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How Carbon-14 Dating Works · Stuff You Should Know

0:00
Speaker 1: Hey, San Francisco, we want to get back to our
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Speaker 1: guys in January. Welcome to Stuff You Should Know, a
0:38
Speaker 1: production of My Heart Radios How Stuff Works. Hey, and
0:46
Speaker 1: welcome to the podcast. I'm Josh Clark. There's Charles W.
0:50
Speaker 1: Chuck Bryan over there. There's Jerry right there, just laughing
0:53
Speaker 1: it up. Yeah, and this is Stuff you should Know.
0:57
Speaker 1: The jokes are Jerry ed issue Dent Science Edition a
1:02
Speaker 1: k a. Chuck Dies Slowly inside Edition. Dude, No, it's
1:06
Speaker 1: not You're gonna do just fine. This is all so intuitive,
1:09
Speaker 1: it's wonderful. I'm not worried about not doing fine, but
1:12
Speaker 1: thanks for the Reachirch. Well then I'm I'm really excited
1:16
Speaker 1: about this. If you know that, I think you're gonna
1:18
Speaker 1: do fine. You are going to as well. I'm going
1:21
Speaker 1: to see to it. I think Jerry's gonna do great. Jerry,
1:24
Speaker 1: how how are you doing over there? Okay, she's pressing
1:26
Speaker 1: buttons like I've never seen her press buttons. Stop to that. Um,
1:31
Speaker 1: I wonder what kind of weird sound effects just happened
1:34
Speaker 1: after touching all those buttons. Jerry just laughed. I don't
1:38
Speaker 1: know if the mic pick that up. All right, everybody's like, okay,
1:42
Speaker 1: you're officially stalling now. Jerry's a quiet laugher. Though you
1:45
Speaker 1: ever noticed that it's all knows, Yeah, she's all knows.
1:51
Speaker 1: This is Jerry laughing hard. There's some doing it right now.
1:56
Speaker 1: Serious a SMR triggering going on right now, that's right.
1:59
Speaker 1: And there's of this not on the microphone cover, all right,
2:02
Speaker 1: Carbon fourteen dating It works sort of the end. It's
2:07
Speaker 1: not the worst description of it ever. Yeah, we can
2:10
Speaker 1: do better than that, though, Yes, and luckily you did
2:13
Speaker 1: a great job with this. But I also you know,
2:15
Speaker 1: my advice to anyone if you don't understand the science thing,
2:19
Speaker 1: and you're an adult, just don't worry about what anyone
2:22
Speaker 1: behind you thinks. Just looking at your laptop and you
2:24
Speaker 1: go to the most rudimentary children's science website you can find,
2:29
Speaker 1: and that always helps. There is no shame in that,
2:31
Speaker 1: no shame because seriously, the people who write those websites
2:34
Speaker 1: are probably some of the best science explainers on the
2:37
Speaker 1: planet and they know how to really just not dumb
2:40
Speaker 1: it down because kids are smart. But that's funny. You
2:43
Speaker 1: flip flopped on kids. Apparently you mean stupid kids. Yeah,
2:47
Speaker 1: you always said they were dumb until just now, So
2:50
Speaker 1: good for you, Chuck. We're all over the map. Well,
2:52
Speaker 1: I feel like we're really growing up these days. So
2:56
Speaker 1: so Carbon four Team, for those of you who don't know,
2:58
Speaker 1: is this um really clever scientific method where you can
3:04
Speaker 1: actually kind of look inside of a material and figure
3:10
Speaker 1: out how much carbon fourteen is in there, and by
3:12
Speaker 1: doing so, you can actually tell how old it is,
3:15
Speaker 1: or at least how long ago it was since the
3:18
Speaker 1: thing you're dating was alive. Yes, and it is a
3:22
Speaker 1: comparative Well, there's another word for that. What's it called
3:25
Speaker 1: relative dating? Yeah, relative dating, I guess comparative isn't the
3:28
Speaker 1: worst word, especially if you're talking about literature, right because
3:33
Speaker 1: what they're doing is comparing it to things that are
3:35
Speaker 1: alive today, and because of all the gobbledygook we're about
3:39
Speaker 1: to talk about, that equals a pretty good estimate. And
3:43
Speaker 1: then from there they are even further things that one
3:46
Speaker 1: can do if one we're so inclined as a scientist,
3:49
