Learn about how stress during pregnancy can affect a newborn’s sex; skipping stone physics in space; and overspending. Stress can make a pregnant person twice as likely to have a girl by Grant Currin Beres, D. (2021, April 13). Stressed-out mothers are twice as likely to give birth to a girl. Big Think; Big Think. https://bigthink.com/surprising-science/stress-pregnancy Romero-Gonzalez, B., Puertas-Gonzalez, J. A., Gonzalez-Perez, R., Davila, M., & Peralta-Ramirez, M. I. (2021). Hair cortisol levels in pregnancy as a possible determinant of fetal sex: a longitudinal study. Journal of Developmental Origins of Health and Disease, 1–6. https://doi.org/10.1017/s2040174420001300 Scientists have shed light on the physics of skipping stones to make landing spacecraft safer by Briana Brownell Tang, J., Zhao, K., Chen, H., & Cao, D. (2021). Trajectory and attitude study of a skipping stone. Physics of Fluids, 33(4), 043316. https://doi.org/10.1063/5.0040158 Stone skipping techniques can improve reentry of space vehicles. (2021). EurekAlert! https://www.eurekalert.org/pub_releases/2021-04/aiop-sst041521.php Advanced Aerospace Medicine On-line. (2018, April 11). FAA.gov. https://www.faa.gov/about/office_org/headquarters_offices/avs/offices/aam/cami/library/online_libraries/aerospace_medicine/tutorial/media/III.4.1.7_Returning_from_Space.pdf Lovell, J., Kluger, J. (1994). Apollo 13. Houghton Mifflin. https://books.google.ca/books?id=LDJ43xYxK5YC&pg=PA258&lpg=PA258&dq=Apollo+13+reentry+angle&source=bl&ots=3Cc9mzZNJR&sig=sLWSkkivIHidkiZ_qY3YjyKypaQ&hl=en&sa=X&ei=BemhUuf2NI6OkAfNioCoCg&redir_esc=y#v=onepage&q=Apollo%2013%20reentry%20angle&f=false C. Clanet, F. Hersen, and L. Bocquet, “ Secrets of successful stone-skipping,” Nature 427, 29–29 (2004). https://doi.org/10.1038/427029a To Avoid Overspending, Think of Money as Hours of Your Life originally aired September 26, 2018 https://omny.fm/shows/curiosity-daily/gardening-with-martian-soil-how-to-stop-overspendi Follow Curiosity Daily on your favorite podcast app to learn something new every day withCody Gough andAshley Hamer — for free!
Learn about how stress during pregnancy can affect a newborn’s sex; skipping stone physics in space; and overspending.
Stress can make a pregnant person twice as likely to have a girl by Grant Currin
Scientists have shed light on the physics of skipping stones to make landing spacecraft safer by Briana Brownell
To Avoid Overspending, Think of Money as Hours of Your Life originally aired September 26, 2018 https://omny.fm/shows/curiosity-daily/gardening-with-martian-soil-how-to-stop-overspendi
Follow Curiosity Daily on your favorite podcast app to learn something new every day with Cody Gough and Ashley Hamer — for free!
Find episode transcript here: https://curiosity-daily-4e53644e.simplecast.com/episodes/stress-during-pregnancy-might-affect-the-babys-sex
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 about a pregnant person’s stress can impact the chances of the baby being born a boy or a girl; how the physics of skipping stones can make space exploration safer; and how to stop overspending.
CODY: Let’s satisfy some curiosity.
Stress affects the entire body. And for pregnant people, it affects the baby, too. New research suggests that moms-to-be who are stressed-out during conception and the earliest phases of pregnancy might be more likely to have a child of a certain sex. Stick around to the end of the episode for the gender rev—
ASHLEY: No, we’re not doing that. It’s a girl. Stress could make having a girl more likely.
CODY: Anyway, here’s how the study went down. Researchers found 164 people who were toward the end of their first trimester. Each one filled out some surveys about their stress levels and donated a lock of their hair. Several months later, the researchers got back in touch with them to find out the sex of their baby. Just over 100 of the participants carried their baby to term and were able to finish the last leg of the research project.
