WEBVTT - How X-Rays Work 0:00:00.960 --> 0:00:04.400 Welcome to Stuff you Should Know from House Stuff Works 0:00:04.440 --> 0:00:13.039 dot com. Hey, and welcome to the podcast. I'm Josh 0:00:13.119 --> 0:00:16.280 Clark with Charles W. Chuck Bryant as always, and there's 0:00:16.360 --> 0:00:20.160 Jerry over there fiddling around with stuff. So it's stuff 0:00:20.160 --> 0:00:23.480 you should know the podcast, not stuff you should know. 0:00:23.520 --> 0:00:27.880 The movie. That's right. You know we were one secrecy 0:00:27.920 --> 0:00:29.600 about that. That'd be a good movie. That'd be a 0:00:29.640 --> 0:00:32.000 bad movie. I don't know, man, I could go either way. 0:00:32.280 --> 0:00:37.000 I always see I imagine it like strange brew. Oh yeah, 0:00:37.360 --> 0:00:39.880 yes they could. Uh, they could based it on the 0:00:39.920 --> 0:00:42.840 Stuff you Should Know tell all book I'm writing. Oh yeah, 0:00:42.880 --> 0:00:45.640 that would be exciting. That would be very exciting. I'm 0:00:45.640 --> 0:00:48.200 looking forward to that book like a lifetime movie the Week. 0:00:48.520 --> 0:00:51.280 Do you like um switch people's names like in my 0:00:51.520 --> 0:00:57.880 um Joe Joe Clack. Yeah, exactly. No, it's sort of like, 0:00:58.080 --> 0:01:00.960 uh like did you see the uh Saved by the 0:01:00.960 --> 0:01:03.720 Bell movie? Oh yeah, I didn't Screech write a book. 0:01:04.280 --> 0:01:06.520 It was based on a book by Screech. Right, yeah. 0:01:06.600 --> 0:01:09.040 It wasn't it like all sex and drugs and stuff? 0:01:09.520 --> 0:01:10.920 Oh it was, you know, it was a bunch of 0:01:10.959 --> 0:01:14.120 teenagers in Hollywood. So sure, there was some of that 0:01:14.200 --> 0:01:15.959 in there, but it was I didn't read the book. 0:01:16.000 --> 0:01:19.880 But the movie was bad and not nearly as salacious 0:01:19.920 --> 0:01:22.440 as you wanted it to be, right. I remember a 0:01:22.480 --> 0:01:25.119 lot of people being disappointed, and I remember, I mean 0:01:25.200 --> 0:01:27.920 I recalled it like two weeks ago when people were 0:01:28.000 --> 0:01:30.080 talking about it when it came out. It stunk. I'll 0:01:30.080 --> 0:01:33.640 watch Emily and I'll watch some of those, um just terrible, 0:01:33.800 --> 0:01:37.640 terrible biopics occasionally on TV, and it's it can be fun. 0:01:38.120 --> 0:01:43.160 Like we watched the who was the one actor Brittany Murphy? 0:01:43.520 --> 0:01:46.000 The Britney Murphy story? Oh? Really? Does she have a 0:01:46.040 --> 0:01:47.760 heck of a story? Is she alive still? Or did 0:01:47.760 --> 0:01:50.880 she die? She passed away because under kind of weird 0:01:50.960 --> 0:01:54.440 circumstances because she and her husband both passed away within 0:01:54.480 --> 0:01:56.960 weeks of each other, and there were all these strange 0:01:57.000 --> 0:02:00.560 claims that her house was poisoned, that they were poisoned, 0:02:00.600 --> 0:02:05.480 and um, yeah, it was it was fun. What's your 0:02:05.480 --> 0:02:08.680 take on it? Oh, I don't know, you just that 0:02:08.720 --> 0:02:11.280 the movie wasn't very good. Who played Brittany Murphy? Do 0:02:11.320 --> 0:02:17.640 you remember someone who didn't look very much like Brittany Murphy? 0:02:18.200 --> 0:02:21.239 Julie Bowen but I was right. The Ashton Kutcher guy 0:02:21.280 --> 0:02:23.680 was pretty good, though. I gotta say Steve Jobs played him. 0:02:23.800 --> 0:02:26.320 They should have just gotten Ashton Kutcher to play himself. 0:02:26.720 --> 0:02:28.600 He's not doing much. He's not my two and a 0:02:28.600 --> 0:02:31.240 half Men. I don't know. That's got to require fifteen 0:02:31.240 --> 0:02:34.160 minutes of work a week. He's selling cameras. Do you 0:02:34.200 --> 0:02:35.840 remember when that whole Two and a half Men thing 0:02:35.840 --> 0:02:38.160 was going down? We were in l a And for 0:02:38.200 --> 0:02:40.480 the one and only time in my entire life, I 0:02:40.480 --> 0:02:44.760 see John Cryer that day. Oh, during the Charlie Sheen meltltown, 0:02:44.800 --> 0:02:47.480 like the day of the meltown, like it happened at night. 