 février 2019

S2019 E3 • Are You Afraid of Holes?

Honeycomb. Strawberries. Flower pods. Some people find these things incredibly scary. We call this extreme fear trypophobia. But why does it exist?

Première diffusion : 27 février 2019

S2019 E4 • Where Do You Weigh The Most?

You may have heard that a kilogram of feathers weighs the same as a kilogram of steel, but that all depends on where you weigh them. This video is all about the difference between mass and weight, and how weirdly awesome Earth’s gravity really is.

Première diffusion : 5 mars 2019

S2019 E5 • Why Are So Many People Allergic To Food?

More people have food allergies than ever before. Peanuts, tree nuts, shellfish, eggs, and even milk… the list of possibly dangerous foods seems to get longer every day. But why do some people’s bodies have deadly reactions food? And why are food allergies on the rise? In this video we explain what food allergies really are, and what the difference is between food allergy and food intolerance. Some fellow YouTubers tell us their stories of what it’s like to live with food allergies, and we bring you the best current science on how to prevent food allergies in kids and adults. It’s a tough nut to crack.

Première diffusion : 20 mars 2019

S2019 E6 • How to be Crushed by the Atmosphere!

Air. I bet you never even notice that it’s there. Yet you are swimming in an ocean of it every day. If there’s a literal ton of air pressing down on you all the time, so why don’t we feel it? We look back at the history of physics to learn how we figured out air pressure, why vacuums don’t suck, and how people like Galileo, Torricelli, and Otto von Guericke changed science forever with a few simple experiments.

Première diffusion : 2 avril 2019

S2019 E7 • Decoding the Great Monarch Butterfly Migration

The monarch butterfly migration is one of nature’s greatest events. This orange-winged wonder travels up to 4,500 km from all over North America to spend the winter hanging from oyamel fir trees in central Mexico’s mountain forests. I got to go there. Seeing tens of millions of butterflies dangling from the treetops is a truly breathtaking sight. But how does an animal with a brain the size of a poppy seed navigate to this one special place, especially since the last monarchs to make the trip lived 4 or 5 generations earlier? Get ready for an amazing story of science, instinct, and navigation.

Première diffusion : 9 avril 2019

S2019 E8 • Mexico’s Monarch Butterfly Migration in VR180

This is a VR180 video so pop on your Google Cardboard or VR Headset to be totally immersed in our world! No headset? No problem. Move your mobile phone around and catch the total 180 experience!

Première diffusion : 9 avril 2019

S2019 E9 • Why We Get Dizzy (…and Astronauts Don’t)

We’ve all gotten dizzy before… but have you ever gotten WEIRD DIZZY? I teamed up with Vanessa Hill from BrainCrat to answer the question “why do we get dizzy?” and in the process we learned about some very strange and hilarious ways to get extra-special dizzy! Get ready to learn about your vestibular system, the system that lets you know where your body is in space. You don’t even notice your vestibular system is there… until it stops working right!

Première diffusion : 26 avril 2019

S2019 E10 • How To Drink Coffee In Space

I love coffee. Like, a lot. You know who else loves coffee? Astronauts! And also the people who help them do awesome things in space (I think NASA might be powered by coffee). But how do astronauts actually drink coffee in space, aboard the International Space Station, in microgravity? I visited astronaut Don Pettit to learn about his invention for having a cup o’ Joe in orbit. This is some awesome science.

Première diffusion : 3 mai 2019

S2019 E11 • Where Your Eye Color Comes From… SurprEYESing Science!

The eyes are often the first thing we see when we look at someone. And when you look at them up close, everyone’s eye color is a kaleidoscope of shapes and hues. How does eye color work? The answer involves some very cool physics, and probably isn’t what you were taught in school. And you’ve probably wondered how is eye color inherited, or why some people have blue eyes even if their parents’ eyes are brown? Get ready for a long look deep into the genetics and physics of eye color.

Première diffusion : 18 mai 2019

S2019 E12 • How To Make One Million Species Disappear

A massive new study has just been released showing that human activities are threatening Earth’s other life forms in some very bad ways. One million species may be at risk of extinction. Just let that sink in. Isn’t the Anthropocene awesome? Check out the study below to learn more and find out how we can stop it.