Speaker 1: and there are a lot of people who are inclined
3:50
Speaker 1: to do this. This is a very exciting, um energetic
3:56
Speaker 1: field of science right now, Like if you want to,
3:59
Speaker 1: if you want to jump into an ever evolving, constantly
4:02
Speaker 1: moving be a um field, the Baracas field kind of
4:08
Speaker 1: um of of science, start studying radiocarbon dating actually wouldn't
4:14
Speaker 1: be a ba Barakas field because didn't that stand for
4:15
Speaker 1: bad attitude? Did it? I think so? Right? Oh, no,
4:18
Speaker 1: one in radiocarbon dating has a bad attitude, but they
4:21
Speaker 1: are be as right. But you're right it it is
4:24
Speaker 1: ever evolving and they're constantly looking for better ways to
4:29
Speaker 1: pinpoint more accurate timelines on things. So it's not like
4:34
Speaker 1: a job you're going to get in and be like,
4:35
Speaker 1: oh this whole thing again, right, No, no, And it's
4:38
Speaker 1: it's just like they're constantly filling in blanks and stuff
4:41
Speaker 1: like that. It's just it's good work. So, um, what
4:44
Speaker 1: they're looking for the people who do radiocarbon dating is
4:47
Speaker 1: carbon fourteen, which I said, and that is radiocarbon. It's
4:51
Speaker 1: called that because it's a radioactive form of carbon, that's right,
4:54
Speaker 1: And it's everywhere on Earth. It's just all over the place.
4:58
Speaker 1: It's part of the carbon side goal and it's part
5:00
Speaker 1: of the web of life. But it starts out way
5:04
Speaker 1: up in outer space as cosmic ray, that's right. Should
5:08
Speaker 1: we give the basis definition before we jump to the
5:12
Speaker 1: radio carbon dat Yeah? Yeah, I mean I think like
5:15
Speaker 1: the most rudimentary definition might help some people out. Um.
5:19
Speaker 1: But like you said, carbon fourteen is everywhere, including inside us,
5:23
Speaker 1: because it's in plants via photosynthesis, and we eat plants,
5:28
Speaker 1: and animals eat plants. Some people eat animals, and because
5:31
Speaker 1: of that, it's kind of in every living thing. Uh.
5:35
Speaker 1: And carbon fourteen dies away very slowly. And because we
5:41
Speaker 1: know this, because we know it happens predictably, then we
5:45
Speaker 1: can measure that in a sample and then compare it,
5:48
Speaker 1: like I said, to something living and then you do
5:52
Speaker 1: a little math Ipso fact though it's probably an ipso
5:55
Speaker 1: facto is it? Presto change, Yeah, presto change about it
5:59
Speaker 1: being about about it being bon Jovi? What was that
6:04
Speaker 1: that was yours? Was it? Yeah? Man? You came up
6:07
Speaker 1: with that on a carousel at Zoo Atlanta in about
6:10
Speaker 1: two thousand and twelve. That's right. That's where that's carbon
6:14
Speaker 1: dated too. Yeah, that joke. But because we know that,
6:18
Speaker 1: we can compare it to something that's alive today and
6:20
Speaker 1: then with a little math we can figure out the
6:22
Speaker 1: rough estimate of how old it is. Yeah, that's I mean,
6:25
Speaker 1: that's radio carbon dating in a nutshell for sure. That's right.
6:27
Speaker 1: But like you said, it starts out as cosmic rays
6:31
Speaker 1: way out in outer space, right, and so a cosmic ray,
6:34
Speaker 1: we're not entirely certain where they come from, but they're
6:37
Speaker 1: super high energy particles, usually like pieces of atoms, that
6:42
Speaker 1: are just shooting towards Earth and through outer space at
6:45
Speaker 1: incredible speeds, and when they encounter the atmosphere, they start
6:50
Speaker 1: running into the atoms that make up the atmosphere. And
6:53
Speaker 1: because these particles are so high energy, these cosmic rays,
6:57
Speaker 1: when they smack into atoms and other particles in all
7:00
Speaker 1: acules and all that. They just burst them apart, not
7:03
Speaker 1: just burst like an adam into like it's protons and neutrons.
7:06
Speaker 1: It'll tear apart of neutron like like it's nothing. Actually
7:10
Speaker 1: creates other high energy particles like muons, pions, x rays, um,
7:19
Speaker 1: what else? Zaxon's No, that was a video game, was it, Zaxon? Yeah?
