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Selects: How X-Rays Work · Stuff You Should Know

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Speaker 1: M Hey everyone, it's me Josh, and for this week's
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Speaker 1: s y s K Selects, I've chosen our episode on
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Speaker 1: X rays. It's from December two thousand fourteen, because what's
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Speaker 1: more Christmas Eve than discussing electrons changing orbits. I love
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Speaker 1: this one because it's a great example that me and
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Speaker 1: Chuck can do anything we put our minds to. It's
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Speaker 1: just some great bare knuckle s y s K explaining.
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Speaker 1: So I hope you enjoy our episode how x rays work.
0:31
Speaker 1: Welcome to Stuff you Should Know, a production of I
0:34
Speaker 1: Heart Radio. Hey, and welcome to the podcast. I'm Josh
0:43
Speaker 1: Clark with Charles W. Chuck Bryant as always, and there's
0:46
Speaker 1: Jerry over there fiddling around with stuff. So it's stuff
0:50
Speaker 1: you should know the podcast, not stuff you should know.
0:53
Speaker 1: The movie. That's right. You know, we were sworn to
0:57
Speaker 1: secrecy about that. They'd be a good movie, that'd be
0:59
Speaker 1: a bad movie. I don't know, man, it could go
1:01
Speaker 1: either way. I always see I imagine it like Strange Brew.
1:06
Speaker 1: Oh yeah, yes they could. Uh, they could base it
1:09
Speaker 1: on the Stuff you Should Know, Tell all book I'm writing.
1:12
Speaker 1: Oh yeah, that would be exciting, that would be very exciting.
1:15
Speaker 1: I'm looking forward to that book like a Lifetime movie
1:17
Speaker 1: of the Week. Do you like, um switch people's names
1:20
Speaker 1: like a my um Joe Joe Clack? Yeah, exactly. No. Uh,
1:27
Speaker 1: it's sort of like, uh like did you see the
1:30
Speaker 1: Say by the Bell movie? Oh? Yeah, I didn't Screech
1:33
Speaker 1: write a book. It was based on a book by Screech. Right, Yeah,
1:36
Speaker 1: it wasn't it like all sex and drugs and stuff.
1:39
Speaker 1: Oh it was. You know, it was a bunch of
1:40
Speaker 1: teenagers in Hollywood, So sure there was some of that
1:44
Speaker 1: in there, but it was I didn't read the book.
1:45
Speaker 1: But the movie was bad and not nearly as salacious
1:49
Speaker 1: as he wanted it to be. Right. I remember a
1:52
Speaker 1: lot of people being disappointed, and I remember, I mean
1:55
Speaker 1: I recalled it like two weeks ago when people were
1:57
Speaker 1: talking about it when it came out. It's stunk. Watch Emily,
2:00
Speaker 1: and I'll watch some of those, um just terrible, terrible
2:04
Speaker 1: biopics occasionally on TV and it's it can be fun.
2:08
Speaker 1: Like we watched the who was the one actor? Brittany Murphy?
2:13
Speaker 1: The Brittany Murphy story? Oh really, does she have a
2:15
Speaker 1: heck of a story. Is she alive still or did
2:17
Speaker 1: she die? She passed away because under kind of weird circumstances,
2:22
Speaker 1: because she and her husband both passed away within weeks
2:24
Speaker 1: of each other, and there were all these strange claims
2:27
Speaker 1: that her house was poisoned, that they were poisoned, and um, yeah,
2:33
Speaker 1: it was. It was fun. What's your take on it? Oh?
2:36
Speaker 1: I don't know. You just that the movie wasn't very good.
2:40
Speaker 1: Who played Brittany Murphy? Do you remember someone who didn't
2:45
Speaker 1: look very much like Brittney Murphy Julie Bowen. But I
2:49
Speaker 1: was right. The Ashton Kutcher guy was pretty good, though.
2:51
Speaker 1: I gotta say Steve Jobs played him. They should have
2:54
Speaker 1: just gotten Ashton Kutcher to play himself. He's not doing much.
2:57
Speaker 1: He's not my two and a half men. I don't
2:59
Speaker 1: know that got to require fifteen minutes of work a week.
3:02
Speaker 1: He's selling cameras. Do you remember when the whole two
3:05
Speaker 1: and a half man thing was going down? We were
3:06
Speaker 1: in l A And for the one and only time
3:09
Speaker 1: in my entire life, I see John Cryer that day. Oh,
3:12
Speaker 1: during the Charlie Sheen meltdown, like the day of the meltdown,
3:16
Speaker 1: like it happened at night, and within eight hours I
3:18
Speaker 1: saw John cryer for the first time in Personette McDonald's
3:22
Speaker 1: did you heal Duckie? No? I left him alone. He
3:25
Speaker 1: looks stressed out. Well, yeah, he's probably like, my career
3:28
Speaker 1: is going down the tubes, but little did he know
3:30
Speaker 1: he's a survivor. His career is just fine. So X rays. Yeah,
3:35
Speaker 1: that's what we're talking about, right, Yep, the lightest part
3:38
Speaker 1: of this podcast. I like this one. This one. It's
3:41
Speaker 1: one of those things where if you can just hang
3:44
Speaker 1: on by your fingernails, it can click and then you
3:48
Speaker 1: lose it again, but that means that it could click
3:50
Speaker 1: again later on. That's what I like about it. Good.
3:55
Speaker 1: I'll leave that to you. I got lots of other
3:57
Speaker 1: stuff about it, but I totally understand good. Good. Um, So,
4:01
Speaker 1: have you ever broken anything and needed an X ray
4:04
Speaker 1: or has it all just been dental stuff? You know? Dude,
4:06
Speaker 1: never broken a bone? Knock on wood? Yeah, I mean
4:09
Speaker 1: I've had My injuries were always um stitches. I was
4:13
Speaker 1: always getting busted open rocks and sprinklers, and I was
4:18
Speaker 1: always getting cut and sewed back up. But I never
4:21
Speaker 1: broke a bone. That's great. Yeah, you should probably knock
4:24
Speaker 1: on wod one more time, just to be safe. Yeah.
