Elsa Chang (2:44)

Okay, kick us off with the Antarctic penguins. What's going on with these guys?

Emily Kwong (2:49)

So, a new study in the Journal of Animal Ecology found that they're breeding earlier than ever in the Antarctic spring. Adelie and Chinstrap penguins are breeding an average of 10 days earlier, and Gentoo penguins almost two weeks earlier. Over the decade, the research researchers observe them.

Regina Barber (3:06)

And while two weeks may not seem like a lot of time, researchers say it's actually a radical shift in the penguins breeding season.

Elsa Chang (3:12)

Wait, so what's causing the shift?

Emily Kwong (3:14)

So penguins time their breeding period to environmental conditions like temperature outside, or whether there's ice on the ground or what food is available. And with climate change, the Antarctic Peninsula is one of the fastest warming areas of the world, and that could be a driver.

Elsa Chang (3:29)

Interesting. So how did they collect all of this data? Like 10 years feels like a very long time to be in Antarctica.

Emily Kwong (3:37)

Yeah. So one of the study's authors, Tom Hart, says they set up 77 cameras across 37 penguin colonies and each camera took photos every hour for a decade.

Elsa Chang (3:48)

Surveillance system.

Regina Barber (3:50)

Yes. It was very clever methodology. We spoke to another penguin researcher who wasn't involved in the paper, Bill Fraser, and he said this camera method is a great way to get long term data in Antarctica, because a lot of work in this region is restricted to human observations. Huh.

Elsa Chang (4:05)

Okay, so then what does all of this mean for the future of Antarctic penguins, you think?

Emily Kwong (4:10)

Well, Tom says that's something they're trying to figure out for future work. Some penguins might thrive. For example, the Gentoo penguins are suited for warmer climates and eat a wider variety of fish. So it seems that Gentoos are doing better than the other species, which could struggle with warmer temperatures.

Elsa Chang (4:26)

Okay, going from Antarctic penguins to the Winter Olympics, which are just a few weeks away.

Regina Barber (4:32)

Yes.

Emily Kwong (4:32)

Yeah.

Elsa Chang (4:33)

And I think, like, this would be a great time then to talk about ice science. Tell us, Emily, what is new about ice?

Regina Barber (4:40)

Well, since Victorian times, there's been this idea that ice has a thin layer of water on top, which makes it slippery. And physicists have been arguing about it ever since. Is there a thin film of water even at temps below zero degrees Celsius? And, like, how thick is this layer of water?

Emily Kwong (4:57)

And there might be an answer now published in the Journal of Chemical Physics. This week, Luis Gonzalez McDowell, a chemist at Complutense University of Madrid, looked at research all the way back to the 1930s to address this debate. He also ran computer simulations to see how ice freezes or melts, really looking at what happens to that surface.

Elsa Chang (5:15)

And what did he find? Like, is that thin film of water there?

Regina Barber (5:20)

DRUMROLL There is a very, very thin layer of water on the ice, even though the ice itself is frozen. And this is true down to minus 10 degrees Celsius that layer of water is about a nanometer thick. And to put that in perspective, a sheet of paper is 100,000 times thicker than that layer of water.

NPR Sponsor Announcer (5:39)

Wow.

Regina Barber (5:40)

Here's Luis.

Emily Kwong (5:41)

The surface of ice, which is solid, is always lubricated. You have always, before you start sliding, already a lubrication layer. And this is interesting because some past theories thought that maybe the pressure from, like, let's say an ice skate may be the thing creating that layer of water on the ice. And he says it's always there down to negative 10 degrees Celsius.

Elsa Chang (6:02)

Okay, so then to apply this to the Winter Olympics, say, what does this mean for winter sports like ice skating or hockey?

Regina Barber (6:09)

Yeah. Well, ice skates, they put pressure on the ice, and when that happens, the water layer actually gets thicker because the friction of the skate blades causes more melting.

Elsa Chang (6:18)

Interesting.

Additional Announcer (6:19)

Yeah.

Emily Kwong (6:19)

And Luis's computer models also took into account humidity and found that humidity levels can also affect the formation and thickness of that water layer. Looking ahead to the Winter Olympics in Italy, there's already been some concern about the ice rinks and whether the ice is smooth enough to skate on. And according to Luis's work, if the humidity isn't quite right, that could also affect the slipperiness. Hmm.