0:02:47.560 --> 0:02:50.440 And within eight hours I saw John Cryer for the 0:02:50.440 --> 0:02:54.000 first time in Personeta McDonald's did you feel Duckie? No, 0:02:54.120 --> 0:02:57.400 I left him alone. He looks sturessed out. Well, yeah, 0:02:57.400 --> 0:02:59.880 he's probably like, my career is going down the tubes. 0:02:59.880 --> 0:03:02.120 But little did he know he's a survivor. His career 0:03:02.240 --> 0:03:06.040 is just fine. So x rays, Yeah, that's what we're 0:03:06.080 --> 0:03:09.680 talking about, right, yep. The lightest part of this podcast. 0:03:10.320 --> 0:03:12.200 I like this one. This one. It's one of those 0:03:12.240 --> 0:03:16.440 things where if you can just hang on by your fingernails. 0:03:16.960 --> 0:03:19.760 It can click and then you lose it again, but 0:03:19.840 --> 0:03:23.119 that means that it could click again later on. That's 0:03:23.160 --> 0:03:26.440 what I like about it. Good. I'll leave that to you. 0:03:26.520 --> 0:03:29.320 I got lots of other stuff about it. I totally 0:03:29.360 --> 0:03:32.640 understand good Good. Um, So, have you ever broken anything 0:03:32.720 --> 0:03:34.720 and needed an X ray? Or has it all just 0:03:34.800 --> 0:03:37.240 been dental stuff? You know? Dude? Never broken a bone? 0:03:38.040 --> 0:03:41.280 Knock on wood? Yeah, I mean I've had My injuries 0:03:41.320 --> 0:03:45.160 were always um stitches. I was always getting busted open 0:03:46.000 --> 0:03:49.880 rocks and sprinklers, and I was always getting cut and 0:03:49.960 --> 0:03:52.839 sewed back up. But I never broke a bone. That's great. Yeah, 0:03:53.240 --> 0:03:55.080 you should probably knock on lee more time, just to 0:03:55.120 --> 0:03:58.160 be safe. Uh So, Yeah, all of my X rays 0:03:58.200 --> 0:04:00.400 to have been like just going to the dentist or whatever. 0:04:00.520 --> 0:04:02.600 You never had a bone broken? I don't want to say, 0:04:02.640 --> 0:04:04.640 because I I don't even know if knocking on wood 0:04:04.680 --> 0:04:07.080 will do it on laminate ikea. That would just be 0:04:07.200 --> 0:04:12.040 so horribly interesting if both of us broke a bone 0:04:12.080 --> 0:04:14.080 after this. Yeah, and we're at the age where like 0:04:14.400 --> 0:04:15.960 you should break bones when you're a kid, were you 0:04:16.000 --> 0:04:18.200 like whatever? I get a cast at this age. It's 0:04:18.240 --> 0:04:21.520 it's a drag. Yeah. I remember reading like a Tom 0:04:21.560 --> 0:04:25.000 Clancy novel and like some kid got an arm torn 0:04:25.040 --> 0:04:27.160 off or whatever, and one of the surgeons was like, 0:04:27.400 --> 0:04:29.440 if the arms in the same room as the kid, 0:04:29.520 --> 0:04:32.440 it can be healed. That doesn't hold true in your 0:04:32.520 --> 0:04:38.440 Tom Clancy's age. No, So, um, you are familiar with 0:04:38.560 --> 0:04:40.360 X rays, so you've seen them before You've watched the 0:04:40.640 --> 0:04:42.919 er surely, Yeah, I mean I've had X rays for 0:04:43.040 --> 0:04:45.240 like the dental ones, like you said, and then um 0:04:45.279 --> 0:04:49.000 just other various like uh like chess X rays for 0:04:49.160 --> 0:04:51.120 sicknesses and things like that, which I think maybe a 0:04:51.160 --> 0:04:54.600 little frivolous to be honest, Yeah, and kind of dangerous 0:04:54.640 --> 0:04:58.760 really conceivably, which we'll get into later. But um, did 0:04:58.800 --> 0:05:01.040 you were you familiar with X raised it all beyond that? 0:05:01.200 --> 0:05:05.560 Did you know that they were invented or discovered accidentally? Yeah? 0:05:05.560 --> 0:05:07.800 I did know that. Um I did not. That's one 0:05:07.800 --> 0:05:09.080 of the few things I know. I thought I saw 0:05:09.080 --> 0:05:11.960 a little like Quickie short on something like it might 0:05:12.000 --> 0:05:14.880 have been actually Science Channel. I looked all over. The 0:05:14.880 --> 0:05:18.919 most I could find was a dude on siemens Um 0:05:18.960 --> 0:05:22.200 just describing it in the most flat affic