Speaker 1: Hey, Chuck, you're almost done. Everybody with the science playlist.
Speaker 1: I hope all of our egghead friends out there got
Speaker 1: into this one. This one is I feel like quite
Speaker 1: a while ago, but it's about X rays. It's called
Speaker 1: How X Rays Work, and it's super nerdy and super fascinating.
Speaker 1: Give it a listen.
Speaker 2: Welcome to Stuff you Should Know from HowStuffWorks dot com.
Speaker 3: Hey, and welcome to the podcast. I'm Josh Clark with
Speaker 3: Charles W. Chuck Bryan as always, and there's Jerry over
Speaker 3: there fiddlin around with stuff. So it's Stuff you should
Speaker 3: know the podcast, not Stuff you should know.
Speaker 4: The movie.
Speaker 3: That's right, you know, we're sworn to secrecy about that.
Speaker 1: That'd be a good movie. That'd be a bad movie.
Speaker 3: I don't know, Man, it could go either way. I
Speaker 3: always see I imagine it like Strange Brew.
Speaker 1: Oh yeah, yes, they could base it on the Stuff
Speaker 1: you Should Know Tell All book I'm writing. Oh yeah,
Speaker 1: that would be exciting.
Speaker 3: That would be very exciting to be I'm looking forward
Speaker 3: to that book like.
Speaker 1: A Lifetime movie of the Week.
Speaker 3: Do you like switch people's names like am I Joe?
Speaker 1: Yeah, Joe Clack, Yeah exactly. Now it's sort of like like,
Speaker 1: did you see the Say It by the Bell movie?
Speaker 4: Oh?
Speaker 3: Yeah, I didn't Screech write a book. It was based
Speaker 3: on a book by Screech. Right, Yeah, wasn't it like
Speaker 3: all sex and drugs and stuff?
Speaker 1: Oh it was, you know, it was a bunch of
Speaker 1: teenagers in Hollywood, So sure there was some of that
Speaker 1: in there, but it was I didn't read the book.
Speaker 1: But the movie was bad and not nearly as sealacious
Speaker 1: as he wanted it to be.
Speaker 3: Right. I remember a lot of people being disappointed, and
Speaker 3: I remember, I mean, I recall the like two weeks
Speaker 3: ago when people were talking about it when it came out.
Speaker 1: It's stunk. I'll watch Emily and I'll watch some of
Speaker 1: those just terrible, terrible biopics occasionally on TV, and it's
Speaker 1: it can be fun. Like we watched the who was
Speaker 1: the one actor? Brittany Murphy? The Britney Murphy story?
Speaker 3: Oh really? Does she have a heck of a story?
Speaker 3: Is she alive still or did she die?
Speaker 1: No, she passed away because under kind of weird circumstances,
Speaker 1: because she and her husband both passed away within weeks
Speaker 1: of each other.
Speaker 3: Weird.
Speaker 1: And there were all these strange claims that her house
Speaker 1: was poisoned, that they were poisoned, and yeah, it was.
Speaker 1: It was fun.
Speaker 3: What's your take on it?
Speaker 1: Oh? I don't know, just that the movie wasn't very good.
Speaker 3: Who played Brittany Murphy? Do you remember so many Bowen?
Speaker 3: Wasn't it? No, she's in all of those.
Speaker 1: Someone who didn't look very much like Britney Murphy, Julie Bowen.
Speaker 3: But I was right.
Speaker 1: The Ashton Kutcher guy was pretty good, though, I.
Speaker 3: Gotta say Steve Jobs played him.
Speaker 1: They should have just gotten Ashton Kutcher to play himself.
Speaker 3: He's not doing much. He's on what two and a
Speaker 3: half Men?
Speaker 1: I don't know.
Speaker 3: That's got to require fifteen minutes of work a week.
Speaker 1: He's selling cameras.
Speaker 3: Do you remember when that whole two and a half
Speaker 3: Men thing was going down? We were in La and
Speaker 3: for the one and only time in my entire life,
Speaker 3: I see John Cryer that day.
Speaker 1: Oh, during the Charlie Sheen mel.
Speaker 3: Meltdown like the day of the meltdown, like it happened
Speaker 3: at night. And within eight hours I saw John Cryer
Speaker 3: for the first time in person at a McDonald's. Did
Speaker 3: gel ducky No, I left him alone he looks stressed out.
Speaker 1: Well, yeah, he's probably like, my career is going down
Speaker 1: the tubes, but little did he know.
Speaker 3: He's a survivor.
Speaker 1: Yeah, his career is just fun. Yep.
Speaker 3: So x rays. Yeah, that's what we're talking.
Speaker 1: About, right, Yep. That the lightest part of this podcast.
Speaker 3: I like this one. This one. It's one of those
Speaker 3: things where if you can just hang on by your fingernails,
Speaker 3: it can click and then you lose it again, but
Speaker 3: that means that it could click again later on. That's
Speaker 3: what I like about it.
Speaker 1: Good. I'll leave that to you. I got lots of
Speaker 1: other stuff about it. Oh you do, but I totally understand.
Speaker 3: Good.
Speaker 1: Good.
Speaker 3: So have you ever broken anything and needed an X
Speaker 3: ray or has it all just been dental stuff?
Speaker 1: You know it? Dude? Never broken a bone?
Speaker 3: Knock on wood?
Speaker 1: Yeah, I mean I've had my injuries were always stitches.
Speaker 1: I was always getting busted open, oh yeah, rocks and sprinklers,
Speaker 1: and I was always getting cut yeah and sewed back up.
Speaker 1: But I never broke a bone.
Speaker 3: That's great. Yeah, you should probably knocking on old one
Speaker 3: more time, just to be safe.
