How X-Rays Work

Like many huge discoveries, X-rays were accidentally stumbled upon. That serendipity led to a medical breakthrough still in use today. Learn about how X-rays are created and why they make such delightful images of our bones.

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Episode Transcript

Speaker 1 (00:00):
Welcome to Stuff you Should Know from House Stuff Works
dot com. Hey, and welcome to the podcast. I'm Josh
Clark with Charles W. Chuck Bryant as always, and there's
Jerry over there fiddling around with stuff. So it's stuff
you should know the podcast, not stuff you should know.

(00:23):
The movie. That's right. You know we were one secrecy
about that. That'd be a good movie. That'd be a
bad movie. I don't know, man, I could go either way.
I always see I imagine it like strange brew. Oh yeah,
yes they could. Uh, they could based it on the
Stuff you Should Know tell all book I'm writing. Oh yeah,
that would be exciting. That would be very exciting. I'm

(00:45):
looking forward to that book like a lifetime movie the Week.
Do you like um switch people's names like in my
um Joe Joe Clack. Yeah, exactly. No, it's sort of like,
uh like did you see the uh Saved by the
Bell movie? Oh yeah, I didn't Screech write a book.
It was based on a book by Screech. Right, yeah.

(01:06):
It wasn't it like all sex and drugs and stuff?
Oh it was, you know, it was a bunch of
teenagers in Hollywood. So sure, there was some of that
in there, but it was I didn't read the book.
But the movie was bad and not nearly as salacious
as you wanted it to be, right. I remember a
lot of people being disappointed, and I remember, I mean
I recalled it like two weeks ago when people were

(01:28):
talking about it when it came out. It stunk. I'll
watch Emily and I'll watch some of those, um just terrible,
terrible biopics occasionally on TV, and it's it can be fun.
Like we watched the who was the one actor Brittany Murphy?
The Britney Murphy story? Oh? Really? Does she have a
heck of a story? Is she alive still? Or did
she die? She passed away because under kind of weird

(01:50):
circumstances because she and her husband both passed away within
weeks of each other, and there were all these strange
claims that her house was poisoned, that they were poisoned,
and um, yeah, it was it was fun. What's your
take on it? Oh, I don't know, you just that
the movie wasn't very good. Who played Brittany Murphy? Do

(02:11):
you remember someone who didn't look very much like Brittany Murphy?
Julie Bowen but I was right. The Ashton Kutcher guy
was pretty good, though. I gotta say Steve Jobs played him.
They should have just gotten Ashton Kutcher to play himself.
He's not doing much. He's not my two and a
half Men. I don't know. That's got to require fifteen
minutes of work a week. He's selling cameras. Do you

(02:34):
remember when that whole Two and a half Men thing
was going down? We were in l a And for
the one and only time in my entire life, I
see John Cryer that day. Oh, during the Charlie Sheen meltltown,
like the day of the meltown, like it happened at night.
And within eight hours I saw John Cryer for the
first time in Personeta McDonald's did you feel Duckie? No,
I left him alone. He looks sturessed out. Well, yeah,

(02:57):
he's probably like, my career is going down the tubes.
But little did he know he's a survivor. His career
is just fine. So x rays, Yeah, that's what we're
talking about, right, yep. The lightest part of this podcast.
I like this one. This one. It's one of those
things where if you can just hang on by your fingernails.
It can click and then you lose it again, but

(03:19):
that means that it could click again later on. That's
what I like about it. Good. I'll leave that to you.
I got lots of other stuff about it. I totally
understand good Good. Um, So, have you ever broken anything
and needed an X ray? Or has it all just
been dental stuff? You know? Dude? Never broken a bone?
Knock on wood? Yeah, I mean I've had My injuries

(03:41):
were always um stitches. I was always getting busted open
rocks and sprinklers, and I was always getting cut and
sewed back up. But I never broke a bone. That's great. Yeah,
you should probably knock on lee more time, just to
be safe. Uh So, Yeah, all of my X rays
to have been like just going to the dentist or whatever.
You never had a bone broken? I don't want to say,