7:27
Speaker 1: With a z uh Yeah. I think it was z
7:30
Speaker 1: A double x O N. I am not familiar with that. Okay,
7:35
Speaker 1: it wasn't a stand up game. Actually it may have been,
7:37
Speaker 1: but I played it on a r because I could
7:39
Speaker 1: see a kid in a Kiss T shirt playing that
7:42
Speaker 1: game stand up in an arcade. Yes, it sounds like
7:45
Speaker 1: that kind of game. That would have been me had
7:47
Speaker 1: I not been deathly afraid of Kiss because they were devil.
7:51
Speaker 1: They were nights in Satan's service obviously. Yeah. Okay, So
7:55
Speaker 1: all these muons, X rays, pions, all that stuff, there's
7:59
Speaker 1: one other little particle that can be created when a
8:02
Speaker 1: cosmic ray collides with an atom, and that is a neutron,
8:06
Speaker 1: a high energy neutron. Right, that's right. Okay, So what's
8:11
Speaker 1: happening now is a chain reaction because cosmic rays are
8:14
Speaker 1: bombarding the atmosphere, that's right, And uh, what can happen
8:18
Speaker 1: is they can get really pushy. Uh if a high
8:22
Speaker 1: energy neutron collides with let's say a nitrogen fourteen atom, Yeah,
8:26
Speaker 1: they'll get real pushy and they'll just knock the proton
8:28
Speaker 1: off and move right in there and say this is
8:30
Speaker 1: my house now, right. So what was once a stable
8:33
Speaker 1: atom nitrogen fourteen, which had seven protons and seven neutron,
8:41
Speaker 1: is now an unstable atom with six protons and eight neutrons,
8:46
Speaker 1: and now it's no longer nitrogen fourteen. What you have, fella,
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Speaker 1: is carbon fourteen. Yes, an unstable meaning radioactive, but not
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Speaker 1: radioactive meaning like scary and dangerous. No, it just means it.
9:00
Speaker 1: It's it's in a higher energy state, and it's temporary.
9:03
Speaker 1: Eventually wants to decay back into that um nitrogen fourteen stately, Yeah,
9:12
Speaker 1: eventually it's sometimes spontaneously, sometime down the road, that neutron
9:17
Speaker 1: will turn back into a proton, which sounds like magic
9:20
Speaker 1: until you realize that atoms and all of the particles
9:24
Speaker 1: that make up atoms are really just vibrations of energy,
9:27
Speaker 1: and it can temporarily go to a higher energy state
9:30
Speaker 1: or a lower energy state. And that is how something
9:32
Speaker 1: would change from like a high energy neutron back to
9:35
Speaker 1: a proton. Right. And he said that carbon fourteen is everywhere,
9:39
Speaker 1: which is true, but that doesn't mean there's like tons
9:43
Speaker 1: and tons of it relative to carbon carbon twelve. Yeah,
9:48
Speaker 1: there's a lot more carbon twelve. Right. So carbon twelve
9:51
Speaker 1: is the stable version of carbon, and it's way more
9:54
Speaker 1: abundant than carbon fourteen. Carbon fourteen is kind of like
9:57
Speaker 1: a freak, a monster that gets made accidentally, and it's
10:02
Speaker 1: extremely rare, even though there's a ton of it, but
10:04
Speaker 1: compared to carbon twelve, it's very rare. Something like one
10:08
Speaker 1: carbon fourteen atom for every trillion carbon atoms. That's that's
10:15
Speaker 1: that's pretty rare. But it also gives us a ratio chuck,
10:18
Speaker 1: And this is a big initial point. Yeah, And like
10:21
Speaker 1: you mentioned before too, or maybe I said it, it's uh,
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Speaker 1: this is part of the carbon cycle. So it's inside
10:27
Speaker 1: all the plants and the animals. Reading the plants were
10:30
Speaker 1: eating plants, some people eat animals, so it's inside all
10:33
Speaker 1: of us and it's everywhere. Uh. But that ratio is
10:37
Speaker 1: really important because, like we said, it starts to decrease
10:41
Speaker 1: because it craves homeostasis and wants to get back to