Additional Announcer (6:40)

Okay.

Elsa Chang (6:41)

Going from the pristineness of ice surfaces to dirty diapers.

Regina Barber (6:46)

What a pivot.

NPR Sponsor Announcer (6:47)

Yeah.

Elsa Chang (6:48)

I am so glad to be child free. What do we got here on this front? Dirty diapers. Talk to me.

Emily Kwong (6:53)

This is inspired by the psychology of disgust. So disgust is really important to our survival as humans because it helps us avoid all kinds of substances that would otherwise make us, like, sick. Remember, disgust was one of the five basic emotions in that movie, Inside Out.

Additional Announcer (7:08)

Yeah.

Emily Kwong (7:09)

Caution, There is a dangerous smell, people. Yucky. I just saved our lives. Yeah, you're welcome.

Elsa Chang (7:15)

I love disgust.

Regina Barber (7:18)

She's an icon. However, there are some kinds of disgusting things that people can get used to. Like the contents of their kids diapers.

Elsa Chang (7:26)

No.

Regina Barber (7:27)

Scientists call this habituation. When you're repeatedly exposed to something, you're.

Emily Kwong (7:31)

Less sensitive to it, especially if you're a parent, which I am. And scientists at the University of Bristol and Whitman College wanted to know, how long do parents hold on to their tolerance for these gross things?

Elsa Chang (7:43)

Okay. I can't help but feel a parallel to owning a dog, because the amount of times I have gotten stuff on my hands, like, I just don't even care anymore, you know? So I am curious for love. Yeah, exactly. But if I were a human parent, I mean, a parent of a human, like, even after my kids have Grown up, would I retain the superpower, this resistance to disgust?

Regina Barber (8:06)

Yeah. So to study that very question, the research team recruited 99 parents and 50 non parents. And they showed them two photos at once on a computer screen. On one side, a photo of something neutral like a stack of towels or clean sink, and on the other side, photos of gross things like vomit on a sidewalk and of course, dirty diapers.

NPR Sponsor Announcer (8:27)

They're all produced by my children, by the way. So big shout out to my kids.

Elsa Chang (8:31)

Aww.

Regina Barber (8:32)

This is the study's lead author, Edwin Dallmeier, who published these results in the Scandinavian Journal of Psychology.

Emily Kwong (8:37)

By tracking the volunteers attention as they, like, looked at these photos, his team found out that the non parents tend to avoid the disgusting photos, whereas the parents showed little to no avoidance. They would look at those pictures of soiled diapers with little aversion, including parents who hadn't changed a dirty diaper in decades, which is like, similar to me. I am not bothered.

Regina Barber (8:57)

Oh, wow.

Elsa Chang (8:58)

So you're like habituated for life once you have a child.

Emily Kwong (9:02)

Maybe.

Regina Barber (9:02)

This superpower does seem to last a while according to this work.

Elsa Chang (9:06)

I mean, if I had to pick my superpower, this is probably not the one I would pick. But big picture, why does this work matter? What would you say?

Emily Kwong (9:14)

Yeah, I mean, discuss. Habituation is actually a good thing in all kinds of jobs. Think about nurses or surgeons or custodians. Edwin would love to see his work be used in those professions.

NPR Sponsor Announcer (9:25)

Even if we can reassure people, hey, it feels a bit gross now, but you'll get used to it over time. Hopefully that ultimately either helps or can lead to things that do help.

Elsa Chang (9:37)

This is fascinating. I wonder if it applies to people who are annoying. You just get used to them over time and they stop bothering you.

Emily Kwong (9:43)

I don't know. But you, Elsa, are always welcome and not annoying us. So thank you so much for coming on the show.

NPR Sponsor Announcer (9:49)

Thanks for having me.

Elsa Chang (9:50)

You're so welcome.

Emily Kwong (9:55)

You can hear Elsa on consider this NPR's afternoon podcast about what the news means for you.

Regina Barber (10:00)

And for more science stories just like this one, follow Shortwave on whatever app you are listening to.

Emily Kwong (10:06)

I'm Emily Kwong. And I'm Regina Barber. Thank you for listening to Shortwave, the science podcast from npr.

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Emily Kwong (10:53)

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