How Nuclear Weapons Work

the podcast. Although today's both senior writer Jonathan Strickland of Herbert West who was my friend in college, and an afterlife I can speak only with extreme terror. Oh that's a good one to start today. Yes, today we wanted to talk about a subject that is, uh, it's pretty terrifying. We're talking about nuclear weapons. Yes, yes, not clear not nuclear he was. I was teasing him about this before and he said that I had better not I'm not

gonna say nuclear, I mean other than just then. Um. And one of the reasons I wanted to uh to talk about this today is because it's been in the news a lot lately. Um. Of course, uh iran um is rumored or depending on whom you ask, more than rumored to be working on nuclear weapons program. And um, you know that that's been a busy topic. I was about to say, a hot topic, let's not go there um lately, and I thought, well, you know, why don't we We've never really talked about, um, the technology that

makes nuclear weapons possible. UM. And while I'm not particularly fond of things that cause death and destruction, uh, the the actual bombs themselves, how they make them work is kind of interesting, and it's it's important stuff. I mean, you know, there's a lot of there are a lot

of discussions about nuclear arms races. You know, we had a famous nuclear arms race between the Soviet Union and the United States during the Cold War, which uh started to look like things were going to to improve, where you know, both nations were starting to dismantle a lot of their nuclear weapon programs. But then you've got other countries like China and India and Pakistan and other countries that are that have either have a nuclear weapons program

or developing. North Korea is another good example. They either have a and a fully fledged out nuclear weapons program or they're working on it. And uh, it adds a lot of concern because these weapons potentially pack an enormous punch and it's the kind of weapon that you know, most weapons, you use them and then the uh, that immediate moment, the aftermath, that's that's all you're dealing with.

And the aftermath is generally, you know, not not uh something that is perpetual, right, I mean, you might have to do some massive clean up or whatever, but that's it. Nuclear weapons are different, and that the aftermath can be as destructive or maybe not as destructive, but but destructive

on their own beyond the initial blast. And so plus plus it's possible that the uh, the effects of the nuclear blast can carry across the terrain to places that the US, as we'll find out in in our discussion, um, that people may not necessarily have been planning on being affected. Yeah you might. You know, it's not just the immediate area. It's not a precision weapon and that Yeah, there's a precision blast area that you're that you can be pretty sure is going to be vaporized when you hit it.

But then there's a large area around that. Depending upon the climate and you know, the specific weather conditions at that time, it could affect neighboring countries, you know, essentially innocent bystanders to whatever. So let's get into this, let's talk first about atoms. Yeah, I mean you think about it that One of the fascinating things about this is that such a devastating reaction can be caused something as

tiny as an atom. Yeah. Uh. And just so that we all have our little a little refresher course, even though I'm sure no one listening needs it. Your basic atom has a nucleus that is orbited by electrons. Now your electrons are you're negatively charged particles. Yes, your nucleus typically contains at least one proton. Actually it has to otherwise it's not an atom. So the proton is a positively charged particle, and the protons positive charge in the

electrons negative charge are attracted to one another. It's pretty powerful. Now, there can also be in that nucleus a and a particle that carries no charge at all, a neutron which has no charge, and neutrons kind of act like glue for protons. Because you know, you've got this this nucleus that could have more than one proton. Well, the problem

is that a similar charges repel one another. So if you have to possibly charged particles and you try and put them close to each other, they're going to start repelling each other. Well, neutrons kind of act like a glue that that allows these protons to group together to form this nucleus. So, uh, if you've I'm getting out of here. No, no, no, no, it's all right, it's all right. Now you can change the number of neutrons

that are within an atom. And if you do that, uh, you know, atoms have typically they have a number of neutrons that you will naturally find within the atoms of that element. Uh. If you find something that's outside of that that either is gut either has more fewer neutrons, it's an isotope. So isotopes of atoms are atoms that contain a different number of neutrons than you would typically find them in nature. Plus baseball team in Springfield, that's

also true. Now, this is not to be confused with ions. And ion is an atom that has either gained or lost in electron, and so it either has a positive charge or a negative charge because of that. So of course, if it's gained an electron, then overall the atom has a negative charge. If it's lost in electron, then overall the atom has a positive charge. So that's the difference between ions and isotopes. Now isotopes. Really that's what ends

up being important in these nuclear weapons. It's it's sort of a key feature. Um. Another thing that's that's important to note is that for the most part, atoms are pretty stable. I mean, once you get them in their natural state, they're unlikely to change all that much. They don't uh, randomly shed electrons or the things unless some

