Science Vs - Nuclear War... Total Annihilation?

Episode Date: April 19, 2018

Nine countries, including North Korea, have nuclear weapons. What would happen if a nuclear bomb was dropped-- say, in New York City? We talk to nuclear historian Dr. Alex Wellerstein, nuclear engineer Dr. Tetsuji Imanaka, and epidemiologist Dr. Eric Grant. UPDATE 04/27: We've adjusted this episode to correct the elevated risk of cancer in survivors of the Hiroshima and Nagasaki nuclear bombs. If you survived the atomic bombs your risk of cancer is 10% higher than someone who is the same age as you. Check out our full transcript here: http://bit.ly/2salOAK Selected readings: Alex’s nuclear weapon simulation website Tetsuji’s paper calculating the radiation exposure of Hiroshima survivors This review of the Life Span Study of atomic bomb survivors This sobering report on nuclear winter To find a list of our sponsors and show-related promo codes, go to gimlet.fm/sponsors This episode has been produced by Heather Rogers, Wendy Zukerman, our senior producer Kaitlyn Sawrey, Rose Rimler, and Shruti Ravindran, with help from Romilla Karnick. We’re edited by Blythe Terrell. Additional thoughts from Lulu Miller. Fact checking by Michelle Harris. Mix and sound design by Emma Munger. Music written by Bobby Lord and Emma Munger. Thanks for recording help from John Wild. For this episode we also spoke to Prof. Richard Wakeford, Dr. Richard Turco, Prof. Brian Toon, Prof. Alan Robock, Dr. Dale Preston, Dr. William Kennedy, Dr. Jonathan D. Pollack, and a bunch of other experts on North Korea and nuclear weapons. Thank you so much. Also, special thanks to Shigeko Sasamori and Kathleen Sullivan. An extra special thanks to the Zukerman family and Joseph Lavelle Wilson. Learn more about your ad choices. Visit podcastchoices.com/adchoices

Hi, I'm Wendy Zuckerman and you're listening to Science Versus from Gimlet Media. This is the show that pits facts against fire and fury. On today's show, nuclear war. More than 70 years ago, the US dropped two nuclear bombs on Japan. One in Hiroshima, another in Nagasaki. It created mass devastation. And now there's talk the world could go through this again with North Korea.

North Korea best not make any more threats to the United States. They will be met with fire and fury, the likes of which this world has never seen before. Thank you. The North Korean nuclear threat got scarier when several months ago they tested their most powerful nuclear bomb yet. North Korea claims it has successfully tested a hydrogen bomb. This blast was so strong it had a magnitude of a 5.3 earthquake.

Donald Trump threatened to completely destroy North Korea. Kim Jong-un calls Trump a mentally deranged US dotard. Should we be worried? Experts say that this bomb is a lot bigger than anything that has ever been dropped on a city before. So what would it look like if North Korea actually dropped that bomb on the US? What would happen? Would cities be flattened and turned into ashes? On today's show, we're going to find out how bad it could get by answering the following questions.

1. What would it look like if a nuclear bomb was dropped on the US? bad it could get by answering the following questions. One, what would it look like if a nuclear bomb was dropped on the US? Two, what's the chance that radiation from that bomb will give you cancer? And three, is it possible to drop so many nukes that the Earth becomes uninhabitable for decades to come? Science vs Nuclear War is coming up just after the break. What does the AI revolution mean for jobs, for getting things done? Who are the people creating this technology? And what do they think? I'm Rana El-Khelyoubi, an AI scientist, entrepreneur, investor, and now host of the new podcast, Pioneers of AI.

Think of it as your guide for all things AI, with the most human issues at the center. Join me every Wednesday for Pioneers of AI. And don't forget to subscribe wherever you tune in. It's season three of The Joy of Why, and I still have a lot of questions. Like, what is this thing we call time? Why does altruism exist?