I've watched 0:05:23.680 --> 0:05:26.080 video yeah, I got to five and five wind Low 0:05:26.120 --> 0:05:27.960 and I was like, forget this. Yeah, if I've never 0:05:28.000 --> 0:05:30.599 loaded for me, I watched the other fourteen though, and 0:05:30.839 --> 0:05:33.520 the whole time I was going, man, these are a 0:05:33.560 --> 0:05:36.360 minute long, please join them all together into one six 0:05:36.400 --> 0:05:38.880 minute video. You know. It was so weird. Yeah, it 0:05:38.960 --> 0:05:41.120 was pretty silly, but and he was he was good. 0:05:41.120 --> 0:05:45.040 He was just very dry. Yeah, and they spent zero 0:05:45.120 --> 0:05:49.479 pennies on any kind of soundtrack or anything like what 0:05:49.640 --> 0:05:53.520 if he grabs papers? You hear papers wrestling in the classrooms. 0:05:53.600 --> 0:05:57.520 It was. It was pretty straightforward. Yes, but that's a 0:05:57.600 --> 0:06:02.160 very wind about, round about way of getting to uh, 0:06:02.240 --> 0:06:09.040 it's discovering German physicists named Wilhelm uh Runtigan, and he 0:06:09.120 --> 0:06:13.080 was testing whether cathode rays could pass through glass. And 0:06:13.160 --> 0:06:16.960 he saw that the fluorescent screen was glowing when he 0:06:17.000 --> 0:06:19.839 turned on his electron electron beam, which wasn't a big deal, 0:06:19.920 --> 0:06:22.560 but he was like, wait, he's got cardboard around it, right, 0:06:22.600 --> 0:06:25.520 there shouldn't be any visible light escaping, which is silly 0:06:25.560 --> 0:06:27.039 to think of. Now, well, yeah it is, but you 0:06:27.080 --> 0:06:29.159 have to put yourself in his shoes, like X rays 0:06:29.600 --> 0:06:32.280 hadn't been discovered because he was literally on the verge 0:06:32.320 --> 0:06:35.080 of discovering them. Right then, that's right, and uh yeah, 0:06:35.120 --> 0:06:36.920 so he was like, this is very curious that this 0:06:36.960 --> 0:06:39.839 is fluorescing. Yeah, and he noticed other things were glowing, 0:06:40.080 --> 0:06:44.760 and eventually he started putting other objects between the tube 0:06:44.760 --> 0:06:47.279 and the screen. They glowed the screen. Did that is 0:06:47.880 --> 0:06:50.320 finally put his hand there. I read his wife's hand. 0:06:50.560 --> 0:06:53.760 Oh really, it's like, come in here for a second. Yeah, 0:06:53.800 --> 0:06:58.919 I want you to try something. Saw bones projected and 0:06:58.960 --> 0:07:03.240 then I guess probably poo pooed his pants. It's a man, 0:07:03.360 --> 0:07:05.440 I think, come onto something here. Yeah. It was really 0:07:05.440 --> 0:07:09.840 that quickly. He was like immediately the application was clear. 0:07:10.160 --> 0:07:12.280 It wasn't one of those things where it took twenty years. 0:07:12.800 --> 0:07:15.040 He's like, hold on, you can see bones. This could 0:07:15.080 --> 0:07:19.360 be really helpful. And he won a Nobel Prize very rightfully, so, 0:07:19.520 --> 0:07:22.280 the first one ever for physics, and he named him 0:07:22.440 --> 0:07:25.840 X rays because he didn't know what the heck it was, no, 0:07:25.960 --> 0:07:28.800 exactly kind of signing your name he'd probably right. I 0:07:28.840 --> 0:07:32.600 think he assumed that later on future scientists would fill 0:07:32.640 --> 0:07:34.280 in the blanks, but they were like, no, we're cool 0:07:34.280 --> 0:07:36.400 with X rays. Well, he probably thought that someone would 0:07:36.400 --> 0:07:39.880 eventually call it like the Rundkin ray for something. He 0:07:39.960 --> 0:07:42.680 wasn't much of a self promoter. He was just like 0:07:42.760 --> 0:07:45.200 all is calling X rays as a place hold. And 0:07:45.240 --> 0:07:47.360 he didn't patent any anything, you know, he never like 0:07:47.480 --> 0:07:50.120 made money off of it. Uh. And then just as 0:07:50.280 --> 0:07:53.840 his wife had hand cancer as a result. Really I 0:07:53.920 --> 0:07:57.480 was laughing, but it was it was just a joke. 0:07:57.560 --> 0:07:59.800 He can proceed with the la plus. I've never heard 0:07:59.800 --> 0:08:03.480 of hand to cancer. It's