force acts on them. They just sort of go along there about their business and stick to themselves, right because if they were if they were unstable, they would very they would not necessarily very quickly. But if they were unstable, they would change to become more stable over time. That's what we call decay. So if you have an atom that is unstable, it will eventually change to a more stable form, and in the process of that, it's going to give up some energy, uh, and it can give

up energy and in multiple ways. There's actually three main types of radioactive decay. There's alpha decay, which is where you've got your nucleus and it it's going to kick out two protons and two neutrons bound together, which is also called an alpha particle. Then you've got beta decay, and this is where a neutron actually changes becomes a proton. Uh. Then the neutron or the proton and the an electron

and an anti anti neutrino are all ejected together. That's the beta particle or actually the ejected electron is the beta particle specifically UM. So yeah, good all anti neutrinos. I tell you they they go opposite the best as the speed of light. So we talked about the whole new trinos whether or not they were going faster than the speed of light with large hatron collider. Right now, it looks like they didn't. Looks like that was all

due to some some issues with the measuring technology. Looking at the scoreboard today right, which could change by the time this podcast gets out. So the third type is spontaneous fission. Now, fission is where you have a nucleus split into two pieces. It's um the opposite of fusion. Fusion is where two nucleuses come together and join, and both vision and fusion you have a release of energy. Now, for radioactive decay, we're specifically talking about fission, not fusion.

So in this the nucleus splits and it might eject neutrons which can become neutron rays, and it also can emit electromagnetic energy called gamma rays, which do not talk about fantast stick for you're looking at me like I was talking about some or the Hulk. I was waiting for you to make that joke. Actually, I think it was cosmic rays with the fantastic gamma radiation for the incredible Hulk. I don't want to get my science wrong.

You're absolutely scientific. My air quotes science wrong. So yeah, gamma rays. It's interesting that they are the only type of nuclear radiation that comes from energy rather than particles. Yes, all right, I bet you learned that on how stuff Works dot com. Yes, there's a really good article about that. We we have we have a couple of articles on how stuff works dot Com that are going to be

really useful as we talk about this. They include how nuclear weapons work, how nuclear how nuclear radiation works, and also how there's an article about the Manhattan Project. We'll talk about the Manhattan Project in a little bit. So we've now got these three different forms of radioactive decay and we know about this new spontaneous fission. Well, what's interesting is that the fission doesn't necessary really have to

be spontaneous. If you find the right kind of unstable atom and you are able to bombard it with neutrons. Then sometimes those atoms will accept a neutron and in the process they will become so unstable as that the nucleus itself will split apart, and in that process the

nucleus will release energy. It also may release other neutrons, which means that if you get a bunch of these unstable items together and you shoot a neutron at them, and then that first that first nucleus splits apart and more neutrons split off of it, it can cause more of these unstable atoms to do the same thing, and

that's where you have a chain reaction. I can't remember who it was that had that the TV show where they had a clear plastic box and on the bottom of the box they had uh mouse traps, and each mouse traps, each mouse trap had two ping pong balls on it, and those represented um the stable. Actually, it's probably been done by five thousand people anyway. You can find clips of the same sort of thing on YouTube and then by lots of different people, and I enjoy

watching it because it's really an excellent demonstration. So each of these these mouse trap atoms with its two ping pong balls represents these unstable atoms, and as soon and the ping pong balls represent the ejected neutrons exactly exactly, And so uh, somebody else will drop a ping pong ball inside a small hole in the box representing the neutron in this case that is bombarding these these atoms.

And as soon as it hits one mouse trap and sets it off, the ping pong balls from that one fly in other directions, thereby setting off the other mouse traps, and it all happens in a very very short period of time. It takes almost no time at all for this thing, for all the the mouse traps to release their part of ping pong balls now. And in the case of a nuclear weapon, these reactions are happening in billions of a second. So now let's get to the

actual elements that are used in nuclear weaponry. So one of them is an isotope of uranium, uranium two thirty five. That's a very complex atom. Yeah, it's got ninety two protons, right, so, but it's got a hundred and forty three neutrons. And the thing about this is that it will accept a neutron if if you bombard uranium two thirty five, it very easily will accept that neutron. Yeah yeah, and then it it makes the uranium unstable, and then it will split apart like I just said in and you'll get

