TRANSCRIPT 🔗
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Hi, I'm Wendy Zuckerman and you're listening to Science Versus
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from Gimlet Media. This is the show that pits facts
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against fire and fury. On today's show, nuclear.
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War.
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More than 70 years ago, the US dropped two nuclear
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bombs on Japan. One in Hiroshima, another in Nagasaki. It
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created mass devastation. And now there's talk the world could
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go through this again with North Korea.
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North Korea best not make any more threats to the
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United States. They will be met with fire and fury,
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the likes of which this world has never seen before.
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Thank you.
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The North Korean nuclear threat got scarier when several months
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ago they tested their most powerful nuclear bomb yet. North
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Korea claims it has successfully tested a hydrogen bomb.
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This blast was so strong it had a magnitude of
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a 5.3 earthquake.
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Donald Trump threatened to completely destroy North Korea.
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Kim Jong-un calls Trump a mentally deranged U.S. dotard.
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Should we be worried? Experts say that this bomb is
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a lot bigger than anything that has ever been dropped
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on a city before. So what would it look like
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if North Korea actually dropped that bomb on the US?
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What would happen? Would cities be flattened and turned into ashes?
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On today's show, we're going to find out how bad
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it could get by answering the following questions. One. What
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would it look like if a nuclear bomb was dropped
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on the US? Two, what's the chance that radiation from
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that bomb will give you cancer? And three, is it
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possible to drop so many nukes that the Earth becomes
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uninhabitable for decades to come? Science vs Nuclear War is
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coming up just after the break. Welcome back. On today's show,
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we're delving into nuclear war and we're asking, what kind
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of damage do these weapons really do? Last year, North
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Korea claimed to have tested a hydrogen bomb. That's a
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super powerful nuclear bomb. And this country talks a big game,
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but whatever they exploded shook the ground so much that
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people felt it over 150 miles away. So whatever they
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have is really powerful. And some say it could be
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a hydrogen bomb. Now, there are still big questions about
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whether they could launch a big bomb and hit the
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US mainland. But what if, say, over the next few years,
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North Korea actually does get that technology and they can target, say,
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New York City, the densest city in the country? If
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they fired that bomb, what would it actually look like?
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Our senior producer, Caitlin Sori, met Alex Wellerstein from the
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Stevens Institute of Technology in New Jersey. And they met
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outside the New York Stock Exchange in Manhattan.
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Hey, how you doing?
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I'm well.
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Nice to meet you.
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Alex has created simulations of what can happen to a
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city when a nuclear bomb is dropped on it. So
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Caitlin asked him, what happens if North Korea's bomb hits
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us right here around Wall Street? What do I see initially?
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Just a flash.
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Bright flash. Bright, bright, bright, bright, bright flash. Like maybe
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tinge a little blue. It's hotter than the sun. So
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it would look just blinding.
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So it's essentially creating a mini sun on Earth.
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Yes.
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That's the sort of heat that turns sand into glass.
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A nuclear bomb can generate so much heat that it
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mangles granite. In a fraction of a second, this intense
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heat forms a fireball that rises into the air, leaving
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a mushroom cloud in its wake. And that cloud is massive.
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It will be bigger than any skyscraper by at least
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10 times, maybe 15 times bigger. It's going to make
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you feel small. It won't look like anything else you've
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ever seen.
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For anyone close to the blast, they'd be turned into...
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A charred corpse.
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You're talking about enough heat to set things and you
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on fire.
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This heat from the fireball, this is actually what kills
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most people near the blast. That's what happened in Hiroshima.
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And even a few miles away, people could suffer horrible burns.
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It would be just shocking, right? I could imagine people
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being just dazed, injured, not sure what to do.
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It's eerie.
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And then the incredible heat from the fireball would create
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what's called a blast wave, this wave of intense pressure
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that would push out more than two miles away. Where
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Caitlin is, just around the corner from Wall Street, everything
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would be devastated.
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Think of this as just a punching of air coming
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out of you, just heavy, heavy air, and it's just
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going to knock lots of things down.
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And it's going to carry everything with it, like this
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police car, that hot dog stand, everything just gets blasted.
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Swept away, swept away. I mean, just at this level
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of closeness to it, yeah, just gone. Dust everywhere.
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Nothing.
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Some people might be hurled against buildings. Others could be
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crushed by them. And windows would smash for miles, hurling
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shards of glass. And Alex says that this is actually
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why American school kids were taught to hide under their
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desks to duck and cover during the Cold War. It
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was to protect them from all that glass flying everywhere,
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not from radiation. But if you're close enough to the blast,
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you will have to worry about radiation. Alex estimates that
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around three quarters of a mile from the bomb.