Speaker 1: Yeah.
Speaker 3: Uh so, Yeah, all of my X rays too, have
Speaker 3: been like just going to the dentist or whatever.
Speaker 1: You never had a bone broken.
Speaker 3: I don't want to say, because I don't even know
Speaker 3: if knocking on wood will.
Speaker 1: Do it on lambin at ikea.
Speaker 3: That would just be so horribly interesting if both of
Speaker 3: us broke a bone after this.
Speaker 1: Yeah, and we're at the age where like you should
Speaker 1: break bones when you're a kid, where you're like, eh, whatever,
Speaker 1: I get a cast at this age, it's a drag.
Speaker 3: Yeah.
Speaker 1: Yeah.
Speaker 3: I remember reading like a Tom Clancy novel and like
Speaker 3: some kid got an arm torn off or whatever, and
Speaker 3: one of the surgeons was like, if the arm's in
Speaker 3: the same room as the kid, it can be healed.
Speaker 1: Right.
Speaker 3: That doesn't hold true in you're Tom Clancy's age.
Speaker 1: No, So.
Speaker 3: You are familiar with X rays, so you've seen them before,
Speaker 3: you've watched er surely?
Speaker 1: Yeah, I mean I've had X rays for like the
Speaker 1: dental ones like you said, and then just other various
Speaker 1: like uh like chest X rays for sicknesses and things
Speaker 1: like that, which I think may be a little frivolous,
Speaker 1: to be honest.
Speaker 3: Yeah, and kind of dangerous really Yeah, conceivably sure, which
Speaker 3: we'll get into later. But did you were you familiar
Speaker 3: with X rays at all. Beyond that, did you know
Speaker 3: that they were invented or discovered accidentally?
Speaker 1: Yeah? I did know that.
Speaker 3: I did not.
Speaker 1: That's one of the few things I know. I saw
Speaker 1: a little like Quickie short on some like it might
Speaker 1: have been actually Science Channel.
Speaker 3: I looked all over. The most I could find was
Speaker 3: a dude on Siemens just describing it in the most.
Speaker 1: Flat affect I've watched.
Speaker 4: Video.
Speaker 3: Yeah. I got to five and five wouldn't load, and
Speaker 3: I was like, forget this.
Speaker 1: Yeah, if I've never loaded for me. I watched the
Speaker 1: other fourteen though, and the whole time I was going, man,
Speaker 1: these are a minute long, please join them all together
Speaker 1: into one six minute video.
Speaker 3: No, it was so weird.
Speaker 1: Yeah, it was pretty silly, but he was he was good.
Speaker 1: He was just very dry.
Speaker 3: Yeah, and they spent zero pennies on any kind of
Speaker 3: soundtrack or anything like if he grabs papers, you hear
Speaker 3: papers wrestling in a classroom. It was pretty straightforward.
Speaker 1: Yes, but that's a very wind about, roundabout way of
Speaker 1: getting to it's discovery in eighteen ninety five by a
Speaker 1: German physicist named Wilhelm Runtiken Nice, and he was testing
Speaker 1: whether cathode rays could pass through glass, and he saw
Speaker 1: that the fluorescent screen was glowing when he turned on
Speaker 1: his electron beam, which wasn't a big deal, but he
Speaker 1: was like, wait, this's got cardboard around it, right.
Speaker 3: There shouldn't be any visible light escaping, which is silly
Speaker 3: to think of. Now, well, yeah it is, but you
Speaker 3: have to put yourself in his shoes like X hadn't
Speaker 3: been discovered because he was literally on the verge of
Speaker 3: discovering them, right.
Speaker 1: Then, that's right.
Speaker 3: And yeah, so he was like, this is very curious
Speaker 3: that this is fluorescing.
Speaker 1: Yeah, and he noticed other things were glowing, and eventually
Speaker 1: he started putting other objects between the tube and the screen.
Speaker 1: They glowed the screen dead. That is finally put his
Speaker 1: hand there.
Speaker 3: I read his wife's hand.
Speaker 1: Oh really. He's like, either way, come.
Speaker 3: In here for a second. Yeah, I want you to
Speaker 3: try something.
Speaker 1: And saw bones projected and then I guess probably poo
Speaker 1: pooed his pants. It's a man, I think, come on
Speaker 1: to something here. Yeah, it was really that quickly. He
Speaker 1: was like immediately the application was clear. It wasn't one
Speaker 1: of those things where it took twenty years. He's like,
Speaker 1: hold on, you can see bones. This could be really helpful. Yes,
Speaker 1: And he won a Nobel Prize very rightfully so, the
Speaker 1: first one ever for physics. And he named him X
Speaker 1: rays because he didn't know what the heck it was. No,
Speaker 1: exactly like kind of signing your name.
Speaker 3: He'd probably right. I think he assumed that later on
Speaker 3: future scientists would fill in the blanks, but they were like, no,
Speaker 3: we're cool with X rays.
Speaker 1: Well, he probably thought that someone would eventually call it
Speaker 1: like the Rundken ray or something.
Speaker 3: He wasn't much of a self promoter. He was just like,
Speaker 3: all this calum X rays is a placeholder.
Speaker 1: And he didn't patent any anything, you know, he never
Speaker 1: like made money off that.
Speaker 3: And then just his wife had hand cancer as a result.
Speaker 3: Really no, oh, I was laughing, but no, she did.
Speaker 1: That would be their it was.
Speaker 3: It was just a joke. You can proceed with the laugh.
Speaker 1: Plus, I've never heard a hand cancer.
Speaker 3: It's gotta be out there.
Speaker 1: And then a couple of years later they were already
Speaker 1: using it in the Balkan War. Was the first time
Speaker 1: it was really put to practical use with the.