that energy and those other neutrons released. So that the problem, the problem with this, many problems with this. One of the issues that the people who first started working on nuclear weapons technology encountered was that, first of all, they weren't sure which elements were going to react this way, because not all of them do, so finding the right elements was tricky. The other part is that uranium two thirty five is relatively rare compared to other isotopes of uranium. Yeah,

that's right. So when you find naturally occurring uranium, the uranium two thirty five in that deposit is going to be relatively sparse, and for a nuclear weapon to work, you need about uranium two thirty five so that you have the right amount of material to perpetuate this chain reaction. Otherwise your your atoms that are unstable, maybe too far apart from each other for that chain reaction to really

take off. Note to all the nuclear physicists who are writing who have paused to podcast and rode in to tell us that there are other types of fuel that can be used for nuclear weapons. Yes, we know that. However we're using we're starting here, starting with uranium because that's where that's where, that's where the scientists started. Yes, plutonium also used as all as their hydrogen bombs that we'll talk about a little bit. But even hydrogen bombs

use uranium and plutonium um. It's just that they're they're using a different mechanism. They're using fusion as opposed to vision. So uranium two thirty five, you have to actually refine your your right, your uranium. Wow, I can't talk today, but yes, you must take uranium, your uranium, yeah, toy boat anyway, you have to take this uranium there we got that works and refine it so that you have

a higher percentage of uranium two thirty five. Which is what you hear about when you when you hear about these these nations like Iran with their nuclear program, you hear about are they making uranium for power facilities or are they trying to make weaponized uranium. This is talking about the enrichment process. Yes, so if you are enriching, if you're if you're creating uranium, so that you've got a section of uranium the is uranium that's indicative of

a weapon that's not. You don't need that kind of concentration for a nuclear power facility. So that's one of those things that that inspectors try to determine when they go and look at a nuclear power facility to make sure that the uranium being produced is not weapons grade uranium. So anyway, that's the basis, that's the basic science behind the fission part of nuclear weapons. Will get into fusion in a second. So how did this all come about? Well,

first we have to look at a fellow named Einstein. Now, Einstein came up with that famous equation E equals MC squared the theory of relativity, which states that energy is equal to mass times the speed of light squared the constant of the speed of light through a vacuum. As it turns out, so that means that you take the you take and a unit of mass, you multiply it by the square of the speed of light speed of light squared rather and and then that's how much energy

you get from that mass. So this tells us that a tiny little bit of mass could equate to an enormous amount of energy because you're multiplying that that unit of mass against a huge number. Well, that starts leading people to think, well, this is true, then there should be some way to tap into the stuff that's around

us and get at huge amounts of energy. And you had a lot of really really smart people working on this, and most of them were probably at least initially working on this as a way of finding a new energy source, not necessarily a weapon. However, World War Two really helped push the the the the research towards finding a way of using this in a military application as opposed to to just a power generation alternative. So then we go up to the nineteen thirties. You've got a fellow named

Enrico Fermi, and hep him in grade school. He's the one who discovered that if you were to shoot neutrons at atoms, you could sometimes form new elements. And they were including ones that just did not show up on the periodic table at all. So most of these are are atoms that are so unstable that you know they

almost immediately decay. But uh that he discovered that, and then a few years later a pair of German scientists Otto Hahn and Fritz Strassman discovered that by bombarding uranium with neutrons that they could create cause the uranium atoms to split. So they're the ones who actually connected the concept of fission with shooting neutrons at an isotope and uh it actually created a radioactive barium isotope once they did that, and that's how they discovered, oh, you know,

this is what happens. If you do this, then you have a couple of other There are so many famous names that we could mention that worked on this, but Neil's Bore and John Wheeler started to theorize that if you were to create a fission reaction within enough of this material, you could cause a chain reaction, and if you were to contain this in some way, you could have a controlled nuclear reaction which would generate huge amounts

of energy. Uh. Now, a controlled nuclear reaction could allow you to have uh power, or a controlled nuclear reaction that then results in an uncontrolled explosion is a weapon. It's a bomb. You know. I'm sort of reminded of our our discussion of quantum computing, which also works with adams. But the thing is that figuring out the predict predictability if you happen to listen to that podcast of where the particle will go and in what direction um is

not always possible. That's one of the things that makes quantum cryptography so useful. But yeah, in this case, UM, it's kind of scary because if you imagine that this this reaction is going to unleash a large amount of power, or maybe it won't. You know, that's that can be a little scary because you don't know for sure exactly what's gonna happen when you do this is which is why UM, you know, they started doing experiments like you know,