Once all that was finished, the researchers started analyzing their data. They divided the new parents into two groups: those who had boys and those who had girls. Then the researchers dug into the data about their stress levels.
Stress levels on the survey were basically the same in both groups, but the hair told a different story.
See, you can use hair to measure cortisol, a stress hormone. These hair samples served as physical records of the moms’ hormonal chemistry around the time of conception and during the first several weeks of their pregnancies. It’s sort of like the way ice cores record the amount of CO2 in the air over time, except instead of burning fossil fuels you’re navigating rush hour and dealing with deadlines.
It turns out that moms who eventually gave birth to girls had way more cortisol in their systems than moms who gave birth to boys. Scientists will need to do a lot of different kinds of research to understand what’s going on here, but the researchers have a few ideas. It could be that stress messes with levels of sex hormones, or that stress makes it harder for XY sperm to find and fertilize the egg. Or it could be something further along in development — scientists aren’t sure.
This isn’t the first study of its kind, and new findings are consistent with some previous work. But other research has pointed in the opposite direction. So we can’t say anything definitive quite yet.
In any case, let’s try to keep the pregnant people in our lives as relaxed as possible. Not so they’ll give birth to boys — just because pregnancy is hard enough as it is.
It’s a cool summer evening and you decide to skip stones into the lake. You might already know the stone to look for: round and flat. You might also know the technique: a sideways toss to give it a good spin and a flat orientation so it hits the water at a low angle.
But did you know your stone-skipping knowledge can help spacecraft land safely?
That’s right. A team of scientists from China recently dug into the physics behind how stones skip, and these findings will be critical to future space travel.
The researchers used an aluminum disc to simulate a flat stone, then unleashed a puff of air to send it skipping over the water. They repeated their experiment with a variety of speeds and spins.
At slightly higher speeds, the disc bounced, just like a stone skipping. At speeds just slightly lower, it would surf across the surface of the water. But when the speed was too low? The disc would sink instead.
The team also made important measurements of the Magnus effect. The Magnus effect is the phenomenon where a spinning object curves away from its path: It’s what makes a curveball curve. In this case, the Magnus effect caused the skipping disc’s path to curve as it hit the water. The research showed how this effect is related to speed, so scientists can accurately predict the resulting path.
And like I said, these experiments have a lot of implications for safe space travel.
One application is the “splashdown” — that’s the dynamics of how a space capsule will move as it lands in the ocean. But you don’t need water for this to be relevant. From space, a planet’s atmosphere is a lot like a lake: it’s a dense layer. That means that the lessons we learn from skipping stones can apply to the techniques we use for spacecraft re-entry.
When a spacecraft re-enters the atmosphere, there’s a delicate balancing act. If the angle is too steep, the spacecraft is subject to an extremely high drag force... and it will burn up. Too shallow, though, and the situation is just as bad. If the spacecraft “skips” on the atmosphere like a stone would, it can completely bounce off and end up back in space.
This re-entry window is extremely narrow. For Apollo 13, the approach needed to be between 5.3 and 7.7 degrees.
But thanks to studies like this one, scientists can generate precise predictions of safe re-entry trajectories. All thanks to a relaxing summer pastime.
It’s easier than ever to spend money. You can get pretty much anything you want with just a few taps on your phone. So we thought we’d bring back some advice from 2018 on how you can spend responsibly. We’re gonna cite some numbers related to commuting to your job — and yeah, we know not as many people are commuting to work these days. But get this: according to a recent survey, nearly half of Americans have NEVER worked from home. So hopefully you’ll still find this helpful. Enjoy these money-saving tips from this story we remastered — just for you.
INCLUDE NOTES ABOUT HOW NEARLY HALF OF AMERICANS HAVE NEVER WORKED FROM HOME at the top (41% according to one poll)
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Let’s recap today’s takeaways
[ad lib optional]
ASHLEY: Today’s writers were Grant Currin and Briana Brownell.
CODY: Our managing editor is Ashley Hamer.
ASHLEY: Our producer and audio editor is Cody Gough.
CODY: Time is money! And that’s why you can join us again tomorrow to learn something new in JUST a few minutes.
ASHLEY: And until then, stay curious!