How Body Armor Works: A Special Request

if it's our first one, then it's exceedingly rare. Um. We got a letter from a soldier in Iraq, right and he says, he says, hey, guys, I'm deployed to a rock right now and just recently subscribe subscribe, excuse me to your podcast. They're great to listen to my downtime. I just listened to the newest one about where it's best to get shot, one of my favorites. Uh, I think the hands and feet are the best also. So he agrees with us, and he wants to request to

do one about body armor. We wear this stuff out here in a rock and some of the guys would kind of like to know how what we wear works. Donald Anderson and Baghdad. Thank you, Mr Anderson. We don't have it, didn't say like Corporal Anderson of whatever battalion. So that's all we have to Should we go so far as to call him Donald? Sure? It seemed like a fairly casual email, civil and uh, well, we're gonna

We're doing this for two reasons. Number One, he legitimized our theory that the hands and feet are the best place to get shot. Sure, what with him being a soldier in Iraq. If he agrees, then yeah, we're legitimate. Secondly, um, Chuck really wanted to do this because he's trying to make up for the fact that his father was a draft dodger. Um. But other than that, that's you know, that's that's pretty much the criteria for us to do

a special request, right. My father doesn't listen to me, so I have no chance of being called out on that, and neither do the Quakers. This is actually a thank you to the soldiers of it there. Yeah, that's much more succinct. Let's get into it, all right. So we started researching a couple of articles on body arm around the site and this is what we came up with. Chuck, you wanna you want to lead off here? Uh? Sure? Um, little history of body armor. I guess it's been around

for a long long time. We're talking thousands of years. It's nothing like the body armor today. No, it was like animal hides or tree bark or something, right. Yeah, early on, I think man figured out that hurled objects hurt when they hit your body, and it might be a smart thing to put tree bark or just whatever I can get my hands on. And that evolved eventually into metal of course, which that works for a really

long time. Yeah, it worked really well because you know, I mean, all you're defending yourself against if you have like chain mail. I don't know how many of you are or if you Chuck ever played Dungeons and Dragons, but there's all sorts of different you know, kind of males armor, um, and you know, you you get more hit points. I believe I haven't played since I was it's been it's been a couple of weeks. Um. But anyway, it works because all you're doing is defending yourself against

the sword. You know, sword loses to chain mail every time, right, But we came up with something. We invented something, and it kind of made armor obsolete, right because armor clearly is bulky heavy, hard to maneuver it is. And also, if you get shot with a bullet, it's probably going to go through a metal plate. And so once we really got gunpowder under control, armored, isn't anybody wearing armor

like that's in trouble. But people were running around getting shot and not necessarily just in the hands or feet. So we needed to come up with something, and finally we come up with modern body armor the kind you see you know, um, Jamie Fox running around a bagdad In in that one movie that I never saw that one. Um, So you know, like a kevlar vest n bulletproof. No, people call these bulletproof Fastin's incorrect. Actually a bullet resistant, right,

bullet resistant is preferred. Um, there's no proof to Okay, it's not all the time. They do their best, but they can't claim to be bulletproof. I think, um, Donald's gonna find this kind of discomforting, right, I think I think they know. Okay, Well, we also probably shouldn't use the word Kevlar is a catch ball because that's actually a specific brand name made by du pont. Right, So that's like calling you know, any copy or xerox or or any kind of pain reliever tile. In all, kevlar

is a specific type of thread, right. It's a fiber. It's a fiber and a pound for pound or ounce perounce or graham for graham, however you'd weigh it. It's what five times stronger than a similar steel strand of fiber same weight. So basically what this is all woven together? Right. I think in the article it uses a good uh frame of reference to help understand it. If you think of a soccer goal with the net in the back, when when you kick the ball into the net, every

piece of the net reacts to it. So even though it hits a very small part, uh, because it's woven together vertically and horizontally, it all absorbs the impact. And it's kind of a similar concept. It's like a big, very very tightly woven net wearing And I guess kind of like if you've ever played tennis, when you hit a ball into the net, it's a loose net. It's going to go onto the other side into the net further. But if you keep that net really tight, it's gonna

bounce off with with barely any movement whatsoever. It's not so good anymore. Yeah, I haven't played in a while. Yeah, but um, okay, so there's the both a tennis and a soccer analogy, which I think is more than enough. But but with with kevlar and other kinds of um soft bulletproof vest, we'll get into hard bulletproof vests momentarily. Um these things, these weaves are so tight that, um, the impact of a bullet is distributed across them exactly.