Columbia University in n um up in New York. They starting to mess around with this to see if they could make it work. University of Chicago squash court. Yes, yes, now that's funny because of underground underneath the famous stag field there at the University of Chicago. UM, they were

Enrico Fermi finally got it to work in the controlled situation. UM, so you know, again, what what if it weren't controlled that might have been a little scary, but uh, you know, he got it to to uh to do what they thought and this This was important because UM again this is they realize is that this could be a seriously potent weapon that they could be building. So UM they realized that if they could harness this and do this in a controlled way, you know, then they could turn

it to their advantage. UM. Around the same time that work was being done on uranium uh and and nuclear fission, scientists over at the University of California at Berkeley back in discovered a new element, element ninety four uh and They thought that this could also work as a potential fuel for nuclear chain reactions. And this element they named plutonium and the dog, Yes, it was named for the dog the it took. It took his name for the

Roman god. But yeah, it was a year later they had actually produced enough plutonium to finally do some experiments on it, because it was not something that was easily found, which I guess we should all be thankful for. UM. And they they figured out that plutonium also would undergo fission when bombarded by neutrons. You know, we should talk about the criticality of about the of the the atoms themselves. Because the thing is, UM say, say you have your

your creative mousetratchs and ping pong balls. You have to make sure that nothing is going to set it off before you mean to set it off. Yeah, you don't want to have something jostle that that system and have it all go off prematurely. And of course with a nuclear bomb, this is truly important because of the the just the enormous amount of damage that it could it could it could cause. So yeah, so there's there's a

couple different concepts here. There's a concept called critical mass, which is the minimum amount of mass necessary for you to have a sustain nuclear fission reaction. And then there's the subcritical mass, which is where you've got lower than that amount, And ideally what you want is to have lower than that amount up until the point where you actually want to detonate the bomb. Yes, because that's going to keep it as safe as you can you can

get it. So there were a lot of challenges in trying to find a way to create a bomb where you had the material set up as subcritical until the moment of detonation, where it would convert to a critical mass, so that that nuclear reaction would remain sustained within it. Otherwise your bomb would still be dangerous. It would still emit radiation, It would still admit a lot of energy, it just wouldn't cause as much damage as it was

designed to do. Right now, now, critical mass is, as Jonathan said, the minimum amount needed to to achieve the fish and reaction. Now uh, ideally for a for a bomb condition, if you're you're trying to do this, um, you would want the fuel to be in a supercritical mass, which basically means there's more than enough necessary to to achieve the fish and reaction. Um uh you know, because in this case it just applies and plenty. You want

to make sure that it's going to happen. You don't wanna, you don't want to have it where through some weird set of circumstances, just some improbable but possible outcome that the bomb that a smaller percentage of the reactions takes place than you had anticipated, because that means that the effect is going to be smaller than you had anticipated. And if you're gonna be building something as nasty and dangerous as a nuclear weapon, you kind of want it

to be effective. Yes. Yeah, The point is again to to operate it when it's going to achieve the desired effect, and not before and which is really I mean, this is where it gets hard to talk about this because the desired effect is so mind numbingly awful. Yeah, I'm trying to speak of it in a in a clinical sense. Um. Yeah, it's it's a little rough. So there there are two different ways to create a supercritical mass within a fission

based bomb. Uh. And actually both of these ways were used in the first two nuclear weapons ever actually used in battle. Um. One of the things that I think of is uh, again in in a clinical sense, but it's it's still kind of amusing to me, is in reading about this. Um. The nuclear weapons that were detonated in Japan too, uh, or i should say over Japan to um end the Second World War were really I mean it seems like, well, they did what they were intended to do, but they were really more like lab

experiments packed in a case and and and created. So I mean, now things are are pretty standardized, but the two those two weapons were very different and the way they did things and uh and really they the scientists weren't certain that they were going to do what they thought they were going to do. Yeah. And those two weapons were called we're called Little Boy and Fat many. Little Boy was the one that was dropped on Hiroshima on August six n and Fat Man was dropped over

Nagasaki on August nine. So these two us two different methods to initiate this supercritical mass and begin the nuclear fission process. A Little Boy used what was was called a bullet. It's ah, you, in order to start this whole reaction, you have to have something that's going to create neutrons, and in this case, it actually was a bullet, although not you know, in the sense of a gun.