And where is Jan 11? I'm here, astrophysicist and co-host, ready for anything. That's right, I'm bringing in the A-team. So brace yourselves. Get ready to learn. I'm Jana Levin. I'm Steve Strogatz. And this is... Quantum Magazine's podcast, The Joy of Why. New episodes drop every other Thursday, starting February 1st. Welcome back. On today's show, we're delving into nuclear war

and we're asking, what kind of damage do these weapons really do? Last year, North Korea claimed to have tested a hydrogen bomb. That's a super powerful nuclear bomb. And this country talks a big game, but whatever they exploded shook the ground so much that people felt it over 150 miles away. So whatever they have is really powerful. And some say it could be a hydrogen bomb.

Now, there are still big questions about whether they could launch a big bomb and hit the US mainland. But what if, say, over the next few years, North Korea actually does get that technology and they can target, say, New York City, the densest city in the country? If they fired that bomb, what would it actually look like? Our senior producer, Caitlin Sori,

met Alex Wellerstein from the Stevens Institute of Technology in New Jersey, and they met outside the New York Stock Exchange in Manhattan. Hey, how you doing? I'm well. Nice to meet you. Alex has created simulations of what can happen to a city when a nuclear bomb is dropped on it.

So, Caitlin asked him, what happens if North Korea's bomb hits us, right here, around Wall Street? What do I see, initially? Just a flash. Bright flash. Bright, bright, bright, bright, bright flash. Like, maybe tinge a little blue. It's hotter than the sun, so it would look just blinding.

So it's essentially creating a mini sun on Earth. Yes, that's the sort of heat that turns sand into glass. A nuclear bomb can generate so much heat that it mangles granite. In a fraction of a second, this intense heat forms a fireball that rises into the air, leaving a mushroom cloud in its wake. And that cloud is massive. It will be bigger than any skyscraper by at least 10 times, maybe 15 times bigger. It's gonna make you feel small. It won't look like anything else you've ever seen. For anyone close to the blast, they'd be turned into... A charred corpse.

You're talking about enough heat to set things and you on fire. This heat from the fireball, this is actually what kills most people near the blast. That's what happened in Hiroshima. And even a few miles away, people could suffer horrible burns. It would be just shocking, right? I could imagine people being just dazed, injured, not sure what to do. It's eerie.

And then the incredible heat from the fireball would create what's called a blast wave, this wave of intense pressure that would push out more than two miles away. Where Caitlin is, just around the corner from Wall Street, everything would be devastated. Think of this as just a punching of air coming out. You're just heavy, heavy air, and it's just going to knock lots of things down.

And it's going to carry everything with it, like this police car, that hot dog stand. Everything just gets swiped. Swept away, swept away. And just at this level of closeness to it, yeah, just gone. Dust everywhere. Nothing.

Some people might be hurled against buildings. Others could be crushed by them. And windows would smash for miles, hurling shards of glass. And Alex says that this is actually why American school kids were taught to hide under their desks to duck and cover during the Cold War. It was to protect them from all that glass flying everywhere, not from radiation.

But if you're close enough to the blast, you will have to worry about radiation. Alex estimates that around three-quarters of a mile from the bomb... Anyone around is going to be hit with this invisible wave of radiation. You won't know it. In Hiroshima and Nagasaki, for people close to the blast, radiation ripped through their whole body, destroying cells in their skin, ovaries, testes, blood and

bones. Their hair started falling out and their stomach was attacked by the radiation, making them vomit. Because North Korea's bomb is thought to be much more powerful than the ones the US dropped on Japan, it's possible that the fireball would be so big that if you're close enough to the bomb to get a big bout of radiation, you actually wouldn't survive long enough to feel these effects. You would just burn almost instantly. And while it's difficult to predict this kind of thing, Alex estimates that if you set off a hydrogen bomb

above the New York Stock Exchange, just near Wall Street, you could kill about half a million people and injure about one and a half million more. And then, what happens next? Alex says... It won't end things. There will be a day after that. Not for everybody, but there will be.