10:44
Speaker 1: its former life. It's a stable particles, a stable boy,
10:49
Speaker 1: stable boy, brush that horse, and it would be it
10:53
Speaker 1: would be an atom because it's going from a carbon
10:55
Speaker 1: fourteen atom to a nitrogen fourteen atom, right, But that
10:59
Speaker 1: ratio is in ard it because as it's you know,
11:01
Speaker 1: dies away, they're going to be fewer and fewer carbon
11:05
Speaker 1: fourteen atoms with that dead organism over time, whereas if
11:09
Speaker 1: something is alive, it has that steady amount. And that's
11:12
Speaker 1: where the comparison comes in, right, because as far as
11:16
Speaker 1: a plant, or you, or a dog or anything living
11:21
Speaker 1: is concerned, there's no difference whatsoever between a carbon fourteen
11:27
Speaker 1: molecule of carbon dioxide and a carbon twelve molecule of
11:31
Speaker 1: carbon dioxide. Yeah. I mean, it sounds hard to digest
11:33
Speaker 1: because we said it's radioactive, but there really is no
11:36
Speaker 1: difference as far as we're concerned, right. Um, It basically
11:39
Speaker 1: takes a human scientists to analyze it using an extremely
11:43
Speaker 1: sophisticated machine to be able to tell the difference. So
11:46
Speaker 1: that means that when it does, you know, come down
11:48
Speaker 1: out of the atmosphere, it's spewed out by a volcano
11:51
Speaker 1: or something like that. Um that it just becomes part
11:54
Speaker 1: of the food chain like any other atom of part
11:58
Speaker 1: of carbon that's locked in with oxygen to form carbon dioxide.
12:02
Speaker 1: So as you're living, like you were saying, you're constantly
12:07
Speaker 1: taking it in, you're constantly eating. It's just a part
12:09
Speaker 1: of life, as carbon fourteen and carbon twelve. Right, But
12:14
Speaker 1: when you die, you stop taking in carbon of all kinds,
12:18
Speaker 1: and all of a sudden that a clock has said
12:20
Speaker 1: because of that decay of carbon fourteen, that's right, And
12:25
Speaker 1: that decay, like we said, it happens spontaneously, and Adam
12:28
Speaker 1: might suddenly convert from carbon fourteen to nitrogen fourteen. You
12:33
Speaker 1: can't predict when that's going to happen because of the uncertainty.
12:36
Speaker 1: That's part of quantum physics, right, But if you have
12:40
Speaker 1: a large enough sample, then you can start to predict
12:43
Speaker 1: when x number or x percentage of that that sample
12:48
Speaker 1: of carbon fourteen will have spontaneously changed from carbon fourteen
12:54
Speaker 1: to nitrogen fourteen. And that's called the half life. That
12:57
Speaker 1: which is everyone has heard of. That's that's half life.
13:00
Speaker 1: It's just standard stuff. Yeah, I think everyone has heard
13:02
Speaker 1: of half life, and about the people that know that
13:06
Speaker 1: term don't really fully grasp it. Well, yeah, it's just
13:09
Speaker 1: this the amount of time it takes for half of
13:13
Speaker 1: the radioactive atoms in any given sample to convert back
13:17
Speaker 1: into a stable form. Yeah, that's it. It's pretty easy. Uh.
13:21
Speaker 1: And we know in this case the half life and
13:23
Speaker 1: we'll get to how we figured all this out, but
13:25
Speaker 1: the half life of carbon fourteen is five thousand, seven
13:29
Speaker 1: hundred and thirty years. Um, if you know you keep going,
13:33
Speaker 1: it goes to a quarter life, then I guess in eight. Yeah,
13:37
Speaker 1: it just keeps going. So like if you have a
13:40
Speaker 1: hundred carbon fourteen atoms, if you come visit it in
13:44
Speaker 1: fifty and thirty years, you're gonna find you a fifty.
13:47
Speaker 1: And if you visit in another thirty years, you're going
13:51
Speaker 1: to have then twelve and a half or thirteen maybe,
13:54
Speaker 1: I don't know. It just keeps going until there's ultimately none.