The gun that fired, it was not the kind of gun that we would think of necessarily, right, This was a So you take take a ball of uranium two thirty five, all right, and then you take a small amount of that two out as a bullet. It's a projectile. It's placed at one end of a long tube. It's got explosives behind it. So when the explosives go off, it propels the bullet down the tube until it impacts the sphere of uranim two five at the other end. And uh so, the here's how it. Here's what happens.

Explosives fire, the bullet goes down the barrel, the bullet hits the sphere and it hits a neutron generator. Like I said, you have to have neutrons to start this fission process. So just dropping uranium two five, that's not that's not going to cause a huge explosion. But by creating these neutrons with this neutron generator, uh, it ends up starting off that that series of reactions within the bomb. So once those neutrons are generating and starts saying the

uranium two thirty five, the fission reaction begins. The individual atoms of uranium two five starts to split, and A two start to eject neutrons, which causes more uranium two thirty five to split, and that reaction continues and the energy builds up until the bomb explodes. So that was the little Boy version, by the way, in case you're

wondering how little little Boy was, uh, it was it. Well, it was able to drop a bomb that was equivalent to fourteen point five kilo tons of T and T wait no, um, yeah, so yeah, so little is a as a relative term. And then we have fat Man.

Fat Man used an implosion triggered bomb. Yes, this is this is different from the bullet method, and what happens here is you've got a sphere of the nuclear fuel, so in this case again uranium two thirty five and then you have plutonium two thirty nine core inside that and and and surrounding the core are some explosives. So what happens is in this bomb, the the sequence of events is the explosives around the plutonium fires and that

creates a shock wave. The shock wave ends up compressing that plutonium to nine and that compression is what triggers the fission reaction within the plutonium. That reaction becomes a chain reaction again, and the energy is build up and then the bomb explodes. So the whole way that this works is that it it creates and then directs that shock wave from the un initial explosion to generate that first fission reaction that becomes the chain reaction. So yeah,

a little different from the bullet method. Uh, and it was it was interesting, you know, both of these methods were being worked on at the same time during the Manhattan Project and uh, actually the implosion triggered bomb. I understand, it was the very first method that was tested. Who's the trinity bomb that was tested back in Los Alamos, which was not prime real estate back in that time

because of all the nuclear testing they did. In fact, back when they did that first nuclear bomb test, no one really knew what the result was going to be, right, I mean, there's just no way of knowing. And uh, it turned out that several of the scientists who are observing the nuclear bomb test back in Los Alamos temporarily lost their vision because the the explosion was so bright that it damaged their eyes. But they were able to

recover their vision after a while. But people didn't know how powerful this was going to be, how intense the energy was going to be, and so they were viewing it with their naked eye, and that turned out to be a mistake, right, And of course, uh, an explosion of that magnitude also spread radioactive material over a very large, uh physical space. So uh, you know, we were talking about that a few minutes ago. When there is a nuclear explosion like this, if there is um you know,

it spreads nuclear material out over an area. Basically, you can think of it in roughly, if you're taking weather out of the picture, um, you know, you would have a huge circular ish area over which this material is spread. Now, of course, if the wind is blowing um, you know or you know, the temperature is right, the the material can drift along with the wind. That can uh you know, get into water supplies, it can you know, cover it can move quite a bit. Um. And you know, the

the effects, the physical effects of course, UM. You know, there's there can be a lot more than just uh, vision problems. I mean there's there's there's cancer has been attributed to it um. There have band cancers attributed to it um and many many other physical conditions um related

to that. So it's not just the people who are atomized, if you will, by the bomb right as they are, they happen to be in close enough proximity that it can have long lasting effects on on many many other people and can make the area radioactive for many many years to come. Yeah, These these elements that are experiencing radioactive decay, they can be in this state for hundreds

of years, depending on the materials. The Yeah. The essential if you are if you're at ground zero of a nuclear explosion, which is which is essentially right at the center of the explosion, yea, the location of the detonation essentially, Um. The the thing that would kill you be the heat. Yes, the heat would be so intense that you would you would be essentially vaporized. Um. But following the heat is the pressure that's created from the shock wave of the explosion.

