In this episode we'll tell the tale of that epic snapshot. Plus we'll explain how Earth and our solar system formed in the first place. We'll talk to astrophysicist Lindy Elkins-Tanton about whether there are other planets like Earth in the universe. Plus we have an all new Mystery Sound and a Moment of Um that answers the question “Why do dreams seem longer than they are?”
So say cheese and enjoy! This episode is sponsored by Pre (eatpre.com and offer code BRAINSON). You can support Brains On at brainson.org/donate
In this episode we'll teach you tricks and tips to navigate on your own. We'll explain how compasses work and we'll tell you who helped move north to the top of the map. Plus, we'll meet a navigator who goes on long journeys using only traditional Hawaiian navigational techniques and we'll stop by a pitstop for some amazing animal migrators.
All that and a Moment of Um on why diamonds are so rare and so valuable.
Today’s episode is sponsored by KiwiCo (kiwico.com/brainson), Little Passports (littlepassports.com/brains), Bombas (bombas.com/brains), and Ozobot (ozobot.com/shop).
In this episode, canine cognition researcher Alexandra Horowitz helps us puzzle out this question. We’ll also find out what happens (or doesn’t) when a dog looks in the mirror. Dogs are always dozing, and we’ll check in to see if they are dreaming too. And, we take a quick trip around the world in the language of barks.
All that, plus a brand new Mystery Sound and moon-filled Moment of Um!
Today’s episode is sponsored by Ozobot (ozobot.com/brains), KiwiCo (kiwico.com/brainson), and the book Horse Meets Dog. You can support Brains On with a contribution at brainson.org/donate
For more recipes and information for young chefs, head to americastestkitchen.com/kids to sign up for their newsletter. Brains On is sponsored today by Children’s Cancer Research Fund (ccrf.org/brainson) and KiwiCo (kiwico.com/brainson).
How is water weird? Let’s start with a water oddity that’s easy to see. Ice, the solid form of water - floats on it’s liquid! Substances can exist in 3 forms or phases: gas, liquid, and solid. These phases are different because the atoms or molecules, what makes up all the stuff in the universe, are arranged differently. Gas molecules move around really quickly, and have lots of space between them. Liquid molecules are much closer together, but still moving and flexible. Solids are packed tight, the atoms right up next to each other. Almost everything gets denser as it moves from gas to liquid to solid. But not water! When water solidifies into ice, it becomes less dense and floats!
NOAA / Flickr
An Arctic iceberg captured on camera aboard the NOAA Ship Fairweather in 2012.
Another weird factoid - hot water seems to freeze faster than cold water! That’s right, in a race to the icy finish line, hot water will get there faster than cold water, despite having further along the thermometer to travel! This phenomenon is known as the Mpemba effect, named after Erasto Mpemba, a Tanzanian high school student who observed this phenomenon while making ice cream! Scientists still aren’t confident they know why this happens.
Erasto Mpemba, the Tanzanian high school student who discovered firsthand that hot water freezes faster than cold water while making ice cream back in the 1960s.
Water is what’s called a “universal solvent” which means it is really good at dissolving stuff. Table salt? No problem. Vitamins and minerals? Easy peasy. A vertical mile of rock? Give water enough time and it can carve the Grand Canyon. Water can climb upwards against gravity, absorb an unusually high amount of heat energy, and transport essential nutrients throughout our body.
Why is water so weird? Well it turns out that it boils down to the forces that hold water together. Like everything, water is made up of atoms, those tiny-building blocks that make up all the stuff in the universe. Atoms combine to form molecules, and in the case of water, two hydrogen atoms combine with one oxygen atom to form H2O!
Every H20 molecule has an end with a positive charge and an end with a negative charge, just like a magnet does. The Oxygen atom has a small negative charge, and the two Hydrogen atoms have an even smaller positive charge. And just like a magnet, negative and positive ends attract one another. These small attractions are called hydrogen bonds, and are indicated by the dotted lines in this picture.
Water molecules: Dotted lines indicate hydrogen bonds
These attractions are called hydrogen bonds because they only form between hydrogen atoms and other charged molecules. These Hydrogen bonds between the different water molecules are a lot weaker than the bonds that hold the two hydrogen atom to the oxygen atom of a single H2O molecule. It’s kind of like the difference between a firm, long lasting handshake and a quick high-five. Plus, Hydrogen bonds exist for just a fraction of a second, 10 picoseconds to be exact (a picosecond is to one second, what one second is to 31,700 years!)
So you’ve got all these water molecules zooming around, “high-fiving” their neighbors, and being pulled together just a little bit more by hydrogen bonds. This little extra pull means water molecules can to stick really well to each other. And it helps them stick to other stuff without getting stuck, since the hydrogen bonds are so easily broken. It also explains why water expands when it freezes, since these H-bonds get “stuck” below 32 ℉, leaving more room between the molecules and making ice less dense than liquid water!
Check out this video to learn more:
What makes water so weird is also what makes it so essential for life. In fact, in addition to supporting life by transporting nutrients and energy, helping our cells do their work, filling the gaps between cells, and even making up the bulk of our bodies (about 70%!), water was likely a crucial player in the origin of life itself! Listen to the podcast to hear all about it!
This episode was powered by the Water Main, a new initiative from American Public Media focused on connecting people to their water resources. Find out more at www.watermain.org
Today: Wings out, eyes wide -- we’re swooping in on a battle between a perfect pair of creatures of the night. Which is cooler: Bats? Or owls? We’re going to hear lots of facts and feelings from our debaters: Brandi Brown and Katie McVay. Who will be chosen the Smash Boom Best? Listen to hear what our judge decides and then head over to smashboom.org to share your opinion with us! And subscribe to Smash Boom Best wherever you get your podcasts to hear the rest of this season's debates.
Click here to vote for who you think won the debate! Team Owl or Team Bat?
Want to learn if you have a lead pipe carrying water into your home? Check out this helpful link from NPR:
Also, did you hear that the Brains On store is open? We couldn't be happier with the t-shirts and other goodies we have to offer. Have a look! brainson.org/shop
Brains On is sponsored today by ButcherBox. Go to butcherbox.com/brainson and enter "BRAINSON" at checkout
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Today Brains On is sponsored by:
• Acer Swift 5 (acer.com -- enter BRAINSON at checkout for 10% discount)
• Mr. Clean Magic Eraser (mrclean.com/brainson)
Music in this episode by Good Old Neon.