Speaker 3: First Balkan War, the one around World War.
Speaker 1: One was that well, No, eighteen ninety seven.
Speaker 3: Oh, that Balkan war. I didn't know that existed until
Speaker 3: just now.
Speaker 1: Yeah, and they said we can see bullets and trapnel
Speaker 1: and stuff now, which is helpful.
Speaker 3: It is extremely helpful. So, like this guy Runken discovers
Speaker 3: X rays and their most practical application in one fell
Speaker 3: swoop basically yep, And a little further study revealed the
Speaker 3: X rays are actually just another part of the electromagnetic spectrum,
Speaker 3: of which radio waves, microwaves what we call visible light. Yeah,
Speaker 3: what else is on there?
Speaker 1: Well, I've got my handy wallet electromagnetic spectrum card. Yeah,
Speaker 1: and X rays fall between gamma rays and ultraviolet rays
Speaker 1: on that spectrum, which are all below. Well you say below,
Speaker 1: I don't know if it's not really an above or
Speaker 1: below situation visible light and then infrared, microwaven radio.
Speaker 3: Waves, so it would be a higher or lower frequency,
Speaker 3: because that's how the whole thing's divided.
Speaker 1: Yeah.
Speaker 3: So, like the visible spectrum of light consists of electromagnetic
Speaker 3: radiation that has a frequency a wavelength that our eyes
Speaker 3: are sensitized to, so we can pick up visible light.
Speaker 3: There's plenty of other stuff on the spectrum of electromagnetic
Speaker 3: radiation and all of it is delineated by the frequency
Speaker 3: the wavelengths. So at the highest end you have gamma rays.
Speaker 1: They're like, yeah, that means the squiggly line is very
Speaker 1: close together exactly.
Speaker 3: And then on the farthest end you have radio waves
Speaker 3: that are like.
Speaker 1: And that means the squiggly line is far apart exactly,
Speaker 1: And that is called chuck science.
Speaker 3: That's good stuff.
Speaker 1: Yeah.
Speaker 3: So back of my wallet xtra, right next to the
Speaker 3: what else you have in there?
Speaker 1: I just have my PAPS blue ribbon membership car, which
Speaker 1: I actually do, do you really, Yeah, but I've had
Speaker 1: it for like twenty years.
Speaker 3: Wow, when you got it when you're like seven eight?
Speaker 1: Yeah, you flatter me.
Speaker 3: So X rays fall, I guess we're about in the well, Yeah,
Speaker 3: the higher and they have a higher frequency as far
Speaker 3: as the electromagnetic spectrum goes. But the point is is
Speaker 3: that it is ultimately the same thing. It's a it's
Speaker 3: a type of electromagnetic energy that is carried on a photon,
Speaker 3: which is a particle of what we would call light.
Speaker 1: Yeah, and we talked about photons a plenty in the show,
Speaker 1: and the same like photons produce the visible light that
Speaker 1: we can see. Photons blast out from the Sun. How
Speaker 1: long does it take?
Speaker 3: Like it takes like one hundred thousand years to get
Speaker 3: from the core to the surface and then like eight
Speaker 3: minutes to get from the surface to Earth. That's right, man,
Speaker 3: I love that fact.
Speaker 1: So this is the only part I understand, so I'll
Speaker 1: lead with it. If you want to imagine an atom,
Speaker 1: a nucleus of an atom and rings around that atiom
Speaker 1: atiom that's a new word, an atom. As orbitals, when
Speaker 1: an electron drops to a lower orbital, it releases energy
Speaker 1: in the form of a photon.
Speaker 3: And the electron will always drop to the lower orbital.
Speaker 1: That's right.
Speaker 3: So like if an orbital is if an electron is
Speaker 3: kicked off of a lower orbital, an electron in the
Speaker 3: higher orbital goes yeah and drops down to that one.
Speaker 1: Yes, And depending on how far it drops, it's going
Speaker 1: to determine the energy level of that photon.
Speaker 3: That's that it releases as energy when it drops, right, Yeah, Because.
Speaker 1: It doesn't have to drop more than one orbital, right,
Speaker 1: you can skip down I don't even know how far,
Speaker 1: but a long way.
Speaker 3: Yeah, it can. And like you said, the greater the
Speaker 3: distance between the two orbitals or the greater the energy differential,
Speaker 3: the greater the energy that photon when released will have.
Speaker 1: Right, that's right.
Speaker 3: And as we said, photons are the energy carriers of
Speaker 3: the electromagnetic spectrum. And depending on that energy or the
Speaker 3: frequency the wavelength of that photon, that determines what kind
Speaker 3: of photon it is, right, whether it's a radio photon
Speaker 3: or an X ray photon, or a photon that we
Speaker 3: can see that's in the visible spectrum.
Speaker 1: That's right. Sometimes when these photons are flying around, they
Speaker 1: will collide with other atoms, and sometimes those atoms absorb
Speaker 1: that photon's energy and then kick it up to that
Speaker 1: higher level.
Speaker 3: Again, right, But it has to be from what I understand,
Speaker 3: and I saw that there's like of course it's science,
Speaker 3: so there's like atomic science, so there's little exceptions. Did
Speaker 3: this and that? Sure, But from what I could see, Chuck,
Speaker 3: there is the energy of that photon has to exactly
Speaker 3: match the energy differential between one orbital and another on
Speaker 3: an atom so that it can kick it up, so
Speaker 3: that it hits that one electron in the lower orbital
Speaker 3: kicks it up to the higher orbital and thus transfers
Speaker 3: its energy, which means that atom just absorbed that energy
Speaker 3: that that photon was carrying. Right, But if it's a
Speaker 3: little less, it's not going to have the energy to
Speaker 3: kick that electron up, which makes sense to me, right.