And that's the really sickening thing to imagine. Millions of people around New York would survive the blast. They'll be far enough away. But what do they do now? Do they have to leave what's left of the city? Will toxic radioactive fallout shower down on them? Well, before we go down that road, let's just take a little detour. It's getting a bit heavy here.

So let's look at how cockroaches might survive a nuclear war. Yeah, let's take a look at the good old cockies. Because you might have heard that when the nuclear apocalypse comes, one creature will reign supreme. Cockroaches. But is that true? Well, to find out, scientists built a little cockroach-sized nuclear bomb, and then they exploded it into a little cockroach-sized city. No, not really. Instead, they exposed hundreds of the poor dudes to radiation. And by doing this, they found that cockies, on a good day,

could handle roughly 40 times more radiation than you and I. Now, that might sound pretty impressive, but get this. There's a cheeky wasp out there that can handle nine times more radiation than a cockroach. And because of this, one entomologist called cockroaches wimps. Harsh, but fair. Still, there's something else out there that can handle way more radiation than both of them. It's a death-defying bacteria

that can happily live in radioactive waste. Ha! Take that, you cockroach reigned supreme during an apocalypse. Myth. OK. So now, back to humans and the devastation. We know that if a nuclear bomb were to drop on a city like New York, hundreds of thousands of people would die almost instantly from the heat. For others, they might be hit by flying objects from the blast.

And if you survive all that, the danger isn't over yet. You still might be hit with something. Something that really freaked out Americans during the Cold War. Danger will come not just from blast or heat or nearby radiation effect, but also from fallout. Fallout. Fallout is radioactive material that can get swept up into the air after an atomic bomb

and then rain down on cities miles away. And there are fears that fallout can contaminate the land and the water for years to come. How will you know if there is fallout can contaminate the land and the water for years to come. How will you know if there is fallout? You can't hear, smell, taste or see the radiation. And these bits of matter can be dangerous. How dangerous, though? Well, to find out, reporter Heather Rogers called up Tetsuji Imanaka, who grew up in Hiroshima.

Hello. Hi, Dr Imanaka. Hi, good morning. How are you? Tetsuji was a nuclear engineer at Kyoto University in Japan. He's recently retired, but had spent his career studying radioactive fallout. And understanding the danger of radiation had high stakes for Tetsuji because his family was affected by the nuclear bomb.

His mum was just a couple of miles away from the blast in Hiroshima, on the south side of the city. At the time of atomic bombing, my mother was the south part of Hiroshima City. And she was behind a small hill. And that small hill shielded her from the blast. Being a nuclear engineer, Tetsuji actually calculated her dose of radiation. And he says she barely got any. Initial radiation was almost zero, I'm sure.

Almost zero. But the morning after the bomb, Tetsuji's mum actually headed back into what was left of the city. Tetsuji's grandmother had been in Hiroshima during the explosion and his mum wanted to find her. Amazingly, she did. Tetsuji's grandma was in really bad shape, but alive. She felt so happy at that time. It was very strange. She felt, my mother told me. Why does that make you laugh? Yeah, yeah, yeah.

This is a Japanese way. Yeah, very sad thing. So, so devastating. It's difficult to say. Tetsuji's grandmother was so close to the bomb when it went off that she was exposed to a lot of radiation and died a week later. Now, all that radiation came directly from the bomb. It wasn't fallout.

But to find out if Tetsuji's mum was safe, he needed to know how bad the fallout was around Hiroshima. And he told Heather that his mum actually didn't get exposed to that much of it. So, not so high. Two or three times CT scan. So it's like as if she had two or three CT scans. Yeah, yeah, yeah, yeah.