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Anyone around is going to be hit with this invisible
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wave of radiation. You won't know it.
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In Hiroshima and Nagasaki, for people close to the blast,
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radiation ripped through their whole bodies. destroying cells in their skin, ovaries, testes,
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blood and bones. Their hair started falling out and their
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stomach was attacked by the radiation, making them vomit. Because
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North Korea's bomb is thought to be much more powerful
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than the ones the US dropped on Japan, it's possible
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that the fireball would be so big that if you're
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close enough to the bomb to get a big bout
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of radiation, you actually wouldn't survive long enough to feel
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these effects. you would just burn almost instantly. And while
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it's difficult to predict this kind of thing, Alex estimates
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that if you set off a hydrogen bomb above the
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New York Stock Exchange, just near Wall Street, you could
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kill about half a million people and injure about one
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and a half million more. And then what happens next?
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Alex says... It won't end things.
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There will be a day after that. Not for everybody,
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but there will be. And that's the really sickening thing
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to imagine.
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Millions of people around New York would survive the blast.
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They'll be far enough away. But what do they do now?
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Do they have to leave what's left of the city?
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Will toxic radioactive fallout shower down on them? Well, before
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we go down that road... Let's just take a little detour.
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It's getting a bit heavy here. So let's look at
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how cockroaches might survive a nuclear war. Yeah, let's take
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a look at the good old cockies. Because you might
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have heard that when the nuclear apocalypse comes, one creature
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will reign supreme.
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Cockroaches.
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But is that true? Well, to find out, scientists built
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a little cockroach-sized nuclear bomb and then they exploded it
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into a little cockroach-sized city. No, not really. Instead, they
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exposed hundreds of the poor dudes to radiation. And by
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doing this, they found that cockies, on a good day,
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could handle roughly 40 times more radiation than you and I. Now,
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That might sound pretty impressive, but get this. There's a
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cheeky wasp out there that can handle nine times more
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radiation than a cockroach. And because of this, one entomologist
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called cockroaches wimps. Harsh, but fair. Still, there's something else
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out there that can handle way more radiation than both
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of them. It's a death-defying bacteria that can happily live
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in radioactive waste.
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Ha!
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Take that, you cockroach reigned supreme during an apocalypse myth. OK.
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So now, back to humans and the devastation. We know
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that if a nuclear bomb were to drop on a
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city like New York, hundreds of thousands of people would
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die almost instantly from the heat. For others, they might
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be hit by flying objects from the blast. And if
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you survive all that, the danger isn't over yet. You
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still might be hit with something, something that really freaked
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out Americans during the Cold War.
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Danger will come not just from blast or heat or
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nearby radiation effects, but also from fallout.
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Fallout.
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Fallout is radioactive material that can get swept up into
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the air after an atomic bomb and then rain down
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on cities miles away. And there are fears that fallout
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can contaminate the land and the water for years to come.
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How will you know if there is fallout? You can't hear, smell,
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taste or see the radiations. And these bits of matter
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can be dangerous.
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How dangerous, though? Well, to find out, reporter Heather Rogers
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called up Tetsuji Imanaka, who grew up in Hiroshima.
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Hello?
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Hi, Dr Imanaka.
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Hi, good morning.
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How are you?
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Tetsuji was a nuclear engineer at Kyoto University in Japan.
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He's recently retired, but had spent his career studying radioactive fallout.
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And understanding the danger of radiation had high stakes for Tetsuji,
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because his family was affected by the nuclear bomb. His
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mum was just a couple of miles away from the
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blast in Hiroshima, on the south side of the city.
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At the time of atomic bombing, my mother was in
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the south part of Hiroshima City. And she was behind
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a small hill.
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And that small hill shielded her from the blast. Being
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a nuclear engineer, Tetsuji actually calculated her dose of radiation.
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And he says she barely got any.
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Initial radiation was almost zero, I'm sure.
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Almost zero. But the morning after the bomb, Tetsuji's mum
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actually headed back into what was left of the city.
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Tetsuji's grandmother had been in Hiroshima during the explosion and
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his mum wanted to find her. Amazingly, she did. Tetsuji's
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grandma was in really bad shape, but alive.
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She felt so happy at that time. It was very strange.
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She felt, my mother told me.
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Why does that make you laugh?
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Yeah, yeah, yeah.
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This is a Japanese way. Yeah, very sad thing. So,
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so devastating. Yeah, it's difficult to say.