Speaker 3: But if it's a little more, this is what doesn't
Speaker 3: make sense to me. It doesn't kick the electron up,
Speaker 3: and then the photon carries on in a diminished energetic state.
Speaker 3: It just doesn't do anything. It doesn't interact with that.
Speaker 3: It has to be exactly, say, like the energy differential
Speaker 3: between orbits is eight, so a photon has to have
Speaker 3: an energy of eight or else it's not going to
Speaker 3: do anything with that atom.
Speaker 1: That's right, Okay, And so depending on the well, let's
Speaker 1: say you have a radio wave. They don't have very
Speaker 1: much energy, so they can't move electrons between these orbitals.
Speaker 1: They just pass through things. X rays are super powerful.
Speaker 1: There's lots of energy, so they can pass through things,
Speaker 1: which is key if you want to check out your
Speaker 1: bones from outside of your body.
Speaker 3: It is and we're gonna explain exactly how right after this. Okay,
Speaker 3: so we're back, Chuck, and you tantalized everybody by saying
Speaker 3: that this difference in absorption is what produces X rays, right,
Speaker 3: was that tantalizing? I was tantalized, okay, and I even
Speaker 3: know it's coming, all right, that's how excited I am
Speaker 3: about X rays.
Speaker 1: Good.
Speaker 3: So consider this, Like different atoms have different atomic weights,
Speaker 3: they have different densities, they're just different, like different atoms are.
Speaker 3: And atoms also have what are called differences in radiological density. Right, Okay,
Speaker 3: So a really high energy, high atomic weight, very dense
Speaker 3: atom is going to be able to absorb a lot
Speaker 3: of energy. Smaller atoms that maybe are looser and have
Speaker 3: a lower atomic weight are going to get kicked around
Speaker 3: by any old photon that wants to come along.
Speaker 1: Yeah, and that's key. Like I said, if you want
Speaker 1: to see bones because your soft tissue, if you've ever noticed,
Speaker 1: when you have an X ray, you'll see the bones,
Speaker 1: but you know the rest is sort of a grayish
Speaker 1: black mess exactly because your soft tissue has smaller atoms.
Speaker 1: Your bones calcium atoms are much larger, so they're going
Speaker 1: to absorb those X ray photons.
Speaker 3: It's exactly right.
Speaker 1: They do it really well.
Speaker 3: Exactly. So imagine you have let's say, Chuck, let's go
Speaker 3: back and hang out with tuk tuk. Right, oh, man,
Speaker 3: let's get back in the way back.
Speaker 1: It's been a while.
Speaker 4: Okay, look at him over there.
Speaker 3: So here we are in France in this cave, Tucktook
Speaker 3: has his hand up against the cave wall, as you'll see,
Speaker 3: and in his other hand he's got that little straw
Speaker 3: filled with pigment, red pigment. He's blowing it on his hand, right,
Speaker 3: And now that he moves his hand away, there's the
Speaker 3: outline of his hand.
Speaker 1: It's called a stencil, right exactly.
Speaker 3: He's just made an early stencil. He's like a banksy,
Speaker 3: basically like a caveman banksy. But if you look at
Speaker 3: the back of Tuktok's hand, don't get too close, but
Speaker 3: look at the back of his hand, it's covered in
Speaker 3: red pigment. Right, So if you can, if you want
Speaker 3: to equate this to an X ray, the hand absorbed
Speaker 3: all of that pigment, and the stuff that passed through
Speaker 3: left the picture on the cave wall. That's kind of
Speaker 3: what happens with an X ray, except with an X
Speaker 3: ray photograph. The X ray photons are absorbed by the
Speaker 3: denser calcium rich bones, yes, and they pass through the
Speaker 3: softer tissue. So the picture that we have is the
Speaker 3: outline the silhouette of the bones because the X rays
Speaker 3: made it through the tissue. Didn't make it through the bones.
Speaker 3: They made it through the tissue and onto the X
Speaker 3: ray plate, which absorbed the picture in negative.
Speaker 1: That's right. And I'm glad you said picture, because that's
Speaker 1: all it is. On the other side of the human being.
Speaker 1: You know that they're shooting the X ray at there's
Speaker 1: a camera and you're just gonna get a regular negative,
Speaker 1: and they could make it a positive, but they leave
Speaker 1: it as a negative because you really don't need the
Speaker 1: positive image, right, And that's what they'll put on that
Speaker 1: little screen to show you your cracked femur.
Speaker 3: Exactly, And they can see the crack because some of
Speaker 3: those X rays will make it through the gap. That's right, right,
Speaker 3: So all you're seeing is the result of X rays
Speaker 3: that made it through the tissue. We're absorbed by the bone,
Speaker 3: so those don't make it to the plate. The ones
Speaker 3: that make it to the plate cause the chemical reaction
Speaker 3: that gives you your negative, your X ray. And it's
Speaker 3: it's pretty simple, really like if you think about it,
Speaker 3: at least in principle. It's also extraordinarily difficult to conceive of.
Speaker 3: But if you understand like the principle behind it, it
Speaker 3: makes uttering complete sense.
Speaker 1: Yeah, And it's a pretty focused shot that they're using there.
Speaker 1: It's not like they don't fill the entire room with
Speaker 1: X rays. You know. They've got a thick lead shield
Speaker 1: around the whole device and it you know, contains everything,
Speaker 1: and it's got a little small window that's just gonna
Speaker 1: let that narrow beam pass through through a series of
Speaker 1: filters and basically hit you wherever they want to hit you.
Speaker 3: Yeah, And the reason that they use lead is because
Speaker 3: lead is an extremely dense element, yeah element, yes, right, sure,
Speaker 3: Oh gotta hope, so with a very high atomic no,
Speaker 3: which means it can absorb tons of energy.