4:25
Speaker 1: Uh so, yeah, all of my X rays to have
4:28
Speaker 1: been like just going to the dentist or whatever. You
4:30
Speaker 1: never had a bone broken. I don't want to say,
4:32
Speaker 1: because I I don't even know if knocking on wood
4:34
Speaker 1: will do it on lambing it ikea. It would just
4:36
Speaker 1: be so horribly interesting if both of us broke a
4:41
Speaker 1: bone after this. Yeah, and we're at the age where
4:43
Speaker 1: like you should break bones when your kid were you
4:45
Speaker 1: like whatever, I get a cast at this age, it's
4:48
Speaker 1: it's a drag. Yeah. I remember reading like a Tom
4:51
Speaker 1: Clancy novel and like some kid got an arm torn
4:54
Speaker 1: off or whatever, and one of the surgeons was like,
4:57
Speaker 1: if the arms in the same room as the kid,
4:59
Speaker 1: it can be yield. That doesn't hold true in your
5:02
Speaker 1: Tom Clancy's age now, So, um, you are familiar with
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Speaker 1: X rays, so you've seen them before You've watched the
5:10
Speaker 1: er surely, Yeah, I mean I've had X rays for
5:12
Speaker 1: like the dental ones, like you said, and then um,
5:15
Speaker 1: just other various like uh like chess X rays for
5:19
Speaker 1: sicknesses and things like that, which I think maybe a
5:21
Speaker 1: little frivolous, to be honest, Yeah, and kind of dangerous
5:24
Speaker 1: really conceivably, which we'll get into later. But um did
5:28
Speaker 1: you were you familiar with X rays it all beyond that?
5:31
Speaker 1: Did you know that they were invented or discovered accidentally? Yeah?
5:35
Speaker 1: I did know that. Um, I did not. That's one
5:37
Speaker 1: of the few things I know. I thought I saw
5:39
Speaker 1: a little like Quickie short on something like it might
5:41
Speaker 1: have been actually Science Channel. I looked all over. The
5:44
Speaker 1: most I could find was a dude on siemens Um
5:48
Speaker 1: just describing it in the most flat affic. I've watched
5:53
Speaker 1: his video. Yeah, I got to five and five wind
5:55
Speaker 1: Low and I was like, forget this. Yeah, if I've
5:57
Speaker 1: never loaded for me, I watched the other fourteen though,
6:00
Speaker 1: and the whole time I was going, man, these are
6:03
Speaker 1: a minute long, please join them all together into one
6:06
Speaker 1: six minute video. No, it was so weird. Yeah, it
6:08
Speaker 1: was pretty silly. But and he was he was good.
6:11
Speaker 1: He was just very dry. Yeah, and they spent zero
6:15
Speaker 1: pennies on any kind of soundtrack or anything like if
6:19
Speaker 1: he grabs papers, you hear papers wrestling in the classrooms.
6:23
Speaker 1: It was. It was pretty straightforward. Yes, but that's a
6:27
Speaker 1: very wind about, roundabout way of getting to uh. It's
6:32
Speaker 1: discovering by German physicist named Wilhelm uh Rundgan, and he
6:39
Speaker 1: was testing whether cathode rays could pass through glass and
6:43
Speaker 1: he saw that the fluorescent screen was glowing when he
6:46
Speaker 1: turned on his electron electron beam, which wasn't a big deal,
6:49
Speaker 1: but he was like, wait, this got cardboard around it, right,
6:52
Speaker 1: there shouldn't be any visible light escaping, which is silly
6:55
Speaker 1: to think of. Now, well, yeah it is, but you
6:57
Speaker 1: have to put yourself in his shoes like X rating
6:59
Speaker 1: had been to discovered because he was literally on the
7:02
Speaker 1: verge of discovering them, right then that's right, and uh yeah,
7:05
Speaker 1: So he was like, this is very curious that this
7:06
Speaker 1: is fluorescing. Yeah, and he noticed other things were glowing,
7:10
Speaker 1: and eventually he started putting other objects between the tube
7:14
Speaker 1: and the screen. They glowed the screen did that is
7:17
Speaker 1: finally put his hand there. I read his wife's hand.
7:20
Speaker 1: Oh really, he's like, either come in here for a second,
7:23
Speaker 1: I want you to try something. It saw bones projected
7:28
Speaker 1: and then I guess probably poo pooed his pants. It's
7:32
Speaker 1: a man, I think, come onto something here. Yeah, it
7:35
Speaker 1: was really that quickly. He was like immediately the application
7:39
Speaker 1: was clear. It wasn't one of those things where it
7:41
Speaker 1: took twenty years. He's like, hold on, you can see bones.
7:44
Speaker 1: This could be really helpful, and he want a Nobel
7:47
Speaker 1: prize very rightfully, so the first one ever for physics.
7:51
Speaker 1: And he named him X rays because he didn't know
7:55
Speaker 1: what the heck it was, no exactly kind of signing
7:57
Speaker 1: your name. He probably right. I think he assumed that
7:59
Speaker 1: later um future scientists would fill in the blanks, but
8:03
Speaker 1: they were like, no, we're cool with X rays. Well,
8:05
Speaker 1: he probably thought that someone would eventually call it like
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Speaker 1: the Rundkin ray for something. He wasn't much of a
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Speaker 1: self promoter. He was just like all this calum X
8:13
Speaker 1: rays as a placeholder. And he didn't patent any anything,
8:16
Speaker 1: you know. He never like made money off that. Uh.
8:19
Speaker 1: And then just as his wife had hand cancer as
8:21
Speaker 1: a result. Really, oh, I was laughing, but no she did.
8:25
Speaker 1: That would be it was. It was just a joke.
8:27
Speaker 1: You can proceed with the la plus I've never heard
8:29
Speaker 1: of hand cancer. It's got to be out there. Uh.
8:33
Speaker 1: And then a couple of years later they were already
8:35
Speaker 1: using it um in the Balkan War was the first
8:37
Speaker 1: time it was really put to practical use. The First
8:40
Speaker 1: Balkan War, the one around World War One. Well no,
8:44
Speaker 1: oh that Baltimore. Um, I didn't know that existed until
8:48
Speaker 1: just now. Yeah, and they said we can see bullets
8:51
Speaker 1: and trapnel and stuff now, um, which is helpful. It
8:54
Speaker 1: is extremely helpful. So like this guy Rundkin discovers X
8:58
Speaker 1: rays and their most practical application in one fell swoop basically,
9:03
Speaker 1: and a little further study revealed the X rays are
9:06
Speaker 1: actually just another part of the electromagnetic spectrum, of which
9:13
Speaker 1: radio waves, microwaves what we call visible light. Um, what
9:19
Speaker 1: else is on there? Uh? Well, I've got handy wallet
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Speaker 1: electromagnetic spectrum card, and X rays fall between gamma rays
9:29
Speaker 1: and ultraviolet rays on that spectrum, which are all below.