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Tetsuji's grandmother was so close to the bomb when it
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went off that she was exposed to a lot of
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radiation and died a week later. Now, all that radiation
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came directly from the bomb. It wasn't fallout. But to
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find out if Tetsuji's mum was safe, he needed to
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know how bad the fallout was around Hiroshima. And he
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told Heather that his mum actually didn't get exposed to
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that much of it.
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So, not so high. Two or three times CT scan.
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So it's like as if she had two or three
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CT scans.
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Yeah, yeah, yeah.
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And for the most part, fallout from Hiroshima or Nagasaki
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didn't come down in dangerous concentrations. And to understand why,
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you have to know this curious thing about nuclear bombs.
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When it comes to fallout, it matters where in the
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sky these bombs blow up. And in Hiroshima, as well
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as Nagasaki, the bombs exploded in the air, hundreds of
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meters up.
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Fireball didn't touch the ground.
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Since the fireball didn't touch the ground, Tetsuchi calculated that
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that meant a lot of the radioactive contamination didn't fall
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on the city. Instead, it went up into the atmosphere.
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So basically, the land isn't ruined, the soil isn't ruined,
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the water isn't poisoned. Is that true?
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Such case in Hiroshima, that's true. So almost radioactive material
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went up to the sky.
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Up into the sky. In fact, tiny bits of radiation
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ended up spreading out thinly all across the globe.
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Some scientists found trace of Nagasaki bombing in the Arctic.
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Yeah, radioactive particles from the Nagasaki nuclear bomb. were found
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in the Arctic. But here's what you have to know.
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These radioactive particles are found in such low doses that
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they're not believed to be harmful. There are no radioactive
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polar bears in the Arctic.
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The radiation is not dangerous now.
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And so the reason why the fallout wasn't that dangerous
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in Hiroshima and Nagasaki was because the bombs exploded in
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the sky.
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But.
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Tetsuji told Heather that if those bombs had exploded on
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the ground, it would have been a completely different story.
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The radioactive contamination would have been really bad.
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And so if that happens, then you probably can't, like
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you won't be able to grow food there.
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And why is it so bad if the fireball hits
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the ground?
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Well.
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That huge fireball is filled with radioactive particles. And when
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it hits the ground, it drags tons of soil and
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burnt rubble into its fiery blaze, which then goes up
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into the atmosphere. And because that soil and rubble is
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relatively heavy, it can fall out of the clouds as
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radioactive dust. Fall out.
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Fall out.
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We know this because during the Cold War, the USSR
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and the US dropped a bunch of test bombs and
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some were detonated really close to the ground and they
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ended up contaminating places miles and miles away. So when
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the US detonated a bomb just seven feet from the
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ground at Bikini Atoll, a strong wind blew that radioactive
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fallout onto nearby islands and it was so bad, that
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almost 300 people got acute radiation poisoning. But will the
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landscape be contaminated with radiation forever after a nuclear bomb? Well,
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while there are some types of radiation that can stick
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around for decades, most of it actually decays fairly quickly. So,
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for example, in Hiroshima... while there was this intense blast
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of radiation as soon as the bomb exploded. Just one
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day later, it was a thousand times lower. A year later,
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radiation levels in Hiroshima were pretty much back to normal.
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Tetsuji's mum ended up staying in Hiroshima her whole life.
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She had three sons and lived to the ripe age
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of 86, eventually dying of lung cancer. And it's cancer...
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So you have to wonder, could it be from the
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radiation of the bomb? After the break, the long-term effects
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of a nuclear bomb. Is cancer how it'll get you
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in the end? Hey, it's Wendy from Science Versus, and
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I want to tell you about a podcast that I love,
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Science Friday. They cover all sorts of amazing things in
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the weird and wonderful world of science, from how concussions
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affect our brain to the inner secrets of a snake
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00:17:59.630 --> 00:18:01.869
with a spider on its tail. tail. It's a lot
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00:18:01.910 --> 00:18:04.589
of news that you can use and some that you can't,
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00:18:04.730 --> 00:18:07.170
but you're going to love anyway. It's hosted by Ira
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00:18:07.210 --> 00:18:10.750
Flato and Flora Lichtman, who is an old friend of
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00:18:10.829 --> 00:18:13.619
the show and loves a pun as much as we do.
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Science Friday is on every day, wherever you get your podcasts.
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Welcome back. We just found out that most of the
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deaths from nuclear bombs come not from the radiation, but
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from a huge fireball and even intense pressure, which can
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shatter glass for miles. There's also the danger from radioactive
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dust that could fall from
the sky. But what if
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you lived through this kind of attack, the fireball, the glass,
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the rubble? What happens years later? Because nuclear bombs can
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spew radiation across a city, and we know radiation can
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cause cancer, does that mean you and everyone you know
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will go on to get cancer?