Speaker 1: Right, Yeah, that's why you're gonna wear a lead apron
Speaker 1: if you're not you know, if you're getting your skull done,
Speaker 1: you're probably gonna wear an apron on your chest. Let's say.
Speaker 3: Sure, so you're so, this lead is being bombarded with
Speaker 3: X ray, photons and electrons and it's just taken it.
Speaker 3: It's fine, and it's not being able to it's not
Speaker 3: able to pass through because it doesn't have high enough energy.
Speaker 3: But yes, they when they put that little window in
Speaker 3: the X ray generating machine. It passes right through there
Speaker 3: and a concentrated beam and Chuck, let's talk about the machine, right, So,
Speaker 3: and this is basically what we use as X ray machines.
Speaker 3: Is essentially what Routkin was, what Made was experimenting with
Speaker 3: when he accidentally discovered them. Because if you look for
Speaker 3: X rays like they're they propagate naturally. But I think
Speaker 3: like twenty percent of the X rays on Earth come
Speaker 3: from humans. Oh really, yeah, like we generate a lot
Speaker 3: of X rays. They don't they don't come like you
Speaker 3: don't find them normally on Earth. They're coming from outer
Speaker 3: space to us. Okay, hence X ray astronomy. But the
Speaker 3: ones here on Earth that are generated on Earth, it's
Speaker 3: not like rocks put out X rays or something like that, right,
Speaker 3: we do. We humans do. Humans and light aprons put
Speaker 3: out X rays and they use this machine like root
Speaker 3: Gin made.
Speaker 1: Yeah, what you have in the machine, and you have
Speaker 1: an electrode pair, cathode and an anode and that's inside
Speaker 1: a good old fashioned glass vacuum tube. Which it's amazing
Speaker 1: how vacuum tubes are still like the best way to
Speaker 1: do many of these things.
Speaker 3: Well, it it allows things to travel at the speed
Speaker 3: of light easily.
Speaker 1: That's right, and allows guitar amps to sound great.
Speaker 3: I didn't know these vacuums in that. Oh is that
Speaker 3: a cathode tube? Yeah?
Speaker 1: Yeah, like a like the best amps are still made
Speaker 1: with vacuum tubes. You can get solid state amps, but
Speaker 1: they're just the sound isn't as rich. So it's kind
Speaker 1: of like this old technology that's still superior.
Speaker 3: Right. They're all pumped out by hand by a ninety
Speaker 3: year old man in Tennessee.
Speaker 1: Mister Marshall. Yes, no, uh So. The cathode is a
Speaker 1: heated filament, just like you might see in a light bulb,
Speaker 1: and the machine's are gonna pass the current through that
Speaker 1: and heat that thing up, and then it's gonna spit
Speaker 1: electrons off that surface, and it's gonna hit a disc
Speaker 1: made of tungsten, and it's gonna draw those across a tube.
Speaker 1: It's basically the tube is sort of the key piece.
Speaker 3: Right, because you've got the positive and the and the
Speaker 3: negative charge the cathode and the anode, right, Yeah, and
Speaker 3: that difference that electrical charge draws as electrons down to
Speaker 3: the anode.
Speaker 1: Yeah, with a lot of force.
Speaker 3: Yeah, And that force means that when those electrons hit
Speaker 3: the tungsten anode, it knocks a bunch of electrons off,
Speaker 3: creates a bunch of X rays in the process, and
Speaker 3: you have a whole box filled with X ray radiation,
Speaker 3: a box full of X rays. That's exactly what it is,
Speaker 3: like you're just I mean, they might as well be
Speaker 3: like a foot crank to this thing, like an old
Speaker 3: sowing machine. For as technologically advanced as it is, there.
Speaker 1: May be for all I know, I don't know what
Speaker 1: goes on in that other room.
Speaker 3: Right, Yeah, you know true, there's some dude in there
Speaker 3: with like his right leg is three times more muscular
Speaker 3: than his left leg because that's the only one who
Speaker 3: uses So in addition, like I said, to X rays
Speaker 3: being created, the other X rays, other photons can go
Speaker 3: on and knock more electrons off. So you have what's
Speaker 3: like a process of chain reaction starting.
Speaker 4: Right.
Speaker 3: It's not like one gets hit and then that's it
Speaker 3: and a photon's created. It just hangs around until it's
Speaker 3: beamed out. Right, You're just generating this huge amount of
Speaker 3: X rays, and the X rays are also continuing to
Speaker 3: propagate themselves because they're knocking more electrons free. And the
Speaker 3: more free electrons you have, the more interactions you have, right, right,
Speaker 3: So one of the ways that more electrons can be
Speaker 3: knocked off. You don't even need a direct transfer of energy,
Speaker 3: where a photon is absorbed or knocks an electron from
Speaker 3: one orbit to another, or knocks it loose entirely. A
Speaker 3: photon actually has this really cool capability of just orbiting
Speaker 3: close by the nucleus of an atom, and when the
Speaker 3: nucleus basically draws it into its orbit, the photon just
Speaker 3: takes a hard left turn.
Speaker 1: Yeah, it just bumps it off its course.
Speaker 3: But even like the dodge viper has to like slow
Speaker 3: down to take a left turn, slow a little bit, right,
Speaker 3: just a little, just a little yeah. But that little
Speaker 3: bit in photon world means a transfer of energy from
Speaker 3: the photon outward.
Speaker 1: Yeah. Yeah.
Speaker 3: And then the photon, like the photon takes that left
Speaker 3: turn and the energy is transferred to the atom.
