Learn why pregnancy cravings might be more cultural than biological; and why raindrops don’t damage delicate insect wings. Then, play along at home and test your podcast knowledge with this month’s Curiosity Challenge trivia game.
Learn why pregnancy cravings might be more cultural than biological; and why raindrops don’t damage delicate insect wings. Then, play along at home and test your podcast knowledge with this month’s Curiosity Challenge trivia game.
Pregnancy cravings are more cultural than biological by Grant Currin
Study shows why speeding raindrops don't damage delicate insect wings by Grant Currin
Episodes referenced in Curiosity Challenge Trivia with Tom
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Find episode transcript here: https://curiosity-daily-4e53644e.simplecast.com/episodes/the-myth-of-pregnancy-cravings-why-raindrops-dont-damage-insect-wings-and-augusts-curiosity-challenge-trivia
CODY: Hi! You’re about to get smarter in just a few minutes with Curiosity Daily from curiosity-dot-com. I’m Cody Gough.
ASHLEY: And I’m Ashley Hamer. Today, you’ll learn why pregnancy cravings might be more cultural than biological; and why raindrops don’t damage delicate insect wings. Then, play along at home and test your podcast knowledge with this month’s Curiosity Challenge trivia game.
CODY: Let’s satisfy some curiosity.
When a pregnant woman has a craving for pickles and ice cream, you get her pickles and ice cream. Doesn’t matter if it’s late at night. Doesn’t matter if she’s gonna dip the pickle in the ice cream. Her body needs the nutrients, and cravings are nature’s elegant way of getting them.
That’s how the story goes, anyway. According to a new analysis of several studies, reality may be a little more complicated.
The first red flag for this time-honored narrative comes from the fact that not all cultures have pregnancy cravings. They’re common in the United States and in other English-speaking countries, but there are a lot of cultures where they don’t happen at all. If the point of cravings is to get biologically important nutrients, how do pregnant people in those cultures manage to eat what their bodies need?
There are also interesting differences among cultures where cravings are a thing. Not everyone is turning to chocolate bars or hot fudge sundaes. In Japan, the most commonly craved food is rice — hardly a classic in the US.
That cross-cultural difference points to a question researchers have been trying to answer for a long time: Do the foods pregnant people crave actually contain nutrients that are important during pregnancy? The answer is a surprising — and maybe disappointing — no. Nutrition is notoriously difficult to study, but research suggests that pregnant people with cravings may be less healthy because they tend to gain more weight than doctors recommend, possibly increasing the risk of complications.
So if there isn’t a biological basis for cravings, what’s with the pickles and ice cream? Experts suspect it has something to do with culture — specifically, the messages cultures send about certain kinds of food. In a lot of places where cravings are common, eating delicious food comes with a hefty side of guilt. Chocolate is so good, but a lot of people keep themselves from eating it and feel really bad about themselves when they do. That creates a recipe for intense cravings.
But you aren’t judged as harshly while you’re pregnant, at least for craving food. Maybe the cravings you’ve always had just rise to the surface during such an unusual time.
And finally, pregnancy is really hard. When partners, family members, or friends help sate those cravings, they’re demonstrating that they’re there to help. So go get those pickles and ice cream. The purpose they serve may not be biological — but they still serve a purpose.
Imagine you’re outside, minding your own business, when you see a bowling ball fall from the sky. And then another. And then like ten. And then way more than you can count. Thousands of bowling balls falling from the sky.
That’s sort of what a rain shower is like for insects. A butterfly is so light that a raindrop hitting its wing is roughly proportional to a bowling ball striking a human. How do they survive an afternoon cloudburst? According to a new paper, it’s all in the evolutionary engineering.
The title of the paper tells it like it is. It’s called “How a Raindrop Gets Shattered on Biological Surfaces,” and it details what researchers saw when they used high-speed cameras to watch little droplets of water hit insect wings, plant leaves, and bird feathers. Those are some of the many super-hydrophobic surfaces that occur in nature and help living things get rid of water very quickly.
The amazing thing is that as different as those surfaces seem, the droplets behaved almost exactly the same way on all of them. As soon as the raindrop hits the surface, it breaks apart into a bunch of tiny droplets that fly off in different directions.
It turns out there are two layers of evolutionary design at work here. At the nanoscale, there’s a very thin layer of wax that repels the water and helps it flow off the surface as quickly as possible. That’s really important because water is so heavy. I mean, just think about the difference between a bowling ball dropping on your foot or sliding across it. The drop would hurt a lot more.
At the slightly larger microscale, there’s a surface of tiny bumps that break a raindrop into smaller pieces. That reduces the amount of time the drop spends on the surface, which lightens the force of impact on the poor butterfly that got caught out in a storm. Again, imagine the difference between getting pelted with a pound of beans in a bag versus out of a bag. This breakage also keeps the cool rainwater from making the wing too cold to function properly.
Engineers and product designers take hints from nature all the time. The researchers behind this study hope the system of microscale bumps and nanoscale wax that they’ve identified will serve as inspiration for products in the future. But the next time you see a butterfly hiding out in a rainstorm, don’t feel too bad. It’s got nanotech on its side.
ASHLEY: Today’s episode is sponsored by KiwiCo. KiwiCo creates super cool hands-on projects designed to expose kids to concepts in STEAM. Which stands for, say it with me now: science, technology, engineering, art, and math. Nice!
CODY: You get a new box every month, which comes with all the supplies you’ll need for that month's project. And each line caters to different age groups and covers a whole range of topics. These projects give kids structure, fun, and opportunities for hands-on exploration at home.
ASHLEY: There are kid-friendly instructions so kids can play and learn independently, but adults, you can totally join in too! It’s a great chance for a little bonding time. With KiwiCo’s hands-on art and science projects, kids can engineer a walking robot, blast off a bottle rocket, explore colorful, kid-friendly chemistry, and more.
CODY: They have everything you need to make STEAM seriously fun — delivered to your doorstep. Get your first month FREE on select crates at kiwico-dot-com-slash-CURIOSITY. That’s K-I-W-I-C-O dot com slash CURIOSITY
It’s time once again for the Curiosity Challenge! Every month, I call up a listener and put them to the test by asking three questions from stories we ran on Curiosity Daily in the previous month. For this Curiosity Challenge, I talked to Tom Webster in Boston. He’s kind of a big deal in the world of podcasting, and we were stoked that he volunteered! [CODY: Although let’s face it: if you’re listening to this podcast, then YOU are a big deal] With that, let’s get started!
[Trivia clip - 1:34]
A perfect score! Tom clearly knows his stuff. How did YOU do? If you’d like to play next month, OR if you have a question you’d like us to answer on the show, shoot us an email at podcast at curiosity dot com, or leave us a voicemail at 312-596-5208!
Leave us a voicemail at 312-596-5208!
CODY: Before we recap what we learned today, here’s a sneak peek at what you’ll hear next week on Curiosity Daily.
ASHLEY: Next week, you’ll learn about why small pleasures are necessary for your well-being;
The big difference between “unscented” and “fragrance free”;
That time some random Guy Stumbled Upon and Translated a Legendary Ancient Text;
Why astronauts are using old sailing technology in space;
HOBO CODE;
And more! Okay, so now, let’s recap what we learned today.
[ad lib optional]
CODY: Today’s stories were written by Grant Currin, and edited by Ashley Hamer, who’s the managing editor for Curiosity Daily.
ASHLEY: Today’s episode was produced and edited by Cody Gough.
CODY: Have a great weekend, and join us again Monday to learn something new in just a few minutes.
ASHLEY: And until then, stay curious!