(04:02):
because I I don't even know if knocking on wood
will do it on laminate ikea. That would just be
so horribly interesting if both of us broke a bone
after this. Yeah, and we're at the age where like
you should break bones when you're a kid, were you
like whatever? I get a cast at this age. It's
it's a drag. Yeah. I remember reading like a Tom
Clancy novel and like some kid got an arm torn

(04:25):
off or whatever, and one of the surgeons was like,
if the arms in the same room as the kid,
it can be healed. That doesn't hold true in your
Tom Clancy's age. No, So, um, you are familiar with
X rays, so you've seen them before You've watched the
er surely, Yeah, I mean I've had X rays for
like the dental ones, like you said, and then um

(04:45):
just other various like uh like chess X rays for
sicknesses and things like that, which I think maybe a
little frivolous to be honest, Yeah, and kind of dangerous
really conceivably, which we'll get into later. But um, did
you were you familiar with X raised it all beyond that?
Did you know that they were invented or discovered accidentally? Yeah?

(05:05):
I did know that. Um I did not. That's one
of the few things I know. I thought I saw
a little like Quickie short on something like it might
have been actually Science Channel. I looked all over. The
most I could find was a dude on siemens Um
just describing it in the most flat affic I've watched
video yeah, I got to five and five wind Low

(05:26):
and I was like, forget this. Yeah, if I've never
loaded for me, I watched the other fourteen though, and
the whole time I was going, man, these are a
minute long, please join them all together into one six
minute video. You know. It was so weird. Yeah, it
was pretty silly, but and he was he was good.
He was just very dry. Yeah, and they spent zero
pennies on any kind of soundtrack or anything like what

(05:49):
if he grabs papers? You hear papers wrestling in the classrooms.
It was. It was pretty straightforward. Yes, but that's a
very wind about, round about way of getting to uh,
it's discovering German physicists named Wilhelm uh Runtigan, and he
was testing whether cathode rays could pass through glass. And

(06:13):
he saw that the fluorescent screen was glowing when he
turned on his electron electron beam, which wasn't a big deal,
but he was like, wait, he's got cardboard around it, right,
there shouldn't be any visible light escaping, which is silly
to think of. Now, well, yeah it is, but you
have to put yourself in his shoes, like X rays
hadn't been discovered because he was literally on the verge
of discovering them. Right then, that's right, and uh yeah,

(06:35):
so he was like, this is very curious that this
is fluorescing. Yeah, and he noticed other things were glowing,
and eventually he started putting other objects between the tube
and the screen. They glowed the screen. Did that is
finally put his hand there. I read his wife's hand.
Oh really, it's like, come in here for a second. Yeah,
I want you to try something. Saw bones projected and

(06:58):
then I guess probably poo pooed his pants. It's a man,
I think, come onto something here. Yeah. It was really
that quickly. He was like immediately the application was clear.
It wasn't one of those things where it took twenty years.
He's like, hold on, you can see bones. This could
be really helpful. And he won a Nobel Prize very rightfully, so,

(07:19):
the first one ever for physics, and he named him
X rays because he didn't know what the heck it was, no,
exactly kind of signing your name he'd probably right. I
think he assumed that later on future scientists would fill
in the blanks, but they were like, no, we're cool
with X rays. Well, he probably thought that someone would
eventually call it like the Rundkin ray for something. He

(07:39):
wasn't much of a self promoter. He was just like
all is calling X rays as a place hold. And
he didn't patent any anything, you know, he never like
made money off of it. Uh. And then just as
his wife had hand cancer as a result. Really I
was laughing, but it was it was just a joke.
He can proceed with the la plus. I've never heard
of hand to cancer. It's got to be out there. Uh.

(08:03):
And then a couple of years later they were already
using it. Um in the Balkan War was the first
time it was really put to practical use. The first
Balkan War, the one around World War One. Well, oh
that Balkan War. Um. I didn't know that existed until
just now. And they said we can see bullets and
trapnel and stuff now, um, which is helpful. It is

(08:24):
extremely helpful. So like this guy Rundkin discovers X rays
and their most practical application and one fell swoop basically
and a little further study revealed the X rays are
actually just a another part of the electromagnetic spectrum, of
which radio waves, microwaves what we call visible light. UM.

