Red Herring

Rod and eggs, volcanic gas, death and decay. What do all these things have in common? Hey, it's me, Matt Kilti. Join Radio Lab on Wednesday, August 26th, for a live podcast taping of viscera gripping tails of the human body, where we will grab a hold of a long overlooked, much-maligned chemical element an element that can be found from the hospital room to outer space. Join us Wednesday, August 26th at 7 p.m. at caveat in New York City to learn how the smell of death might actually be the surest sign of life. Find out more at caveat.nyc/radiolab. Hey, it's Lulu. This is Radio Lab and it's summer. In the past, there has been hot girl summer. There's been hot vac summer. This summer arguably is kind of turning into hot diarrhea summer. The one that no one wanted. But we here at Radio Lab are offering you something different, which we are calling cold war summer. Or I'm calling it that because we just realize this will be our third story that involves the cold war in a month. This one is really special. We're bubbling it up from the archives. It's a tale of espionage. It's a real who'd done it that involves submarines, periscopes, hydrophones, a bunker. And I didn't see the answer coming. Enough out of me. Let's jump into this tale. Comes from the archives, was reported by Annie McEwan. And it is called red herring. Yeah, wait, wait, you're listening. OK. All right. OK. You're listening to Radio Lab. Radio from WNYC. Hello. I'm Lulu Miller. This is Radio Lab. And today, boom, boom. Oh, hello. Hi, a story from producer Annie McEwan from her bathroom. I'm actually like straddling the bathtub here. So good thing I did a year over the last night. I do think our thing is like underwater mysteries from the '90s. Yes. OK, so today I have a story. It's like a Tom Clancy international underwater spy thriller with a little spicy science thrown in. All right, I am grabbing my popcorn. Take me away. Yeah, OK. Let's begin with-- Yeah, OK. Thank you, Magnus. Magnus. Not wrong, yeah. How do you pronounce your last name? It depends on where you come from. So most Americans would say Valberg or Valberg or something like that. What do you say? Well, that's also depends in Sweden. It's Val, Barry. Oh, wow. But in Denmark, it becomes a bit more like Vailbauer or something. Wow. Yeah. OK, anyway, Magnus is an associate professor at the University of Southern Denmark, where he studies underwater sound. So let's start off in 1981. Yes. Let's go back to that time. Yeah, so that's a defining year. How old are you? I was 13 years old, and I was living in Stockholm, the capital of Sweden. OK. And it was an extremely tense period. Because in Stockholm-- You know, we had the Baltic Sea right in front of us. There was only about 140 miles of water separating Sweden from-- The Soviet Union. And Magnus said to him, and a lot of other Swedes, there was just this fear of what was on the other side of the water. I remember this still in the school. You had a map, you could see all the details of the Western Europe. Small towns, all these roads, the colors of different countries. And then across the Baltic, it was just white. There was just nothing. And that was Soviet Union. We didn't really know even what was there. Just this mysterious nothingness. Yeah, and not very far away. Now, Magnus says it's important to know-- And Sweden was this kind of island politically, because Sweden was neutral. But because of a lot of this mystery, a fear of communism, there was always the sense that one of their greatest threats was the Soviet Union. We heard about it all the time. We were even practicing a little bit in school. And we were really living in a time when we were worrying about a nuclear war almost daily. So 1981, the defining year, it's late October. Sort of when it gets really dark here, and cold and damp. It's about four in the morning, pitch black. A fisherman leaves his home, gets in his boat, and heads off to check his nets. Sweden has this super long coastline that's filled with these really complex inlets. Full of islands. There are rocks like granite islands everywhere. And just as the sun is starting to come up, this fisherman makes his way into one of these rocky inlets. And all of a sudden, out of the darkness, looming up out of the water right in front of them. There is this big Russian stop standing there. It's huge. It's like this long, almost bullet, dark bullet in the water. And it is like towering out of the sea. Just sitting there. It's insane. What was it doing there? Exactly. So-- The fisherman called the Navy. And we all woke up to the news. Soviet submarine beached unsweetened shores. It's a huge story, like, all the papers right about it. And everyone is like, what on earth is going on? So the military comes down at their helicopters, circling overhead, many, many boats. But at this time, Sweden was-- people would also say we were incredible naive, because we didn't have any wars for-- The last war was like 18. It was like, yeah, it was like Napoleon wars. We didn't really-- we're involved in anything. So Magnus said the military sent some guys out to the submarine. And we kind of knocked