And so let's say that you're far enough out where you're not going to be vaporized by that heat, that pressure could be enough to knock over the building you're in totally. It could crush you. So you have that to look forward to. Then you've got, like like Chris was saying, the radiation and the radioactive fallout. So you can think of that sort of a bull's eye target, right, Like the very center of that target is where the

heat is going to be the most intense. Just outside of that is the general area where the pressure from the shock wave is going to be intense enough to be deadly. Just outside of that is the radiation, where the radiation could be strong enough where you're you could suffer severe radiation sickness, uh, just from the exposure from that.

And then the radioactive fallout could affect the largest area, and like you were saying, the weather can end up carrying particles that have this radioactivity to them and contaminate other areas miles and miles away from the site of the bombing. It can affect living cells, uh, you know, preventing them from behaving normally. I mean they can cause birth defects in in future generations. Um. So this is

this is very very serious stuff of course. Um. Now, later after one of the things that they realized after using these weapons was these these fission bombs work very well. Obviously they're very effective. But um they began thinking that, uh, perhaps fusion would be a more effective or create a more effective weapon. And that's the course they began following, right, And they in some cases they first started looking at fusion.

Back in there was a physicist by the name of Edward Teller, and he came up with an idea called boosting. And this is a process where you create a fusion reaction in order to generate neutral ons, and those neutrons then go on to create a fission reaction. So it's a hybrid really. Uh. Now, like we said, fusion is where you've got the two atoms that combine together to form a heavier single atom, and in that process it

gives off quite a bit of energy. Uh. And you can use different kinds of atoms to do this, but typically in a thermonuclear weapon. We're talking about hydrogen, and hydrogen has different isotopes, right, there's uh, deuterium and tritium. Yes, And this is all talk. Normally a hydrogen atom, uh just has the one proton, Yes, But if you add the if you start adding neutrons, then you get deuterium and tritium. And deuterium is stable. If you have a

deuterium atom, it's stable. It's not gonna decay. You can actually create water with deuterium, but it will in enough, in large enough amounts. Deuterium is toxic, so it's not something you want to have around you. Uh. Is that heavy water? Is that heavy? You know what I couldn't tell you. All I remember about heavy water is uh

from Batman? Should it? Pretty sure? That's not very scit, But then you think, you know, it would make sense in a in a in a sense because deuterium, you've got the neutron at it, which means that the actual atom itself is heavier, which means any molecule created out of that atom that would take the place of the normal is or the the natural state of that atom

would be intern heavier. Sorry, you can keep talking. This is one of those times when uh, it's something didn't click to me until we were actually talking about it. And I'll let's see if I can find something like And I'm not a nuclear physicist, so I honestly can't answer all those questions off top of my head. But tritium is not uh stable, it will it will decay retive relatively quickly. So it's a bit of a challenge. But what what is it, Chris, Yes, it's it's water

made with deuterium. There you go. And so trying to create a fusion bomb is a little bit tricky because tritium is one of those elements that is typically used in these but it is not it's not easy to store, and it's got a very short half life. So so if you have this problem with storage and how do you keep tritium stable so that you can have fusion reaction in order to start off the fission that's going to ultimately lead to this destructive force. Scientists came up

with a fairly creative solution. First, they created a lithium deuterate, which is a solid compound and it does not have the problem of undergoing radioactive decay at room temperatures at normal temperatures or even you know, normal operating temperatures of a nucle your bomb until you detonate it. And then with the tritium problem, they began to rely upon a reaction of fission reaction which will produce tritium from lithium.

So first they have to induce a fission reaction with the lithium, and then the lithium in turn will produce tritium. And then you've got the uh chance, you've got the the the right elements in place to have the fusion reaction,

so you have fission to fusion to fission again to boom. Yes, it's a little complicated, right, and uh that fission reaction with lithium, it also gives off a lot of X rays, and the X rays are actually what allow uh well, the X rays end up increasing the temperature within the bomb, all right, And those that increased temperature and the pressures that are associated with it are the that's the energy that goes into the system that allows fusion to happen.

Because this is one of the tricky things about fusion. You gotta or energy into the system in order diffused two atoms together, right, right, and the components of the bomb are separated by casings that prevent accidental or or or maybe premature detonation, so that that initial explosion UH and causing the X rays basically UH causes the deterioration of those materials and allows the bomb to continue detonating. Yeah, so let's it's it's it's a little complicated to talk

about this without an illustration. Yes, but the way this fusion bomb would work is that you've got an implosion fission bomb with the cylinder casing of uranium two thirty eight, which is acting as a tamper. A tamper is the thing that is controlling this reaction so that you get

as much energy involved before it actually unleashes the energy. Um. The within inside that that tamper of uranium two thirty eight is the lithium deuteride, and there's also a hollow rod of plutonium two thirty nine in the very center of all that. And then separating this this cylinder of a tamper of the uranium two eight from the implosion bomb is the shield of uranium and some plastic foam.