(08:48):
What else is there. Well, I've got handy wallet electromagnetic
spectrum card, and X rays fall between gamma rays and
ultra bio let rays on that spectrum, which are all below.
Well you say below, I don't know if it's it's
not really an above or below situation. Visible light and

(09:10):
then infrared, microwaven, radio waves, so it would be a
higher or lower frequency, because that's how the whole thing
is divided. Yeah. So, like the visible spectrum of light
consists of electromagnetic radiation that has a frequency, a wavelength
that our eyes are sensitized too, so we can pick
up visible light. There's plenty of other stuff on this

(09:31):
spectrum of electromagnetic radiation, and all of it is delineated
by the frequency the wavelengths. So at the highest end
you have gamma rays, They're like, yeah, that means the
squiggly line is very close together exactly. And then on
the farthest end you have radio waves. Are like, and
that means the squiggly line is far apart exactly, and

(09:53):
that is called chuck science. That's good stuff. Yeah. So
back in my wallet, x RA right next to the
what else you have in there? I just have my
PEPs blue ribbon membership, which actually do do you really? Yeah?
But I've had it for like twenty years. When you
you got it, when you're like seven eight, flatter me. So, uh,

(10:18):
X rays fall, I guess we're about in the well, Yeah,
the higher and they have a higher frequency as far
as the electro magnetic spectrum goes. But the point is
is that it is ultimately the same thing. It's a
it's a type of electro magnetic energy that is carried
on a photon, which is a particle of what we
would call light. Yeah, and we talked about photons a

(10:39):
plenty in the show, and uh the same like photons
produce the visible light that we can see photons blast
out from the sun. How long does it take? Like
it takes like a hundred dozen years to get from
the core to the surface and then like eight minutes
to get from the surface to Earth. That's right, man,
that's I love that pack. So this is the only

(11:01):
part I understand, So I'll lead with it. If you
want to imagine um an atom, the nucleus of an
atom and rings around that adiom adium and adam as orbitals. Uh,
when an electron drops to a lower orbital it releases
energy in the form of a photon, and the electron

(11:22):
will always drop to the lower orbital. That's right. So
like if an orbital is if an electron is kicked
off of a lower orbital, an electron in the higher
orbital goes and drops down to that one. Yes, And
depending on how far it drops is going to determine
the energy level of that photon that it's that it
releases his energy when it drops, right, yeah, because it
doesn't have to, you know, drop more than one orbital.

(11:44):
You can skip down I don't even know how far,
but a long way, yeah, I can. And like you
said that, the greater the distance between the two orbitals are,
the greater the energy differential, the greater the energy that photon,
when released, will have, right, that's right. And as we said,
photons are the energy carriers of the electromagnetic spectrum. And
depending on that energy or the frequency the wavelength of

(12:07):
that photon, that determines what kind of photon it is, right,
whether it's a radio photon or a an X ray photon,
or a photon that we can see that's in the
visible spectrum. That's right. Uh. Sometimes when these photons are
flying around, they will collide with other atoms, and sometimes
those atoms absorb that photons energy and then kick it

(12:29):
up to that higher level again, right, but it has
to be from what I understand, and I saw that
there's like, of course it's science, so there's like atomic science,
so there's little exceptions to this and that. But from
what I can see, Chuck, there is the energy of
that photon has to exactly match the energy differential between

(12:52):
one orbital and another on an atom so that it
can kick it up, so that it hits that one
electron and lower orbital kicks it up to the higher
orbital and thus transfers its energy, which means that atom
just absorbed that energy that that photon was carrying. Right.
But if it's a little less, it's not going to
have the energy to kick that electron up, which makes

(13:14):
sense to me, right. But if it's a little more,
this is what doesn't make sense to me. It doesn't
kick the electron up, and then the photon carries on
in a diminished energetic state. It just doesn't do anything.
It doesn't interact with that. It has to be exactly, say,
like the energy differential between orbits is eight, so photon

(13:36):
has to have an energy of eight or else it's
not gonna do anything with the atom. That's right, okay. Uh,
and so depending on the um, Well, let's say you
have a radio wave. They don't have very much energy,
so they can't move electrons between these orbitals. They just
passed through things. X rays are super powerful. There's lots

(13:57):
of energy, so they can through things, which is key
if you want to check out your bones from outside
of your body. It is. And we're going to explain
exactly how right after this. Okay, so we're back chucking.
You tantalized everybody by saying that this, this difference in
absorption is what produces X rays. Right was that tantalizing?

