M Hey everyone, it's me Josh, and for this week's s y s K Selects, I've chosen our episode on X rays. It's from December two thousand fourteen, because what's more Christmas Eve than discussing electrons changing orbits. I love this one because it's a great example that me and Chuck can do anything we put our minds to. It's just some great bare knuckle s y s K explaining. So I hope you enjoy our episode how x rays work. Welcome to Stuff you Should Know, a production of I Heart Radio. Hey, and welcome to the podcast. I'm Josh Clark with Charles W. Chuck Bryant as always, and there's Jerry over there fiddling around with stuff. So it's stuff you should know the podcast, not stuff you should know. The movie. That's right. You know, we were sworn to secrecy about that. They'd be a good movie, that'd be a bad movie. I don't know, man, it could go either way. I always see I imagine it like Strange Brew. Oh yeah, yes they could. Uh, they could base it on the Stuff you Should Know, Tell all book I'm writing. Oh yeah, that would be exciting, that would be very exciting. I'm looking forward to that book like a Lifetime movie of the Week. Do you like, um switch people's names like a my um Joe Joe Clack? Yeah, exactly. No. Uh, it's sort of like, uh like did you see the Say by the Bell movie? Oh? Yeah, I didn't Screech write a book. It was based on a book by Screech. Right, Yeah, it wasn't it like all sex and drugs and stuff. Oh it was. You know, it was a bunch of teenagers in Hollywood, So sure there was some of that in there, but it was I didn't read the book. But the movie was bad and not nearly as salacious as he wanted it to be. Right. I remember a lot of people being disappointed, and I remember, I mean I recalled it like two weeks ago when people were talking about it when it came out. It's stunk. Watch Emily, and I'll watch some of those, um just terrible, terrible biopics occasionally on TV and it's it can be fun. Like we watched the who was the one actor? Brittany Murphy? The Brittany Murphy story? Oh really, does she have a heck of a story. Is she alive still or did she die? She passed away because under kind of weird circumstances, because she and her husband both passed away within weeks of each other, and there were all these strange claims that her house was poisoned, that they were poisoned, and um, yeah, it was. It was fun. What's your take on it? Oh? I don't know. You just that the movie wasn't very good. Who played Brittany Murphy? Do you remember someone who didn't look very much like Brittney Murphy Julie Bowen. But I was right. The Ashton Kutcher guy was pretty good, though. I gotta say Steve Jobs played him. They should have just gotten Ashton Kutcher to play himself. He's not doing much. He's not my two and a half men. I don't know that got to require fifteen minutes of work a week. He's selling cameras. Do you remember when the whole two and a half man thing was going down? We were in l A And for the one and only time in my entire life, I see John Cryer that day. Oh, during the Charlie Sheen meltdown, like the day of the meltdown, like it happened at night, and within eight hours I saw John cryer for the first time in Personette McDonald's did you heal Duckie? No? I left him alone. He looks stressed out. Well, yeah, he's probably like, my career is going down the tubes, but little did he know he's a survivor. His career is just fine. So X rays. Yeah, that's what we're talking about, right, Yep, the lightest part of this podcast. I like this one. This one. It's one of those things where if you can just hang on by your fingernails, it can click and then you lose it again, but that means that it could click again later on. That's what I like about it. Good. I'll leave that to you. I got lots of other stuff about it, but I totally understand good. Good. Um, So, have you ever broken anything and needed an X ray or has it all just been dental stuff? You know? Dude, never broken a bone? Knock on wood? Yeah, I mean I've had My injuries were always um stitches. I was always getting busted open rocks and sprinklers, and I was always getting cut and sewed back up. But I never broke a bone. That's great. Yeah, you should probably knock on wod one more time, just to be safe. Yeah. Uh so, yeah, all of my X rays to have been like just going to the dentist or whatever. You never had a bone broken. I don't want to say, because I I don't even know if knocking on wood will do it on lambing it ikea. It would just be so horribly interesting if both of us broke a bone after this. Yeah, and we're at the age where like you should break bones when your kid were you like whatever, I get a cast at this age, it's it's a drag. Yeah. I remember reading like a Tom Clancy novel and like some kid got an arm torn off or whatever, and one of the surgeons was like, if the arms in the same room as the kid, it can be yield. That doesn't hold true in your Tom Clancy's age now, So, um, you are familiar with X rays, so you've seen them before You've watched the er surely, Yeah, I mean I've had X rays for like the dental ones, like you said, and then um, just other various like uh like chess X rays for sicknesses and things like that, which I think maybe a little frivolous, to be honest, Yeah, and kind of dangerous really conceivably, which we'll get into later. But um did you were you familiar with X rays it all beyond that? Did you know that they were invented or discovered accidentally? Yeah? I did know that. Um, I did not. That's one of the few things I know. I thought I saw a little like Quickie short on something like it might have been actually Science Channel. I looked all over. The most I could find was a dude on siemens Um just describing it in the most flat affic. I've watched his video. Yeah, I got to five and five wind Low and I was like, forget this. Yeah, if I've never loaded for me, I watched the other fourteen though, and the whole time I was going, man, these are a minute long, please join them all together into one six minute video. No, it was so weird. Yeah, it was pretty silly. But and he was he was good. He was just very dry. Yeah, and they spent zero pennies on any kind of soundtrack or anything like if he grabs papers, you hear papers wrestling in the classrooms. It was. It was pretty straightforward. Yes, but that's a very wind about, roundabout way of getting to uh. It's discovering by German physicist named Wilhelm uh Rundgan, and he was testing whether cathode rays could pass through glass and he saw that the fluorescent screen was glowing when he turned on his electron electron beam, which wasn't a big deal, but he was like, wait, this got cardboard around it, right, there shouldn't be any visible light escaping, which is silly to think of. Now, well, yeah it is, but you have to put yourself in his shoes like X rating had been to discovered because he was literally on the verge of discovering them, right then that's right, and uh yeah, So he was like, this is very curious that this is fluorescing. Yeah, and he noticed other things were glowing, and eventually he started putting other objects between the tube and the screen. They glowed the screen did that is finally put his hand there. I read his wife's hand. Oh really, he's like, either come in here for a second, I want you to try something. It saw bones projected and then I guess probably poo pooed his pants. It's a man, I think, come onto something here. Yeah, it was really that quickly. He was like immediately the application was clear. It wasn't one of those things where it took twenty years. He's like, hold on, you can see bones. This could be really helpful, and he want a Nobel prize very rightfully, so the first one ever for physics. And he named him X rays because he didn't know what the heck it was, no exactly kind of signing your name. He probably right. I think he assumed that later um future scientists would fill in the blanks, but they were like, no, we're cool with X rays. Well, he probably thought that someone would eventually call it like the Rundkin ray for something. He wasn't much of a self promoter. He was just like all this calum X rays as a placeholder. And he didn't patent any anything, you know. He never like made money off that. Uh. And then just as his wife had hand cancer as a result. Really, oh, I was laughing, but no she did. That would be it was. It was just a joke. You can proceed with the la plus I've never heard of hand cancer. It's got to be out there. Uh. And then a couple of years later they were already using it um in the Balkan War was the first time it was really put to practical use. The First Balkan War, the one around World War One. Well no, oh that Baltimore. Um, I didn't know that existed until just now. Yeah, and they said we can see bullets and trapnel and stuff now, um, which is helpful. It is extremely helpful. So like this guy Rundkin discovers X rays and their most practical application in one fell swoop basically, and a little further study revealed the X rays are actually just another part of the electromagnetic spectrum, of which radio waves, microwaves what we call visible light. Um, what else is on there? Uh? Well, I've got handy wallet electromagnetic spectrum card, and X rays fall between gamma rays and ultraviolet rays on