And this is what once you start detonating at the sequence of events, is that the fission bomb, So that first explosion goes off, and this generates the really intense X rays which increased the temperature and the pressure within the bomb. Uh the shield, that uranium two shield with the foam, it actually is what keeps that contains that that explosion so that it does not prematurely detonate the

rest of the fuel. But the heat causes the tamper that cylinder of the uranium two thirty eight to start to expand and it begins to burn away. It starts put more pressure on the lithium deuterate, which is squeezed so hard that it causes shock waves that initiate fission within the plutonium rod. So here's you've got your second fission reaction. So you've got the first fission reaction which causes the shock wave. Ultimately that begins a second fission

reaction within the plutonium rod. Now that reaction starts to give off radiation, so it begins to to expel neutrons, and also it gives off a lot of heat, so now you've got even more heat in addition to the heat that was generated by the X rays. The neutrons go into the lithium deuterate, which then combine with the

lithium and that makes tritium. So now you've got this environment of incredibly high temperature, this incredible pressure, and it allows the tritium and deuterium and also deuterium deuterium fusion reactions to occur. So you've got tritium combining with deuterium and deuterium combining with itself in these reactions, which produces

even more heat, more radiation, more neutrons. Those neutrons from those fusion reactions induce a final fission reaction in the uranium two eight pieces that are making up that tamper, and the the shield that's around the whole thing, which of course creates even more radiation and heat, and then the bomb goes boom. So you've got these this series of explosions going on in a fusion bomb, several which

are fission, one of which is fusion. The reason for that, you may wonder, well, why do you need so many reactions to go on for a bomb to explode? Well, when we were talking about Little Boy, Uh, the interesting thing to me about Little Boy is that it was incredibly destructive weapon, but only one point five percent of the material the fission norble material within that bomb actually underwent fission one five percent, so it could have been

even more destruction. Yes, the energy it unleashed could have been orders of magnitude larger than it was, so a fusion one. A fusion bomb is designed in part to try and create as efficient a series of explosions and reactions, really we shouldn't even say explosions reactions within the bomb, um as as many as possible or as much of that material as possible, so that what it does detonate, it unleashes the largest amount of energy it possibly can

for the the amount of payload that it has. Now, this also means that we have been able to reduce the size of the actual payloads because we can create just as an effective and explosion but with a smaller amount of material as we could from several decades ago. Yeah, the weapons these days are far more reliable than than those early ones. UM. And we've gone from dropping them from planes to mounting them on cruise missiles and I

see b MS intercontinental ballistic missiles UM. And of course, uh, you know these these weapons now travel under their own power at a certain point anyway, and um, you know the the I C B ms can they actually leave the atmosphere and re enter the atmosphere so they can travel very very long distances that way. Um, and we we wouldn't really be able to to accomplish that if we hadn't moved to a fusion method where we could be so efficient with the way that we eliminate the

existence of other people on the planet. I hate to put it that way, but you know, ultimately, even though we're talking about something that's really scientific, the application of

this is absolutely horrifying. But it's not even to get away from that, but the uh yeah, because if if we hadn't done that, if we hadn't come up with the fusion process, then it would be much less efficient, and we might not have the option of putting something on a missile because it would the pay it could be too great for for a missile to be uh practical, because at that point you would have to build a missile that would be able to carry enough fuel so

that it could propel both the missile itself and the payload to wherever it is you're going to send it. And it could just become a matter of scale and and it just would not be It would be possible but not practical. By making it way more efficient, we can now put it on top of lots of stuff, including you know, not just missiles, but weapons aboard submarines. I mean that's all sorts of stuff, right, so terrifying in a way, but yeah, we we have we have