on the door of the submarine. Wait, they knocked on the side of the sub? I don't know if they knocked. But they kind of asked kindly, can we come in and have a look? And they said, no, no, of course not. And then they said, oh, OK, sorry about that. But some-- there were some clever physicists. They parked a small boat beside of the sub. And through some clever measurements, they could measure that there were nuclear weapons inside. Oh, scary. You know, we have these defining moments for a nation in the states. You have the Kennedy murder, the 9/11. And this is one of those for Swedes. And people started immediately to say, hey, this is war. Like, we are in war. And eventually, because again, maybe we were too soft. What happened is that the commander of the Soviet sub told the Swedish military that all of their navigation instruments on board had malfunctioned all at once. Sort of sorry, we navigated wrongly. You know, we lost our way. We ran ashore. Like, we made a mistake. Yeah. So the Swedish military sent a bunch of ships out to the sub, pulled it off the bottom. And they returned it to international waters. And it left. And for a 30-year-old magnus. It was super weird, because you could see that adults and the politicians, everyone, were completely, how to say, like, taken where their pants down, right? It was like, what? No one could, of course, explain this. So the navy, of course, they got a lot of money. So they became more vigilant. They had to now start to see if they could, you know, could they protect the Swedish coasts? And, you know, it's not an easy thing to do. It's a huge coastline over 1,000 miles. So how do you, like, patrol that? And an obvious way to do that is with sound. Forget ships and sonar. Sounds propagate very well on the water. We're just going to listen for the subs. Yeah. Does that mean they, like, they hung hydrophones on buoys out in the water at the all along the coast? Like, just, just a whole bunch of them? Well, not everywhere, of course. But it started to listen into this more carefully after all the politicians promised us that now we have bought all these gears. And now we are ready to tackle this problem and, you know, no problem. And, you know, then we went into sleep again. And then in October 82, we had the next wake up call. This time in this big harbor. Very close to Stockholm. Right outside of a Swedish naval base. People started to see periscopes. One after another, after another, after another. Hopping up out of the water. And the Swedish military was like, we have detected them, and we have them. So this time, the Swedes send in a bunch of ships. With nets? These big metal nets that they used to block the exits of the harbor, so there's no way a big sub can get out. And then they send in a bunch of helicopters that have hydrophones. And they dip those hydrophones into the water. And they start listening for submarines. And before long, one of those hydrophones would pick up the unmistakable sound of a Soviet sub. And what does that sound like? I'm going to get to that. But what happened is when the Swedes heard this sound, they would drop a bomb from the helicopter. They would hit the water, sink down to a predetermined depth, and then big explosion. And helicopters and the ships, they would just wait to see if the explosion would damage or scare one of the Soviet subs up to the surface. And so they waited, and waited, and nothing. No Soviet sub-emergency. Not even a piece of one, and this Swedish military kept this up for a month, chasing down subs they hear, dropping bombs, and by the end of the month, nothing comes of it. They don't capture a single submarine. What? I know. Isn't that crazy? Did they just somehow get out of the barricade? They don't know. They don't know. I mean, I guess they could even be down there today. They could have hurt the sub, the sub fell, the sub filled with water, they could be down at the bottom of the harbor. I guess these are just, this is just a huge harbor, and they just couldn't really find any evidence of any Soviet sub. Yeah. It just ended in nothing. And then things started to get more and more bizarre. So through the 1980s, every half a year or every year, we would have these submarine chases. So all of a sudden, somewhere on the coast, the military would have given alarm. Oh, there is a sub, and then you would have these helicopters, bombs, nothing. Really? And then six months would pass. Once it was right outside the Royal Castle in Stockholm. So were people getting like annoyed, like, come on, crying off a little bit, or are people still very afraid? I think, you know, the Cold War is still going on. Magnus said there was just this fear. The bear is coming. You know, the Russian bear is coming. We just have to spend more money to find them. Were they still seeing periscopes? Yeah. So that's the thing. What did they see? What were they hearing and seeing? So they started to ask people, if anyone sees something, you should report it. Call this number. Call this Swedish military. And they got tons of calls. Many thousands of observations. But then the problem is, it's just like on a crime