that spectrum, which are all below. Well you say below, I don't know if it's it's not really an above or below situation visible light and then infrared, microwave and radio waves, so it would be a higher or lower frequency, because that's how the whole thing is divided. Yeah. So, like the visible spectrum of light consists of electromagnetic radiation that has a frequency a wavelength that our eyes are sensitized too, so we can pick up visible light. There's plenty of other stuff on the spectrum of electromagnetic radiation, and all of it is delineated by the frequency the wavelengths. So at the highest end you have gamma rays. They're like, yeah, that means the squiggly line is very close together exactly. And then on the farthest end you have radio waves are like, and that means the squiggly line as far apart exactly, And that is called chuck science. That's good stuff. Yeah. So back in my wallet X raight right next to the what else you have in there? I just have my PEPs Blue Ribbon membership, which actually do do you really? Yeah, but I've had it for like twenty years. When you you got it when you're like seven eight, flatter me. So, uh, X rays fall, I guess we're about in the well, Yeah, the higher and they have a higher frequency as far as the electro magnetic spectrum goes. But the point is is that it is ultimately the same thing to It's a type of electro magnetic energy that is carried on a photon, which is a particle of what we would call light. Yeah, and we talked about photons a plenty in the show, and uh, the same, like photons produce the visible light that we can see photons blast out from the Sun. How long does it take? Like it takes like a hundred years to get from the core to the surface and then like eight minutes to get from the surface to Earth. That's right, man, that's I love that fact. So this is the only part I understand, So I'll lead with it. If you want to imagine um an atom, a nucleus of an atom and rings around that adiom atium and adam as orbitals. Uh, when an electron drops to a lower orbital, it releases energy in the form of a photon, and the electron will always drop to the lower orbital. That's right. So like if an orbital is if an electron is kicked off of a lower orbital and allow trn in the higher orbital goes yet and drops down to that one. Yes, and depending on how far it drops is going to determine the energy level of that photon. That it's that it releases his energy when it drops, right, yeah, because it doesn't have to, you know, drop more than one orbital. You can skip down I don't even know how far, but a long way, yeah, I can. And like you said that, the greater the distance between the two orbitals are the greater the energy differential, the greater the energy that photon when released will have. Right, that's right. And as we said, photons are the energy carriers of the electromagnetic spectrum. And depending on that energy or the frequency the wavelength of that photon, that determines what kind of photon it is, right, whether it's a radio photon or a an X ray photon, or a photon that we can see that's in the visible spectrum. That's right. Uh, Sometimes when these photons are flying around, they will collide with other atoms, and sometimes those atoms absorb that photons energy and then kick it up to that higher level again, right, But it has to be from what I understand, and I saw that there's like of course it's science, so there's like atomic science, so there's little exceptions did this and that. But from what I could see, Chuck, there is the energy of that photon has to exactly match the energy differential between one orbital and another on an atom so that it can kick it up, so that it hits that one electron in the lower orbital kicks it up to the higher orbital and thus transfers its energy, which means that atom just absorbed that energy that that photon was carrying. Right, But if it's a little less, it's not going to have the energy to kick that electron up, which makes sense to me, right. But if it's a little more, this is what doesn't make sense to me. It doesn't kick the electron up, and then the photon carries on in a diminished energetic state. It just doesn't do anything. It doesn't interact with that. It has to be exactly, say, like the energy differential between orbits is eight, So a photon has to have an energy of eight or else it's not gonna do anything with the atom, that's right, Okay, uh, And so depending on the um. Well, let's say you have a radio wave. They don't have very much energy, so they can't move electrons between these orbitals. They just passed through things. X rays are super powerful. There's lots of energy, so they can pass through things, which is key if you want to check out your bones from outside of your body. It is, so we're back chucking. You tantalized everybody by saying that this, this difference in absorption is what produces X rays, Right? Was that tantalizing? I was tantalized and I even know it's coming. All right, that's how excited I mean about X rays. So consider this, Like different atoms have different atomic weights, they have different densities, they're just different. Like different atoms are different, and atoms also have what are called differences in radiological density. Okay, so a really high energy, high atomic weight, very dense atom is going to be able to absorb a lot of energy. Smaller atoms that maybe are looser and have a lower atomic weight are going to get kicked around by any old photon that wants to come along. Yeah, and that's that's key. Like I said, if you want to see bones because you're soft tissue, if you've ever noticed when you have an X ray, you'll see the bones, but you know the rest is just sort of a grayish black mess exactly because your soft tissue has smaller atoms. Your bones, uh, calcium adams are much larger, so they're gonna absorb those X ray photons. It's exactly right to do it, really well exactly. So um imagine you have uh, let's say, Chuck, let's go back and hang out with Tuck Tuck. Right, Oh man, let's get back in the way back when she's been a while. Okay, look at him over there. So here we are in France in this cave, um Tuck Tuck has his hand up against the cave wall, as you'll see, and in his other hand he's got that little straw filled with pigment, red pigment. He's blowing it on his hand, right, And now that he moves his hand away, there's the outline of his hand. It's called a stencil, right exactly. He's just made an early stencil. He's like banks He basically like a caveman Banksy. But if you look at the back of Tuk Tuk's hand, don't get too close, but look at the back of his hand, it's covered in red pigment, right, So if you can, if you want to equate this to an X ray, the hand absorbed all of that pigment, and the stuff that passed through left the picture on the cave. All that's kind of what happens with an X ray, except with an X ray photograph. The X ray photons are absorbed by the denser calcium rich bones and they passed through the softer tissue. So the picture that we have is the outline the silhouette of the bones because the X rays made it through the tissue, didn't make it through the bones. They made it through the tissue and onto the X ray plate, which absorbed the picture in negative. That's right. And I'm glad you said picture, because that's all it is. On the other side of the human being. You know that they're shooting the X ray at there's a camera and you're just gonna get a regular negative, and they could make it a positive, but they leave it as a negative because you really don't need the positive image. Uh, And that's what they'll put on that little screen to show you your cracked femur exactly. And they can see the crack because some of those X rays will make it through the gap, that's right, right, So all you're seeing is the result of X rays that made it through the tissue were absorbed by the bone, so those don't make it to the plate. The ones that make it to the plate cause the chemical reaction that gives you your negative, your X ray. And it's it's pretty simple, really like if you think about it, at least in principle. It's also extraordinarily difficult to conceive of. But if you if you understand like the principle behind it, it makes uttering complete sense. Yeah. And it's a pretty focused shot that they're using there. It's not like they don't fill the entire room with X rays. You know, They've got a thick lead shield around the whole device, and and it, you know, contains contains everything. It's got a little small window that's just gonna let that narrow beam pass through, uh, through a series of filters and basically hit you wherever they want to hit you. Yeah. And the reason that the they use lead is because lead is an extremely dense uh yeah element, yes, right, sure, oh god, I hope so with a with a very high atomic number, which means it can absorb tons of energy. Right, Yeah, that's why you're gonna wear a lead apron. Um if you're not, you know, if you're getting your skull done, you're probably gonna wear an apron in your chest. Let's say, sure, so you're you're so, this lead is being bombarded with X ray, photons and electrons and it's just taking it. It's fine, and it's not being able to it's not able to pass through