It would be a lot easier to study the science of dreaming if we weren't asleep every time we did it. Why do we dream? What does dreaming do for our brains? How did dreaming evolve? Here's a look at the current theories from psychology and neuroscience.

is zero something even if it's nothing? Is nothing just an idea? And if nothing is the opposite of something, does it actually exist?

The biggest thing that has ever lived on Earth… is a tree? Hard to believe, but it's true. Travel with me to the Rocky Mountains of Colorado to go inside the most massive species on our planet, and learn what unique and special evolutionary adaptations let them get so big.

How can sand, blown by the wind, form such intricate and beautiful patterns as ripples and dunes? The answer is a surprising secret of self-organization. In this video, we travel to Great Sand Dunes National Park in Colorado to climb the largest sand dunes in North America and bring you the science of how wind and sand combine to create ordered landforms out of chaos. The science must flow.

After a year and a half, we are still experiencing the effects Covid. Let's see where we are now.

Would you believe the answer is… math? This is the story of a WWII wartime codebreaker and his quest to decode nature's most beautiful patterns. Alan Turing uncovered a simple code that explains everything from stripes to spots and all the patterns in between… he was just too far ahead of his time. Only recently have biologists found evidence that his pattern-forming system.

Bits of you are always breaking down, being thrown out, and being replaced. Even right now, parts of you are dying. Some of your cells even died before you were born. And some will never come back. These are all very strange, mildly uncomfortable things to think about. And what's even stranger than that is a big fraction of your body is, was, and will never be alive. So how much of you is dead?

Why does sex exist? You might think the obvious answer is "reproduction" but there are plenty of organisms on Earth that don't require sex to reproduce. And the more that scientists examined sex, the more they realized that it's an expensive and inefficient way to get your genes to the next generation. The true purpose of sex is actually one of the longest-standing mysteries in biology.

Hold on to your butts. This episode is about… butts. The science and evolutionary history of your rear end, the down-low on your derriere, shining a little light where the sun don't shine… you get the picture. But(t) seriously, we don't talk about this all-important hole enough, and how, from an evolutionary perspective, it might be the most important orifice on your body.

How do neurons actually work? Maybe you've heard that it involves electricity, but does that mean you've got little zaps and lightning bolts running through your veins like Pikachu? Don't worry, here we are to set you straight on what a neuron is, what an action potential is, and how fast your nervous system really communicates.

A human with the metabolism of a hummingbird would need to eat about 80,000 calories a day to survive. That's because staying warm by making your own heat takes a ton of energy; creating your own body heat is incredibly expensive. So, why aren't cold-blooded… like crocodiles? Here's the science.

Ocean currents are our planet's circulatory system, and they keep everything from ecosystems to the climate healthy. But we're changing Earth in ways that threaten to disrupt and even break critical ocean currents like the planet-wide Great Ocean Conveyor. We explain how ocean currents work, how climate change is threatening to disrupt them, and what we can do to stop that from happening.

The finest burritos in the world are made in San Francisco's Mission District. But how can you get a hot & fresh one in New York City in time for lunch? Physics, that's how. For this very serious and scientific video, we dug a classic documentary out of the vault that tells the story of the transcontinental burrito tunnel, and its successor, the transcontinental burrito hypertunnel.

Could humans ever evolve to have wings? Why don't fish have propellers? Why don't tigers have wheels? Why don't zebras have laser turrets? These might all seem like stupid questions (and maybe they are!) but they can teach us a lot about how evolution actually works, and how it doesn't work.

The golden ratio. Some say it's the most mythical number in the universe. Others say it underlies everything from nature's patterns to beauty in art and design. But, like, what is it? And does the myth of the golden ratio hold up to its mathematical reality? Let's find out.

When is now? Seems like a pretty simple question… just look at your watch. But do you and I share the same "now"? Let's journey from Einstein's thought experiments about relativity to cutting-edge neuroscience research to try and answer that question.

Since the start of the coronavirus COVID-19 pandemic, the term "herd immunity" has been all over the news. But what does it really mean? One thing most people don't realize about vaccines is that they aren't just to protect the person who gets the shot. They also protect the population as a whole, even people who didn't get the shot. We use mousetraps & ping-pong balls to show you how that works.

Everyone lies. Even you and even me. We lie about small things and we lie about big things. We lie to help ourselves and we lie to protect others. Powerful people lie, all the way down to little kids telling fibs. Why do we do this if we're supposed to be the most socially developed species on Earth? Why can't we tell the truth? Are we doomed to lie? Well, maybe. Here's why.