(14:21):
I was tantalized and I even know it's coming, all right,
that's how excited I am about X rays. So consider this,
Like different atoms have different atomic weights, they have different densities,
they're just different. Like different atoms are different, and atoms
also have order called differences in radiological density. Okay, so

(14:46):
a really high energy, high atomic weight, very dense atom
is going to be able to absorb a lot of energy.
Smaller atoms that maybe are looser and have a lower
atomic weight are gonna get kicked around by any old
photon that wants to come along. Yeah, and that's that's key.

(15:06):
Like I said, if you want to see bones because
you're soft tissue. If you've ever noticed when you have
an X ray, you'll see the bones, but you know
the rest is sort of a grayish black mess because
your soft tissue has smaller atoms. Your bones, Uh, calcium
atoms are much larger, so they're gonna absorb those X
ray photons. It's exactly right to do it, really well exactly.

(15:28):
So um, imagine you have uh, let's say, Chuck, let's
go back and hang out with Tuck Tuck right, Oh man,
let's get back in the way back when it's been
a while. Okay, look at him over there. So here

(15:49):
we are in France in this cave, um Tuck. Tuck
has his hand up against the cave wall, as you'll see,
and in his other hand he's got that little straw
filled with pig meant red pigment. He's blowing it on
his hand right and now that he moves his hand away,
there's the outline of his hand right exactly. He's just

(16:11):
made an early stencil. He's like a banks He basically
like a caveman Banksy. But if you look at the
back of Tuk Tuk's hand, don't get too close, but
look at the back of his hand. It's covered in
red pigment, right, So if you can, if you want
to equate this to an X ray, the hand absorbed
all of that pigment and the stuff that passed through

(16:34):
left the picture on the cave wall. That's kind of
what happens with an X ray, except with an X
ray photograph. The X ray photons are absorbed by the denser,
calcium rich bones and they passed through the softer tissue.
So the picture that we have is the outline the
silhouette of the bones because the X rays made it

(16:57):
through the tissue. Didn't make it through the bones. They
made it are the tissue and onto the X ray plate,
which absorbed the picture in negative. That's right, And I'm
glad he said picture, because that's all it is. On
the other side of the human being. You know that
they're shooting the X ray at there's a camera and
you're just gonna get a regular negative and they could

(17:17):
make it a positive, but they leave it as a
negative because you really don't need the positive image. Uh,
And that's what they'll put on that little screen to
show you your cracked femur exactly. And they can see
the crack because some of those X rays will make
it through the gap, that's right, right, So all you're
seeing is the result of X rays that made it

(17:38):
through the tissue were absorbed by the bone, so those
don't make it to the plate. The ones that make
it to the plate cause the chemical reaction that gives
you your negative your X ray. And it's it's pretty simple, really,
like if you think about it, at least in principle.
It's also extraordinarily difficult to conceive of. But if you

(17:59):
if you understand like the principle behind it, it makes
uttering complete sense. Yeah. And it's a pretty focused shot
that they're using there. It's not like they don't fill
the entire room with X rays. You know, they've got
a thick lead shield around the whole device and it
you know, contains contains everything. It's got a little small
window that's just gonna let that narrow beam pass through

(18:22):
through a series of filters and basically hit you wherever
they want to hit you. Yeah, And the reason that
the they use lead is because lead is an extremely
dense uh yeah element, yes right, sure, oh god, I
hope so with a with a very high atomic number,
which means it can absorb tons of energy. Right. Yeah,
that's why you're gonna wear a lead apron. Um if

(18:44):
you're not, you know, if you're getting your skull done,
you're probably gonna wear an apron in your chest. Let's say,
so you're you're so this lead is being bombarded with
X ray photons and electrons and it's just taking it.
It's fine, and it's not being able to it's not
able to pass through because it doesn't have high enough energy. Um.
But yes, they when they put that little window in

(19:05):
the X ray generating machine, it passes right through there
in a concentrated beam. And Chuck, let's talk about the machine, right. So,
and and this is basically what we use as X
ray machines is essentially what Rooken was made, what made
was experimenting with when he accidentally discovered them. Because if
you look for X rays like they're they propagate naturally.