Speaker 1: Yeah. And one of the byproducts. If this sounds like
Speaker 1: it's gonna create a lot of heat, it's because it will.
Speaker 1: And in order to combat this, they rotate this anode
Speaker 1: to keep it. It would just melt down if you
Speaker 1: kept it in place, and apparently there's a cool oil
Speaker 1: bath that helps absorb heat as well, which I never
Speaker 1: have heard of that either.
Speaker 3: It sounds oily a cool oil bat. Yeah, it doesn't
Speaker 3: sound refreshing at all. It sounds like the opposite of refreshing.
Speaker 1: Yeah. Cool and oil don't really go together.
Speaker 3: No, Yeah, and I misspoke. That's an electron that can
Speaker 3: be drawn into the nucleus of an atom, appropriately enough,
Speaker 3: because they orbit nuclei anyway, right, But it doesn't have
Speaker 3: to hook up with that atom. When it takes that
Speaker 3: hard left, it emits the photon like you said.
Speaker 1: That's right, And like I said earlier, there's a camera
Speaker 1: on the other side of the patient and it's going
Speaker 1: to record that pattern of light when it passes through
Speaker 1: the body. And it's not so different from a regular camera.
Speaker 1: And then the injur're just gonna get a picture, like
Speaker 1: I said, a negative image.
Speaker 3: Yeah. And if you hook it up with a computer
Speaker 3: that allows you to take X rays basically in slices,
Speaker 3: you can come up with commuter computerized tomography.
Speaker 1: Yeah, you aka CT, right, a CT scan exactly.
Speaker 3: If you use if you get a breast exam, you're
Speaker 3: using a type of X ray called mimmography yep. And
Speaker 3: then there's a fluoroscopy, which the man in the extraordinarily
Speaker 3: dry presentation from Semens said was basically like moving picture.
Speaker 3: It's like exactly, and then he showed us what the
Speaker 3: movie is with a flip book, right.
Speaker 1: That old flip book trick.
Speaker 3: And if you listen to this podcast, I'm sorry. I
Speaker 3: just want to apologize for both of us. Semens guy.
Speaker 3: Oh yeah, like, hats off to you for doing that
Speaker 3: at all.
Speaker 1: Yeah, because he's probably saying, well, at least I was
Speaker 1: correct and everything I said exactly.
Speaker 3: It's a good point, sir. But with fluoroscopy, it's basically
Speaker 3: like a movie of an X ray movie, and you
Speaker 3: would do this to make sure like a heart is
Speaker 3: beating correctly because you wanted to see it. But you
Speaker 3: have to have an additional instrument because, as we've said,
Speaker 3: X rays will pass through tissue like heart tissue and
Speaker 3: muscle tissue and all and blood vessels and all this stuff.
Speaker 3: You want to get pictures of you an X ray,
Speaker 3: so you have to use something called the contrast media
Speaker 3: for it.
Speaker 1: Yeah. A contrast agent is basically more dense than the
Speaker 1: soft tissue. So if you want to let's say swallow.
Speaker 1: It's usually like a barium compound. If you want to
Speaker 1: examine like your blood vessels or your circulatory system, you're
Speaker 1: sometimes they can inject that, or you might drink it
Speaker 1: to see if you're doing like a gastro intestinal like
Speaker 1: a GI tract. You're going to swallow that stuff, which
Speaker 1: I've never had to do. I think my dad had
Speaker 1: to do that. Yeah, I don't think it's super pleasant.
Speaker 3: I get the impression not too but my dad did
Speaker 3: it as well.
Speaker 1: Yeah, it's an old guy thing, so I should be
Speaker 1: getting one soon. And then it allows you, you know,
Speaker 1: to see a moving image basically how that liquid is
Speaker 1: if there's any blockage. There's all sorts of applications for it.
Speaker 3: Yeah, because you're that liquid has a high radiological density,
Speaker 3: which means that the X rays don't just pass right
Speaker 3: through your the tissue that it's being suspended in, like
Speaker 3: your blood vessels, it absorbs it for it. So you
Speaker 3: get a picture of your blood vessels, your circulatory system,
Speaker 3: which is pretty cool. It's pretty clever. It's also extraordinarily
Speaker 3: elementary and principle. That's right, my dear Watson.
Speaker 1: And that single picture, I think we you know, we
Speaker 1: mentioned CT and mimography and all that and philoscopy, but
Speaker 1: the single picture is just called standard radiography. And that's
Speaker 1: when you're you know, taking a photo of your skull
Speaker 1: right or your lungs or your bones or your teeth.
Speaker 3: And so so. Speaking of the lead apron thing, man,
Speaker 3: it's always made me kind of nervous, Like if the
Speaker 3: rest of my body has to wear a lead apron,
Speaker 3: but you're shooting an X ray into my head, am
Speaker 3: I going to be? Okay?
Speaker 1: Well, we'll answer that right after this message. Oh all right,
Speaker 1: X rays are they bad for you? The answer is yes,
Speaker 1: pretty unequivocally. But like all things, it's it's in moderation
Speaker 1: is the key. In the nineteen thirties and forties and
Speaker 1: into the fifties, they had X ray machines at shoe stores.
Speaker 1: Oh yeah, they could X ray your feet to get
Speaker 1: a better fit, and they didn't realize at the time
Speaker 1: that they were X raying people way way too much.
Speaker 3: You had talkative kids in class, they just shoot them
Speaker 3: with an X ray and with they no, they probably
Speaker 3: did I've got you like twice, Well no, I believe that, Like, hey,
Speaker 3: let's look at his brain.
Speaker 1: There may be a mouse running around inside of it.
Speaker 3: People in the thirties were dumb.