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There's a lot of fear of radiation. When I grew up,
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this was one of the big fears in life.
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This is Eric Grant, and he's been studying the effects
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of radiation on people for decades. He's American, but he
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lives in Hiroshima and still remembers when he first came
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to the city back in 1985.
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You know, I was a bit nervous about it, actually.
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What was it like? We did this? Is that the feeling?
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I guess so. You know, it was all-out war and
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the United States dropped that bomb and a lot of
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people died and here I was.
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Eric now works at the Radiation Effects Research Foundation, which
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has a study which tracks the health of tens of
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thousands of atomic bomb survivors. And if you want to
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know if a nuclear bomb will give you cancer, this
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is the study to look at. It's been going since 1950,
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just five years after the bomb hit, making it one
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of the longest public health studies in the world. And
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it actually started out as a US military operation.
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And the United States is very anxious to learn how
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effective the weapons were.
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Wow, but it was born out of the military wanting
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to know how dangerous their weapon was.
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That's exactly right. And I think there's still some underlying resentment.
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And the way they recruited survivors for their study probably
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didn't help. Japan was still occupied by the US in
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those days.
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We did have our own fleet of Jeeps and they
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used to crawl through the city and interview people for
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where you were at the time of the bombing and
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where was your husband.
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The US military would go to these centres where people
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asked for food rations, including pregnant women.
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And when they came to that window and said, I'm pregnant,
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I'd like this extra ration of rice, people would approach
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them and say, congratulations on your pregnancy and We would
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very much like to see how your child does.
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The study ended up recruiting around 120,000 survivors and would
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eventually split from the military, tracking cancer rates in those
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survivors for decades to come. So, what has it found?
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Did the atomic bomb increase the risk of cancer for
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these people? Eric says, yes, for cancers in all sorts
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of places.
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Your lungs, for instance, or your breast or your liver.
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But there was one cancer that was spotted almost immediately. Leukemia.
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This is the first thing that they saw. Especially among children,
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you seem like you're doing great, and then five years
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later you get a leukemia. And this was considered the
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A-bomb disease.
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So leukemia showing up in kids is pretty scary. But
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the actual number of people who got leukemia as a
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result of the bomb, well, it wasn't as high as
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you might expect. Eric and his team have found that
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out of the tens of thousands of survivors, only about
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100 more people than usual got leukemia as a result
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of the bomb. So your chance of getting leukemia if
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you survived Hiroshima was actually really, really low.
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So not huge numbers.
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Wow.
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So the rates really are quite low.
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Right.
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That's right. That's exactly right. It's lower than people generally think.
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So that's leukemia. What about the other cancers? Well, Eric
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says that his study found that if you survive to
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Hiroshima or Nagasaki, your risk of cancer is about 10%
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higher than someone who's the same age as you but
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wasn't around the bomb.
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Chances are... you're not going to suffer a cancer that
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was due to the radiation exposure.
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Well, Eric wants us to be careful with this stat.
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It's an average of the survivors in his study. And
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he says that overall, the more radiation that survivors got,
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the higher their cancer risk. Plus, this study started five
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years after the bombs went off. So there's a chance
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that some people got cancer and died before it started. Still, though,
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on average, it does seem that the number of cancers
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from Hiroshima and Nagasaki was relatively low. There were other concerns, though.
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Because nobody really knew how radiation from the bomb would linger,
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there were fears that the effect of radiation could be
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passed down to the next generation, the children of the
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atomic bomb survivors, people like Tetsuji. Well, Eric's study, which
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has now followed more than 75,000 kids of survivors for
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half a century, actually can't find any increased risk of
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cancer in these kids.
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So we haven't seen those effects, which is one of
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the silver linings, I guess, with this whole story.
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From your study, it made me think that nuclear bombs
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aren't as dangerous as I had thought.
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I guess... When you think about the long-term health effects
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of the atomic bombings, you're right that radiation risks of
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cancer are not as high as initially thought. And we
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don't see generational problems. So those two things are true.
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But the initial weapon is devastating and will take out
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huge portions of populations in cities.
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OK, so from what we found out about the bombs
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in Japan, it does seem that decades later, the radiation
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they left behind wasn't as scary as we'd initially thought.
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Hiroshima and Nagasaki were bombed at the start of the
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nuclear age, though. 70 years on, it's a very different
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world that we live in. Nine nations now have nuclear weapons.
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And if one nuclear bomb got dropped, that might not
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be the end of it. It'd probably lead to retaliation.