scene. If you ask people to say what they saw, it's a long structure sticking up from the water. So is that a periscope or is it a boat? Could be a small whale. It could be a sub. But who knows? So what the Swedish military did is they came up with this ranking system for observations. On one end, you had ranked six. Six is, we cannot tell. No one knows. Could be anything. Okay. And then you have like rank one is a definite sub. Definitely a sub. Okay. Now, the thing is, for a rank one, definitely a Soviet sub, pretty much every time in the report, it said, we heard the typical sounds, the typical sound. We heard a typical sound. What is a typical sound? So when the typical sound is basically when the Swedes were sure that they were encountering a Soviet sub, those hydrophones in the water would always pick up this particular sound. It was called the typical sound because it was believed to be the sound that, you know, just like a typical Soviet sub would make. And so anytime the Swedish military encountered that sound, it was automatically giving a one. It meant that encounter was 100% a sub. And then the whole, oh, sorry, go. And do we know what that sounds like? Well, not yet, because it's classified. Yeah. No one could listen to this sound and no one could knew what it was. But all the hydrophones were picking up the, they were picking up the typical sound. For years. Yeah. I kept hearing the secret Soviet sub sound in their waters. So then the strange thing happens, right, in 1989, everything is changing. Thousands and thousands of West Germans come to make the point that the wall has suddenly become irrelevant. The iron curtain falls, the Berlin wall falls. You know, everything opened up and all of a sudden, over one night, basically, the world has changed for us. Changes were just sweeping across this continent. It's something unreal for me. All these places that had been almost impossible to go to, were all open. It's as if that white blank space on the map was starting to actually get some color and shapes and names. But while all of this is going on, something very weird is happening. Because the Swedish military is continuing to report hearing the sounds of Russian submarines invading their waters. 20, 30 incidents every year. And Magnus said by 1994, at that time, we had a prime minister Carl Bildt. And he got so upset about this. He wrote a very angry letter to Boris Jeltsin saying, "Now you really have to stop. Now you have created your own country and the first thing you do is to try to occupy Sweden." Or stick of this. Stop. But Boris Jeltsin's like, "I don't know what you're talking about." Jeltsin said, "Well, we are, of course, not there. You can see all our subs are on land. What are you talking about? You're crazy." He denies everything. So as this whole mystery is unfolding, Magnus is watching from the sidelines. And by 1996. You know, at that time, I was a university student. He's studying underwater biological sounds. And I got a job in the fishery department, because my mentor, he was sort of the, he was called Hawke and Vesterberg, he still is, he's still around. That's Hawken. Retired oceanographer and fisheries biologist. I started with telemetry acoustic cracking in the 70s. And he was one of the few in Sweden who really was an authority on underwater biological sounds. And one day Magnus is standing in Hawken's office. I was quite fresh on my job. When the phone on Hawken's desk rings. He was not there. And I just took his phone and they, you just answered the phone on his desk? Yeah, yeah. But we had a very, we had a very colligial relationship. And on the other end of the line, it's the Royal Swedish Navy calling. They said they wanted to talk to my boss, of course. But then because he wasn't there, they started to talk to me. And they said, well, they are forming this committee. This top secret government investigation. They would like me and my boss to be a part of that. So they say, yes, there's a background check. Yeah, and cleared by the secret police. They were very secretive. And then he and Hawken are on a train to Stockholm. To this hugely naval base. It's just like in a James Bond movie. You have a whole submarine base inside the rocks. Wait, what? You can sort of open the rocks and you'll go in there with your boats and you can have boats inside. How do you open the rocks? Boats inside? I don't know. Do you have some big rock door or something like that? Yeah. Yeah, something like that. What? So we went in there and you know it. So Magnus and Hawken who are not totally sure why they're there are winding their way through this military base. Long tunnels. Two Navy captains were our liarsons. Yeah. And eventually. You come into this meeting room with all these electronic gadgets. It's a lot of recording equipment. They have a world map and they can follow the whole world from in there. Kind of like mission control at NASA. It was super exciting. Finally, they take their seats at a long table. And sitting there around the table are a bunch of other academic types like them. But they were also some very high rank military people. So it was really like