9:33
Speaker 1: Well you say below, I don't know if it's it's
9:35
Speaker 1: not really an above or below situation visible light and
9:40
Speaker 1: then infrared, microwave and radio waves, so it would be
9:43
Speaker 1: a higher or lower frequency, because that's how the whole
9:45
Speaker 1: thing is divided. Yeah. So, like the visible spectrum of
9:48
Speaker 1: light consists of electromagnetic radiation that has a frequency a
9:54
Speaker 1: wavelength that our eyes are sensitized too, so we can
9:58
Speaker 1: pick up visible light. There's plenty of other stuff on
10:01
Speaker 1: the spectrum of electromagnetic radiation, and all of it is
10:04
Speaker 1: delineated by the frequency the wavelengths. So at the highest
10:08
Speaker 1: end you have gamma rays. They're like, yeah, that means
10:12
Speaker 1: the squiggly line is very close together exactly. And then
10:15
Speaker 1: on the farthest end you have radio waves are like,
10:20
Speaker 1: and that means the squiggly line as far apart exactly,
10:23
Speaker 1: And that is called chuck science. That's good stuff. Yeah.
10:27
Speaker 1: So back in my wallet X raight right next to
10:30
Speaker 1: the what else you have in there? I just have
10:34
Speaker 1: my PEPs Blue Ribbon membership, which actually do do you really? Yeah,
10:39
Speaker 1: but I've had it for like twenty years. When you
10:43
Speaker 1: you got it when you're like seven eight, flatter me. So, uh,
10:48
Speaker 1: X rays fall, I guess we're about in the well, Yeah,
10:52
Speaker 1: the higher and they have a higher frequency as far
10:54
Speaker 1: as the electro magnetic spectrum goes. But the point is
10:57
Speaker 1: is that it is ultimately the same thing to It's
11:00
Speaker 1: a type of electro magnetic energy that is carried on
11:04
Speaker 1: a photon, which is a particle of what we would
11:07
Speaker 1: call light. Yeah, and we talked about photons a plenty
11:10
Speaker 1: in the show, and uh, the same, like photons produce
11:15
Speaker 1: the visible light that we can see photons blast out
11:18
Speaker 1: from the Sun. How long does it take? Like it
11:21
Speaker 1: takes like a hundred years to get from the core
11:24
Speaker 1: to the surface and then like eight minutes to get
11:26
Speaker 1: from the surface to Earth. That's right, man, that's I
11:29
Speaker 1: love that fact. So this is the only part I understand,
11:32
Speaker 1: So I'll lead with it. If you want to imagine
11:35
Speaker 1: um an atom, a nucleus of an atom and rings
11:38
Speaker 1: around that adiom atium and adam as orbitals. Uh, when
11:45
Speaker 1: an electron drops to a lower orbital, it releases energy
11:50
Speaker 1: in the form of a photon, and the electron will
11:52
Speaker 1: always drop to the lower orbital. That's right. So like
11:55
Speaker 1: if an orbital is if an electron is kicked off
11:58
Speaker 1: of a lower orbital and allow trn in the higher
12:00
Speaker 1: orbital goes yet and drops down to that one. Yes,
12:03
Speaker 1: and depending on how far it drops is going to
12:05
Speaker 1: determine the energy level of that photon. That it's that
12:08
Speaker 1: it releases his energy when it drops, right, yeah, because
12:11
Speaker 1: it doesn't have to, you know, drop more than one orbital.
12:14
Speaker 1: You can skip down I don't even know how far,
12:16
Speaker 1: but a long way, yeah, I can. And like you
12:18
Speaker 1: said that, the greater the distance between the two orbitals
12:21
Speaker 1: are the greater the energy differential, the greater the energy
12:24
Speaker 1: that photon when released will have. Right, that's right. And
12:28
Speaker 1: as we said, photons are the energy carriers of the
12:31
Speaker 1: electromagnetic spectrum. And depending on that energy or the frequency
12:36
Speaker 1: the wavelength of that photon, that determines what kind of
12:39
Speaker 1: photon it is, right, whether it's a radio photon or
12:43
Speaker 1: a an X ray photon, or a photon that we
12:46
Speaker 1: can see that's in the visible spectrum. That's right. Uh,
12:49
Speaker 1: Sometimes when these photons are flying around, they will collide
12:53
Speaker 1: with other atoms, and sometimes those atoms absorb that photons
12:58
Speaker 1: energy and then kick it up to that higher level again, right,
13:01
Speaker 1: But it has to be from what I understand, and
13:04
Speaker 1: I saw that there's like of course it's science, so
13:06
Speaker 1: there's like atomic science, so there's little exceptions did this
13:11
Speaker 1: and that. But from what I could see, Chuck, there
13:14
Speaker 1: is the energy of that photon has to exactly match
13:20
Speaker 1: the energy differential between one orbital and another on an
13:25
Speaker 1: atom so that it can kick it up, so that
13:28
Speaker 1: it hits that one electron in the lower orbital kicks
13:31
Speaker 1: it up to the higher orbital and thus transfers its energy,
13:34
Speaker 1: which means that atom just absorbed that energy that that
13:38
Speaker 1: photon was carrying. Right, But if it's a little less,
13:41
Speaker 1: it's not going to have the energy to kick that
13:43
Speaker 1: electron up, which makes sense to me, right. But if
13:46
Speaker 1: it's a little more, this is what doesn't make sense
13:49
Speaker 1: to me. It doesn't kick the electron up, and then
13:52
Speaker 1: the photon carries on in a diminished energetic state. It
13:56
Speaker 1: just doesn't do anything. It doesn't interact with that. It
14:00
Speaker 1: has to be exactly, say, like the energy differential between
14:03
Speaker 1: orbits is eight, So a photon has to have an
14:06
Speaker 1: energy of eight or else it's not gonna do anything
14:10
Speaker 1: with the atom, that's right, Okay, uh, And so depending
14:15
Speaker 1: on the um. Well, let's say you have a radio wave.
