Zoos are where you go to look at "them," the animals. But not in this video of a zoo in Amsterdam. Here, differences melt away, and all the animals, including the ones with hats, coats and strollers, are just as curious, just as odd, just as silly as the monkeys, hippos and tigers.

Ready, get set, go! Let's compare a sperm whale plowing through the ocean to a human sperm plowing through a glass of water: The whale barely notices the water it's in; the sperm — oh, gee — it's got a problem. How it solves that problem — being much closer to the size of the water molecules around it — is ... well, masterful.

Our latest podcast, Poop Train, is packed with unexpected facts about what happens after New Yorkers flush. For even more sewer trivia, take our Poop Quiz.

In the book "Arabian Nights," Prince Husain, the eldest son the Sultan, buys a magic carpet which comes with these instructions: Think of a far away place and "Whoever sitteth on this carpet ... will, in the twinkling of an eye ... be borne thither." We're updating that tale, with a real magic carpet — but this time with feathers.

Monkbot is our affectionate nickname for a mechanical man commissioned by King Philip II of Spain almost 450 years ago. We tell the clockwork model's story in our Ghost Stories episode -- if you haven't heard it, take a listen while you check out ...

It's been frustrating, this 100-year search by physicists all over the world for a Unified Theory of Everything, and Tim Blais, physics grad student, a capella singer, Queen fan, feels their collective pain in this — his Bohemian Rhapsody on String Theory. Don't miss the Albert Einstein hand puppet in a hail storm, crying his heart out.

Two short tales: One about bad guys in a fishing village in Pakistan, the other about good guys in Baghdad. And the question is posed: in the long arc of time, which side prevails, those with the impulse to take or those with the impulse to give?

We built a bookshelf stocked with tons of recommendations inspired by Radiolab podcasts. Introducing our new visual archive... Radiolab Reads.

What I'm going to say sounds ridiculous, but once upon a time it wasn't ridiculous at all. You could wake up one morning in North America and decide to walk to Morocco, have breakfast, and a few hours later, there you are — in Africa. No sweat. Or wander from Australia into Bangladesh. Not a problem. Let me show you how.

NASA is reporting that Voyager 1 has finally left the heliosphere and is now cruising through interstellar space!

Suppose you wanted to slip into a space quietly, secretly. Would you wear a dazzling, many-colored ball gown? I think not. So how do we explain what the Dutch government is doing on Google Maps? Is this any way to keep a secret?

If you care about the environment, if you're a good person, you try (in many little ways) to cut back, do with less, live more simply. But when nobody's watching, when you're feeling naughty, you dream of "More-ing," which is both totally irresponsible and crazy fun.

If we had enough time, enough brain power, the right computers, the occasional genius, is there any limit to what we can know about the universe? Or is nature designed to keep its own secrets, no matter how hard we try to crack the code? What can we never know?

There was a spruce tree in Stanley's garden, and when September rolled around, a family of garden snakes used it to sunbathe. They'd squiggle out on a branch, flop down and warm themselves in the sunshine — sometimes dangling in braided pairs. Stanley, envious, decided to join in ... and here's what happened next.

Snails getting ready for winter are natural carpenters. They construct doors, or maybe you'd call them walls, inside their shells. They do this without hammers, nails or cement. Instead, they use their foot — and of course, their favorite material, mucus. Welcome to the ingenious world of snail construction.

Drones are for spying, right? Right. But if Jasper van Loenen's idea works, drones will also become private moving vans. Crows won't like this. Trees won't like this. I'm not sure I like this. But you've got to see Jasper's instant-drone deliver a bicycle wheel across campus ...

A New York design team has just produced an invisibility cloak for your cell phone. Pop it in and no government, no merchants, no friends, no one knows where your phone is. Another design team in Canada says they could do stuff like this — but they won't. Who's right?

What happens if you take a beach creature, a little worm, or an oyster, and move it to an aquarium far from the sea? Will it still imagine tides? Yes, it will. But whose tides will wake it up every day, get it moving? The tides back home? Or the tides — even if there aren't any — in its new time zone? A puzzle.

What surgeons see when they open us up and look inside is not pretty — unless you're a surgeon. But when designer Kelli Anderson opens us up, we are feathery, pipe filled, ivory-boned, wired, clean, elegant — just gorgeous. Plus, we are entirely made of colored paper. Check out this new transparent (and interactive!) human body — perfect for kids.