because it doesn't have high enough energy. Um. But yes, they when they put that little window in the X ray generating machine, it passes right through there in a concentrated beam. And Chuck, let's talk about the machine, right, So and and this is basic what we use as X ray machines is essentially what root Can was made, what made was experimenting with when he accidentally discovered them. Because if you look for X rays like they're they propagate naturally. But I think like the X rays on Earth come from humans. Really, Yeah, Like we generate a lot of X rays. They don't. They don't come like you don't find them normally on Earth. They're coming from outer space to us, hence X ray astronomy. But the ones here on Earth that are generated on Earth, they don't. It's not like rocks put out X rays or something like that. We do. We humans do. Humans and light aprons put out X rays and they use this machine like root Can made. Yeah, what you have in the machine, you have an electrode pair, cathode, and an anode and that's inside a good old fashioned glass vacuum tube, which, um, it's amazing how vacuum tubes are still like the best way to do many of these things. Well, it allows things to travel at the speed of light easily. It's right, and allows guitar amps to sound great. I didn't know these vacuums and that Oh is that a cathode tube? Yeah? Yeah, like a like the best amps are still made with vacuum tubes. You can get solid state amps, but they're just the sound isn't as rich, So it's kind of like this old technology that's still superior. They're all pumped out by hand by a ninety year old man in Tennessee, Mr Marshall. Yes. Uh so. The cathode is a heated filament, just like you might see in a light bulb, and the machine's gonna pass a current through that and heat that thing up, and then it's gonna spit electrons off that surface, and it's gonna hit a disc made of tungsten and it's gonna draw those across the tube. It's basically the tube is sort of the key piece, right, because you've got the positive and the and the negative charge the cathode and the anode, right yeah. Um, and that difference that electrical charge draws as electrons down to the anode. Yeah, with a lot of force. Yeah, And that forest means that when those electrons hit the tungsten anode, it knocks a bunch of electrons off, creates a bunch of X rays in the process, and um, you have a whole box filled with X ray radiation. That's exactly what it is, like you're just I mean there, there might as well be like a foot crank to this thing, like an old sewing machine. For as as technologically advanced as it is, there may be for all I know, I don't know what goes on in that other room, right, Yeah, there's some dude in there with like his right leg is three times more muscular than his left leg because that's the only one he uses. So um. In addition, like I said to to X rays being created, the the other X rays, other photons can go on and knock more electrons off. So you you have what's like a process of chain reactions starting. Right. It's not like one gets hit and then that's it, and the photons creating it just hangs around until it's beamed out. But you're just generating this huge amount of X rays, and the X rays are also continuing to propagate themselves because they're knocking more electrons free, and the more free electrons you have, the more interactions you have, right, So one of the ways that more electrons can be knocked off. You don't even need a direct transfer of energy where a photon is absorbed or knocks an electron from one orbit to another, or knocks it loose entirely. A photon actually has this really cool um capability of just orbiting close by the nucleus of an atom, and when the nucleus basically draws it into its orbit, the photon just takes a hard left turn, just bumps it off its course. But even like the dodge viper has to like slow down to take a left turn, slow a little bit right, just a little, just a little, But that little bit in the photon world means a transfer of energy from the photon outward an X ray. Yeah, and then the photon, like the photon takes that left turn and and the energy is transferred to the atom. Yeah. And one of the byproducts, h If this sounds like it's gonna create a lot of heat, it's because it will. And in order to combat this, they rotate this anode to keep it. It It would just melt down if you kept it in place. And apparently there's a cool oil bath that helps absorb heat as well, which I never have heard of that either. It sounds oily cool oil bath. Yeah, it doesn't sound refreshing at all. It sounds like the opposite of refreshing. Yeah. Cool and oil don't really go together. Yeah, and I misspoke. That's an electron that can be drawn too into the nucleus of an anom appropriately enough because they orbit nuclei anyway. But it doesn't have to hook hook up with that atom. When it takes that hard left, it admits the photon like you said, that's right. And like I said earlier, there's a camera on the other side of the patient and it's going to record that pattern of light when it passes through the body. And it's not so different from a regular camera. Um. And then the and you're just gonna get a picture, like I said, a negative image. Yeah. And if you hook it up with a computer that allows you to take X rays basically in slices, you can come up with community computerized tomography. If you make a c T right, let's set scan exactly. Um. If you uh, if you use if you get a breast exam, you're using a type of X ray called momography, um, and then there's a fluoroscopy, which the man in the extraordinarily dry presentation from Siemens said, um was basically like moving picture. It's like a movie exactly. And then he showed us what the movie is with a flipbook, right, that old flipbook trick. And if you listen to this podcast, I'm sorry, I just want to apologize for both of us. Semens. Guy. Oh yeah, uh, like, hats off to you for doing that at all. Yeah, um, because he's probably saying, well, at least I was correct and everything I said exactly. It's a good point, sir um. But with fluoroscopy, it's basically like a movie of an X ray movie, and you would do this to make sure like a heart is beating correctly because you wanted to see it. But you have to have an additional um instrument because, as we've said, X rays will pass through tissue like heart tissue and muscle tissue and all and blood vessels and all this stuff you want to get pictures of using an X ray, so you have to use something called the contrast media for it. Yeah. Um. A contrast agent is basically more dense than the soft tissue. So if you want to, uh, let's say, swallow, it's usually like a barium compound. If you want to examine like your blood vessels or your circulatory system, you're sometimes they can inject that, or you might drink it to see if you're doing like a gastro intestinal like a GI tract, You're gonna swallow that stuff, which I've never had to do. I think my dad had to do that. Yeah. I don't think it's super pleasant. I get the impression not too but my dad did as well. Yeah, it's an old dying Yeah, so I should be getting one soon. Uh. And then it allows you, you know, to see him moving image. Uh, basically how that liquid is if there's any blockage. Uh. There's all sorts of applications for it. Yeah, because you're that liquid has a high radiological density, which means that the X rays don't just pass right through your the tissue that it's being suspended in, like your blood vessels, It absorbs it for it. So you get a picture of your blood vessels, your circulatory system, which is pretty cool. It's pretty clever. It's also extraordinarily elementary and principle my dear Watson. Uh, and that single picture I think we know we mentioned CT and momography and all that in philoscopy, but the single picture is just called standard radiography. And that's when you're you know, taking a photo of your skull or your lungs, or your bones or your teeth and so so. Speaking of the lead apron thing, man, it's always made me kind of nervous, Like if I the rest of my body has to wear lead apron, and but you're shooting an X ray into my head? Am I going to be? Okay? Well we'll answer that right after this message. All right, X rays are they bad for you? The answer is yes, uh, pretty unequivocally. Um, But like all things, it's it's in moderation is the key. Uh. In the nineteen thirties and forties and into the fifties, they had X ray machines at shoe stores. They can extra your feet to get a better fit, and um, they didn't realize at the time that they were X raying people way way too much. Yeah, talkative kids in class, they just shoot him with an X ray and they probably did I've got you like twice. Well, now I would believe that like Hey, let's look at his brain. There may be a mouse running around side of it. Um. People in the thirties were dumb. Well, it's basically radiation sickness. Um, it's a form of ionization or ionizing radiation. So what can happen? Like, if just normal light hits an atom, is no big deal. But when an X ray hits an atom, it knocks electrons off of it creates an ion, which is an electrically charged atom, and basically anything from uh, cellular death to mutation can happen at that point, and mutation can spread and it