13:58
Speaker 1: Laughed over a long enought touch of time, which is
14:01
Speaker 1: with carbon fourteen, like fifty or sixty thousand years. Yeah,
14:04
Speaker 1: I saw sixty thousand mostly, but then I think it
14:08
Speaker 1: starts can get a little hinky at fifty, So fifty
14:11
Speaker 1: to sixty is pretty good, and I think it gets
14:13
Speaker 1: hinky at this point because our because of the equipment
14:17
Speaker 1: we're using to measure it. I think as our equipment
14:20
Speaker 1: gets more and more sensitive, that time will go further
14:23
Speaker 1: and further out, because as long as you have two atoms,
14:25
Speaker 1: you should still be able to measure them, you know,
14:28
Speaker 1: for sure, or even one. Probably, I'm not going to
14:32
Speaker 1: go out on a limb for that one, but I'm gonna.
14:37
Speaker 1: I'm gonna caveat that with them probably. Okay, Well, let's
14:40
Speaker 1: take a little break here and we're gonna come back
14:43
Speaker 1: here in a second. Talk about the very smart dude
14:46
Speaker 1: who figured all this stuff out quite a few years ago.
15:00
Speaker 1: All right, Chuck, Just to recap real quick, because I
15:02
Speaker 1: think this this episode bears it. Okay, Okay, you've got
15:05
Speaker 1: carbon fourteen. It's part of the food chain. You take
15:08
Speaker 1: it in as you're living. When you die, you stop
15:11
Speaker 1: taking it in, and so those carbon fourteen adams start
15:14
Speaker 1: to decay, which means that if you compared a dead
15:18
Speaker 1: organism to a living organism, and the ratio of carbon
15:22
Speaker 1: fourteen to carbon twelve in the dead organism compared to
15:25
Speaker 1: the living organism, you be able to tell how long
15:28
Speaker 1: ago the dead organism was alive and taking him more carbon.
15:32
Speaker 1: And that's the basis of radio carbon dating. That's right.
15:35
Speaker 1: So that is Uh, we have Amanda thank from the
15:38
Speaker 1: University of Chicago name Willard Libby. That's a great name.
15:43
Speaker 1: I heard his name was wild Man or wild Bill,
15:48
Speaker 1: wild Man, Willard Libby, Yeah, because he's just crazy. I
15:52
Speaker 1: guess you must have been a party animal. Who knows.
15:55
Speaker 1: You don't get a nickname like wild Bill for nothing.
15:59
Speaker 1: They don't go around handing those out to just anybody. Yeah,
16:02
Speaker 1: not even just figuring out carbon fourteen dating. You wouldn't
16:05
Speaker 1: get a wild man for that. No, No, like even
16:08
Speaker 1: Chris Farley wasn't called wild Bill. I think Lillard Livy
16:12
Speaker 1: had a side a side gig. Yeah, you know, but
16:16
Speaker 1: he was the party monster maybe at the University of
16:19
Speaker 1: Chicago in the nineteen forties. Perhaps, so he figured out
16:24
Speaker 1: how carbon fourteen worked and how it could be used
16:27
Speaker 1: to do this before we were even positive science even
16:32
Speaker 1: knew for a fact that there was such a thing
16:34
Speaker 1: as carbon fourteen. That's a pretty impressive, uh. And in fact,
16:38
Speaker 1: it was just a few short years after we had
16:41
Speaker 1: discovered cosmic rays. So he was really on the leading
16:45
Speaker 1: edge of science. You know he was a wild man, right,
16:48
Speaker 1: He's like, these particles, we're not even sure they exist,
16:51
Speaker 1: but if they do, we could figure out how to
16:52
Speaker 1: use them to date dead organisms. And he won a
16:55
Speaker 1: Nobel Prize in nineteen sixty for this, I think rightfully.