And for the most part, fallout from Hiroshima or Nagasaki didn't come down in dangerous concentrations. And to understand why, you have to know this curious thing about nuclear bombs. When it comes to fallout, it matters where in the sky these bombs blow up. And in Hiroshima, as well as Nagasaki, the bombs exploded in the air, hundreds of metres up. Fireball didn't touch the ground. Since the fireball didn't touch the ground, Tetsuji calculated that that meant a lot of the radioactive contamination didn't fall on the city. Instead, it went up into the atmosphere.

So basically, the land isn't ruined, the soil isn't ruined, the water isn't poisoned. Is that true? Such case in Hiroshima, that's true. So almost radioactive material went up to the sky. Up into the sky. In fact, tiny bits of radiation ended up spreading out thinly all across the globe. Some scientists found traces of Nagasaki bombing in the Arctic. Yeah, radioactive particles from the Nagasaki nuclear bomb were found in the Arctic. Yeah, radioactive particles from the Nagasaki nuclear bomb were found in the Arctic.

But here's what you have to know. These radioactive particles are found in such low doses that they're not believed to be harmful. There are no radioactive polar bears in the Arctic. The radiation is not dangerous now. And so the reason why the fallout wasn't that dangerous in Hiroshima and Nagasaki was because the bombs exploded in the sky. But Tetsuji told Heather that if those bombs had exploded on the ground, it would have been a completely different story. The radioactive contamination would have been really bad. Really bad, bad. Strong contamination.

And so if that happens, then you probably can't, like you won't be able to grow food there. Yeah, yeah, yeah, yeah, yeah, yeah. So big problem. And why is it so bad if the fireball hits the ground? Well, that huge fireball is filled with radioactive particles. And when it hits the ground, it drags tons of soil and burnt rubble into its fiery blaze, which then goes up into the atmosphere. And because that soil and rubble is relatively heavy, it can fall out of the clouds as radioactive dust. Fall out. Fall out.

We know this because during the Cold War, the USSR and the US dropped a bunch of test bombs. And some were detonated really close to the ground. And they ended up contaminating places miles and miles away. So when the US detonated a bomb just seven feet from the ground at Bikini Atoll, a strong wind blew that radioactive fallout onto nearby islands. And it was so bad that almost 300 people got acute radiation poisoning.

But will the landscape be contaminated with radiation forever after a nuclear bomb? Well, while there are some types of radiation that can stick around for decades, most of it actually decays fairly quickly. So, for example, in Hiroshima, while there was this intense blast of radiation as soon as the bomb exploded. Just one day later, it was a thousand times lower. A year later, radiation levels in Hiroshima were pretty much back to normal. Tetsuji's mum ended up staying in Hiroshima her whole life. She had three sons and lived to the ripe age of 86, eventually dying of lung cancer. And it's cancer, so you have to wonder,

could it be from the radiation of the bomb? After the break, the long-term effects of a nuclear bomb. Is cancer how it'll get you in the end. Welcome back. We just found out that most of the deaths from nuclear bombs come not from the radiation, but from a huge fireball and even intense pressure, which can shatter glass for miles. There's also the danger from radioactive dust that could fall from the sky. But what if you lived through this kind of attack,

the fireball, the glass, the rubble? What happens years later? Because nuclear bombs can spew radiation across a city, and we know radiation can cause cancer, does that mean you and everyone you know will go on to get cancer? There's a lot of fear of radiation. When I grew up, this was one of the big fears in life. This is Eric Grant, and he's been studying the effects of radiation on people for decades. He's American, but he lives in Hiroshima

and still remembers when he first came to the city back in 1985. You know, I was a bit nervous about it, actually. What was it like? We did this? Is that the feeling? I guess so. You know, it was all-out war and the United States dropped that bomb, and a lot of people died, and here I was.

Eric now works at the Radiation Effects Research Foundation, which has a study which tracks the health of tens of thousands of atomic bomb survivors. And if you want to know if a nuclear bomb will give you cancer, this is the study to look at. It's been going since 1950, just five years after the bomb hit, making it one of the longest public health studies in the world. And it actually started out as a US military operation. And the United States is very anxious to learn how effective the weapons were.