can cause cancer. Right because stable atoms are neutral, right, because they have an equal number of protons and electrons. You lose an electron all of a sudden, you have a positively charged ion and that negatively charged electron running around and it just causes trouble. And you said light, Visible light can be absorbed and it's no big deal because visible light is exists on a wavelength that's about in tune with the soft tissues of our body, right, so we know how to absorb it and it makes us tan and that's cool, right. But Um, with these ionized atoms, these positively charged atoms like going around in your body. It can cause a lot of problems like mutations like cancer. Right. Yeah, I mean if you break that DNA chain, that's not good. No, it is. And one of the results is the d The DNA can basically lose its ability to regulate itself and the cell replicates more frequently than it should and all of a sudden, you have a tumor on your hands and that can spread. It can also be a problem if that d NA break occurs in utero, because then that can lead to birth defects, which is why pregnant women shouldn't get X rays um. And it can also just lead to plain old cellular death. If you have cellular death, then the tissues that are made up by those cells breakdown, and uh, you have a problem on your hands with that as well. So here's the deal. We get exposed to radiation every day just walking around on the planet. Yeah. Um, it depends on where you live. But every year, um, the average person is going to be exposed to anywhere from one to four Uh. It's measured in millisieverts per year um. Like I said, depending on where you are. I think in higher elevations it's less then at sea level. So if you live in Denver, Colorado, you're going to be exposed to less well yeah, because definitely you're higher up in the atmosphere and that makes a difference. Exactly you have less protection, right Yeah. So, um, you know what they what they want to do medically speaking, they want to use, or they're supposed to use the minimum amount to achieve the pictures you need. It's not like the old days where they're just like, let's twenty X rays. Yeah, like, let's do the minimum amount we need to get the information that we need. A CT scan can can get your you know, you lay down in the tube and it rotates around you and your whole body can be photographed in less than five seconds days. But um, you know there are concerns if you get too many X rays still, uh like a dental panorama. I think would I say one to four millisy verts per year and it's cumulative to you should like, it's not. It's not like you get one and then you know, eight months later you get another one and that first one went away, Like it accumulates over the course of a year. Yeah. So here's just a few examples of how much radiation you're being exposed to with X rays. UM, a dental panorama is going to be point zero one millisy verts, so not very much. UM, Like two chest X rays might be point one mam or grammars around point four. Uh, your pelvis point six, your back, upper back maybe one point zero. Uh. I wonder why because there's so maybe yeah, maybe you have to do with exposure to Yeah, that makes sense. I got a ton of bone of my upper back. A full CT scan, it depends on what you are, UM, it depends on what you're X raying. But CT scan is obviously more like an abdominal or pelvis c T CT scan because be as many as ten millis everts. So that's like up to two or three years worth of radiation in a single CT scan, which can be problematic, which is why they don't say get in the CT machine like every other week. UM. But you know some of the reasons you might if you had a traumatic injury, they're gonna X ray you a lot of times for disease confirmation. They'll use an X ray machine. Uh. During surgery as a visual guide, Like if you do endoscopic surgery, the surgeons actually needs to look at something, so sometimes the X rays for that or to monitor your healing process. Um, you know, when you break a bone, it's not just that first X ray. You're gonna keep getting them to see how you're healing up video. Huh no, it isn't. Okay, I don't think so. I mean I look at so much stuff at all other cumulative research. So, uh, I did a brain stuff on siverts and how many we can take and uh, yeah, it's it's kind of like it's a little alarming. Sure how much radiation we're expposed to. People who fly a lot too, are exposed to tons of radiation because you're again higher up in the atmosphere, so you're less protected by the atmosphere. Speaking of flying, of course, baggage that is X rayed. The food industries is X rays a lot. Um archaeologists use it if they don't want to like destroy an object and they want to see what's inside, or earth sciences will use X rays for rocks to see what kind of mineral composition. So there's all sorts of applications. It's not just medical. Um space, yeah, X ray telescopes out on on satellites apparently you can see a lot um. You can see things you can't detect from an earthbound telescope because X rays are absorbed by our atmosphere, so he can't like shoot it into space like that. So this article makes a pretty good point if you ask me, it says like, yes, X rays are like are bad for you, and you should use them with care and caution. And one one good point is to always ask if there's an alternative to an X ray, just to basically say, hey, doc or dennists, slow your role. Let's is there another way we can get this information without an X ray. I know it's the easiest, but what are the alternatives? But then the article makes the point like it's still safer than the ultimate alternative, the thing that X rays replaced, which was exploratory surgery. Yeah, back in the day, if you they thought you had cancer, they would cut you open and see and this is definitely better than that or broken bone. Imagine getting that arm cut open just to see how it's doing. They're like, no, it's not broken, right, And we haven't invented anesthetic yet. So good luck with your dentist. By the way, because um, I always get the feeling that the dentists are like, No, your insurance allows us to build for so many per years, said, that's how many you're going to get? These X rays are putting my kid through college. Yeah. Uh, you got anything else on X rays? No, that was a fine amount of stuff. I'm feeling good about it. You feel good about this one? Sure I do too. Yeah. Uh. If you want to know more about X rays, you can check out this really informative article on how stuff works dot com. It's got some great diagrams that explain a lot of the stuff we were saying visually. Uh. And you can type x ray into the search bar how stuff works and it will bring that up. Since I said search parts. Time for listener mail. Uh, this is from my buddy Poppy and Vancouver. Uh stuff you should don't listen to them, meant while I was there, and um, Poppy as this is say, he's got a pretty cool job. He listened to the PTSD show and wanted to write in about another option that he works with. He's a registered acupuncturist in Vancouver with special training and trauma and addictions. He's a program called Neurotrophic Stimulation Therapy h n T. S T and a large part of the program uses ear acupuncture and electro acupuncture to promote neuroplasticity in the brain. He says, you can't necessarily directly fix the brain, but you can stimulate the ear nerves and will help the brain reregulate certain functionality so it can heal itself. He's been treating trauma and PTSD patients for several years and the evidence for his efficacy is high. It can be done with acupuncture needles alone or in combination with a mild electrical stimulation UM. Remember we talked about UM. Transcranial electro magnetic stimulation. Yeah, transdermal cranial stimulation. He says that's one of the things that he's also using to treat PTSD, which is pretty cool, and he said it makes cognitive behavioral therapies so much easier to introduce because it promotes neuroplasticity and the results help a PTSD suffer to be more open to and able to receive positive social programming. So he has a program we want to promote. If you want to see all the components in action in his program, you can visit Last or Recovery Society at Last Door dot org, slash nt s T or you can donate funds to help purchase a brain scanner so that they can scientifically measure the results of the program, which would really help show the validity of the therapies. And if you're interested in helping out Poppies, cause there because he's really big on treating veterans in Canada in the US, um I shortened his little U r L too bitley b I T dot L Y slash one one y n l o Q and that is from Poppy and he says, no mistay, thanks a lot, Poppy. Is it Poppy with the O P O P P I nice? Uh. If you want to get in touch with us, you can tweet to us at s y s K podcast. You can join us on Facebook, dot com, slash Stuff you Should Know. You can send us an email to stuff podcast at how stuff Works dot com. That's right, uh, and as always, join us at at home on the web. Stuff you Should Know dot Com. Stuff you Should Know is a pretty action of I heart Radio. For more podcasts my heart Radio, visit the i heart Radio app, Apple Podcasts, or wherever you listen to your favorite shows. H