14:19
Speaker 1: They don't have very much energy, so they can't move
14:21
Speaker 1: electrons between these orbitals. They just passed through things. X
14:25
Speaker 1: rays are super powerful. There's lots of energy, so they
14:29
Speaker 1: can pass through things, which is key if you want
14:31
Speaker 1: to check out your bones from outside of your body.
14:35
Speaker 1: It is, so we're back chucking. You tantalized everybody by
15:00
Speaker 1: saying that this, this difference in absorption is what produces
15:04
Speaker 1: X rays, Right? Was that tantalizing? I was tantalized and
15:08
Speaker 1: I even know it's coming. All right, that's how excited
15:10
Speaker 1: I mean about X rays. So consider this, Like different
15:15
Speaker 1: atoms have different atomic weights, they have different densities, they're
15:22
Speaker 1: just different. Like different atoms are different, and atoms also
15:26
Speaker 1: have what are called differences in radiological density. Okay, so
15:31
Speaker 1: a really high energy, high atomic weight, very dense atom
15:37
Speaker 1: is going to be able to absorb a lot of energy.
15:41
Speaker 1: Smaller atoms that maybe are looser and have a lower
15:44
Speaker 1: atomic weight are going to get kicked around by any
15:46
Speaker 1: old photon that wants to come along. Yeah, and that's
15:51
Speaker 1: that's key. Like I said, if you want to see
15:52
Speaker 1: bones because you're soft tissue, if you've ever noticed when
15:55
Speaker 1: you have an X ray, you'll see the bones, but
15:58
Speaker 1: you know the rest is just sort of a grayish
16:00
Speaker 1: black mess exactly because your soft tissue has smaller atoms.
16:04
Speaker 1: Your bones, uh, calcium adams are much larger, so they're
16:08
Speaker 1: gonna absorb those X ray photons. It's exactly right to
16:12
Speaker 1: do it, really well exactly. So um imagine you have uh,
16:17
Speaker 1: let's say, Chuck, let's go back and hang out with
16:19
Speaker 1: Tuck Tuck. Right, Oh man, let's get back in the
16:22
Speaker 1: way back when she's been a while. Okay, look at
16:33
Speaker 1: him over there. So here we are in France in
16:35
Speaker 1: this cave, um Tuck Tuck has his hand up against
16:39
Speaker 1: the cave wall, as you'll see, and in his other
16:42
Speaker 1: hand he's got that little straw filled with pigment, red pigment.
16:46
Speaker 1: He's blowing it on his hand, right, And now that
16:50
Speaker 1: he moves his hand away, there's the outline of his hand.
16:54
Speaker 1: It's called a stencil, right exactly. He's just made an
16:56
Speaker 1: early stencil. He's like banks He basically like a caveman Banksy.
17:01
Speaker 1: But if you look at the back of Tuk Tuk's hand,
17:03
Speaker 1: don't get too close, but look at the back of
17:05
Speaker 1: his hand, it's covered in red pigment, right, So if
17:09
Speaker 1: you can, if you want to equate this to an
17:11
Speaker 1: X ray, the hand absorbed all of that pigment, and
17:17
Speaker 1: the stuff that passed through left the picture on the cave.
17:21
Speaker 1: All that's kind of what happens with an X ray,
17:23
Speaker 1: except with an X ray photograph. The X ray photons
17:28
Speaker 1: are absorbed by the denser calcium rich bones and they
17:33
Speaker 1: passed through the softer tissue. So the picture that we
17:36
Speaker 1: have is the outline the silhouette of the bones because
17:41
Speaker 1: the X rays made it through the tissue, didn't make
17:44
Speaker 1: it through the bones. They made it through the tissue
17:45
Speaker 1: and onto the X ray plate, which absorbed the picture
17:48
Speaker 1: in negative. That's right. And I'm glad you said picture,
17:51
Speaker 1: because that's all it is. On the other side of
17:53
Speaker 1: the human being. You know that they're shooting the X
17:56
Speaker 1: ray at there's a camera and you're just gonna get
18:00
Speaker 1: a regular negative, and they could make it a positive,
18:03
Speaker 1: but they leave it as a negative because you really
18:05
Speaker 1: don't need the positive image. Uh, And that's what they'll
18:09
Speaker 1: put on that little screen to show you your cracked
18:11
Speaker 1: femur exactly. And they can see the crack because some
18:15
Speaker 1: of those X rays will make it through the gap,
18:18
Speaker 1: that's right, right, So all you're seeing is the result
18:21
Speaker 1: of X rays that made it through the tissue were
18:25
Speaker 1: absorbed by the bone, so those don't make it to
18:28
Speaker 1: the plate. The ones that make it to the plate
18:30
Speaker 1: cause the chemical reaction that gives you your negative, your
18:33
Speaker 1: X ray. And it's it's pretty simple, really like if
18:36
Speaker 1: you think about it, at least in principle. It's also
18:39
Speaker 1: extraordinarily difficult to conceive of. But if you if you
18:45
Speaker 1: understand like the principle behind it, it makes uttering complete sense. Yeah.
18:49
Speaker 1: And it's a pretty focused shot that they're using there.
18:51
Speaker 1: It's not like they don't fill the entire room with
18:54
Speaker 1: X rays. You know, They've got a thick lead shield
18:57
Speaker 1: around the whole device, and and it, you know, contains
19:01
Speaker 1: contains everything. It's got a little small window that's just
19:04
Speaker 1: gonna let that narrow beam pass through, uh, through a
19:07
Speaker 1: series of filters and basically hit you wherever they want
19:11
Speaker 1: to hit you. Yeah. And the reason that the they
19:13
Speaker 1: use lead is because lead is an extremely dense uh
19:17
Speaker 1: yeah element, yes, right, sure, oh god, I hope so
19:22
Speaker 1: with a with a very high atomic number, which means
19:24
Speaker 1: it can absorb tons of energy. Right, Yeah, that's why
19:27
Speaker 1: you're gonna wear a lead apron. Um if you're not,
19:30
Speaker 1: you know, if you're getting your skull done, you're probably
19:32
Speaker 1: gonna wear an apron in your chest. Let's say, sure,
19:34
Speaker 1: so you're you're so, this lead is being bombarded with
19:38
Speaker 1: X ray, photons and electrons and it's just taking it.
19:41
Speaker 1: It's fine, and it's not being able to it's not
19:44
Speaker 1: able to pass through because it doesn't have high enough energy. Um.