So it's layered. There's different layers. I think they're covered in plastic film. Uh yeah. Sometimes there's a resin, and then there's there's sandwich like each each layers made more rigid with like a plastic a plastic layer on either side of the kemblar weave, and then that's a layer, and then there's layer upon layers, so you know, maybe fourteen or fifteen layers, depending on how how thick it is,

the problem is it's like a piece of paper. If you take a piece of paper, you can easily fold it. If you take a ream of paper, it makes it much more difficult to fold. So, such as the case with layer upon layer of bullet resistant material. But obviously the more you have, the better off you're gonna be. Although you want to still be able to draw your gun. You don't want to be like Randy and a Christmas story. You can't put his arms down. You know exactly, you're

gonna be in big trouble. So we've reached the point. Here's the point in contention. You want protection that can stop a bullet and or fragment or fragment shore in the case of war um or. But at the same time, you want flexibility, you want motion absolutely And when we're talking about um hard body armor. These are actually like ceramic plates. It's not like ceramic like a coffee mug that would be almost useless. What what's it called, Chuck,

It's like alumina or something like that. There's a it's a type of ceramic right. Let me check on that as you continue. Anyway, it's a right solumina. Uh, it's a type of ceramic plate. And it's exceedingly hard and uh it doesn't shetter like you know, a ceramic coffee mug would. Um and these things are they'll they will stop a bullet. Yeah, that's pretty much guaranteed. The problem is they're thick, um, and you only want to wear them when you know somebody's going to be shooting at you. Right.

I think the key here to the ceramic plates, as they will stop a rifle bullet, whereas your average kevlar vest soft fest will stop a nine millimeter pistol round. So if you know, like you said, if you know you're gonna get shot, which is probably not a good feeling, or if you have a hunch that you're gonna get shot. Um. They make a lot of these soft vests now with pockets that you can slip the ceramic plate into and out of, which is good. So if you're walking around Detroit,

you can just wear the soft vest. If you're walking around Bagdad, you should probably keep these ceramic plates in it all times. I would say, okay, um, all right, So that's the that's the soft body armor, the hard body armor. Um and Chuck, I actually went a little off. I found another article called liquid body armor. Yeah, that's the problem. We were talking about flexibility but also strength. Um,

they may have it licked. How's that. There's a stuff called sheer thickening fluid that's t F and basically what it is is it's these tiny little particles of silica, right, and they're suspended in uh some kind of oily, kind of slick, oily substance. Uh, polyethylene glycol i believe is what it's usually used. And so the particles are just sitting there and they're actually repelled by one another. They

don't want to be around one another. There's kind of taken up space, so they slide over one another very easily. So it's kind of liquid e right, right, But an impact actually it overwhelms the repulsive forces and all of a sudden, these silica particles formed the shield. Yeah, and it happens in a few milliseconds, so, I mean, the moment the bullet starts to touch that vest, it turns

into the shield. But the but, but the beauty part is is that after the bullets you know, been stopped and bounced off for whatever, um, this liquid, these the silica particles start to repel once once more and now this average ordinary kevlar vests body armor. It goes back to being you know, supple and easy to move in. How cool is that? That sounds like some Batman stuff? It totally does, and um, it does actually I love it when you bring in the supplemental stuff that you

don't even tell me about. Josh, we'll get it. Like I'm learning, I'd like to keep you on point the the Apparently in tests of these this kind of this what is it, sheer thickening fluid and actually our our colleague Tracy Wilson used a great example. It's like corn starch and water. If you put in equal parts, um, they just kind of um. It's it's still liquid e. But you can make it into a ball because you're

applying pressure. But when you put the ball back down, it's gonna go back into more of a liquidity state. It's very much the same except not quite. Okay. The beauty thing about sheer thickening fluid is that in tests, from what I understand, uh, they you need four layers of kevlar um to get the same stopping power with the STF on it to get the same stopping power as fourteen layers of plain old also called neat kevlar.

So it's much more flexible, but it works. Now are they is this in use right now or is it still in development? I believe it has exited development and started to go into production. Yeah. Yeah, So if you can get your hands on a on a kevlar vest, piece of body armor with stf right, that's the one you want, you know, because you can draw a gun faster than anybody. Sure, and that's important. I know they say a lot of times that with the heavier vest,

police officers are less likely to use them. So what good is a vest if it's in your police car. Yeah, So they try to make them as comfortable as possible, so the so the officers of the law and military will be more likely to put them on. Yeah. Well, there's one other aspect that you have to we have to take any consideration that we don't necessarily, but you know, manufactures of bullet resistant body armor should. Um, and that is blunt force trauma. Okay, So that the both the

tennis and the soccer analogy had a commonality. Um, when that ball hits that net, the net gives. Sure, you don't want your kevlar I'm sorry, you don't want your body armor to give, right, because it's still touching your body and even if it's not piercing, it could do some serious internal damage. I would imagine. Yeah, when we were talking about best place to get shot. We talked about cavitation, and I imagine this would be kind of similar,

