JUDY WOODRUFF: And now to our NewsHour Shares, something that caught our eye that we thought you might be interested in too. Earlier this winter, Henrik Trygg filmed his friend Marten Ajne skating on some very thin ice, less than two inches thick, in fact. The result was a mini-documentary that captured the eerie, beautiful sounds of bending ice, and it went viral. We recently spoke with Trygg by Skype about that day and those unique noises.
HENRIK TRYGG, Photographer: My name is Henrik Trygg, and I'm Swedish outdoor photographer. I have been ice-skating for 25 years. And I think Marten has skated 35 years. The lake is just south of Stockholm. It's just 2,000 meters long and 50 meters wide. The sound was really extraordinary that day, because the lake is so narrow and the ice was so thin, and then the quality was so good. It's just two-, 2.5-day-old ice. It's very pristine in the beginning. It's not too thick. It's alive. You feel it. You hear it. So, this is like the Holy Grail. It's like the ice is singing. You hear it when it's getting thinner. The pitch gets higher. The frequency gets higher. So, we just started recording. You hear the noise best when you skate 10 to 20 meters away. So, I just took it in -- directly into my camera. It's a very high-pitched tone. So, it was fairly OK to record it with the built-in mic. So it's nothing fancy about it. I skate here because there's not -- nothing much more to do in the Stockholm winter, and I really enjoy the adventure. I'm very curious. I want to see, how far can we go, where can we go? You can have adventure just outside your doorstep. You don't have to travel to the other side of the world. You can get your fix here.
JUDY WOODRUFF: My question is, how does he not fall through the ice? We will let him answer that. You will find more online, where we explain the math behind this skater's thin ice feat. That's on our web site, pbs.org/NewsHour.