Première diffusion : 24 mai 2019

S2019 E13 • See INSIDE a Chrysalis! - Painting Wings with CRISPR

Butterfly metamorphosis is still a bit of a mystery. What happens inside a chrysalis to turn a caterpillar into a beautifully painted butterfly? Does it really turn to soup? I visited Dr. Arnaud Martin, who uses the CRISPR genetic modification technology to learn about how genes build bodies. Dr. Martin uses CRISPR to disrupt certain genes, and then looks for changes in butterfly wing patterns, creating designs we never see in nature. This tells us which genes control which part of the "wing painting" process. In the process of visiting Dr. Martin’s lab, I had my mind blown about what REALLY happens during butterfly metamorphosis. You will too.

Première diffusion : 18 juin 2019

S2019 E14 • Could You Be a Chimera?

Ever feel like you aren't totally yourself? Well, maybe you aren't. In this video, we explore the idea of human chimeras. In mythology, the "Chimaera" was a beast made from different animals combined into one. But in biology, a chimera is a single organism whose body is made from parts of two or more genetically distinct individuals of the same species. Biological chimeras were once thought to be rare, but modern genetics has shown us that these genetic mashups are so common, that you yourself may actually be a chimera. And even if you don't have part of another body in you, your body is certainly not just one thing. We also discuss the idea of mosaicism and how it relates to cancer, Tasmanian devils, and circus sideshow attractions.

Première diffusion : 21 juin 2019

S2019 E15 • Seeing a Black Hole with a Planet-Sized Telescope - STELLAR

It took about a century for black holes to go from impossible, to theoretical, to real. And it was just this year, in 2019, when we finally saw the first picture of a black hole! But how to you take a photo of something so massively dense that not even light can escape its gravitational pull? You use a telescope the size of the Earth!

Première diffusion : 3 juillet 2019

S2019 E16 • Apollo’s Most Important Discovery (Inside NASA’s Moon Rock Vault!)

Fifty years ago, we sent the first astronauts to walk on the moon’s face. But what they brought back is just as important as what got them there. I’m talking about moon rocks, guys. And I got to go visit NASA’s lunar sample vault to learn more about them! NASA’s moon rock collection has helped us learn so much about the early solar system, the formation of rocky planets like ours, and where our moon came from. And let me tell you, the story of our moon is a VIOLENT one. It involves the word “magmoon”. That’s an awesome word! Enjoy this video, and I hope you learn not just some lunar geology, but also how exploring the moon helped change what the space program was all about.

Première diffusion : 9 juillet 2019

S2019 E17 • Why We Are Losing the Night Sky

It never gets dark anymore. Not REALLY dark, anyway. Not like it used to. Most humans on Earth live under light polluted skies. That's because, for the past century and a half, since the dawn of electric light, we’ve been losing our connection to the night. We need artificial light for modern society, of course. The problem is, we need darkness for our health, and for the health of wildlife and ecosystems, and we’re not getting enough of it. I traveled to McDonald Observatory in far west Texas, one of the darkest places in North America, to learn what people are doing in order to preserve dark skies, and to see truly dark skies for myself (and so I could show them to you!). This video features time lapse night sky images that I’ve been collecting for the past few years, and I hope they make you feel something special. Turn out the lights, keep looking up, and don’t be afraid of the dark.

Première diffusion : 14 juillet 2019

S2019 E18 • Is This Why We Haven’t Found Alien Civilizations? - STELLAR

Looking up at the stars makes you wonder: what and who is out there? And why haven’t we seen any other intelligent civilizations given the vast size and age of the universe? They’re complicated questions and although we haven’t met any other space-faring species we do have a way of calculating just how many alien civilizations might be out there as well as some rather frightening ideas as to why we might not have met them.

Première diffusion : 22 juillet 2019

S2019 E19 • Do Trees Talk?