a wow moment for me. And we were sitting down there and then they said, well, ladies and gentlemen, you are the first civil people who were listened to this sound. The typical sound is famous sound then. So now we will actually play the typical sound for you. So it's been top secret for the last 15, 15 years. For 15 years. Yeah. No one has been, no one outside the military was able or allowed to listen to it. Wow. So were you excited? Extremely. Of course. This was like, wow. Being the said he expected to hear was something like, you know, what he'd heard in the movies. You know these movies when they sit in a shop and so I was thinking it must be something like that, right? But then one of the Navy officers turns to a tape recorder and hits play. And this is what comes out. Huh. God, is it, are they picking up voices? Are like radio static? Oh, so that's always what it sounds like. Yeah. This is the sound they've been recording every year since that first sub showed up. It's intriguing. It sounds a bit like a few Donald ducks at a very long distance. What? What do you mean? Well, you know, like Donald Duck, this kind of his voice. If you imagine you had like 10 Donald ducks and they would be maybe like 100 meters away or so. I think it would be something like that. And it also sounds a bit like an old shoe that kind of gets like, oh yeah, it has this squeaky part to it. And then we are sitting there with all these generals and they are playing this sound. Did you look around the room at the table of scientists and military people? Well, everyone is sitting there and you know, all these professors, they were kind of stiff upper lip. So they were just sitting there and listening kind of carefully. But my boss, he's more like, he's a very relaxed guy, you know. I think we looked at each other with a very confused gaze. But we were kind of keeping a stiff face also. Oh yeah, yeah, yeah. Cool. Gotta play a cool, yeah. Yeah, exactly, yeah. So after they played the sound, the naval officers turned to the scientists and say basically, Okay, now that you've heard the typical sound, we'd like each of you to try it out. try to figure out who or what is making it. And even in that moment, sitting at the table, Hock and Magnus turn to each other, and they don't say anything, but they're both thinking, "This is very strange. This is definitely not the sub." After the break, Magnus and Hock and follow their intuition deep into a cloud of mystery. And they get to the bottom of it, or they get right up close to the bottom of the mystery radio lab and stay with us. Magnus and Hock and are standing outside, talking about the sound, and both of them find what this must be, a biological sound. But what? And then I remember saying to Hock and air bubbles. This sounds like air bubbles. If you think of a scuba diver who gets a whole pinched in his pipe, it's like an air bubble stream coming out of a hose, it sounds a bit like that. So their question is, which animal releases air under the water? Incredibly, you can find this hunch in New York City, but it helps to have a car. And a friend. So I called up producer Matt Kilti, who's a friend with a car, and I also brought a large bucket. Okay, so, I only told Matt we were driving to the Hudson River. That was it. Okay, so we're taking the bridge. Yeah, yeah, yeah. We drove through Brooklyn, over the Manhattan Bridge. Okay, so now that we're. Is your cup. Is this the couple? Uh, it's my one cup holder. Drove up Manhattan, up to the riverfront. We can sneak and look for parking. Oh, there's a firehider right there. For a while. I don't know if I could park. A long while. It's a red light. How many firehiders do you need on one block? It's a red light. Oh my god, that's a spot. Good on rivers, like some. We're on riverside, right? Okay, let's go up it. There's no parking any time. This is not gonna work any time. Well, how long are we gonna be here? I don't know. We need to wander around a bit. I don't even know what we're doing. I'm looking for parking. What are you? What are you? Can you just. What are you looking for? What was a hunch? Yes. Okay, so we got down to like the rocky shoreline of the Hudson River. That was a piece of a dead fish. That might be a whole fish. Where we found it. Herring. Herring fish. I think that evening we were like, let's try herring. Oh my gosh. Can we get down there? So, for reasons that will become clear very soon, I tried to buy herring, but you can't buy fresh herring in New York City in December and so I dragged Matt out to the Hudson River because I had read in an article that herring fish had been washing up dead on the shores of the Hudson. Hmm. And nobody really knows why. It could be pollution. It could be water temperature. So, unclear. Exactly why that happened. And you know what you're looking for. Like, what exactly does a herring look like? Oh. Okay. Yeah. So. How am I going to pick it up? That is the question. I picked up this dead one we found. Yes, I'll just put my hands around it. Oh. And. Very slippery. Whoa. Herring are. Very big. I don't know, maybe 10 inches. It's a big dead fish. Shiny. Wow. They are the