(19:28):
But I think like the X rays on Earth come
from humans. Yeah, like we generate a lot of X rays.
They don't they don't come like, you don't find them
normally on Earth. They're coming from outer space to us,
hence X ray astronomy. But the ones here on Earth
that are generated on Earth, they don't. It's not like

(19:49):
rocks put out X rays or something like that. We do.
We humans, humans and lead aprons put out X rays
and they use this machine like Rootkin made. Yeah. What
you have in the machine and you have an electrode pair,
a cathode and an anode, and that's inside a good
old fashioned glass vacuum tube, which, um, it's amazing how
vacuum tubes are still like the best way to do

(20:10):
many of these things. Well, it allows things to travel
at the speed of light easily, that's right, and allows
guitar amps to sound great. I didn't know these vacuums
in that. Oh is that a cathode tube? Yeah, yeah,
like a like the best amps are still made with
vacuum tubes. You can get solid state amps, but they're
just the sound isn't as rich, So it's kind of
like this old technology that's still superior. They're all pumped

(20:32):
out by hand by a ninety year old man in Tennessee.
Mr Marshall yes. Uh So the cathode is a heated
filament just like you might see in a light bulb,
and the machine's gonna pass the current through that and
heat that thing up, and then it's gonna spit electrons
off that surface, and it's gonna hit a disc made

(20:53):
of punksten and it's gonna draw those across the tube.
It's basically the tube is sort of the key peat, right,
because you've got the positive and the and the negative
charge the cathode and the anode, right, um, and that
difference that electrical charge draws his electrons down to the anode. Yeah,

(21:15):
And that force means that when those electrons hit the
tungusten anode, it knocks a bunch of electrons off, creates
a bunch of X rays in the process, and um,
you have a whole box filled with X ray radiation.
That's exactly what it is, like you're just I mean,

(21:35):
there there might as well be like a foot crank
to this thing, like an old sewing machine. For as
as technologically advanced as it is, there may be for
all I know, I don't know what goes on in
that other room, right, Yeah, there's some dude in there
with like his right leg is three times more muscular
than his left leg because that's the only one he uses.
So um. In addition, like I said to to X

(21:58):
rays being created, the the other X rays, other photons
can go on and knock more electrons off. So you
you have what's like a process of chain reactions starting, right.
It's not like one gets hit and then that's it,
and the photons creating it just hangs around until it's
beamed out. But you're just generating this huge amount of
X rays, and the X rays are also continuing to

(22:20):
propagate themselves because they're knocking more electrons free. And the
more free electrons you have, the more interactions you have. Right,
So one of the ways that more electrons can be
knocked off, you don't even need a direct transfer of
energy where a photon is absorbed or knocks an electron
from one orbit to another, or knocks it loose entirely.

(22:41):
A photon actually has this really cool um capability of
just orbiting close by the nucleus of an atom, and
when the nucleus basically draws it into its orbit, the
photon just takes a hard left turn, just bumps it
off its course. But even like the dodge via for
it has to like slow down to take a left turn,

(23:03):
slow a little bit, right, just a little, just a little.
But that little bit in photon world means a transfer
of energy from the photon outward. Yeah. And then the photon,
like the photon takes that left turn and and the
energy is transferred to the atom. Yeah. And one of
the byproducts. If this sounds like it's gonna create a

(23:25):
lot of heat, it's because it will. And in order
to combat this, they rotate this anode to keep it.
It would just melt down if you kept it in place.
And apparently there's a cool oil bath that helps absorb
heat as well, which I never have heard of that either.
It sounds oily oil bath. Yeah, it doesn't sound refreshing
at all. It sounds like the opposite of refreshing. Yeah.