Speaker 1: Well, it's basically radiation sickness. It's a form of ionization
Speaker 1: or ionizing radiation. So what can happen, Like if just
Speaker 1: normal light hits an atom, is no big deal. But
Speaker 1: when an X ray hits an atom, it knocks electrons
Speaker 1: off of it creates an ion, which is an electrically
Speaker 1: charged atom, and basically anything from cellular death to mutation
Speaker 1: can happen at that point, and mutation can spread and
Speaker 1: it can cause cancer.
Speaker 3: Right Because stable atoms are neutral, right, because they have
Speaker 3: an equal number of protons and electrons. You lose an
Speaker 3: electron all of a sudden, you have a positively charged
Speaker 3: ion and that negatively charge electron running around and it
Speaker 3: just causes trouble. And you said light. Visible light can
Speaker 3: be absorbed and it's no big deal because visible light
Speaker 3: exists on a wavelength that's about in tune with the
Speaker 3: soft tissues of our body, right, So we know how
Speaker 3: to absorb it and it makes us tan and that's cool, right,
Speaker 3: But with these ionized atoms, these positively charged atoms like
Speaker 3: going around in your body, it can cause a lot
Speaker 3: of problems like mutations like cancer, right.
Speaker 1: Yeah, I mean if you break that DNA chain, that's
Speaker 1: not good.
Speaker 3: No, it is. And one of the results is the
Speaker 3: DNA can basically lose its ability to regulate itself and
Speaker 3: the cell replicates more frequently than it should. All of
Speaker 3: a sudden, you have a tumor on your hands, and
Speaker 3: that can spread. It can also be a problem if
Speaker 3: that DNA break occurs in utero, because then that can
Speaker 3: lead to birth defects. Yeah, sure, which is why pregnant
Speaker 3: women shouldn't get X rays yea. And it can also
Speaker 3: just lead to plane old cellular death.
Speaker 1: Yeah.
Speaker 3: If you have cellular death, then the tissues that are
Speaker 3: made up by those cells break down and you have
Speaker 3: a problem on your hands with that as well.
Speaker 1: So here's the deal. We get exposed to radiation every
Speaker 1: day just walking around on the planet. It depends on
Speaker 1: where you live, but every year, the average person is
Speaker 1: going to be exposed to anywhere from one to four
Speaker 1: It's measured in milliseaverts per year. Like I said, depending
Speaker 1: on where you are. I think in higher elevations it's
Speaker 1: less than at sea level. So if you live in Denver, Colorado,
Speaker 1: you're going to be exposed to less.
Speaker 3: Well, yeah, because of Death Valley, you're higher up in
Speaker 3: the atmosphere and that makes a difference. Exactly, you have
Speaker 3: less protection, right.
Speaker 1: Yeah, So you know, they what they want to do
Speaker 1: medically speaking, they want to use, or they're supposed to use,
Speaker 1: the minimum amount to achieve the pictures you need. It's
Speaker 1: not like the old days where they're just like, let's
Speaker 1: do twenty X rays. Yeah, like, let's do the minimum
Speaker 1: amount we need to get the information that we need.
Speaker 1: A CT scan can can get your you know, you
Speaker 1: lay down in the tube and it rotates around you
Speaker 1: and your whole body can be photographed in less than
Speaker 1: five seconds these days. Nice, but you know there are
Speaker 1: concerns if you get too many X rays still, like
Speaker 1: a dental panorama. I think what I say, one to
Speaker 1: four milisiverts per year.
Speaker 3: And it's cumulative too, you should yeah, like it's not.
Speaker 3: It's not like you get one and then you know,
Speaker 3: eight months later, you get another one in that first
Speaker 3: one went away, Like it accumulates over the course of
Speaker 3: a year.
Speaker 1: Yeah. So here's just a few examples of how much
Speaker 1: radiation you're being exposed to with X rays. A dental
Speaker 1: panorama is going to be point zero one milliseiverts, so
Speaker 1: not very much like two chest X rays might be
Speaker 1: point one mam or gram is around point four your
Speaker 1: pelvis point six your back upper back maybe one point zero.
Speaker 3: I wonder why, because there's so incent bone there.
Speaker 1: Maybe yeah, maybe you have to do with exposure to Yeah,
Speaker 1: that makes sense.
Speaker 3: I got a ton of bone in my upper back.
Speaker 1: A full CT scan, it depends on what you are.
Speaker 1: It depends on what your X raying. But a CT
Speaker 1: scan is obviously more like an abdominal or pelvis CT
Speaker 1: scan could be as many as ten milliseiverts. Yeah, so
Speaker 1: that's like up to two or three years worth of
Speaker 1: radiation in a single CT scan, which can be problematic,
Speaker 1: which is why they don't say get in the CT
Speaker 1: machine like every other week. But you know some of
Speaker 1: the reasons you might if you had a traumatic injury,
Speaker 1: they're going to X ray you a lot of times
Speaker 1: for disease confirmation. Go use an X ray machine during
Speaker 1: surgery is a visual guide. Like if you do endoscopic surgery,
Speaker 1: the surgeons actually needs to look at something, so sometimes
Speaker 1: it was X rays for that or to monitor your
Speaker 1: healing process. You know when you break a bone, it's
Speaker 1: not just that first X ray. You're gonna keep getting
Speaker 1: them to see how you're healing up.
Speaker 3: This is right out of the Semens video. Huh no,
Speaker 3: uh uh okay.
Speaker 1: I don't think so. I mean I looked at so
Speaker 1: much stuff all together, cumulative research.
Speaker 3: So I did a brain stuff on sieverts and how
Speaker 3: many we can take. Yeah, and yeah, it's it's kind
Speaker 3: of like it's a little alarming. Sure, how much radiation
Speaker 3: we're exposed to. People who fly a lot too, are
Speaker 3: exposed to tons of radiation because you're again higher up in
Speaker 3: the atmosphere, so you're less protected by the atmosphere.