16:58
Speaker 1: So in chemistry, yeah, for sure, even though as we'll see,
17:02
Speaker 1: he got a few things wrong. And the one thing
17:05
Speaker 1: that's kind of tough to wrap your head around here
17:08
Speaker 1: is he and this is it just is what it
17:13
Speaker 1: is at this point, I think. But he selected nineteen fifty,
17:16
Speaker 1: the year nineteen fifty is year zero for his experimentation,
17:20
Speaker 1: and he compared all the samples against this, and that
17:24
Speaker 1: is still what we do today. That we didn't. We
17:27
Speaker 1: didn't revise a lot of this stuff. It's interesting, no, Like,
17:31
Speaker 1: they definitely are, like, okay. I think the reason why
17:33
Speaker 1: is because by the time it started to start to
17:36
Speaker 1: become sophisticated and and more refined, so many samples had
17:41
Speaker 1: gone through that it's like, we're just gonna stick with
17:44
Speaker 1: this for now. It's really interesting. So nineteen fifty, when
17:48
Speaker 1: you're radio carbon dating an object, that is year zero,
17:51
Speaker 1: So um, anytime you get a date back, which we'll
17:53
Speaker 1: talk about it's actually saying this is how long before
17:56
Speaker 1: nineteen fifty this thing was last alive? Right, and we're
18:00
Speaker 1: not talking it just it doesn't have to be like
18:02
Speaker 1: a plant fossil um because we said carbon is in
18:06
Speaker 1: you know, virtually everything. So a leather belt comes from
18:09
Speaker 1: a cow, cow ate the plant um. What else wouldn't
18:14
Speaker 1: plant in ships a pig fabrica. We find poop, of course,
18:19
Speaker 1: old poop, old old alcohol, old beer because of yeast.
18:24
Speaker 1: There are many, many, many things obviously bodies, oats, Yeah,
18:28
Speaker 1: our pal. Yeah, as long as whatever you are dating
18:34
Speaker 1: was at one point alive, which means it wasn't a
18:37
Speaker 1: rock or a mineral from birth like it's you can
18:42
Speaker 1: date it. You should be able to date as long
18:43
Speaker 1: as it's about fifty or sixty thousand years or younger. Yeah,
18:48
Speaker 1: But there was a problem early on in this process
18:50
Speaker 1: because you needed a lot of this material, uh to
18:54
Speaker 1: basically destroy to find out how old it is. And
18:58
Speaker 1: people didn't want to give up these gray eight fines,
19:00
Speaker 1: Like they're like, I found a a skull and they're like, well,
19:05
Speaker 1: can we destroy that skull to find out how old
19:07
Speaker 1: it is? And you know they would turn around and
19:09
Speaker 1: say no, it's my skull, right right, And then the
19:11
Speaker 1: radio carbon researchers saying, like I was just asking to
19:14
Speaker 1: be pleasant, give me that skull. Yeah, but then you
19:16
Speaker 1: would say, no, it's my skull and I'm just happy
19:20
Speaker 1: to call it old right, And WELLRD Libby would step
19:22
Speaker 1: in and just do like a wild man pile driver
19:25
Speaker 1: on the guy with this skull got the name. You
19:28
Speaker 1: would just come in and crush people hiding maybe in
19:32
Speaker 1: another room and back or something, just pound someone to go,
19:37
Speaker 1: he would swarm. Um. But here's the thing. We've gotten
19:40
Speaker 1: a lot better over time. The equipment has gotten a
19:43
Speaker 1: lot better, more sophisticated, so we don't need that much now.
19:46
Speaker 1: And people are giving up their fines because you can
19:49
Speaker 1: have a little gram bone from the skull and I
19:53
Speaker 1: think everything will be okay. Yeah. And so because of that,
19:56
Speaker 1: like it's gotten way more common to radio carbon dates
20:00
Speaker 1: stuff I read in the UK. Um they really started
20:04
Speaker 1: dating everything they found because the UK passed a lot
20:07
Speaker 1: of that said, if you're a developer and you turn
20:09
Speaker 1: up any sort of archaeological evidence, I'm like one of
20:12
Speaker 1: your buildings or developments, you have to pay to have
20:15
Speaker 1: it dated. And so like it started to kind of
20:18
Speaker 1: get the burden for paying for it was shifted to industry,
20:21
Speaker 1: and so it started to really blow up, and that
20:23
Speaker 1: helped kind of push the technology along and help lower
20:26
Speaker 1: the expense and increase the sophistication of the machines that
20:30
Speaker 1: were being used. Yeah, it's pretty pretty neat how that happens. Well,
20:34
Speaker 1: here's what you gotta do if you're gonna start out
20:36
Speaker 1: this process is you've got to really clean your sample
20:39
Speaker 1: very well. Otherwise it's gonna um you can mess up everything,
20:44
Speaker 1: and not just the test that you're making. If you
20:46
Speaker 1: have what's called a hot sample, which means you didn't
20:49
Speaker 1: clean it well enough for it's contaminated a graham of
20:51
Speaker 1: hot sample, you can destroy a lab basically to the
20:57
Speaker 1: point where they'll just have to shut down for for
20:59
Speaker 1: weeks or even months to get everything right, and everything
21:02
Speaker 1: in there might be destroyed, like, yeah, all the other
21:05
Speaker 1: samples that may be super valuable my skull. Yeah, you know. Sorry. Um,
21:10
Speaker 1: so it's a big deal if something isn't cleaned right,
21:13
Speaker 1: because it really throws everything off and CARU and everything else.