would be like cavitation without a puncture wound. You know, it could probably do some serious damage the soft tissue, maybe even create enough of a shock wave to break a bone. They've got this problem, Lick though. Body armor manufacturers have that this this exceedingly tight weave to take advantage of, like you said, the horizontal in the vertical we've and it so efficiently distributes the force of the bullet that you'll feel it, but you actually won't feel

where the bullet hit. It'll just your your whole your whole torso will will feel the impact. Right. Actually, twist the wires too, fibers, I'm sorry as well. So they're twisted and woven and twisted so which you get as a really dense, dense weave. Yeah, they go to a lot of trouble and for good reasons, exactly. All right. So there's some other stuff that's on the horizon, and I understand things like chicken feathers. Yeah, did you hear about this? I did? Uh. Kevlar you know, works pretty well,

but they are there. People are always searching for better and better ways to protect our soldiers and officers of the law and citizens if you'd like one, Yeah, I don't want to discount the citizen. Definitely walk around with one if you like. Well, there's one called fiber called vetran, and vetran is about twice as strong as kevlar, which is five to ten times stronger than steel, which is good. They're experimenting with spider silk, believe it or not. Yeah,

they've actually genetically engineered goats to produce spider silk. And I take it maybe their hair grows like that. I have no idea, because I don't know where the silk would come out of the poor goat. Yeah, well we'll look into that, and uh, I think that's a question of the day right there. Yeah, we'll touch on how how do you produce biers still and chicken feathers, as

you said, is a possibility. Um. Researchers in Nebraska are spinning these feathers into a cloth, and it's turns out it's really sturdy because of the honeycomb texture of the feather. So very cool. Go figure one day your body armor might be the same thing that's in your pillow. Yes, And to find out how bullet resistant chickens are. You could shooting with a gun. You can conduct your own field tests. I guess you could. All right, well, chuck,

that's body armor, and actually there's a lot more to it. Um. I would strongly recommend Donald or anyone else who's very interested in it to check it out on our handy search bar. I think this body armor will do. We'll probably bring up some stuff absolutely well. But before we let you go, how was some listener mail? It sounds good to me. So today, keeping with the bullet thing that we've got going on the body armor, we're gonna

read a couple of suggestions for where to get shot. Yes, which one of our recent podcasts we left one part off we did, and both these are pretty good suggestions, So I'll read him real quick. William Hartel, who was a dentist in St. Louis rights and suggests the mouth is a good place to get shot. He is a dentist, like I said, and during his hospital training, he treated

a man who had been shot in the face. When he examined him, it became clear that he had been shot at close range in the cheek and it basically went through one side went out the other never hit any teeth and only did slight damage to the dorsum of his tongue, he said, and obviously two holes in his cheeks. Where's the dorsum? I don't know. I have to look that out. Maybe William can write his back us. Uh the exit side was badly bruised, he said, which

I would figure. But they basically uh stitched him up a few stitches and that was that was all he needed. So the mouth, if you can manage to get shot through your cheeks without it touching anything else, I would agree that your tongue. And then we have Lewis from North Carolina parent parentheses born in Ethiopia says it's very interesting. He said the hand or foot was the best place. Uh even I'm sorry we said that. But he suggests the buttocks. And he's not the only one. There was

another person who suggested the buttocks. Right and now in the podcast we mentioned the bundle of nerves in the pelvic region and he said, if you could manage to get shot in the buttocks and avoid this region, presumably again like the cheek, maybe from the side it would go in this cheek and out the other. I would say that's probably not a bad place to get shot either, other than the fact that you wouldn't be able to sit down and you'd have to land your stomach for

a while, the dorsum of your tongue would remain intact. True. So those are both pretty good suggestions from our readers for a good nice to get shot. And so if you can manage, if you know if you're held at gunpoint, to get the cheek in there, or whether it's on your back side or your face, then you might be doing well. I'd still take a foot any day of

the week. I'd like that not to be challenged. So we want to thank them for writing in, and we want to thank Donald especially a friend in the military serving the United States and Iraq, and all of our friends in the military thing exactly. Thank you very much. I hope you get this podcast and I hope it finds you well along with your fellow soldiers. And maybe

you know what you're wearing protecting you right now. Yeah, and if you want to send an email to us to let us know what you're doing at a given point in time, whether it's walking the streets of Detroit or the streets of Baghdad or whatever. You can email us at Stuff Podcast, how stuff works dot Com for more on this and thousands of other topics. Does it How stuff works dot Com brought to you by the reinvented two thousand twelve camera. It's ready, Are you