got to be out there. Uh. 0:08:03.520 --> 0:08:05.080 And then a couple of years later they were already 0:08:05.120 --> 0:08:07.080 using it. Um in the Balkan War was the first 0:08:07.120 --> 0:08:10.119 time it was really put to practical use. The first 0:08:10.120 --> 0:08:15.120 Balkan War, the one around World War One. Well, oh 0:08:15.200 --> 0:08:18.400 that Balkan War. Um. I didn't know that existed until 0:08:18.480 --> 0:08:21.320 just now. And they said we can see bullets and 0:08:21.400 --> 0:08:24.320 trapnel and stuff now, um, which is helpful. It is 0:08:24.400 --> 0:08:28.760 extremely helpful. So like this guy Rundkin discovers X rays 0:08:28.960 --> 0:08:32.640 and their most practical application and one fell swoop basically 0:08:33.640 --> 0:08:36.760 and a little further study revealed the X rays are 0:08:36.760 --> 0:08:42.960 actually just a another part of the electromagnetic spectrum, of 0:08:43.000 --> 0:08:48.840 which radio waves, microwaves what we call visible light. UM. 0:08:48.960 --> 0:08:53.800 What else is there. Well, I've got handy wallet electromagnetic 0:08:53.920 --> 0:08:59.400 spectrum card, and X rays fall between gamma rays and 0:08:59.520 --> 0:09:03.040 ultra bio let rays on that spectrum, which are all below. 0:09:03.720 --> 0:09:05.959 Well you say below, I don't know if it's it's 0:09:06.000 --> 0:09:10.360 not really an above or below situation. Visible light and 0:09:10.400 --> 0:09:13.360 then infrared, microwaven, radio waves, so it would be a 0:09:13.480 --> 0:09:15.760 higher or lower frequency, because that's how the whole thing 0:09:15.800 --> 0:09:18.960 is divided. Yeah. So, like the visible spectrum of light 0:09:19.200 --> 0:09:25.040 consists of electromagnetic radiation that has a frequency, a wavelength 0:09:25.440 --> 0:09:28.640 that our eyes are sensitized too, so we can pick 0:09:28.720 --> 0:09:31.360 up visible light. There's plenty of other stuff on this 0:09:31.480 --> 0:09:35.600 spectrum of electromagnetic radiation, and all of it is delineated 0:09:35.640 --> 0:09:38.959 by the frequency the wavelengths. So at the highest end 0:09:39.160 --> 0:09:42.240 you have gamma rays, They're like, yeah, that means the 0:09:42.280 --> 0:09:45.599 squiggly line is very close together exactly. And then on 0:09:45.800 --> 0:09:50.640 the farthest end you have radio waves. Are like, and 0:09:50.679 --> 0:09:53.400 that means the squiggly line is far apart exactly, and 0:09:53.480 --> 0:09:58.040 that is called chuck science. That's good stuff. Yeah. So 0:09:58.120 --> 0:10:00.640 back in my wallet, x RA right next to the 0:10:01.640 --> 0:10:04.640 what else you have in there? I just have my 0:10:04.800 --> 0:10:09.520 PEPs blue ribbon membership, which actually do do you really? Yeah? 0:10:09.559 --> 0:10:13.439 But I've had it for like twenty years. When you 0:10:13.440 --> 0:10:17.760 you got it, when you're like seven eight, flatter me. So, uh, 0:10:18.080 --> 0:10:22.400 X rays fall, I guess we're about in the well, Yeah, 0:10:22.559 --> 0:10:24.640 the higher and they have a higher frequency as far 0:10:24.679 --> 0:10:27.840 as the electro magnetic spectrum goes. But the point is 0:10:27.840 --> 0:10:30.240 is that it is ultimately the same thing. It's a 0:10:30.720 --> 0:10:33.880 it's a type of electro magnetic energy that is carried 0:10:34.080 --> 0:10:36.800 on a photon, which is a particle of what we 0:10:36.840 --> 0:10:39.839 would call light. Yeah, and we talked about photons a 0:10:39.960 --> 0:10:44.640 plenty in the show, and uh the same like photons 0:10:44.880 --> 0:10:48.800 produce the visible light that we can see photons blast 0:10:48.840 --> 0:10:51.520 out from the sun. How long does it take? Like 0:10:51.880 --> 0:10:53.800 it takes like a hundred dozen years to get from 0:10:53.840 --> 0:10:56.120 the core to the surface and then like eight minutes 0:10:56.160 --> 0:10:58.680 to get from the surface to Earth. That's right, man, 0:10:58.679 --> 0:11:01.600 that's I love that pack. So this is the only 0:11:01.600 --> 0:11:04.640 part I