19:48
Speaker 1: But yes, they when they put that little window in
19:50
Speaker 1: the X ray generating machine, it passes right through there
19:53
Speaker 1: in a concentrated beam. And Chuck, let's talk about the machine, right,
19:58
Speaker 1: So and and this is basic what we use as
20:01
Speaker 1: X ray machines is essentially what root Can was made,
20:05
Speaker 1: what made was experimenting with when he accidentally discovered them.
20:09
Speaker 1: Because if you look for X rays like they're they
20:12
Speaker 1: propagate naturally. But I think like the X rays on
20:16
Speaker 1: Earth come from humans. Really, Yeah, Like we generate a
20:19
Speaker 1: lot of X rays. They don't. They don't come like
20:23
Speaker 1: you don't find them normally on Earth. They're coming from
20:25
Speaker 1: outer space to us, hence X ray astronomy. But the
20:29
Speaker 1: ones here on Earth that are generated on Earth, they don't.
20:33
Speaker 1: It's not like rocks put out X rays or something
20:35
Speaker 1: like that. We do. We humans do. Humans and light
20:40
Speaker 1: aprons put out X rays and they use this machine
20:42
Speaker 1: like root Can made. Yeah, what you have in the machine,
20:45
Speaker 1: you have an electrode pair, cathode, and an anode and
20:48
Speaker 1: that's inside a good old fashioned glass vacuum tube, which, um,
20:53
Speaker 1: it's amazing how vacuum tubes are still like the best
20:55
Speaker 1: way to do many of these things. Well, it allows
20:57
Speaker 1: things to travel at the speed of light easily. It's right,
21:00
Speaker 1: and allows guitar amps to sound great. I didn't know
21:03
Speaker 1: these vacuums and that Oh is that a cathode tube? Yeah? Yeah,
21:06
Speaker 1: like a like the best amps are still made with
21:10
Speaker 1: vacuum tubes. You can get solid state amps, but they're
21:12
Speaker 1: just the sound isn't as rich, So it's kind of
21:14
Speaker 1: like this old technology that's still superior. They're all pumped
21:18
Speaker 1: out by hand by a ninety year old man in Tennessee,
21:21
Speaker 1: Mr Marshall. Yes. Uh so. The cathode is a heated filament,
21:26
Speaker 1: just like you might see in a light bulb, and
21:29
Speaker 1: the machine's gonna pass a current through that and heat
21:32
Speaker 1: that thing up, and then it's gonna spit electrons off
21:35
Speaker 1: that surface, and it's gonna hit a disc made of
21:39
Speaker 1: tungsten and it's gonna draw those across the tube. It's
21:42
Speaker 1: basically the tube is sort of the key piece, right,
21:45
Speaker 1: because you've got the positive and the and the negative
21:49
Speaker 1: charge the cathode and the anode, right yeah. Um, and
21:53
Speaker 1: that difference that electrical charge draws as electrons down to
21:57
Speaker 1: the anode. Yeah, with a lot of force. Yeah, And
22:01
Speaker 1: that forest means that when those electrons hit the tungsten anode,
22:06
Speaker 1: it knocks a bunch of electrons off, creates a bunch
22:09
Speaker 1: of X rays in the process, and um, you have
22:13
Speaker 1: a whole box filled with X ray radiation. That's exactly
22:19
Speaker 1: what it is, like you're just I mean there, there
22:21
Speaker 1: might as well be like a foot crank to this thing,
22:23
Speaker 1: like an old sewing machine. For as as technologically advanced
22:27
Speaker 1: as it is, there may be for all I know,
22:28
Speaker 1: I don't know what goes on in that other room, right, Yeah,
22:32
Speaker 1: there's some dude in there with like his right leg
22:36
Speaker 1: is three times more muscular than his left leg because
22:38
Speaker 1: that's the only one he uses. So um. In addition,
22:42
Speaker 1: like I said to to X rays being created, the
22:45
Speaker 1: the other X rays, other photons can go on and
22:49
Speaker 1: knock more electrons off. So you you have what's like
22:52
Speaker 1: a process of chain reactions starting. Right. It's not like
22:55
Speaker 1: one gets hit and then that's it, and the photons
22:57
Speaker 1: creating it just hangs around until it's beamed out. But
23:00
Speaker 1: you're just generating this huge amount of X rays, and
23:04
Speaker 1: the X rays are also continuing to propagate themselves because
23:07
Speaker 1: they're knocking more electrons free, and the more free electrons
23:10
Speaker 1: you have, the more interactions you have, right, So one
23:14
Speaker 1: of the ways that more electrons can be knocked off.
23:17
Speaker 1: You don't even need a direct transfer of energy where
23:20
Speaker 1: a photon is absorbed or knocks an electron from one
23:23
Speaker 1: orbit to another, or knocks it loose entirely. A photon
23:26
Speaker 1: actually has this really cool um capability of just orbiting
23:33
Speaker 1: close by the nucleus of an atom, and when the
23:36
Speaker 1: nucleus basically draws it into its orbit, the photon just
23:40
Speaker 1: takes a hard left turn, just bumps it off its course.
