PBS

Did Thomas Edison pave the way for today's EduTubers? Danielle tracks the path from Edison's Christmas light demonstrations in the late 19th century all the way to the science explainer videos of today.

How successful are we compared to other species? It turns out that biomass, or what things weigh, can be more important than how many of something there are. Find out how our numbers stack up against everything from bugs to bacteria, and get ready for some mind-blowing numbers!

Love is a complicated combination of brain chemicals and behavior that scientists are only just beginning to figure out. And it's remarkable that in every society that we have looked at on Earth, romantic love exists. So if love is so universal, and there are 7 billion other people out there looking for it, why can it seem like it's so hard to find?

Space might seem like an empty place, but the area surrounding Earth is constantly being bombarded by waves of charged particles released by the Sun: The solar wind. Luckily, thanks to Earth's swirling, molten core (and the magnetic field it provides), we are protected from this planet-sterilizing onslaught like an invisible force field. The visual result? The Auroras.

Why is the sky blue? It's a question that you'd think kids have been asking for thousands of years, but it might not be that old at all. The ancient Greek poet Homer never used a word for blue in The Odyssey or The Iliad, because blue is one of the last colors that cultures pick out a word for.

Earth's atmosphere is big, but not as big as many people think. All the air that keeps us alive is just a thin candy shell around our planet. In this episode, echoing the words of John F. Kennedy, I'll show you the science of how we all share the same air. So let's be careful about what we're putting in it.

Wind is everywhere. The air is constantly moving, sometimes gently, sometimes violently. Why? Pressure, temperature and rotation come together to make wind. Here's how.

It seems like every week someone tells us how the internet and the digital age are overloading our brains. Sure, sometimes it feels like we're being fed more information than we can handle, that we're paying attention to the wrong things. Are we giving our brain a fair shot?

Bees are amazing social insects, and their relationship with flowers is one of nature's coolest examples of "mutualism". It got me wondering: How do bees see the world? Enjoy this look at how bees see in ultraviolet and even sense electric fields!

There is no sound in space. In the near-vacuum of space, there is nothing to transmit the physical waves that we need to perceive sound. But that doesn't mean we can't MAKE sound from space.

Dorothy went over one. LeVar Burton read to us under one. In a song, Kermit the Frog connected us to one. Even Mork's suspenders were made of them. Our culture, and our skies, are full of rainbows, but do you know how they form? Do we all see the same rainbow? Could cyborg-enhanced mantis shrimp eyes ever see a bigger rainbow?

Teeth. We’ve all got ‘em (most of us, anyway). But how do they grow? Teeth are made from some biological nanotechnology that will blow your mind. They are strong enough to last hundreds of millions of years. Oh, and if you’ve ever wondered how adult teeth replace your baby teeth, get ready to see something terrifying.

What’s the largest river on Earth? If you said “the Amazon”… you’re only half right. Scientists have discovered an even bigger river in South America, and it’s in the sky above the Amazon rainforest. Turns out, this sky river is the reason there’s a rainforest at all…

The flu might feel like some minor illness that you don’t need to worry about much, but tens of thousands of people still die from it every year. And back in 1918, Flu killed up to 5% of the world’s population. Could a flu that bad happen again?

Can an unreliable narrator help readers see the world through multiple lenses?

Has a fifth fundamental force been discovered and how will this effect our understanding of the universe?

We’ll soon be capable of building self-replicating robots. This will not only change humanity’s future but reshape the galaxy as we know it.

The Hubble Telescope found more evidence of vast plumes of water bursting through the icy surface of Jupiter’s moon Europa. What does this tell us about the potential for life on Europa?

Scientists studying quantum vortices and their impact on superconductivity just won the Nobel Prize.

Using geometry we can not only understand, but visualize how causality dictates the order of events in our universe.

You’ve discovered a habitable exoplanet, but so has an an evil interplanetary mining corporation. Can you get to the planet before they strip it bare and leave it unsuitable for life? You’re going to need a ship, the Lorentz Transformation and the Wait Equation. Hang on, it’s going to be a bumpy ride.

By choosing the right path and the right reference frames, any superluminal motion can lead to information or objects returning to their origin before they depart.

Can we ever achieve absolute cold?

It turns out that "nothing" is one of the most interesting somethings in all of physics.

It’s the holiday season and we all know that means seeing old St. Nick in his big red suit. But have you ever stopped to wonder why he doesn’t wear any other color? Because he used to be seen wearing blue suits, purple suits, yellow suits and sometimes he was even skinny! So how did we end up a jolly bearded Santa who only dresses in red? Watch the episode to find out.