understand, So I'll lead with it. If you 0:11:04.640 --> 0:11:07.880 want to imagine um an atom, the nucleus of an 0:11:07.920 --> 0:11:15.400 atom and rings around that adiom adium and adam as orbitals. Uh, 0:11:15.480 --> 0:11:19.680 when an electron drops to a lower orbital it releases 0:11:19.840 --> 0:11:22.719 energy in the form of a photon, and the electron 0:11:22.760 --> 0:11:25.600 will always drop to the lower orbital. That's right. So 0:11:25.640 --> 0:11:28.080 like if an orbital is if an electron is kicked 0:11:28.080 --> 0:11:30.760 off of a lower orbital, an electron in the higher 0:11:30.840 --> 0:11:33.920 orbital goes and drops down to that one. Yes, And 0:11:33.960 --> 0:11:36.080 depending on how far it drops is going to determine 0:11:36.120 --> 0:11:39.120 the energy level of that photon that it's that it 0:11:39.200 --> 0:11:41.439 releases his energy when it drops, right, yeah, because it 0:11:41.480 --> 0:11:43.720 doesn't have to, you know, drop more than one orbital. 0:11:44.280 --> 0:11:46.319 You can skip down I don't even know how far, 0:11:46.520 --> 0:11:48.440 but a long way, yeah, I can. And like you 0:11:48.480 --> 0:11:51.640 said that, the greater the distance between the two orbitals are, 0:11:51.679 --> 0:11:55.360 the greater the energy differential, the greater the energy that photon, 0:11:55.760 --> 0:11:59.000 when released, will have, right, that's right. And as we said, 0:11:59.040 --> 0:12:03.640 photons are the energy carriers of the electromagnetic spectrum. And 0:12:03.679 --> 0:12:07.439 depending on that energy or the frequency the wavelength of 0:12:07.480 --> 0:12:11.000 that photon, that determines what kind of photon it is, right, 0:12:11.000 --> 0:12:14.840 whether it's a radio photon or a an X ray photon, 0:12:15.400 --> 0:12:17.360 or a photon that we can see that's in the 0:12:17.440 --> 0:12:21.400 visible spectrum. That's right. Uh. Sometimes when these photons are 0:12:21.520 --> 0:12:25.559 flying around, they will collide with other atoms, and sometimes 0:12:26.040 --> 0:12:29.839 those atoms absorb that photons energy and then kick it 0:12:29.920 --> 0:12:32.760 up to that higher level again, right, but it has 0:12:32.840 --> 0:12:35.120 to be from what I understand, and I saw that 0:12:35.160 --> 0:12:39.760 there's like, of course it's science, so there's like atomic science, 0:12:39.760 --> 0:12:42.719 so there's little exceptions to this and that. But from 0:12:42.720 --> 0:12:47.240 what I can see, Chuck, there is the energy of 0:12:47.280 --> 0:12:52.120 that photon has to exactly match the energy differential between 0:12:52.760 --> 0:12:56.880 one orbital and another on an atom so that it 0:12:56.920 --> 0:12:59.319 can kick it up, so that it hits that one 0:12:59.360 --> 0:13:01.920 electron and lower orbital kicks it up to the higher 0:13:02.040 --> 0:13:06.079 orbital and thus transfers its energy, which means that atom 0:13:06.160 --> 0:13:10.079 just absorbed that energy that that photon was carrying. Right. 0:13:10.120 --> 0:13:12.040 But if it's a little less, it's not going to 0:13:12.120 --> 0:13:14.760 have the energy to kick that electron up, which makes 0:13:14.760 --> 0:13:17.600 sense to me, right. But if it's a little more, 0:13:18.000 --> 0:13:20.760 this is what doesn't make sense to me. It doesn't 0:13:20.880 --> 0:13:23.800 kick the electron up, and then the photon carries on 0:13:24.080 --> 0:13:28.120 in a diminished energetic state. It just doesn't do anything. 0:13:28.160 --> 0:13:31.600 It doesn't interact with that. It has to be exactly, say, 0:13:31.640 --> 0:13:36.160 like the energy differential between orbits is eight, so photon 0:13:36.280 --> 0:13:39.160 has to have an energy of eight or else it's 0:13:39.200 --> 0:13:43.800 not gonna do anything with the atom. That's right, okay. Uh, 0:13:43.840 --> 0:13:48.000 and so depending on the um, Well, let's say you 0:13:48.040 --> 0:13:50.480 have a radio wave. They don't have very much energy, 0:13:50.559 --> 0:13:54.440 so they can't move electrons between these orbitals. They just 0:13:54.480 --> 0:13:57.880 passed through things. X rays are super powerful. There's lots 0:13:57.880 --> 0:14:01.400 of energy, so they can through things, which is key 0:14:01.440 --> 0:14:04.600 if you want to check out your bones from outside 0:14:04.600 --> 0:14:06.800 of your body. It is. And we're going to explain 0:14:06.880 --> 0:14:13.320 exactly how right after this. Okay, so we're back chucking. 