23:43
Speaker 1: But even like the dodge viper has to like slow
23:46
Speaker 1: down to take a left turn, slow a little bit right,
23:50
Speaker 1: just a little, just a little, But that little bit
23:53
Speaker 1: in the photon world means a transfer of energy from
23:57
Speaker 1: the photon outward an X ray. Yeah, and then the photon,
24:02
Speaker 1: like the photon takes that left turn and and the
24:05
Speaker 1: energy is transferred to the atom. Yeah. And one of
24:07
Speaker 1: the byproducts, h If this sounds like it's gonna create
24:11
Speaker 1: a lot of heat, it's because it will. And in
24:13
Speaker 1: order to combat this, they rotate this anode to keep
24:16
Speaker 1: it. It It would just melt down if you kept it
24:17
Speaker 1: in place. And apparently there's a cool oil bath that
24:22
Speaker 1: helps absorb heat as well, which I never have heard
24:25
Speaker 1: of that either. It sounds oily cool oil bath. Yeah,
24:28
Speaker 1: it doesn't sound refreshing at all. It sounds like the
24:30
Speaker 1: opposite of refreshing. Yeah. Cool and oil don't really go together. Yeah,
24:34
Speaker 1: and I misspoke. That's an electron that can be drawn
24:37
Speaker 1: too into the nucleus of an anom appropriately enough because
24:40
Speaker 1: they orbit nuclei anyway. But it doesn't have to hook
24:44
Speaker 1: hook up with that atom. When it takes that hard left,
24:47
Speaker 1: it admits the photon like you said, that's right. And
24:50
Speaker 1: like I said earlier, there's a camera on the other
24:52
Speaker 1: side of the patient and it's going to record that
24:54
Speaker 1: pattern of light when it passes through the body. And
24:58
Speaker 1: it's not so different from a regular camera. Um. And
25:01
Speaker 1: then the and you're just gonna get a picture, like
25:03
Speaker 1: I said, a negative image. Yeah. And if you hook
25:05
Speaker 1: it up with a computer that allows you to take
25:08
Speaker 1: X rays basically in slices, you can come up with
25:11
Speaker 1: community computerized tomography. If you make a c T right,
25:16
Speaker 1: let's set scan exactly. Um. If you uh, if you
25:19
Speaker 1: use if you get a breast exam, you're using a
25:21
Speaker 1: type of X ray called momography, um, and then there's
25:25
Speaker 1: a fluoroscopy, which the man in the extraordinarily dry presentation
25:31
Speaker 1: from Siemens said, um was basically like moving picture. It's
25:36
Speaker 1: like a movie exactly. And then he showed us what
25:39
Speaker 1: the movie is with a flipbook, right, that old flipbook trick.
25:42
Speaker 1: And if you listen to this podcast, I'm sorry, I
25:45
Speaker 1: just want to apologize for both of us. Semens. Guy.
25:48
Speaker 1: Oh yeah, uh, like, hats off to you for doing
25:52
Speaker 1: that at all. Yeah, um, because he's probably saying, well,
25:55
Speaker 1: at least I was correct and everything I said exactly.
25:58
Speaker 1: It's a good point, sir um. But with fluoroscopy, it's
26:01
Speaker 1: basically like a movie of an X ray movie, and
26:05
Speaker 1: you would do this to make sure like a heart
26:07
Speaker 1: is beating correctly because you wanted to see it. But
26:10
Speaker 1: you have to have an additional um instrument because, as
26:14
Speaker 1: we've said, X rays will pass through tissue like heart
26:19
Speaker 1: tissue and muscle tissue and all and blood vessels and
26:22
Speaker 1: all this stuff you want to get pictures of using
26:24
Speaker 1: an X ray, so you have to use something called
26:26
Speaker 1: the contrast media for it. Yeah. Um. A contrast agent
26:29
Speaker 1: is basically more dense than the soft tissue. So if
26:32
Speaker 1: you want to, uh, let's say, swallow, it's usually like
26:37
Speaker 1: a barium compound. If you want to examine like your
26:40
Speaker 1: blood vessels or your circulatory system, you're sometimes they can
26:44
Speaker 1: inject that, or you might drink it to see if
26:46
Speaker 1: you're doing like a gastro intestinal like a GI tract,
26:49
Speaker 1: You're gonna swallow that stuff, which I've never had to do.
26:52
Speaker 1: I think my dad had to do that. Yeah. I
26:54
Speaker 1: don't think it's super pleasant. I get the impression not
26:56
Speaker 1: too but my dad did as well. Yeah, it's an
26:59
Speaker 1: old dying Yeah, so I should be getting one soon. Uh.
27:03
Speaker 1: And then it allows you, you know, to see him
27:05
Speaker 1: moving image. Uh, basically how that liquid is if there's
27:10
Speaker 1: any blockage. Uh. There's all sorts of applications for it. Yeah,
27:13
Speaker 1: because you're that liquid has a high radiological density, which
27:19
Speaker 1: means that the X rays don't just pass right through
27:21
Speaker 1: your the tissue that it's being suspended in, like your
27:25
Speaker 1: blood vessels, It absorbs it for it. So you get
27:28
Speaker 1: a picture of your blood vessels, your circulatory system, which
27:31
Speaker 1: is pretty cool. It's pretty clever. It's also extraordinarily elementary
27:34
Speaker 1: and principle my dear Watson. Uh, and that single picture
27:38
Speaker 1: I think we know we mentioned CT and momography and
27:41
Speaker 1: all that in philoscopy, but the single picture is just
27:43
Speaker 1: called standard radiography. And that's when you're you know, taking
27:47
Speaker 1: a photo of your skull or your lungs, or your
27:51
Speaker 1: bones or your teeth and so so. Speaking of the
27:54
Speaker 1: lead apron thing, man, it's always made me kind of nervous,
27:57
Speaker 1: Like if I the rest of my body has to
27:59
Speaker 1: wear lead apron, and but you're shooting an X ray
28:02
Speaker 1: into my head? Am I going to be? Okay? Well
28:05
Speaker 1: we'll answer that right after this message. All right, X
28:24
Speaker 1: rays are they bad for you? The answer is yes, uh,
28:28
Speaker 1: pretty unequivocally. Um, But like all things, it's it's in
28:32
Speaker 1: moderation is the key. Uh. In the nineteen thirties and
28:35
Speaker 1: forties and into the fifties, they had X ray machines
28:38
Speaker 1: at shoe stores. They can extra your feet to get
28:42
Speaker 1: a better fit, and um, they didn't realize at the
28:45
Speaker 1: time that they were X raying people way way too much. Yeah,
28:48
Speaker 1: talkative kids in class, they just shoot him with an
28:51
Speaker 1: X ray and they probably did I've got you like twice. Well,
28:55
Speaker 1: now I would believe that like Hey, let's look at
28:57
Speaker 1: his brain. There may be a mouse running around side
29:00
Speaker 1: of it. Um. People in the thirties were dumb. Well,
29:03
Speaker 1: it's basically radiation sickness. Um, it's a form of ionization
29:08
Speaker 1: or ionizing radiation. So what can happen? Like, if just
29:12
Speaker 1: normal light hits an atom, is no big deal. But
29:14
Speaker 1: when an X ray hits an atom, it knocks electrons
29:18
Speaker 1: off of it creates an ion, which is an electrically
29:21
Speaker 1: charged atom, and basically anything from uh, cellular death to
29:26
Speaker 1: mutation can happen at that point, and mutation can spread
29:30
Speaker 1: and it can cause cancer. Right because stable atoms are neutral, right,
29:34
Speaker 1: because they have an equal number of protons and electrons.