M Hey everyone, it's me Josh, and for this week's s y s K Selects, I've chosen our episode on X rays. It's from December two thousand fourteen, because what's more Christmas Eve than discussing electrons changing orbits. I love this one because it's a great example that me and Chuck can do anything we put our minds to. It's just some great bare knuckle s y s K explaining. So I hope you enjoy our episode how x rays work. Welcome to Stuff you Should Know, a production of I Heart Radio. Hey, and welcome to the podcast. I'm Josh Clark with Charles W. Chuck Bryant as always, and there's Jerry over there fiddling around with stuff. So it's stuff you should know the podcast, not stuff you should know. The movie. That's right. You know, we were sworn to secrecy about that. They'd be a good movie, that'd be a bad movie. I don't know, man, it could go either way. I always see I imagine it like Strange Brew. Oh yeah, yes they could. Uh, they could base it on the Stuff you Should Know, Tell all book I'm writing. Oh yeah, that would be exciting, that would be very exciting. I'm looking forward to that book like a Lifetime movie of the Week. Do you like, um switch people's names like a my um Joe Joe Clack? Yeah, exactly. No. Uh, it's sort of like, uh like did you see the Say by the Bell movie? Oh? Yeah, I didn't Screech write a book. It was based on a book by Screech. Right, Yeah, it wasn't it like all sex and drugs and stuff. Oh it was. You know, it was a bunch of teenagers in Hollywood, So sure there was some of that in there, but it was I didn't read the book. But the movie was bad and not nearly as salacious as he wanted it to be. Right. I remember a lot of people being disappointed, and I remember, I mean I recalled it like two weeks ago when people were talking about it when it came out. It's stunk. Watch Emily, and I'll watch some of those, um just terrible, terrible biopics occasionally on TV and it's it can be fun. Like we watched the who was the one actor? Brittany Murphy? The Brittany Murphy story? Oh really, does she have a heck of a story. Is she alive still or did she die? She passed away because under kind of weird circumstances, because she and her husband both passed away within weeks of each other, and there were all these strange claims that her house was poisoned, that they were poisoned, and um, yeah, it was. It was fun. What's your take on it? Oh? I don't know. You just that the movie wasn't very good. Who played Brittany Murphy? Do you remember someone who didn't look very much like Brittney Murphy Julie Bowen. But I was right. The Ashton Kutcher guy was pretty good, though. I gotta say Steve Jobs played him. They should have just gotten Ashton Kutcher to play himself. He's not doing much. He's not my two and a half men. I don't know that got to require fifteen minutes of work a week. He's selling cameras. Do you remember when the whole two and a half man thing was going down? We were in l A And for the one and only time in my entire life, I see John Cryer that day. Oh, during the Charlie Sheen meltdown, like the day of the meltdown, like it happened at night, and within eight hours I saw John cryer for the first time in Personette McDonald's did you heal Duckie? No? I left him alone. He looks stressed out. Well, yeah, he's probably like, my career is going down the tubes, but little did he know he's a survivor. His career is just fine. So X rays. Yeah, that's what we're talking about, right, Yep, the lightest part of this podcast. I like this one. This one. It's one of those things where if you can just hang on by your fingernails, it can click and then you lose it again, but that means that it could click again later on. That's what I like about it. Good. I'll leave that to you. I got lots of other stuff about it, but I totally understand good. Good. Um, So, have you ever broken anything and needed an X ray or has it all just been dental stuff? You know? Dude, never broken a bone? Knock on wood? Yeah, I mean I've had My injuries were always um stitches. I was always getting busted open rocks and sprinklers, and I was always getting cut and sewed back up. But I never broke a bone. That's great. Yeah, you should probably knock on wod one more time, just to be safe. Yeah. Uh so, yeah, all of my X rays to have been like just going to the dentist or whatever. You never had a bone broken. I don't want to say, because I I don't even know if knocking on wood will do it on lambing it ikea. It would just be so horribly interesting if both of us broke a bone after this. Yeah, and we're at the age where like you should break bones when your kid were you like whatever, I get a cast at this age, it's it's a drag. Yeah. I remember reading like a Tom Clancy novel and like some kid got an arm torn off or whatever, and one of the surgeons was like, if the arms in the same room as the kid, it can be yield. That doesn't hold true in your Tom Clancy's age now, So, um, you are familiar with X rays, so you've seen them before You've watched the er surely, Yeah, I mean I've had X rays for like the dental ones, like you said, and then um, just other various like uh like chess X rays for sicknesses and things like that, which I think maybe a little frivolous, to be honest, Yeah, and kind of dangerous really conceivably, which we'll get into later. But um did you were you familiar with X rays it all beyond that? Did you know that they were invented or discovered accidentally? Yeah? I did know that. Um, I did not. That's one of the few things I know. I thought I saw a little like Quickie short on something like it might have been actually Science Channel. I looked all over. The most I could find was a dude on siemens Um just describing it in the most flat affic. I've watched his video. Yeah, I got to five and five wind Low and I was like, forget this. Yeah, if I've never loaded for me, I watched the other fourteen though, and the whole time I was going, man, these are a minute long, please join them all together into one six minute video. No, it was so weird. Yeah, it was pretty silly. But and he was he was good. He was just very dry. Yeah, and they spent zero pennies on any kind of soundtrack or anything like if he grabs papers, you hear papers wrestling in the classrooms. It was. It was pretty straightforward. Yes, but that's a very wind about, roundabout way of getting to uh. It's discovering by German physicist named Wilhelm uh Rundgan, and he was testing whether cathode rays could pass through glass and he saw that the fluorescent screen was glowing when he turned on his electron electron beam, which wasn't a big deal, but he was like, wait, this got cardboard around it, right, there shouldn't be any visible light escaping, which is silly to think of. Now, well, yeah it is, but you have to put yourself in his shoes like X rating had been to discovered because he was literally on the verge of discovering them, right then that's right, and uh yeah, So he was like, this is very curious that this is fluorescing. Yeah, and he noticed other things were glowing, and eventually he started putting other objects between the tube and the screen. They glowed the screen did that is finally put his hand there. I read his wife's hand. Oh really, he's like, either come in here for a second, I want you to try something. It saw bones projected and then I guess probably poo pooed his pants. It's a man, I think, come onto something here. Yeah, it was really that quickly. He was like immediately the application was clear. It wasn't one of those things where it took twenty years. He's like, hold on, you can see bones. This could be really helpful, and he want a Nobel prize very rightfully, so the first one ever for physics. And he named him X rays because he didn't know what the heck it was, no exactly kind of signing your name. He probably right. I think he assumed that later um future scientists would fill in the blanks, but they were like, no, we're cool with X rays. Well, he probably thought that someone would eventually call it like the Rundkin ray for something. He wasn't much of a self promoter. He was just like all this calum X rays as a placeholder. And he didn't patent any anything, you know. He never like made money off that. Uh. And then just as his wife had hand cancer as a result. Really, oh, I was laughing, but no she did. That would be it was. It was just a joke. You can proceed with the la plus I've never heard of hand cancer. It's got to be out there. Uh. And then a couple of years later they were already using it um in the Balkan War was the first time it was really put to practical use. The First Balkan War, the one around World War One. Well no, oh that Baltimore. Um, I didn't know that existed until just now. Yeah, and they said we can see bullets and trapnel and stuff now, um, which is helpful. It is extremely helpful. So like this guy Rundkin discovers X rays and their most practical application in one fell swoop basically, and a little further study revealed the X rays are actually just another part of the electromagnetic spectrum, of which radio waves, microwaves what we call visible light. Um, what else is on there? Uh? Well, I've got handy wallet electromagnetic spectrum card, and X rays fall between gamma rays and ultraviolet rays