Wow, but it was born out of the military wanting to know how dangerous their weapon was. That's exactly right. And I think there's still some underlying resentment. And the way they recruited survivors for their study probably didn't help. Japan was still occupied by the US in those days. We did have our own fleet of Jeeps,

and they used to crawl through the city and interview people for where you were at the time of the bombing and where was your husband. The US military would go to these centres where people asked for food rations, including pregnant women. And when they came to that window and said, I'm pregnant, I'd like this extra ration of rice, people would approach them and say,

congratulations on your pregnancy, we would very much like to see how your child does. The study ended up recruiting around 120,000 survivors and would eventually split from the military, tracking cancer rates in those survivors for decades to come. So, what has it found? Did the atomic bomb increase the risk of cancer for these people? Eric says, yes, for cancers in all sorts of places.

Your lungs, for instance, or your breast or your liver. But there was one cancer that was spotted almost immediately. Leukemia. This is the first thing that they saw. Especially among children, you seem like you're doing great, and then five years later you get a leukaemia. And this was considered the A-bomb disease. So leukaemia showing up in kids is pretty scary.

But the actual number of people who got leukaemia as a result of the bomb, well, it wasn't as high as you might expect. Eric and his team have found that out of the tens of thousands of survivors, only about 100 more people than usual got leukaemia as a result of the bomb. So your chance of getting leukaemia if you survived Hiroshima was actually really, really low. So not huge numbers. Wow. So the rates really are quite low. Right. That's right. That's exactly right.

It's lower than people generally think. So that's leukaemia. What about the other cancers? Well, Eric says that his study found that if you survive to Roshima or Nagasaki, your risk of cancer is about 10% higher than someone who's the same age as you but wasn't around the bomb. Chances are you're not going to suffer a cancer that was due to the

radiation exposure. Well, Eric wants us to be careful with this stat. It's an average of the survivors in his study. And he says that overall, the more radiation that survivors got, the higher their cancer risk. Plus, this study started five years after the bombs went off, so there's a chance that some people got cancer and died before it started. Still though, on average, it does seem that the number of cancers from Hiroshima and Nagasaki was relatively low. There were other concerns though. Because nobody really knew how radiation from the bomb would linger, there were fears that the effect of radiation could be passed down to the next generation, the children of the atomic bomb survivors, people like Tetsuji.

Well, Eric's study, which has now followed more than 75,000 kids of survivors for half a century. Actually, can't find any increased risk of cancer in these kids. So we haven't seen those effects, which is one of the silver linings, I guess, with this whole story. From your study, you know, it made me think that nuclear bombs aren't as dangerous as I had thought. I guess when you think about the long-term health effects of the atomic bombings, you're right that radiation risks of cancer are not as high as initially thought. And we don't see generational problems.

So those two things are true. But the initial weapon is devastating and will take out huge portions of populations in cities. Okay, so from what we found out about the bombs in Japan, it does seem that decades later, the radiation they left behind wasn't as scary as we'd initially thought. Hiroshima and Nagasaki were bombed at the start of the nuclear age, though. 70 years on, it's a very different world that we live in. Nine nations now have nuclear weapons. And if one nuclear bomb got dropped, that might not be the end of it.

It'd probably lead to retaliation, with more and more bombs. And maybe even an all-out nuclear war. And some scientists have argued that this wouldn't just mean devastation for the two warring nations. It could have serious consequences for the entire world. During the Cold War, this was something that Carl Sagan talked a lot about. Here he is speaking on CNN.

So it now appears that nuclear war almost certainly will destroy the global civilization and might just possibly destroy the human species. Destroy the human species. And here's how. Some scientists thought that a nuclear war could lead to a world where the skies would turn black, the world would go cold and you couldn't grow food. People would starve to death. It was called a nuclear winter.