29:37
Speaker 1: You lose an electron all of a sudden, you have
29:39
Speaker 1: a positively charged ion and that negatively charged electron running
29:43
Speaker 1: around and it just causes trouble. And you said light,
29:47
Speaker 1: Visible light can be absorbed and it's no big deal
29:50
Speaker 1: because visible light is exists on a wavelength that's about
29:54
Speaker 1: in tune with the soft tissues of our body, right,
29:56
Speaker 1: so we know how to absorb it and it makes
29:58
Speaker 1: us tan and that's cool, right. But Um, with these
30:02
Speaker 1: ionized atoms, these positively charged atoms like going around in
30:07
Speaker 1: your body. It can cause a lot of problems like
30:11
Speaker 1: mutations like cancer. Right. Yeah, I mean if you break
30:13
Speaker 1: that DNA chain, that's not good. No, it is. And
30:16
Speaker 1: one of the results is the d The DNA can
30:19
Speaker 1: basically lose its ability to regulate itself and the cell
30:25
Speaker 1: replicates more frequently than it should and all of a sudden,
30:28
Speaker 1: you have a tumor on your hands and that can spread.
30:31
Speaker 1: It can also be a problem if that d NA
30:34
Speaker 1: break occurs in utero, because then that can lead to
30:38
Speaker 1: birth defects, which is why pregnant women shouldn't get X
30:40
Speaker 1: rays um. And it can also just lead to plain
30:44
Speaker 1: old cellular death. If you have cellular death, then the
30:47
Speaker 1: tissues that are made up by those cells breakdown, and uh,
30:51
Speaker 1: you have a problem on your hands with that as well.
30:54
Speaker 1: So here's the deal. We get exposed to radiation every
30:57
Speaker 1: day just walking around on the planet. Yeah. Um, it
31:01
Speaker 1: depends on where you live. But every year, um, the
31:04
Speaker 1: average person is going to be exposed to anywhere from
31:07
Speaker 1: one to four Uh. It's measured in millisieverts per year um.
31:12
Speaker 1: Like I said, depending on where you are. I think
31:14
Speaker 1: in higher elevations it's less then at sea level. So
31:18
Speaker 1: if you live in Denver, Colorado, you're going to be
31:20
Speaker 1: exposed to less well yeah, because definitely you're higher up
31:23
Speaker 1: in the atmosphere and that makes a difference. Exactly you
31:27
Speaker 1: have less protection, right Yeah. So, um, you know what
31:31
Speaker 1: they what they want to do medically speaking, they want
31:34
Speaker 1: to use, or they're supposed to use the minimum amount
31:38
Speaker 1: to achieve the pictures you need. It's not like the
31:40
Speaker 1: old days where they're just like, let's twenty X rays. Yeah, like,
31:44
Speaker 1: let's do the minimum amount we need to get the
31:46
Speaker 1: information that we need. A CT scan can can get
31:50
Speaker 1: your you know, you lay down in the tube and
31:52
Speaker 1: it rotates around you and your whole body can be
31:54
Speaker 1: photographed in less than five seconds days. But um, you
31:59
Speaker 1: know there are concerns if you get too many X
32:01
Speaker 1: rays still, uh like a dental panorama. I think would
32:05
Speaker 1: I say one to four millisy verts per year and
32:09
Speaker 1: it's cumulative to you should like, it's not. It's not
32:12
Speaker 1: like you get one and then you know, eight months
32:15
Speaker 1: later you get another one and that first one went away,
32:18
Speaker 1: Like it accumulates over the course of a year. Yeah.
32:20
Speaker 1: So here's just a few examples of how much radiation
32:23
Speaker 1: you're being exposed to with X rays. UM, a dental
32:26
Speaker 1: panorama is going to be point zero one millisy verts,
32:30
Speaker 1: so not very much. UM, Like two chest X rays
32:33
Speaker 1: might be point one mam or grammars around point four. Uh,
32:38
Speaker 1: your pelvis point six, your back, upper back maybe one
32:42
Speaker 1: point zero. Uh. I wonder why because there's so maybe yeah,
32:49
Speaker 1: maybe you have to do with exposure to Yeah, that
32:52
Speaker 1: makes sense. I got a ton of bone of my
32:55
Speaker 1: upper back. A full CT scan, it depends on what
32:59
Speaker 1: you are, UM, it depends on what you're X raying.
33:03
Speaker 1: But CT scan is obviously more like an abdominal or
33:06
Speaker 1: pelvis c T CT scan because be as many as
33:09
Speaker 1: ten millis everts. So that's like up to two or
33:13
Speaker 1: three years worth of radiation in a single CT scan,
33:16
Speaker 1: which can be problematic, which is why they don't say
33:19
Speaker 1: get in the CT machine like every other week. UM.
33:23
Speaker 1: But you know some of the reasons you might if
33:25
Speaker 1: you had a traumatic injury, they're gonna X ray you
33:28
Speaker 1: a lot of times for disease confirmation. They'll use an
33:31
Speaker 1: X ray machine. Uh. During surgery as a visual guide,
33:35
Speaker 1: Like if you do endoscopic surgery, the surgeons actually needs
33:39
Speaker 1: to look at something, so sometimes the X rays for
33:42
Speaker 1: that or to monitor your healing process. Um, you know,
33:46
Speaker 1: when you break a bone, it's not just that first
33:48
Speaker 1: X ray. You're gonna keep getting them to see how
33:50
Speaker 1: you're healing up video. Huh no, it isn't. Okay, I
33:57
Speaker 1: don't think so. I mean I look at so much
33:59
Speaker 1: stuff at all other cumulative research. So, uh, I did
34:04
Speaker 1: a brain stuff on siverts and how many we can
34:06
Speaker 1: take and uh, yeah, it's it's kind of like it's
34:10
Speaker 1: a little alarming. Sure how much radiation we're expposed to.
34:13
Speaker 1: People who fly a lot too, are exposed to tons
34:15
Speaker 1: of radiation because you're again higher up in the atmosphere,
34:18
Speaker 1: so you're less protected by the atmosphere. Speaking of flying,
34:22
Speaker 1: of course, baggage that is X rayed. The food industries
34:26
Speaker 1: is X rays a lot. Um archaeologists use it if
34:29
Speaker 1: they don't want to like destroy an object and they
34:31
Speaker 1: want to see what's inside, or earth sciences will use
34:35
Speaker 1: X rays for rocks to see what kind of mineral composition.