on that spectrum, which are all below. Well you say below, I don't know if it's it's not really an above or below situation visible light and then infrared, microwave and radio waves, so it would be a higher or lower frequency, because that's how the whole thing is divided. Yeah. So, like the visible spectrum of light consists of electromagnetic radiation that has a frequency a wavelength that our eyes are sensitized too, so we can pick up visible light. There's plenty of other stuff on the spectrum of electromagnetic radiation, and all of it is delineated by the frequency the wavelengths. So at the highest end you have gamma rays. They're like, yeah, that means the squiggly line is very close together exactly. And then on the farthest end you have radio waves are like, and that means the squiggly line as far apart exactly, And that is called chuck science. That's good stuff. Yeah. So back in my wallet X raight right next to the what else you have in there? I just have my PEPs Blue Ribbon membership, which actually do do you really? Yeah, but I've had it for like twenty years. When you you got it when you're like seven eight, flatter me. So, uh, X rays fall, I guess we're about in the well, Yeah, the higher and they have a higher frequency as far as the electro magnetic spectrum goes. But the point is is that it is ultimately the same thing to It's a type of electro magnetic energy that is carried on a photon, which is a particle of what we would call light. Yeah, and we talked about photons a plenty in the show, and uh, the same, like photons produce the visible light that we can see photons blast out from the Sun. How long does it take? Like it takes like a hundred years to get from the core to the surface and then like eight minutes to get from the surface to Earth. That's right, man, that's I love that fact. So this is the only part I understand, So I'll lead with it. If you want to imagine um an atom, a nucleus of an atom and rings around that adiom atium and adam as orbitals. Uh, when an electron drops to a lower orbital, it releases energy in the form of a photon, and the electron will always drop to the lower orbital. That's right. So like if an orbital is if an electron is kicked off of a lower orbital and allow trn in the higher orbital goes yet and drops down to that one. Yes, and depending on how far it drops is going to determine the energy level of that photon. That it's that it releases his energy when it drops, right, yeah, because it doesn't have to, you know, drop more than one orbital. You can skip down I don't even know how far, but a long way, yeah, I can. And like you said that, the greater the distance between the two orbitals are the greater the energy differential, the greater the energy that photon when released will have. Right, that's right. And as we said, photons are the energy carriers of the electromagnetic spectrum. And depending on that energy or the frequency the wavelength of that photon, that determines what kind of photon it is, right, whether it's a radio photon or a an X ray photon, or a photon that we can see that's in the visible spectrum. That's right. Uh, Sometimes when these photons are flying around, they will collide with other atoms, and sometimes those atoms absorb that photons energy and then kick it up to that higher level again, right, But it has to be from what I understand, and I saw that there's like of course it's science, so there's like atomic science, so there's little exceptions did this and that. But from what I could see, Chuck, there is the energy of that photon has to exactly match the energy differential between one orbital and another on an atom so that it can kick it up, so that it hits that one electron in the lower orbital kicks it up to the higher orbital and thus transfers its energy, which means that atom just absorbed that energy that that photon was carrying. Right, But if it's a little less, it's not going to have the energy to kick that electron up, which makes sense to me, right. But if it's a little more, this is what doesn't make sense to me. It doesn't kick the electron up, and then the photon carries on in a diminished energetic state. It just doesn't do anything. It doesn't interact with that. It has to be exactly, say, like the energy differential between orbits is eight, So a photon has to have an energy of eight or else it's not gonna do anything with the atom, that's right, Okay, uh, And so depending on the um. Well, let's say you have a radio wave. They don't have very much energy, so they can't move electrons between these orbitals. They just passed through things. X rays are super powerful. There's lots of energy, so they can pass through things, which is key if you want to check out your bones from outside of your body. It is, so we're back chucking. You tantalized everybody by saying that this, this difference in absorption is what produces X rays, Right? Was that tantalizing? I was tantalized and I even know it's coming. All right, that's how excited I mean about X rays. So consider this, Like different atoms have different atomic weights, they have different densities, they're just different. Like different atoms are different, and atoms also have what are called differences in radiological density. Okay, so a really high energy, high atomic weight, very dense atom is going to be able to absorb a lot of energy. Smaller atoms that maybe are looser and have a lower atomic weight are going to get kicked around by any old photon that wants to come along. Yeah, and that's that's key. Like I said, if you want to see bones because you're soft tissue, if you've ever noticed when you have an X ray, you'll see the bones, but you know the rest is just sort of a grayish black mess exactly because your soft tissue has smaller atoms. Your bones, uh, calcium adams are much larger, so they're gonna absorb those X ray photons. It's exactly right to do it, really well exactly. So um imagine you have uh, let's say, Chuck, let's go back and hang out with Tuck Tuck. Right, Oh man, let's get back in the way back when she's been a while. Okay, look at him over there. So here we are in France in this cave, um Tuck Tuck has his hand up against the cave wall, as you'll see, and in his other hand he's got that little straw filled with pigment, red pigment. He's blowing it on his hand, right, And now that he moves his hand away, there's the outline of his hand. It's called a stencil, right exactly. He's just made an early stencil. He's like banks He basically like a caveman Banksy. But if you look at the back of Tuk Tuk's hand, don't get too close, but look at the back of his hand, it's covered in red pigment, right, So if you can, if you want to equate this to an X ray, the hand absorbed all of that pigment, and the stuff that passed through left the picture on the cave. All that's kind of what happens with an X ray, except with an X ray photograph. The X ray photons are absorbed by the denser calcium rich bones and they passed through the softer tissue. So the picture that we have is the outline the silhouette of the bones because the X rays made it through the tissue, didn't make it through the bones. They made it through the tissue and onto the X ray plate, which absorbed the picture in negative. That's right. And I'm glad you said picture, because that's all it is. On the other side of the human being. You know that they're shooting the X ray at there's a camera and you're just gonna get a regular negative, and they could make it a positive, but they leave it as a negative because you really don't need the positive image. Uh, And that's what they'll put on that little screen to show you your cracked femur exactly. And they can see the crack because some of those X rays will make it through the gap, that's right, right, So all you're seeing is the result of X rays that made it through the tissue were absorbed by the bone, so those don't make it to the plate. The ones that make it to the plate cause the chemical reaction that gives you your negative, your X ray. And it's it's pretty simple, really like if you think about it, at least in principle. It's also extraordinarily difficult to conceive of. But if you if you understand like the principle behind it, it makes uttering complete sense. Yeah. And it's a pretty focused shot that they're using there. It's not like they don't fill the entire room with X rays. You know, They've got a thick lead shield around the whole device, and and it, you know, contains contains everything. It's got a little small window that's just gonna let that narrow beam pass through, uh, through a series of filters and basically hit you wherever they want to hit you. Yeah. And the reason that the they use lead is because lead is an extremely dense uh yeah element, yes, right, sure, oh god, I hope so with a with a very high atomic number, which means it can absorb tons of energy. Right, Yeah, that's why you're gonna wear a lead apron. Um if you're not, you know, if you're getting your skull done, you're probably gonna wear an apron in your chest. Let's say, sure, so you're you're so, this lead is being bombarded with X ray, photons and electrons and it's just taking it. It's fine, and it's not being able to it's not able to pass through