And during the Cold War, it even got the attention of Presidents Ronald Reagan and Mikhail Gorbachev. But is this idea of a nuclear winter based on good science? I mean, I know Carl Sagan is like a science god and stuff, but maybe he went off the rails with this one. Well, what is supposed to lead to a nuclear winter isn't radiation. It's actually smoke. You see, nuclear bombs create so much heat that they burn skyscrapers, houses, bridges, and all of that fire creates all of this smoke that then goes up into the atmosphere.

Here's our nuclear war researcher, Alex Wellerstein, again. The idea is if you burn enough stuff, you'll put up a lot of smoke. You put up enough smoke and you start to reflect sunlight. That black smoke absorbs some of the sun's energy so it can't reach Earth. 200 years ago, a big volcano blew up in Indonesia and it cooled the world by about half a degree Celsius for a year. This became known as the year without summer. So if the ash from one volcano could cool the earth a bit, what would happen if you had the smoke from the fires of an all-out nuclear war? Now, will that be enough to actually alter the climate and put you into a state where, like,

you start having a really cold all year round and global famines and things. Well, research suggests that to cause a nuclear winter, you've got to throw a lot of nuclear bombs, like a lot of nuclear bombs. One researcher from NASA calculated that 100 Hiroshima-sized bombs would drop the temperature of the world by a little over a degree Celsius. That's almost two degrees Fahrenheit, and that would last for several years. So bad, but not enough to destroy the human species. A report from the National Academy of Sciences said that a large-scale environmental catastrophe would only happen if thousands of nuclear weapons

were detonated. The truth is, though, we don't know exactly how many bombs we'd need to throw the world into a nuclear winter. For Alex, he says even though the science isn't perfect here, it is good enough for us to start asking this question. Do we need thousands of nuclear weapons? Only two countries have thousands. Everyone else has hundreds.

And those two countries are, of course, the US and Russia. It's estimated they have roughly 10,000 nuclear weapons between them. So theoretically, it is possible that they could plunge us into a nuclear winter. So when it comes to science versus nuclear war, does it stack up? One, if North Korea dropped a nuclear bomb on New York City, perhaps half a million people would die, mostly from the heat and flying fragments, not from radiation. Two, how dangerous is radioactive fallout?

Well, it depends on where the bomb drops and where the wind blows. In Hiroshima and Nagasaki, the fallout actually wasn't that harmful. But if a bigger bomb detonates on land instead of air, that could be a different story. And three, finally, is it possible to drop so many bombs that the Earth becomes uninhabitable for decades to come? Well, if thousands of bombs were dropped, it might create enough smoke to affect the climate of the planet.

And the US and Russia? They probably have enough bombs to do it. That's science versus nuclear war. This episode has been produced by Heather Rogers, me, Wendy Zuckerman, our senior producer, Caitlin Sori, Rose Rimler, Shruti Ravindran, with help from Romila Karnik. We're edited by Blythe Terrell. Additional thoughts from Lulu Miller. Fact-checking by Michelle Harris.

Mix and sound design by Emma Munger. Music written by Bobby Lord and Emma Munger. Thanks for recording help from John Wild. For this episode, we also spoke to Professor Richard Wakeford, Dr Richard Turco, Professor Brian Toon, Professor Alan Robach, Dr Dale Preston, Dr William Kennedy, Dr Jonathan D. Polak and a bunch of other experts on North Korea and nuclear weapons. Thank you so much. Also, a special thanks to Shigeiko on North Korea and nuclear weapons. Thank you so much.

Also, a special thanks to Shigeko Sasamori and Kathleen Sullivan. And an extra special thanks to the Zuckerman family and Joseph Lavelle Wilson. Next week, we're tackling the ketogenic diet. Can you become your best, healthiest self by eating bucket loads of fat? If a drug did everything that the ketogenic diet did, it would be an enormous blockbuster drug worth billions of dollars. I'm Wendy Zuckerman. Back to you next time.