(23:46):
Cool and oil don't really go together. Yeah, and I misspoke.
That's an electron that can be drawn too into the
nucleus of an anom appropriately enough, because they orbit nuclei anyway.
But it doesn't have to hook hook up with that them.
When it takes that hard left it admits the photon.
Like you said, that's right, And like I said earlier,
there's a camera on the other side of the patient

(24:08):
and it's going to record that pattern of light when
it passes through the body. And it's not so different
from a regular camera. Um. And then the and you're
just gonna get a picture, like I said, a negative image. Yeah.
And if you hook it up with a computer that
allows you to take X rays basically in slices, you
can come up with commuter computerized tomography. If you ak

(24:30):
a CT right, let's scan exactly. Um. If you uh,
if you use if you get a breast exam, you're
using a type of X ray called momography. Um. And
then there's a fluoroscopy, which the man in the extraordinarily
dry presentation from Siemens said, um was basically like moving picture.

(24:50):
It's like a movie exactly. And then he showed us
what the movie is with a flipbook, right, that old
flipbook trick. And if you listen to this podcast, I'm sorry,
I just want to apologize for both of us. Semens guy,
Oh yeah, uh, like, hats off to you for doing
that at all. Yeah, um, because he's probably saying, well,
at least that was correct, and everything I said it's

(25:13):
a good point, sir um. But with fluoroscopy, it's basically
like a movie of an X ray movie, and you
would do this to make sure like a heart is
beating correctly because you wanted to see it. But you
have to have an additional um instrument because as we said,
X rays will pass through tissue like heart tissue and

(25:34):
muscle tissue and all and blood vessels and all the
stuff you want to get pictures of using an X ray,
so you have to use something called a contrast media
for it. Yeah, a contrast agent is basically more dense
than the soft tissue. So if you want to uh,
let's say, swallow, it's usually like a barium compound. If
you want to examine like your blood vessels or your

(25:55):
circulatory system, you're sometimes they can inject that, or you
might drink it to see if you're doing like a
gastro intestine, like a GI tract. You're gonna swallow that stuff,
which I've never had to do. I think my dad
had to do that. Yeah, I don't think it's super pleasant.
I get the impression not too, but my dad did
as well. Yeah, it's an old guy thing, so I
should be getting one soon. Uh, and then it allows you,

(26:19):
you know to see him moving image. Uh. Basically how
that liquid is if there's any blockage. Uh, there's all
sorts of applications for it. Yeah, because you're that liquid
has a high radiological density, which means that the X
rays don't just pass right through your the tissue that
it's being suspended in, like your blood vessels. It absorbs

(26:42):
it for it. So you get a picture of your
blood vessels, your circulatory system, which is pretty cool. It's
pretty clever. It's also extraordinarily elementary and principle, my dear Watson. Uh.
And that single picture I think we you know, we
mentioned CT and momography and all that in philoscopy, but
the single picture is just called standard radiography. And that's
when you're you know, taking a photo of your skull

(27:04):
or your lungs, or your bones or your teeth and
so so. Speaking of the lead apron thing, man, it's
always made me kind of nervous, Like if I the
rest of my body has to wear lead apron, but
you're shooting an X ray into my head, am I
going to be? Okay? Well we'll answer that right after
this message. All right, X rays. Are they bad for you?

(27:35):
The answer is yes, uh, pretty unequivocally. Um. But like
all things, it's it's in moderation is the key. Uh.
In the nineteen thirties and forties and into the fifties,
they had X ray machines at shoe stores. Oh yeah,
I can extra your feet to get a better fit,
and um, they didn't realize at the time that they
were X raying people way way too much. Yeah, talkative

(27:58):
kids in class. They just shoot him with an X
ray and they probably did I've got you like twice. Well,
now I would believe that, like, hey, let's look at
his brain. There may be a mouse running around inside
of it. People in the thirties were dumb. Well, it's
basically radiation sickness. Um, it's a form of ionization or
ionizing radiation. So what can happen? Like, if just normal

(28:21):
light hits an atom, is no big deal. But when
an X ray hits an atom, it knocks electrons off
of it creates an ion, which is an electrically charged atom,
and basically anything from uh, cellular death to mutation can
happen at that point, and mutation can spread and it
can cause cancer. Right because stable atoms are neutral, right,