because it doesn't have high enough energy. Um. But yes, they when they put that little window in the X ray generating machine, it passes right through there in a concentrated beam. And Chuck, let's talk about the machine, right, So and and this is basic what we use as X ray machines is essentially what root Can was made, what made was experimenting with when he accidentally discovered them. Because if you look for X rays like they're they propagate naturally. But I think like the X rays on Earth come from humans. Really, Yeah, Like we generate a lot of X rays. They don't. They don't come like you don't find them normally on Earth. They're coming from outer space to us, hence X ray astronomy. But the ones here on Earth that are generated on Earth, they don't. It's not like rocks put out X rays or something like that. We do. We humans do. Humans and light aprons put out X rays and they use this machine like root Can made. Yeah, what you have in the machine, you have an electrode pair, cathode, and an anode and that's inside a good old fashioned glass vacuum tube, which, um, it's amazing how vacuum tubes are still like the best way to do many of these things. Well, it allows things to travel at the speed of light easily. It's right, and allows guitar amps to sound great. I didn't know these vacuums and that Oh is that a cathode tube? Yeah? Yeah, like a like the best amps are still made with vacuum tubes. You can get solid state amps, but they're just the sound isn't as rich, So it's kind of like this old technology that's still superior. They're all pumped out by hand by a ninety year old man in Tennessee, Mr Marshall. Yes. Uh so. The cathode is a heated filament, just like you might see in a light bulb, and the machine's gonna pass a current through that and heat that thing up, and then it's gonna spit electrons off that surface, and it's gonna hit a disc made of tungsten and it's gonna draw those across the tube. It's basically the tube is sort of the key piece, right, because you've got the positive and the and the negative charge the cathode and the anode, right yeah. Um, and that difference that electrical charge draws as electrons down to the anode. Yeah, with a lot of force. Yeah, And that forest means that when those electrons hit the tungsten anode, it knocks a bunch of electrons off, creates a bunch of X rays in the process, and um, you have a whole box filled with X ray radiation. That's exactly what it is, like you're just I mean there, there might as well be like a foot crank to this thing, like an old sewing machine. For as as technologically advanced as it is, there may be for all I know, I don't know what goes on in that other room, right, Yeah, there's some dude in there with like his right leg is three times more muscular than his left leg because that's the only one he uses. So um. In addition, like I said to to X rays being created, the the other X rays, other photons can go on and knock more electrons off. So you you have what's like a process of chain reactions starting. Right. It's not like one gets hit and then that's it, and the photons creating it just hangs around until it's beamed out. But you're just generating this huge amount of X rays, and the X rays are also continuing to propagate themselves because they're knocking more electrons free, and the more free electrons you have, the more interactions you have, right, So one of the ways that more electrons can be knocked off. You don't even need a direct transfer of energy where a photon is absorbed or knocks an electron from one orbit to another, or knocks it loose entirely. A photon actually has this really cool um capability of just orbiting close by the nucleus of an atom, and when the nucleus basically draws it into its orbit, the photon just takes a hard left turn, just bumps it off its course. But even like the dodge viper has to like slow down to take a left turn, slow a little bit right, just a little, just a little, But that little bit in the photon world means a transfer of energy from the photon outward an X ray. Yeah, and then the photon, like the photon takes that left turn and and the energy is transferred to the atom. Yeah. And one of the byproducts, h If this sounds like it's gonna create a lot of heat, it's because it will. And in order to combat this, they rotate this anode to keep it. It It would just melt down if you kept it in place. And apparently there's a cool oil bath that helps absorb heat as well, which I never have heard of that either. It sounds oily cool oil bath. Yeah, it doesn't sound refreshing at all. It sounds like the opposite of refreshing. Yeah. Cool and oil don't really go together. Yeah, and I misspoke. That's an electron that can be drawn too into the nucleus of an anom appropriately enough because they orbit nuclei anyway. But it doesn't have to hook hook up with that atom. When it takes that hard left, it admits the photon like you said, that's right. And like I said earlier, there's a camera on the other side of the patient and it's going to record that pattern of light when it passes through the body. And it's not so different from a regular camera. Um. And then the and you're just gonna get a picture, like I said, a negative image. Yeah. And if you hook it up with a computer that allows you to take X rays basically in slices, you can come up with community computerized tomography. If you make a c T right, let's set scan exactly. Um. If you uh, if you use if you get a breast exam, you're using a type of X ray called momography, um, and then there's a fluoroscopy, which the man in the extraordinarily dry presentation from Siemens said, um was basically like moving picture. It's like a movie exactly. And then he showed us what the movie is with a flipbook, right, that old flipbook trick. And if you listen to this podcast, I'm sorry, I just want to apologize for both of us. Semens. Guy. Oh yeah, uh, like, hats off to you for doing that at all. Yeah, um, because he's probably saying, well, at least I was correct and everything I said exactly. It's a good point, sir um. But with fluoroscopy, it's basically like a movie of an X ray movie, and you would do this to make sure like a heart is beating correctly because you wanted to see it. But you have to have an additional um instrument because, as we've said, X rays will pass through tissue like heart tissue and muscle tissue and all and blood vessels and all this stuff you want to get pictures of using an X ray, so you have to use something called the contrast media for it. Yeah. Um. A contrast agent is basically more dense than the soft tissue. So if you want to, uh, let's say, swallow, it's usually like a barium compound. If you want to examine like your blood vessels or your circulatory system, you're sometimes they can inject that, or you might drink it to see if you're doing like a gastro intestinal like a GI tract, You're gonna swallow that stuff, which I've never had to do. I think my dad had to do that. Yeah. I don't think it's super pleasant. I get the impression not too but my dad did as well. Yeah, it's an old dying Yeah, so I should be getting one soon. Uh. And then it allows you, you know, to see him moving image. Uh, basically how that liquid is if there's any blockage. Uh. There's all sorts of applications for it. Yeah, because you're that liquid has a high radiological density, which means that the X rays don't just pass right through your the tissue that it's being suspended in, like your blood vessels, It absorbs it for it. So you get a picture of your blood vessels, your circulatory system, which is pretty cool. It's pretty clever. It's also extraordinarily elementary and principle my dear Watson. Uh, and that single picture I think we know we mentioned CT and momography and all that in philoscopy, but the single picture is just called standard radiography. And that's when you're you know, taking a photo of your skull or your lungs, or your bones or your teeth and so so. Speaking of the lead apron thing, man, it's always made me kind of nervous, Like if I the rest of my body has to wear lead apron, and but you're shooting an X ray into my head? Am I going to be? Okay? Well we'll answer that right after this message. All right, X rays are they bad for you? The answer is yes, uh, pretty unequivocally. Um, But like all things, it's it's in moderation is the key. Uh. In the nineteen thirties and forties and into the fifties, they had X ray machines at shoe stores. They can extra your feet to get a better fit, and um, they didn't realize at the time that they were X raying people way way too much. Yeah, talkative kids in class, they just shoot him with an X ray and they probably did I've got you like twice. Well, now I would believe that like Hey, let's look at his brain. There may be a mouse running around side of it. Um. People in the thirties were dumb. Well, it's basically radiation sickness. Um, it's a form of ionization or ionizing radiation. So what can happen? Like, if just normal light hits an atom, is no big deal. But when an X ray hits an atom, it knocks electrons off of it creates an ion, which is an electrically charged atom, and basically anything from uh, cellular death to mutation can happen at that point, and mutation can spread and it