silver of the oceans because they are all these reflections from their scales. They just kind of look like if a kid drew a fish, it would be this fish. Yeah. But the really important thing about a herring, the whole reason why Magnus and Huck and had this hunch is because of what is going on inside of a herring. Now, Lou, I know you've written a whole book about why fish should not be called fish. But have you ever wondered how does a fish just float around in the water? I don't think I have actually wondered that. Let me go ahead and tell you. So it turns out in most fish, they have this thing called the swim bladder, the swim bladder. The swim bladder, which is basically this tiny sack, filled with gas, but regulates the fish's buoyancy, similar to the buoyancy tank of a submarine. So if you're a fish and you want to go up or down in the water column, you do this by either pulling air into your swim bladder sack or pushing it out. Then most fish do this through their bloodstream and their gills, which means it's quiet, silent, like basically invisible. But not the herring. The herring is different. Yeah. The herring is special because they have a canal straight from the swim bladder to the anal opening. So when a herring needs to get air out of its swim bladder, it basically pushes it through this canal, out its butt into the water, and Magnus says when this happens, you will have this sort of small string of air bubbles, which yet a hunch might just sound like bubbles coming out of a hose under water. Yeah. So his guess is like this submarine sound is actually just bubbles that come out there but oh, so his guess is fish farts. Technically, these are not farts because they do not come from like digestive gases. Okay, but this makes me feel better. I feel like I can continue to engage with this story with them. Are you like anti-fart or something? I'm just very grossed out by them. Yeah. Like I just, are you not? No. Well, how are you? Why are you? It's like even saying the word makes me like, I'm like, I don't want to be in this space even linguistically, let alone a real aromatic thing. This is like, wow, this is so interesting. I would never, how are you not? Because they're the funniest thing in the world because they're a thing we all do. If we can't, that's upsetting. They make you feel better immediately. Like even animals like find them funny kind of, I don't know, they're just, they're wonderful. They connect us all. They connect us all. They connect us all. Okay. I am, you're, I just appreciate the meaning you draw while also being simultaneously relieved. These are not actual farts carry on. Okay. So, Hawken and Magnus, they now have their like fish farts theory, but now they needed to figure out, did the fish fart actually sound like the submarine sound? And we approach that roller crumbly. Basically Magnus went to a fish shop, bought a couple of herrings. They were dead. What sort of lab? Rigged up the hydrophone. Okay. And then Magnus took this herring, submerged it underwater. And I squeezed it. It's so weird to squeeze a fish though, it's very weird. But I squeezed it pretty hard. I don't think anything is coming out. And you just kept squeezing it. So it was like kind of, oh, what is, it's, I made it poo. It was like a really big blur of, you know, hearing poo and things coming out. I'm sorry. Okay. Toss them over. So then, you want to squeeze one? Hawken tried. You should get this feeling. It's a weird feeling. Maybe it'll be lucky. I got the magic touch. Really? I got the fart fingers. He put the herring in the water. Gentle. Gentle. Gentle. Gentle. A little butt. And then, oh. Oh. It did. Bubbles. Such bubbles. It was a tiny little bubble. Okay. That's good. You do with fart fingers. And then you would hear this kind of very airy, poppy sound. This kind of the perfect typical sound we thought. Turns out, they thought wrong. Because when they look at the recording of the fish fart, compared to the recording of the subsound, they just, they don't really match. Absolutely not. Okay. This is just becoming very depressing. But I mean, this is a dead fish in an aquarium. So then, they went out into a bay with this little tube. Connected to a vacuum pump. Oh no. Managed to get a wild herring in there. Got a different. Yeah. That sound didn't match. No. But then, they had this thought. We need to get more realistic here. We need to get out into the wild. Because herring aren't solo fish. They travel together in schools. These schools can be huge like a square kilometer. Like, sometimes we're talking billions of fish all traveling together. And so they thought, if we're right about this, the sound we're looking for isn't the sound of one fish farting. It's the sound of a lot of fish farting. Oh, like a lot, a lot. Yes. And, you know, we were working for the fishery science in Sweden. So we knew a lot of fishermen. And they would tell us, when herring goes into a net, they get stressed. And the net starts boiling, they say. Wow. So Magnus follows this clue onto a boat and out to a fishing trap. Beneath him in the shadow of the boat, he could see thousands of herring just