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with more and more bombs, and maybe even an all-out
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nuclear war. And some scientists have argued that this wouldn't
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just mean devastation for the two warring nations. It could
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have serious consequences for the entire world. During the Cold War,
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this was something that Carl Sagan talked a lot about.
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Here he is speaking on CNN.
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So it now appears that that nuclear war, almost certain,
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will destroy the global civilization. And it might just possibly
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destroy the human species.
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Destroy the human species. And here's how. Some scientists thought
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that a nuclear war could lead to a world where
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the skies would turn black, the world would go cold,
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and you couldn't grow food. People would starve to death.
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It was called a nuclear winter. And during the Cold War,
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it even got the attention of Presidents Ronald Reagan and
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Mikhail Gorbachev. But is this idea of a nuclear winter
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based on good science? I mean, I know Carl Sagan
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is like a science god and stuff, but maybe he
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went off the rails with this one. Well, what is
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supposed to lead to a nuclear winter isn't radiation.
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It's actually smoke.
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You see, nuclear bombs create so much heat that they
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burn skyscrapers, houses, bridges, and all of that fire creates
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all of this smoke that then goes up into the atmosphere.
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Here's our nuclear war researcher, Alex Wellerstein, again.
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The idea is if you burn enough stuff, you'll put
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up a lot of smoke. You put up enough smoke
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and you start to reflect sunlight.
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That black smoke absorbs some of the sun's energy, so
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it can't reach Earth. 200 years ago, a big volcano
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blew up in Indonesia and it cooled the world by
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about half a degree Celsius for a year. This became
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known as the year without summer. So if the ash
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from one volcano could cool the Earth a bit, what
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would happen if you had the smoke from the fires
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of an all-out nuclear war?
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Now, will that be enough to... actually alter the climate
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and put you into a state where, like, you start
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having really cold all year round and global famines and things.
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Well, research suggests that to cause a nuclear winter, you've
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got to throw a lot of nuclear bombs, like a
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lot of nuclear bombs. One researcher from NASA calculated that
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100 Hiroshima-sized bombs would drop the temperature of the world
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by a little over a degree Celsius. That's almost two
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degrees Fahrenheit, and that would last for several years. So, bad.
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But not enough to destroy the human species. A report
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from the National Academy of Sciences said that a large-scale
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environmental catastrophe would only happen if thousands of nuclear weapons
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were detonated. The truth is, though, we don't know exactly
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how many bombs we'd need to throw the world into
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a nuclear winter. For Alex, he says even though the
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science isn't perfect here, it is good enough for us
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to start asking this question.
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Do we need thousands of nuclear weapons? Only two countries
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have thousands. Everyone else has hundreds.
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And those two countries are, of course, the US and Russia.
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It's estimated they have roughly 10,000 nuclear weapons between them.
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So theoretically, it is possible that they could plunge us
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into a nuclear winter. So when it comes to science
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versus nuclear war, does it stack up? One, if North
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Korea dropped a nuclear bomb on New York City, perhaps
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half a million people would die. mostly from the heat
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and flying fragments, not from radiation. Two, how dangerous is
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radioactive fallout? Well, it depends on where the bomb drops
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and where the wind blows. In Hiroshima and Nagasaki, the
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fallout actually wasn't that harmful. But if a bigger bomb
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detonates on land instead of air, that could be a
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different story. And three, finally, is it possible to drop
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so many bombs that the Earth becomes uninhabitable for decades
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to come? Well, if thousands of bombs were dropped, it
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might create enough smoke to affect the climate of the planet.
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And the US and Russia, they probably have enough bombs
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to do it. That's science versus nuclear war. Music written
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by Bobby Lord and Emma Munger. Thanks for recording help
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from John Wild. For this episode, we also spoke to
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00:30:41.059 --> 00:30:45.700
Professor Richard Wakeford, Dr Richard Turco, Professor Brian Toon, Professor
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Alan Robach, Dr Dale Preston, Dr William Kennedy, Dr Jonathan D.
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Polak and a bunch of other experts on North Korea
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and nuclear weapons. Thank you so much. Also, a special
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thanks to Shigeko Sasamori and Kathleen Sullivan. And an extra
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special thanks to the Zuckerman family and Joseph Lavelle-Wilson. Next week,
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we're tackling the ketogenic diet. Can you become your best,
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healthiest self by eating bucket loads of fat?
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If a drug did everything that the ketogenic diet did,
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it would be an enormous blockbuster drug worth billions of dollars.
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I'm Wendy Zuckerman. Back to you next time.