0:14:13.360 --> 0:14:16.760 You tantalized everybody by saying that this, this difference in 0:14:16.840 --> 0:14:21.000 absorption is what produces X rays. Right was that tantalizing? 0:14:21.160 --> 0:14:24.560 I was tantalized and I even know it's coming, all right, 0:14:24.720 --> 0:14:28.760 that's how excited I am about X rays. So consider this, 0:14:29.000 --> 0:14:36.400 Like different atoms have different atomic weights, they have different densities, 0:14:36.680 --> 0:14:40.640 they're just different. Like different atoms are different, and atoms 0:14:40.680 --> 0:14:46.360 also have order called differences in radiological density. Okay, so 0:14:46.560 --> 0:14:52.480 a really high energy, high atomic weight, very dense atom 0:14:52.600 --> 0:14:55.440 is going to be able to absorb a lot of energy. 0:14:56.200 --> 0:14:59.000 Smaller atoms that maybe are looser and have a lower 0:14:59.040 --> 0:15:01.880 atomic weight are gonna get kicked around by any old 0:15:02.680 --> 0:15:06.400 photon that wants to come along. Yeah, and that's that's key. 0:15:06.640 --> 0:15:08.480 Like I said, if you want to see bones because 0:15:08.560 --> 0:15:10.480 you're soft tissue. If you've ever noticed when you have 0:15:10.520 --> 0:15:13.480 an X ray, you'll see the bones, but you know 0:15:13.520 --> 0:15:17.120 the rest is sort of a grayish black mess because 0:15:17.160 --> 0:15:21.560 your soft tissue has smaller atoms. Your bones, Uh, calcium 0:15:21.560 --> 0:15:25.400 atoms are much larger, so they're gonna absorb those X 0:15:25.480 --> 0:15:28.800 ray photons. It's exactly right to do it, really well exactly. 0:15:28.840 --> 0:15:33.480 So um, imagine you have uh, let's say, Chuck, let's 0:15:33.520 --> 0:15:36.200 go back and hang out with Tuck Tuck right, Oh man, 0:15:36.320 --> 0:15:37.760 let's get back in the way back when it's been 0:15:37.800 --> 0:15:49.800 a while. Okay, look at him over there. So here 0:15:49.840 --> 0:15:52.640 we are in France in this cave, um Tuck. Tuck 0:15:52.960 --> 0:15:56.440 has his hand up against the cave wall, as you'll see, 0:15:56.680 --> 0:15:58.760 and in his other hand he's got that little straw 0:15:58.840 --> 0:16:02.440 filled with pig meant red pigment. He's blowing it on 0:16:02.480 --> 0:16:06.760 his hand right and now that he moves his hand away, 0:16:06.800 --> 0:16:11.160 there's the outline of his hand right exactly. He's just 0:16:11.240 --> 0:16:14.520 made an early stencil. He's like a banks He basically 0:16:14.880 --> 0:16:17.160 like a caveman Banksy. But if you look at the 0:16:17.200 --> 0:16:19.240 back of Tuk Tuk's hand, don't get too close, but 0:16:19.320 --> 0:16:21.600 look at the back of his hand. It's covered in 0:16:21.640 --> 0:16:24.880 red pigment, right, So if you can, if you want 0:16:24.880 --> 0:16:30.040 to equate this to an X ray, the hand absorbed 0:16:30.360 --> 0:16:33.720 all of that pigment and the stuff that passed through 0:16:34.120 --> 0:16:37.080 left the picture on the cave wall. That's kind of 0:16:37.120 --> 0:16:40.120 what happens with an X ray, except with an X 0:16:40.240 --> 0:16:44.720 ray photograph. The X ray photons are absorbed by the denser, 0:16:45.320 --> 0:16:50.080 calcium rich bones and they passed through the softer tissue. 