Regina Barber

You're listening to Shortwave from NPR.

And we're going to get into a debate about ice skating that may now have an answer.

Huh.

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.

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.

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?

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 negative 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.

Wow.

Here's Luis.

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.