The Times They Are a-Changin'
This episode appears to contain dynamically inserted ads. Transcript timestamps may be approximate.
At the start of this new year we crack open some fossils, peer back into ancient seas, and look up at lunar skies to find that a year is not quite as fixed as we thought it was.
Hosted by Simplecast, an AdsWizz company. See pcm.adswizz.com for information about our collection and use of personal data for advertising.
Don't you wait, you're listening to Radio Lab Radio Lab from WNYC and NPR Hey, I'm Jad Abumrod I'm Robert Krollwich. This is Radio Lab, the podcast. It is almost New Year's. Actually, we were recording this a few hours before New Year's Eve. Well, it's not a few. I mean, today's Monday, tomorrow night, so... 50 hours. We have 50 hours left to 20. No, less than that, 20. Well, whatever. I just, because it's that time of year, I want to tell you a story about a discovery I made. Not me, I just learned about it from other people, but it has made me completely reconsider what a year means and specifically how big a year really is. How big a year. It what? How big a year really is. I don't know how was a year. Well, if you're confused now, I think I can confuse you even more. I'm going to begin this investigation by introducing you to a little creature in the sea called a coral. Coral's a shelly animal, a little creature. That's Neil Schubert. I'm a paleontologist, an evolutionary biologist at the University of Chicago. Just like a clam has an animal, a clam shell has an animal inside it, so do corals. A little fleshy, wormy thing? Exactly, and it wears its skeleton on the outside. And because they sit in the same place for their whole life, they're really sensitive to local environmental changes. Meaning what? Think about it this way. Let's just sort of think about what happens to a creature as it lives. It's life in the water, which is what these things do. You know, we live in a world of cycles, of cycles on cycles. Temperature rises and falls. Light rises and falls. The tides rise and falls several times in the course of a day. So you think about what that means for creatures living in water. What it means for corals, says Neil, is that they're growing. They're slapping on new skeleton, if you will, new shell. In time, with these cycles of rise and fall and light and dark, hot and cold, and-- Hello, hello. Hi. You can actually see these changes written onto their shells, maybe into their shells. Emily. Andy. And that's why Andy Mills and I called up our pal Emily Grassley, whose job is-- What is it? I'm the Chief Curiosity Correspondent of the Field Museum in Chicago. That's your actual title. The Chief Curiosity Correspondent, yes. It is. You brought some corals, did you? We have many corals. We have corals all over the studio desk right now. All right. All right. Let's cut it. Because when you cut into these shells-- Oh, it's warm. A little bit of water. We can spritz it on there and cool it off. Right off, you can see a pattern. You see these gray stripes. And they're all, I mean, they're all different variations of gray, but some are really dark gray and some are tan. They're like bands running either through or across the shell. They kind of radiate out like the bands of a tree. And between the bands, there are spaces. You got a stripe, then a space, a stripe, then a space, a stripe, then a space. But when you hold it up close to your eye, if you look closer in between the stripes, you can see sort of-- Wow. You can see the lines. Wow. You can see that the spaces are filled with faint little lines. And that's where the piece of this story is just so fascinating. Because in 1962, a paleontologist-- Professor John Wells was looking at some corals just like these. He was just sitting there saying, "Okay, well, what can we figure out from coral shells?" So what he did is he did something really simple. He says, "Well,cology, why don't I count the number of little lines between these bands, just, you know, just to see?" So he starts counting as, you know, 100, 200 lines, 300 lines, 310, 320. And every time he counted-- He got a number around-- Around 360, 365. Wait a second. Familiar number, no? Doesn't take a lot of inference that, hey, maybe those individual rings represent, you know, a daily pattern. Meaning each of these little lines actually equaled a day. And why-- They're not just making a gray mark after 365. What are the gray lines? Well, the thicker lines are the times of the year when the coral grows a lot. But if you've got a summer coral that it grows a lot of one summer, then it goes quiet. Then it grows a lot the next summer. So that's, again, that marks a year. Those big bands are kind of like, "Ah, nah, nah, nah, nah, nah, nah, nah, nah, happy new year, nah, nah, nah, nah, nah, nah, happy new year, nah, nah, nah, nah, nah, nah, happy new year." They're actually calendars and clocks
Transcription truncated.
At the start of this new year we crack open some fossils, peer back into ancient seas, and look up at lunar skies to find that a year is not quite as fixed as we thought it was.