Einstein a thing for it. So next time you see that guy, well, UM, one of the things that I wanted to mention too. And we don't have to get into it in great depth because we're getting there as far as time goes. But um is the testing of

these these weapons traditionally UM. Of course, as Jonathan mentioned earlier, in the very very early days before they had been actually used, UH, scientists wanted to test them to to find out if it was even possible to make uh the weapon of mass destruction that they envisioned, to to to see exactly what would do, how well it would work. UM. So they did all this testing outside, um and above ground. Now they've a lot of in a lot of cases they've done well, they've done tests pretty much in all

sorts of forms. I mean they still do them outside, but uh, in a lot of cases now they uh weapons engineers do this underground um in an attempt to contain the reaction. Of course, although it UH, a nuclear reaction can produce such force that it can vaporize large amounts of rock, so they have to be very careful where they do this. UM. You know, for a long time, many governments around the world would use UH islands to to test their their weapons, places that they felt were

uh somewhat unoccupied. UM. And for for example, UH actually that inspired uh the Godzilla series of movies, UM, where they a lizard was irradiated on an island. Where it's a series of documentary documentaries where uh, the the the the one, the one lizard who was irradiated by this this nuclear explosion turns into Godzilla and not you know, all of the other animals that happened to be living there. Um he got just the right amount of deust apparently.

So UM. They've tested weapons underwater, um, you know, and in space, but people are are gradually moving to computer testing, UM, which allows scientists to get a much better idea of how things might work without having to actually blow something up, actually blow something up uh and create the environmental conditions UM, the the fallout and and reactions that would follow UM.

And they've found that this can be actually beneficial. I was reading an article I believe it was in the Washington Post that was saying that uh uh computer modeling had allowed engineers to discover problems that they hadn't realized existed with the weapons system that they built UM and uh prevented it from becoming you know, they re engineered the weapons that were in existence because there was a possibility that it may not then it may cause problems

and wouldn't be a stable UM and uh, you know, it's it's interesting. But of course they've found out through testing that that fallout can travel UM through air currents and water. And uh, I think that's one of the things that leads to UM fear that keeps people from using nuclear weapons more freely, because people really understand now more than they did UM years ago, that you know, this is not something that should be done casually. You know.

There's also the fear of the hypothetical nuclear winter, yes, which you know, the particulate matter from multiple explosions basically causing clouds above the earth right which would block the sun's light from reaching the ground, thus killing off a lot of the plant life that depends upon sunlight and then that it ends up that ends up killing off the species that all depend on plants, humans being one of them. So it could end up being a global

extinction event. It could also be something where it just changes the climate globally where you know, we actually do have a really harsh winter because the sun's light just isn't hitting the surface and warming it the way it usually would. Uh. And we see, we see things that could point us into like suggest that that's true by by things like like a volcanic eruptions where a lot of matters is ejected into the atmosphere and it can

affect uh, local weather patterns. Now, when we're talking about a nuclear winner, we're talking about something that would last longer than a you know, just a month or two. So it's pretty it's a it's a it's a one of those doomsday scenarios. It's a sobering thought, to be sure. Um And uh, you know, it's one of the reasons I'm interested in this is, you know, to see the flip side, you know, the idea that that nuclear energy can be used as a very efficient and clean source

of power. Of course, we saw we we talked about the Fukushima UM reactor last year, right after it happened. UM, but that's not the same as an intentionally intentionally using nuclear power to cause the destruction of many people. So UM, it's it's amazing to me personally that a little tiny atom can be used to do these amazing things, whether they're you know, and I mean amazing and the clinical

good thing, instructive or destructive. It's it's amazing. It is amazing, And well, probably I think what we'll need to do is in a future podcast, we'll have to do a full episode just on the Manhattan Project, because the if you look at a list of names of the people associated with it, if you've ever taken any any classes in physics, you're going to recognize a lot of those names. I mean, the era that the Manhattan Project existed in was remarkable in the sense of it was it was

an unprecedented era of scientific exploration and innovation. UM. One of those where you just it was phenomenal the amount of of uh work and scientific discovery that went on at that time, and in no small part that was due to things like World War World. World War two was definitely one of the reasons why that those those advances were made at the pace they were. It's not the only reason. It was one of those things where a lot of stuff doing together all at once and

kind of created this environment. Anyway. Hence for another podcast, because this one's gone on long enough. If you guys have any suggestions for topics that Chris and I should talk about in the future, I welcome you to email us. Our address is tech stuff at Discovery dot com, or let us know on Facebook and Twitter. You can find us there with the handle text stuff hs W and Chris and I will talk to you again really soon. Be sure to check out our new video podcast, Stuff

from the Future. Join how stupp Work staff as we explore the most promising and perplexing possibilities of tomorrow the house Stuff Works. I Find app has arrived down at it today on iTunes, brought to you by the reinvented two thousand twelve camera. It's ready, are you