(28:43):
because they have an equal number of protons and electrons.
You lose an electron, all of a sudden you have
a positively charged ion and that negatively charged electron running
around and it just causes trouble. And you said light.
Visible light can be absorbed and it's no big deal
because visible light is exists on a wavelength that's about
in tune with the soft tissues of our body, right,

(29:06):
so we know how to absorb it and it makes
us tan and that's cool, right. But um, with these
ionized atoms, these positively charged atoms like going around in
your body, it can cause a lot of problems, like
mutations like cancer. Right, yeah, I mean if you break
that DNA chain, that's not good. No, it is, And

(29:26):
one of the results is the d The DNA can
basically lose its ability to regulate itself and the cell
replicates more frequently than it should, and all of a sudden,
you have a tumor on your hands and that can spread.
It can also be a problem if that DNA break
occurs in utero, because then that can lead to birth defects,

(29:48):
which is why pregnant women shouldn't get X rays UM,
and it can also just lead to plain old cellular death.
If you have cellular death and the tissues that UM
are made up by those cells break down, uh, you
have a problem on your hands with that as well.
So here's the deal. We get exposed to radiation every
day just walking around on the planet. Um. It depends

(30:10):
on where you live. But every year, um, the average
person is going to be exposed to anywhere from one
to four. Uh. It's measured in millisieverts per year UM.
Like I said, depending on where you are. I think
in higher elevations it's less then at sea level. So
if you live in Denver, Colorado, you're gonna be exposed
to less well yeah, because you're higher up in the

(30:33):
atmosphere and that makes a difference. Exactly, you have less protection,
right yeah. So um, you know what they what they
want to do medically speaking, they want to use, or
they're supposed to use the minimum amount to achieve the
pictures you need. It's not like the old days where
they're just like let's X rays. Yeah, Like let's do

(30:53):
the minimum amount we need to get the information that
we need. A CT scan can can get your you know,
you lay down in the tube and it rotates around
you and your whole body can be photographed in less
than five seconds these days. But um, you know there
are concerns if you get too many X rays still, Uh,
like a dental panorama, I think, would I say one

(31:15):
to four millisy verts per year and it's cumulative to
you should yeah, Like it's not. It's not like you
get one and then you know, eight months later you
get another one in that first one went away, Like
it accumulates over the course of a year. Yeah. So
here's just a few examples of how much radiation you're
being exposed to with X rays. Um, a dental panorama

(31:37):
is going to be point zero one millisy verts, so
not very much. Um, Like two chest X rays might
be point one mam or grammas around point four. Uh,
your pelvis point six, your back upper back maybe one
point zero. Uh. I wonder why because there's maybe, yeah,

(31:58):
maybe you have to do with exposure to Uh. Yeah
that makes sense. I got a ton of bone in
my upper back. A full CT scan, it depends on
what you are, Um, it depends on what you're X raying.
But a CT scan is obviously more like an abdominal
or pelvis c T CT scan could be as many

(32:19):
as ten millis everts, So that's like up to two
or three years worth of radiation in a single CT scan,
which can be problematic, which is why they don't say
get in the CT machine like every other week. Um,
but you know some of the reasons you might if
you had a traumatic injury, they're gonna X ray you
a lot of times for disease confirmation. They'll use an

(32:40):
X ray machine. Uh, during surgery as a visual guide,
Like if you do endoscopic surgery, the surgeons actually needs
to look at something, so sometimes the X rays for
that or to monitor your healing process. Um, you know,
when you break a bone, it's not just that first
X ray. You're gonna keep getting them to see how
your healing up. Right out of the Siemens video, huh no,

(33:04):
they isn't okay, I don't think so. I mean I
looked at so much stuff together, cumulative research. So uh,
I did a brain stuff on siverts and how many
we can take and uh yeah, it's it's kind of
like it's a little alarming how much radiation we're expected
to People who fly a lot too are exposed to

(33:24):
tons of radiation because you're again higher up in the atmosphere,
so you're less protected by the atmosphere. Speaking of flying,
of course, baggage that is X rayed. The food industries
is X rays a lot um. Archaeologists use it if
they don't want to like destroy an object and they
want to see what's inside, or earth sciences they'll use
X rays for rocks to see what kind of mineral composition.