0:16:50.400 --> 0:16:53.120 So the picture that we have is the outline the 0:16:53.200 --> 0:16:56.880 silhouette of the bones because the X rays made it 0:16:57.160 --> 0:16:59.600 through the tissue. Didn't make it through the bones. They 0:16:59.640 --> 0:17:02.000 made it are the tissue and onto the X ray plate, 0:17:02.040 --> 0:17:05.400 which absorbed the picture in negative. That's right, And I'm 0:17:05.400 --> 0:17:07.679 glad he said picture, because that's all it is. On 0:17:07.720 --> 0:17:10.280 the other side of the human being. You know that 0:17:10.320 --> 0:17:14.199 they're shooting the X ray at there's a camera and 0:17:14.720 --> 0:17:17.800 you're just gonna get a regular negative and they could 0:17:17.800 --> 0:17:19.280 make it a positive, but they leave it as a 0:17:19.320 --> 0:17:23.399 negative because you really don't need the positive image. Uh, 0:17:23.400 --> 0:17:25.720 And that's what they'll put on that little screen to 0:17:25.760 --> 0:17:29.359 show you your cracked femur exactly. And they can see 0:17:29.359 --> 0:17:31.840 the crack because some of those X rays will make 0:17:31.880 --> 0:17:34.960 it through the gap, that's right, right, So all you're 0:17:34.960 --> 0:17:37.960 seeing is the result of X rays that made it 0:17:38.240 --> 0:17:42.400 through the tissue were absorbed by the bone, so those 0:17:42.440 --> 0:17:44.840 don't make it to the plate. The ones that make 0:17:44.880 --> 0:17:47.120 it to the plate cause the chemical reaction that gives 0:17:47.119 --> 0:17:50.600 you your negative your X ray. And it's it's pretty simple, really, 0:17:50.600 --> 0:17:53.240 like if you think about it, at least in principle. 0:17:53.960 --> 0:17:59.320 It's also extraordinarily difficult to conceive of. But if you 0:17:59.520 --> 0:18:02.040 if you understand like the principle behind it, it makes 0:18:02.119 --> 0:18:05.720 uttering complete sense. Yeah. And it's a pretty focused shot 0:18:05.960 --> 0:18:08.280 that they're using there. It's not like they don't fill 0:18:08.320 --> 0:18:11.080 the entire room with X rays. You know, they've got 0:18:11.320 --> 0:18:15.159 a thick lead shield around the whole device and it 0:18:15.359 --> 0:18:17.800 you know, contains contains everything. It's got a little small 0:18:17.840 --> 0:18:21.240 window that's just gonna let that narrow beam pass through 0:18:22.240 --> 0:18:25.520 through a series of filters and basically hit you wherever 0:18:25.560 --> 0:18:27.359 they want to hit you. Yeah, And the reason that 0:18:27.440 --> 0:18:30.080 the they use lead is because lead is an extremely 0:18:30.119 --> 0:18:35.800 dense uh yeah element, yes right, sure, oh god, I 0:18:35.800 --> 0:18:39.040 hope so with a with a very high atomic number, 0:18:39.080 --> 0:18:41.720 which means it can absorb tons of energy. Right. Yeah, 0:18:41.720 --> 0:18:44.440 that's why you're gonna wear a lead apron. Um if 0:18:44.480 --> 0:18:46.679 you're not, you know, if you're getting your skull done, 0:18:46.720 --> 0:18:48.720 you're probably gonna wear an apron in your chest. Let's say, 0:18:49.320 --> 0:18:52.680 so you're you're so this lead is being bombarded with 0:18:53.000 --> 0:18:55.960 X ray photons and electrons and it's just taking it. 0:18:55.960 --> 0:18:58.760 It's fine, and it's not being able to it's not 0:18:58.840 --> 0:19:02.920 able to pass through because it doesn't have high enough energy. Um. 0:19:02.960 --> 0:19:05.280 But yes, they when they put that little window in 0:19:05.320 --> 0:19:08.600 the X ray generating machine, it passes right through there 0:19:08.680 --> 0:19:13.400 in a concentrated beam. And Chuck, let's talk about the machine, right. So, 0:19:13.800 --> 0:19:16.159 and and this is basically what we use as X 0:19:16.240 --> 0:19:20.639 ray machines is essentially what Rooken was made, what made 0:19:21.080 --> 0:19:24.800 was experimenting with when he accidentally discovered them. Because if 0:19:24.840 --> 0:19:28.320 you look for X rays like they're they propagate naturally. 