Why the forest is more than the trees

Première diffusion : 27 juillet 2019

S2019 E20 • How Blind People See With Sound…

I met Molly Burke a few months ago. She’s awesome. I absolutely love what she’s done on YouTube to bring awareness to living with disability, and turning it into ability. And her guide dog Gallop is awesome too! When Molly and I first met, we started talking about how she navigates the world, because I’m a nerd and I always steer the conversation toward science. I was not prepared for what she told me. She said she uses echolocation! Molly’s brain has adapted to listen to sounds in her environment in ways that most of us sighted people can’t even imagine. I went to meet her in LA and brought a special surprise, to see if my brain could learn what hers has.

Première diffusion : 10 août 2019

S2019 E21 • Why Don’t Birds Lay Square Eggs?

What is “egg-shaped” even? I used to think it was the shape of a chicken egg. Then one day I saw a collection of eggs from lots of different bird species, and I realized just how many different kind of egg shapes there really are! I had to know why. And it turns out a couple teams of scientists had wondered the same thing. Here’s what science says about why eggs are egg-shaped, if that's even a thing, which I’ve learned it might not be. Evolution of bird eggs, go!

Première diffusion : 19 août 2019

S2019 E22 • 7 Scientific Urban Legends Debunked!

It sounds like such an incredible fact. “Our own cells are outnumbered by our microbes 10 to 1!” I don’t remember where I first heard it. But I read it in science papers and articles by journalists, so I believed it without question. I even made one of my first videos based on this fact. Problem is, this fact is not true. So how did it remain firmly planted in our common knowledge for almost four decades without any scientific scrutiny? And how can you prepare yourself to not be fooled by other scientific urban legends? I look at a few of the most famous incorrect factoids in science, and give a few suggestions for how to make our common knowledge more correct.

Première diffusion : 6 septembre 2019

S2019 E23 • Money Is A Technological Fiction (The Invention of $$$)

Money. We all use it. But is it real? I mean, you can touch a coin or bill, but who decided that’s worth anything? And what about all those 1’s and 0’s getting swapped and traded by computers thousands of times per second? How are those worth anything? We trace the history of money, from physical barter to bitcoin, and discover that money isn’t just a lie we all agree to share, it’s been built on the back of technology and invention for millennia.

Première diffusion : 29 septembre 2019

S2019 E24 • What’s In a 20,000 Year-Old Cube of Ice?

Earth’s climate is changing in a big way, and it’s because there's more carbon dioxide in the atmosphere than at any point in our species’ history. But Earth’s climate has changed before. How do we know that this time we’re the cause? We know thanks to tiny bubbles of ancient atmosphere trapped in ice.

Première diffusion : 7 octobre 2019

S2019 E25 • This Face Changes the Human Story

Greetings, fellow Homo sapiens. Our species is the only remaining member of the genus of upright, walking apes known as Homo. Where did we come from? Our history just got a whole lot more complicated (in a good way) thanks to some incredible new fossils unearthed in South Africa over the past few years. I got to visit them, and the scientists who discovered them, to learn their story and ours. Meet your cousin: Homo naledi

Première diffusion : 21 octobre 2019

S2019 E26 • What Would Trees Look Like On Other Planets?

Why are trees and other plants green? Seems like a simple question. But the answer is full of surprises. Using a special camera that can pick up light just beyond the visible range, into the near-infrared, you’ll get to see trees like you’ve never seen them before. And these other-worldly images can teach us not only why trees are green on Earth, but what color photosynthetic life on other planets might be.

Première diffusion : 25 octobre 2019

S2019 E27 • IN YOUR FACE EXPLOSIVE CHEMISTRY!! (VR180)

This is a VR180 video so pop on your Google Cardboard or VR Headset to be totally immersed in our world! No headset? No problem. Move your mobile phone around and catch the total 180 experience!

Première diffusion : 2 novembre 2019

S2019 E28 • What Color Is A Banana?

What color is a banana? Duh, it’s yellow. But what is yellow? Now that you mention it, how do we see color in the first place? That’s the series of questions that led me to making this video. It started simple and took me down a rabbit hole of decoding our visual system. Turns out it’s way more interesting than I ever thought possible. You might even call it complex. In fact, it’s a wonder it even works. Biology… wow, right?

Première diffusion : 9 novembre 2019