(33:47):
So there's all sorts of applications. It's not just medical.
Um space. Yeah, X ray telescopes out on on satellites
apparently you can see a lot um. You can see
things you can't detect from an earthbound telescope because X
rays are absorbed by our atmospheres. He can't like shoot
it into space like that. So this article makes a

(34:08):
pretty good point if you ask me, it says like, yes,
X rays are like are bad for you, and you
should use them with care and caution. And one one
good point is to always ask if there's an alternative
to an X ray, just to basically say, hey, doc
or Dennis, slow your role. Let's is there another way

(34:28):
we can get this information without an X ray. I
know it's the easiest, But what are the alternatives? But
then the article makes the point like it's still safer
than the ultimate alternative, the thing that X rays replaced,
which was exploratory surgery. Yeah, back in the day, if
you they thought you had cancer, they would cut you
open and see. And this is definitely better than that
or broken bone. Imagine getting that arm cut open just

(34:51):
to see how it's doing. They're like, no, it's not broken, right,
And we haven't invented anesthetic yet. So good luck with
your dentist, by the way, because um, I always get
the feeling that the dentists are like, no, your insurance
allows us to build for so many per years, he said,
that's how many you are going to get. These X
rays are putting my kid through college. Yeah. Uh, you

(35:14):
got anything else on X rays? That was a fine
amount of stuff. I'm feeling good about it. You feel
good about this one, sure too? Yeah. Uh. If you
want to know more about X rays, you can check
out this really informative article on how stuff works dot com.
It's got some great diagrams that explain a lot of
the stuff we were saying visually. Uh, And you can
type x ray into the search part how stuff works

(35:35):
and it will bring that up. Since I said search
parts time for listener mail. Uh this is from my
buddy Poppy and Vancouver. Uh stuff you shouldn't listener to.
That meant while I was there, and um, Poppy as
this to say he's got a pretty cool job. He
listened to the PTSD show and wanted to write in
about another option that he works with. He's a registered

(35:56):
acupuncturist in Vancouver with special training and AMMA and addictions.
He's a program called neurotrophic stimulation Therapy NTSD. In a
large part of the program uses ear acupuncture and electro
acupuncture to promote neuroplasticity in the brain. He says, you
can't necessarily directly fix the brain, but you can stimulate

(36:16):
the ear nerves will help the brain reregulate certain functionality
so it can heal itself. He's been treating trauma and
PTSD patients for several years and the evidence for his
efficacy is high. It can be done with acupuncture needles
alone or in combination with a mild electrical stimulation. UM.
Remember we talked about UM. Transcranial electromagnation. Yeah, transdermal cranial stimulation.

(36:41):
He says that's one of the things that he's also
using to treat PTSD, which is pretty cool, and he
said it makes cognitive behavioral therapies so much easier to
introduce because it promotes neuroplasticity and the results help a
PTSD suffer to be more open to and able to
receive positive social programming. So he has a program we
want to promote. If you want to see all the

(37:02):
components in action in this program, you can visit Last
Door Recovery Society at last door dot org slash nt
s T, or you can donate funds to help purchase
a brain scanner so that they can scientifically measure the
results of the program, which would really help show the
validity of the therapies. And if you're interested in helping

(37:22):
out Poppies, cause there because he's really big on treating
veterans in Canada. In the US, um I shortened as
a little U R L too bitley b I T
dot L Y slash one one y n l o
Q and that is from Poppy and he says not
misstay thanks a lot, Poppy. Is it poppy with the

(37:44):
O P O P P I nice? Uh if you
want to get in touch with us, you can tweet
to us at s y s K podcast. You can
join us on Facebook dot com, slash stuff you Should Know.
You can send us an email to Stuff Podcast to
how Stuff workstt com. That's right, uh and as always,
joined us at home on the web, Stuff you Should

(38:04):
Know dot com. For more on this and thousands of
other topics, visit how Stuff Works dot com