34:38
Speaker 1: So there's all sorts of applications. It's not just medical.
34:41
Speaker 1: Um space, yeah, X ray telescopes out on on satellites
34:46
Speaker 1: apparently you can see a lot um. You can see
34:49
Speaker 1: things you can't detect from an earthbound telescope because X
34:53
Speaker 1: rays are absorbed by our atmosphere, so he can't like
34:55
Speaker 1: shoot it into space like that. So this article makes
34:58
Speaker 1: a pretty good point if you ask me, it says like, yes,
35:02
Speaker 1: X rays are like are bad for you, and you
35:06
Speaker 1: should use them with care and caution. And one one
35:10
Speaker 1: good point is to always ask if there's an alternative
35:13
Speaker 1: to an X ray, just to basically say, hey, doc
35:16
Speaker 1: or dennists, slow your role. Let's is there another way
35:19
Speaker 1: we can get this information without an X ray. I
35:21
Speaker 1: know it's the easiest, but what are the alternatives? But
35:24
Speaker 1: then the article makes the point like it's still safer
35:27
Speaker 1: than the ultimate alternative, the thing that X rays replaced,
35:31
Speaker 1: which was exploratory surgery. Yeah, back in the day, if
35:34
Speaker 1: you they thought you had cancer, they would cut you
35:36
Speaker 1: open and see and this is definitely better than that
35:39
Speaker 1: or broken bone. Imagine getting that arm cut open just
35:42
Speaker 1: to see how it's doing. They're like, no, it's not broken, right,
35:47
Speaker 1: And we haven't invented anesthetic yet. So good luck with
35:51
Speaker 1: your dentist. By the way, because um, I always get
35:55
Speaker 1: the feeling that the dentists are like, No, your insurance
35:58
Speaker 1: allows us to build for so many per years, said,
36:00
Speaker 1: that's how many you're going to get? These X rays
36:02
Speaker 1: are putting my kid through college. Yeah. Uh, you got
36:05
Speaker 1: anything else on X rays? No, that was a fine
36:07
Speaker 1: amount of stuff. I'm feeling good about it. You feel
36:10
Speaker 1: good about this one? Sure I do too. Yeah. Uh.
36:12
Speaker 1: If you want to know more about X rays, you
36:14
Speaker 1: can check out this really informative article on how stuff
36:17
Speaker 1: works dot com. It's got some great diagrams that explain
36:20
Speaker 1: a lot of the stuff we were saying visually. Uh.
36:23
Speaker 1: And you can type x ray into the search bar
36:25
Speaker 1: how stuff works and it will bring that up. Since
36:27
Speaker 1: I said search parts. Time for listener mail. Uh, this
36:32
Speaker 1: is from my buddy Poppy and Vancouver. Uh stuff you
36:35
Speaker 1: should don't listen to them, meant while I was there,
36:38
Speaker 1: and um, Poppy as this is say, he's got a
36:40
Speaker 1: pretty cool job. He listened to the PTSD show and
36:43
Speaker 1: wanted to write in about another option that he works with.
36:46
Speaker 1: He's a registered acupuncturist in Vancouver with special training and
36:50
Speaker 1: trauma and addictions. He's a program called Neurotrophic Stimulation Therapy
36:55
Speaker 1: h n T. S T and a large part of
36:57
Speaker 1: the program uses ear acupuncture and electro acupuncture to promote
37:02
Speaker 1: neuroplasticity in the brain. He says, you can't necessarily directly
37:05
Speaker 1: fix the brain, but you can stimulate the ear nerves
37:08
Speaker 1: and will help the brain reregulate certain functionality so it
37:12
Speaker 1: can heal itself. He's been treating trauma and PTSD patients
37:15
Speaker 1: for several years and the evidence for his efficacy is high.
37:19
Speaker 1: It can be done with acupuncture needles alone or in
37:21
Speaker 1: combination with a mild electrical stimulation UM. Remember we talked
37:26
Speaker 1: about UM. Transcranial electro magnetic stimulation. Yeah, transdermal cranial stimulation.
37:32
Speaker 1: He says that's one of the things that he's also
37:35
Speaker 1: using to treat PTSD, which is pretty cool, and he
37:38
Speaker 1: said it makes cognitive behavioral therapies so much easier to
37:40
Speaker 1: introduce because it promotes neuroplasticity and the results help a
37:43
Speaker 1: PTSD suffer to be more open to and able to
37:46
Speaker 1: receive positive social programming. So he has a program we
37:51
Speaker 1: want to promote. If you want to see all the
37:53
Speaker 1: components in action in his program, you can visit Last
37:56
Speaker 1: or Recovery Society at Last Door dot org, slash nt
38:00
Speaker 1: s T or you can donate funds to help purchase
38:04
Speaker 1: a brain scanner so that they can scientifically measure the
38:07
Speaker 1: results of the program, which would really help show the
38:09
Speaker 1: validity of the therapies. And if you're interested in helping
38:13
Speaker 1: out Poppies, cause there because he's really big on treating
38:16
Speaker 1: veterans in Canada in the US, um I shortened his
38:20
Speaker 1: little U r L too bitley b I T dot
38:23
Speaker 1: L Y slash one one y n l o Q
38:29
Speaker 1: and that is from Poppy and he says, no mistay,
38:32
Speaker 1: thanks a lot, Poppy. Is it Poppy with the O
38:35
Speaker 1: P O P P I nice? Uh. If you want
38:38
Speaker 1: to get in touch with us, you can tweet to
38:41
Speaker 1: us at s y s K podcast. You can join
38:44
Speaker 1: us on Facebook, dot com, slash Stuff you Should Know.
38:47
Speaker 1: You can send us an email to stuff podcast at
38:49
Speaker 1: how stuff Works dot com. That's right, uh, and as always,
38:53
Speaker 1: join us at at home on the web. Stuff you
38:55
Speaker 1: Should Know dot Com. Stuff you Should Know is a
38:59
Speaker 1: pretty action of I heart Radio. For more podcasts my
39:02
Speaker 1: heart Radio, visit the i heart Radio app, Apple Podcasts,
39:06
Speaker 1: or wherever you listen to your favorite shows. H