Speaker 1: Speaking of flying, and of course baggage that is X rayed.
Speaker 1: The food industry uses X rays a lot. Are geologists
Speaker 1: use it if they don't want to destroy an object
Speaker 1: and they want to see what's inside. Or earth sciences,
Speaker 1: I'll use X rays for rocks to see what kind
Speaker 1: of mineral composition. So there's all sorts of applications. It's
Speaker 1: not just medical space.
Speaker 3: Yeah.
Speaker 1: X ray telescopes out on satellites apparently you can see
Speaker 1: a lot. You can see things you can't detect from
Speaker 1: an earthbound telescope. Because X rays are absorbed by our atmosphere,
Speaker 1: so you can't like shoot it into space like that.
Speaker 3: So this article makes a pretty good point if you
Speaker 3: ask me. It says like, yes, X rays are like
Speaker 3: are bad for you, and you should use them with
Speaker 3: care and caution. And one good point is to always
Speaker 3: ask if there's an alternative to an X ray, just
Speaker 3: to basically say, hey, doc or Dennis, slow your role, Yeah,
Speaker 3: is there another way we can get this information without
Speaker 3: an X ray? I know it's the easiest, but whatever
Speaker 3: the alternatives. But then the article makes the point like
Speaker 3: it's still safer than and then the ultimate alternative, the
Speaker 3: thing that X rays replaced, which was exploratory surgery.
Speaker 1: Yeah, and in the day, if they thought you had cancer,
Speaker 1: they would cut you open and see yeah, and this
Speaker 1: is definitely better than that.
Speaker 3: Yeah, or broken bone. Imagine getting that on cut open
Speaker 3: just to see how yeah it's doing.
Speaker 1: They're like, no, it's not broken, right.
Speaker 3: And we haven't invented anesthetic yet.
Speaker 1: So good luck with your dentists, by the way, because
Speaker 1: I always get the feeling that the dentists are like, no,
Speaker 1: your insurance allows us to bill for so many per
Speaker 1: year exact that's how many are going to get.
Speaker 3: These X rays are putting my kid through college. Yeah,
Speaker 3: you got anything else on X rays? No, that was
Speaker 3: a fine amount of stuff. I'm feeling good about it.
Speaker 3: You feel good about this one? Sure? I do too.
Speaker 1: Yeah.
Speaker 3: If you want to know more about X rays, you
Speaker 3: can check out this really informative article on HowStuffWorks dot com.
Speaker 3: It's got some great diagrams that explain a lot of
Speaker 3: the stuff we were saying visually. And you can type
Speaker 3: x ray into the search bar at how stuff Works
Speaker 3: and it'll bring that up. Since I said it's part,
Speaker 3: it's time for listener mail.
Speaker 1: This is from my buddy Poppy in Vancouver. Stuff you
Speaker 1: should don't listener that I met while I was there,
Speaker 1: and Poppy as this is to say, he's got a
Speaker 1: pretty cool job. He listened to the PTSD show and
Speaker 1: wanted to write in about another option that he works with.
Speaker 1: He's a registered acupuncturist in Vancouver with special training in
Speaker 1: trauma and addictions. He's a program called Neurotrophic Stimulation Therapy
Speaker 1: NTSD in A large part of the program uses ear
Speaker 1: acupuncture and electro acupuncture to promote neuroplasticity in the brain.
Speaker 1: He says, you can't necessarily directly fix the brain, but
Speaker 1: you can stimulate the ear nerves and will help the
Speaker 1: brain reregulate certain functionality so it can heal itself. He's
Speaker 1: been treating trauma and PTSD patients for several years and
Speaker 1: the evidence for his efficacy is high. It can be
Speaker 1: done with acupuncture needles alone or in combination with a
Speaker 1: mild electrical stimulation. Remember we talked.
Speaker 3: About transcranial electromagnetic stimulation.
Speaker 1: Yeah, transdermal cranial stimulation. He says that's one of the
Speaker 1: things that he's also using to treat PTSD, which is
Speaker 1: pretty cool wow. And he said it makes cognitive behavioral
Speaker 1: therapies so much easier to introduce because it promotes neuroplasticity
Speaker 1: and the results help a PTSD suffer to be more
Speaker 1: open to and able to receive positive social programming. So
Speaker 1: he has a program we want to promote. If you
Speaker 1: want to see all the components in action in his program,
Speaker 1: you can visit Lastdoor Recovery Society at lastdoor dot org,
Speaker 1: slash ntst, or you can donate funds to help purchase
Speaker 1: a brain scanner so that they can scientifically measure the
Speaker 1: results of the program, which would really help show the
Speaker 1: validity of the therapies. And if you're interested in helping
Speaker 1: out Poppy's cause there because he's really big on treating
Speaker 1: veterans in Canada. In the US, I shortened his little
Speaker 1: URL to bitley bit dot l y slash one one
Speaker 1: y n l Q and that is from Poppy and
Speaker 1: he says, I'm mistay.
Speaker 3: Thanks a lot, Poppy, Is it Poppy with a oh
Speaker 3: p O P P I nice. If you want to
Speaker 3: get in touch with us, you can tweet to us
Speaker 3: at s y s K podcast. You can join us
Speaker 3: on Facebook dot com slash stuff you Should Know. You
Speaker 3: can send us an email to stuff Podcast at HowStuffWorks
Speaker 3: dot com. That's right, and as always, joined us at
Speaker 3: our home on the web, stuff youshould Know dot com.
Speaker 2: For more on this and thousands of other topics, visit
Speaker 2: HowStuffWorks dot com.