0:19:28.760 --> 0:19:31.760 But I think like the X rays on Earth come 0:19:31.880 --> 0:19:35.480 from humans. Yeah, like we generate a lot of X rays. 0:19:35.520 --> 0:19:38.800 They don't they don't come like, you don't find them 0:19:38.840 --> 0:19:41.680 normally on Earth. They're coming from outer space to us, 0:19:42.359 --> 0:19:45.800 hence X ray astronomy. But the ones here on Earth 0:19:46.240 --> 0:19:49.040 that are generated on Earth, they don't. It's not like 0:19:49.119 --> 0:19:52.520 rocks put out X rays or something like that. We do. 0:19:52.920 --> 0:19:56.440 We humans, humans and lead aprons put out X rays 0:19:56.600 --> 0:19:59.320 and they use this machine like Rootkin made. Yeah. What 0:19:59.400 --> 0:20:01.359 you have in the machine and you have an electrode pair, 0:20:01.760 --> 0:20:04.560 a cathode and an anode, and that's inside a good 0:20:04.560 --> 0:20:08.639 old fashioned glass vacuum tube, which, um, it's amazing how 0:20:08.720 --> 0:20:10.720 vacuum tubes are still like the best way to do 0:20:10.840 --> 0:20:13.359 many of these things. Well, it allows things to travel 0:20:13.400 --> 0:20:15.719 at the speed of light easily, that's right, and allows 0:20:15.800 --> 0:20:18.880 guitar amps to sound great. I didn't know these vacuums 0:20:18.880 --> 0:20:21.160 in that. Oh is that a cathode tube? Yeah, yeah, 0:20:21.240 --> 0:20:24.879 like a like the best amps are still made with 0:20:25.040 --> 0:20:27.560 vacuum tubes. You can get solid state amps, but they're 0:20:27.600 --> 0:20:29.760 just the sound isn't as rich, So it's kind of 0:20:29.760 --> 0:20:32.919 like this old technology that's still superior. They're all pumped 0:20:32.960 --> 0:20:35.600 out by hand by a ninety year old man in Tennessee. 0:20:36.400 --> 0:20:41.080 Mr Marshall yes. Uh So the cathode is a heated 0:20:41.080 --> 0:20:43.399 filament just like you might see in a light bulb, 0:20:44.119 --> 0:20:46.520 and the machine's gonna pass the current through that and 0:20:46.560 --> 0:20:49.680 heat that thing up, and then it's gonna spit electrons 0:20:49.840 --> 0:20:53.760 off that surface, and it's gonna hit a disc made 0:20:53.760 --> 0:20:57.399 of punksten and it's gonna draw those across the tube. 0:20:57.520 --> 0:21:00.320 It's basically the tube is sort of the key peat, right, 0:21:00.359 --> 0:21:04.240 because you've got the positive and the and the negative 0:21:04.320 --> 0:21:08.520 charge the cathode and the anode, right, um, and that 0:21:08.920 --> 0:21:15.240 difference that electrical charge draws his electrons down to the anode. Yeah, 0:21:15.400 --> 0:21:19.440 And that force means that when those electrons hit the 0:21:19.480 --> 0:21:24.080 tungusten anode, it knocks a bunch of electrons off, creates 0:21:24.080 --> 0:21:28.080 a bunch of X rays in the process, and um, 0:21:28.160 --> 0:21:32.040 you have a whole box filled with X ray radiation. 0:21:33.800 --> 0:21:35.919 That's exactly what it is, like you're just I mean, 0:21:35.960 --> 0:21:37.679 there there might as well be like a foot crank 0:21:37.720 --> 0:21:40.199 to this thing, like an old sewing machine. For as 0:21:40.320 --> 0:21:43.280 as technologically advanced as it is, there may be for 0:21:43.320 --> 0:21:44.760 all I know, I don't know what goes on in 0:21:44.760 --> 0:21:48.960 that other room, right, Yeah, there's some dude in there 0:21:49.000 --> 0:21:52.520 with like his right leg is three times more muscular 0:21:52.560 --> 0:21:54.720 than his left leg because that's the only one he uses. 0:21:55.400 --> 0:21:58.480 So um. In addition, like I said to to X 0:21:58.600 --> 0:22:03.480 rays being created, the the other X rays, other photons 0:22:03.560 --> 0:22:06.359 can go on and knock more electrons off. So you 0:22:06.359 --> 0:22:09.240 you have what's like a process of chain reactions starting, right. 0:22:09.240 --> 0:22:11.560 It's not like one gets hit and then that's it, 0:22:11.600 --> 0:22:14.280 and the photons creating it just hangs around until it's 0:22:14.320 --> 0:22:17.800 beamed out. But you're just generating this huge amount of 0:22:18.080 --> 0:22:20.760 X rays, and the X rays are also continuing to 0:22:20.760 --> 0:22:24.399 propagate themselves because they're knocking more electrons free. And the 0:22:24.440 --> 0:22:27.760 more free electrons you have, the more interactions you have. Right, 0:22:28.320 --> 0:22:30.879 So one of the ways that more electrons can be 0:22:30.960 --> 0:22:34.119