can cause cancer. Right because stable atoms are neutral, right, because they have an equal number of protons and electrons. You lose an electron all of a sudden, you have a positively charged ion and that negatively charged electron running around and it just causes trouble. And you said light, Visible light can be absorbed and it's no big deal because visible light is exists on a wavelength that's about in tune with the soft tissues of our body, right, so we know how to absorb it and it makes us tan and that's cool, right. But Um, with these ionized atoms, these positively charged atoms like going around in your body. It can cause a lot of problems like mutations like cancer. Right. Yeah, I mean if you break that DNA chain, that's not good. No, it is. And one of the results is the d The DNA can basically lose its ability to regulate itself and the cell replicates more frequently than it should and all of a sudden, you have a tumor on your hands and that can spread. It can also be a problem if that d NA break occurs in utero, because then that can lead to birth defects, which is why pregnant women shouldn't get X rays um. And it can also just lead to plain old cellular death. If you have cellular death, then the tissues that are made up by those cells breakdown, and uh, you have a problem on your hands with that as well. So here's the deal. We get exposed to radiation every day just walking around on the planet. Yeah. Um, it depends on where you live. But every year, um, the average person is going to be exposed to anywhere from one to four Uh. It's measured in millisieverts per year um. Like I said, depending on where you are. I think in higher elevations it's less then at sea level. So if you live in Denver, Colorado, you're going to be exposed to less well yeah, because definitely you're higher up in the atmosphere and that makes a difference. Exactly you have less protection, right Yeah. So, um, you know what they what they want to do medically speaking, they want to use, or they're supposed to use the minimum amount to achieve the pictures you need. It's not like the old days where they're just like, let's twenty X rays. Yeah, like, let's do the minimum amount we need to get the information that we need. A CT scan can can get your you know, you lay down in the tube and it rotates around you and your whole body can be photographed in less than five seconds days. But um, you know there are concerns if you get too many X rays still, uh like a dental panorama. I think would I say one to four millisy verts per year and it's cumulative to you should like, it's not. It's not like you get one and then you know, eight months later you get another one and that first one went away, Like it accumulates over the course of a year. Yeah. So here's just a few examples of how much radiation you're being exposed to with X rays. UM, a dental panorama is going to be point zero one millisy verts, so not very much. UM, Like two chest X rays might be point one mam or grammars around point four. Uh, your pelvis point six, your back, upper back maybe one point zero. Uh. I wonder why because there's so maybe yeah, maybe you have to do with exposure to Yeah, that makes sense. I got a ton of bone of my upper back. A full CT scan, it depends on what you are, UM, it depends on what you're X raying. But CT scan is obviously more like an abdominal or pelvis c T CT scan because be as many as ten millis everts. So that's like up to two or three years worth of radiation in a single CT scan, which can be problematic, which is why they don't say get in the CT machine like every other week. UM. But you know some of the reasons you might if you had a traumatic injury, they're gonna X ray you a lot of times for disease confirmation. They'll use an X ray machine. Uh. During surgery as a visual guide, Like if you do endoscopic surgery, the surgeons actually needs to look at something, so sometimes the X rays for that or to monitor your healing process. Um, you know, when you break a bone, it's not just that first X ray. You're gonna keep getting them to see how you're healing up video. Huh no, it isn't. Okay, I don't think so. I mean I look at so much stuff at all other cumulative research. So, uh, I did a brain stuff on siverts and how many we can take and uh, yeah, it's it's kind of like it's a little alarming. Sure how much radiation we're expposed to. People who fly a lot too, are exposed to tons of radiation because you're again higher up in the atmosphere, so you're less protected by the atmosphere. Speaking of flying, of course, baggage that is X rayed. The food industries is X rays a lot. Um archaeologists use it if they don't want to like destroy an object and they want to see what's inside, or earth sciences will use X rays for rocks to see what kind of mineral composition. So there's all sorts of applications. It's not just medical. Um space, yeah, X ray telescopes out on on satellites apparently you can see a lot um. You can see things you can't detect from an earthbound telescope because X rays are absorbed by our atmosphere, so he can't like shoot it into space like that. So this article makes a pretty good point if you ask me, it says like, yes, X rays are like are bad for you, and you should use them with care and caution. And one one good point is to always ask if there's an alternative to an X ray, just to basically say, hey, doc or dennists, slow your role. Let's is there another way we can get this information without an X ray. I know it's the easiest, but what are the alternatives? But then the article makes the point like it's still safer than the ultimate alternative, the thing that X rays replaced, which was exploratory surgery. Yeah, back in the day, if you they thought you had cancer, they would cut you open and see and this is definitely better than that or broken bone. Imagine getting that arm cut open just to see how it's doing. They're like, no, it's not broken, right, And we haven't invented anesthetic yet. So good luck with your dentist. By the way, because um, I always get the feeling that the dentists are like, No, your insurance allows us to build for so many per years, said, that's how many you're going to get? These X rays are putting my kid through college. Yeah. Uh, you got anything else on X rays? No, that was a fine amount of stuff. I'm feeling good about it. You feel good about this one? Sure I do too. Yeah. Uh. If you want to know more about X rays, you can check out this really informative article on how stuff works dot com. It's got some great diagrams that explain a lot of the stuff we were saying visually. Uh. And you can type x ray into the search bar how stuff works and it will bring that up. Since I said search parts. Time for listener mail. Uh, this is from my buddy Poppy and Vancouver. Uh stuff you should don't listen to them, meant while I was there, and um, Poppy as this is say, he's got a pretty cool job. He listened to the PTSD show and wanted to write in about another option that he works with. He's a registered acupuncturist in Vancouver with special training and trauma and addictions. He's a program called Neurotrophic Stimulation Therapy h n T. S T and a large part of the program uses ear acupuncture and electro acupuncture to promote neuroplasticity in the brain. He says, you can't necessarily directly fix the brain, but you can stimulate the ear nerves and will help the brain reregulate certain functionality so it can heal itself. He's been treating trauma and PTSD patients for several years and the evidence for his efficacy is high. It can be done with acupuncture needles alone or in combination with a mild electrical stimulation UM. Remember we talked about UM. Transcranial electro magnetic stimulation. Yeah, transdermal cranial stimulation. He says that's one of the things that he's also using to treat PTSD, which is pretty cool, and he said it makes cognitive behavioral therapies so much easier to introduce because it promotes neuroplasticity and the results help a PTSD suffer to be more open to and able to receive positive social programming. So he has a program we want to promote. If you want to see all the components in action in his program, you can visit Last or Recovery Society at Last Door dot org, slash nt s T or you can donate funds to help purchase a brain scanner so that they can scientifically measure the results of the program, which would really help show the validity of the therapies. And if you're interested in helping out Poppies, cause there because he's really big on treating veterans in Canada in the US, um I shortened his little U r L too bitley b I T dot L Y slash one one y n l o Q and that is from Poppy and he says, no mistay, thanks a lot, Poppy. Is it Poppy with the O P O P P I nice? Uh. If you want to get in touch with us, you can tweet to us at s y s K podcast. You can join us on Facebook, dot com, slash Stuff you Should Know. You can send us an email to stuff podcast at how stuff Works dot com. That's right, uh, and as always, join us at at home on the web. Stuff you Should Know dot Com. Stuff you Should Know is a pretty action of I heart Radio. For more podcasts my heart Radio, visit the i heart Radio app, Apple Podcasts, or wherever you listen to your favorite shows. H