swimming around down there. I put the hydrofoam in the water. And. Huh. The typical sound. The whole box was just singing of these sounds. It was just incredible. It was just his cacophony of hearing. Wow. Their findings were harder for some members of the Navy than others to accept. I mean, there were people that their whole career was chasing submarines. But finally, in 1999, it became official. The typical sound that had haunted the Swedish Navy for over a decade was not made by Soviet submarines. Instead, for over a decade, the Swedish Navy had been straining their ears to hear the sound of thousands and thousands and thousands of hearing, all farting, oh my god, together. Okay. So that was the end of the typical sound? Man, I just can't believe you guys so quickly had all these ideas. But why did the military not think for 15 years? Are there no scientists in the military that would have any of your experience? Or like, why was it? Yeah, so I think they didn't have the know how. And the other thing is this whole thing of the military having this culture that you keep think secret, which means that it's very hard to have like an open, and it's very top down. So it's very hard to have an open discussion about like a scientific discussion going on around these topics. I mean, now I make it sound like they're very different from the rest of us. But in a way, there are just human beings. And you can easily wind yourself up in some kind of explanation. If you have a few authorities telling you how things are, you can easily start to collect evidence that that must be how it was. Magnus told me that the Swedish military actually used sonar to investigate this sound. And what they saw on the screen in front of them was that sound coming from an object. And then they would watch that object split apart. And then it could go back into one again. Whoa. And now we can guess that what they were probably seeing was the school of hearings, splitting apart, splitting apart again. But at the time, this was a Soviet sub. So they must have thought these subs are like super high tech. Exactly. They had people investigating how can it be that Russia can build a sub that can suddenly be decomposed into two and the four and then back to one. No way. You have like military scientists sitting and trying to build a model of a Russian sub that can sort of disintegrate into four. I mean, that doesn't make any sense. That is amazing. I think this is something to look after all of us in our times. That you can always laugh at it and say how wrong they were. But I wonder what people will think about us in 20 years. Oh, totally. I think about that all the time. Yeah. Like what is the fish part of today? Exactly. There's just one more little thing that I take away from this story. Because as I was doing research, I learned that hearing have just been fished forever. Yeah. It really fished. All these, it's going to even countries. They were built on hearing basically. Right. It's been what people have been eating and fishing for for thousands of years. Right. And not just that. Like cities have been founded on it. Cultures have been founded on it. Yeah. Like millions have been made. And these fish have just been like running for their lives for millennia. Yeah. And it's like in this one moment or in this one decade or period of time, like hearings just got back at humans in some way. And like sort of gave them a wild chase, you know. Yeah. And just for once they had the power and the upper. It played an important part of a concrete forum policy. Yeah. Yeah. Yeah. It's almost like in the end, this story is just a very long-winded fart joke on us humans. Yeah, exactly. It is. That's what it is. When did see what you did there, McEwen. This very long-winded fart joke was bravely reported by Annie McEwen and beautifully produced by Matt Kilty, Annie McEwen and Sarkari, with sound design by Jeremy Bloom, reporting and translation help from Magnus Ormstad. Huge thanks to Ben Wilson, who's done his own fascinating research into the hearing. Toots, and to Ola Tunender, Hans Gordon, Andreas Timmelstad, Klaus Helmersen, and Meg Bulls. Catch you on the flip, friends. May your sanity stay intact. And your wind broke in. Good. Hi, I'm Gabby. I'm from the Bay Area, California, and here are the staff credits. Radio Lab is hosted by Lulu Miller and Let's If Not Sir. Soren Wheeler is our executive editor. Sarah Sandbach is our executive director. Our managing editor is Pat Welters. Dylan Keefe is our director of sound design. Our staff includes Jeremy Bloom, W. Harry Fortuna, David Gable, Maria Paz Gutierrez, Sindu Nainasambandan, Matt Kielty, Mona Morgalker, Alex Neeson, Sarah Kari, Natalia Ramirez, Joanna Stroghats, Anisa Vica, Aryan Wack, Molly Webster, and Jessica Young, with help from Gabby Santas and Maya Applebee Milamed. Our fact checkers are Diane Kelly, Emily Krieger, Natalie Middleton, Angelie Mercado, and Sophie Semi. Leadership Support for Radio Lab Science Programming is provided by the Simon's Foundation and the John Templeton Foundation. Foundational Support for Radio Lab was provided by the Alfred P. Sloan Foundation.