21:16
Speaker 1: But once you do have it cleaned, um, when you
21:19
Speaker 1: date it, there's a few different methods that you can use,
21:21
Speaker 1: but the one that I saw is the most common
21:24
Speaker 1: is actually turning that carbon based sample into carbon graphite,
21:30
Speaker 1: like pure carbon. And then you take that little piece
21:33
Speaker 1: of pure carbon that you've just created and you shoot
21:37
Speaker 1: a beam of energy through it, a lot of energy. Yeah,
21:41
Speaker 1: like two million volts, which is a lot, just all
21:45
Speaker 1: once I think they ramp it up, don't they, Yeah,
21:47
Speaker 1: over time, but at some point it's got it's it's
21:50
Speaker 1: been accelerated to two million volts of energy, okay. And
21:55
Speaker 1: then so once you have this thing basically a particle
21:58
Speaker 1: mini particle accelerators pass through a spectrometer which can actually
22:02
Speaker 1: measure the different masses of the atoms in this beam
22:08
Speaker 1: that you've shot through the graphite. That's right, it's detecting
22:11
Speaker 1: the little bits of carbon. Yeah, that's pretty impressive stuff.
22:15
Speaker 1: I mean, this is the kind this is the level
22:16
Speaker 1: of technology we're at right now in two thousand nineteen,
22:19
Speaker 1: and this has been around since like the eighties or nineties.
22:21
Speaker 1: Just think of what's coming next. What do they use
22:24
Speaker 1: Before the spectrometer, they used something beta counting, and it
22:29
Speaker 1: was clunky and expensive and not nearly as reliable. But
22:32
Speaker 1: basically what it did was something different where it would
22:35
Speaker 1: sit there and and study a piece of graphite or gas.
22:40
Speaker 1: They often gasify stuff to pure gas, and then it
22:44
Speaker 1: would just like shoot a beam through and study I
22:46
Speaker 1: think a beam. It would somehow study the sample for
22:50
Speaker 1: days maybe, and it would count the number of atoms
22:55
Speaker 1: that had spontaneously converted from carbon four team new carbon twelve,
23:01
Speaker 1: and then it would do a little mathematic rigamarole and
23:03
Speaker 1: say this is how this is how at this rate
23:06
Speaker 1: of decay, this is how old this organism is. Well,
23:08
Speaker 1: thank goodness, we have the spectrometer now then, because it's
23:11
Speaker 1: much more precise and it sounds more futuristic too. Yeah,
23:15
Speaker 1: mass pectrometers. So you're gonna shoot this beam, you're gonna
23:20
Speaker 1: throw it in the Wonder machine. Actually not the Wonder machine,
23:22
Speaker 1: We've already taken that. Yeah, it's a thoughtless piece of crap. Fight. Uh.
23:28
Speaker 1: And then you compare that ratio to the again year zero,
23:32
Speaker 1: which is the ratio in which is still a little confusing. Yeah,
23:37
Speaker 1: it's clunky, It is very clunky. And then that difference, basically,
23:42
Speaker 1: like we've said eight times now, shows how many years
23:45
Speaker 1: have passed to produce the amount of decay in that sample. Right,
23:49
Speaker 1: So if you took like a sample of wood from
23:52
Speaker 1: an old ship, an old boat, you found out right,
23:57
Speaker 1: that's the new right by the way, did you say
23:59
Speaker 1: route yeah? Um? And you analyze and you found that
24:03
Speaker 1: based on the amount of carbon fourteen in there, it
24:06
Speaker 1: was something like, um, it dated to like eight hundred
24:10
Speaker 1: and forty five b C E. Okay, you'd be like, great,
24:14
Speaker 1: now we know where this ship is from. But if
24:16
Speaker 1: you try to go out and publish a study with that,
24:19
Speaker 1: hopefully your radio carbon colleagues would be like, whoa, whoa,
24:22
Speaker 1: there's a few more steps involved here here, and that's
24:25
Speaker 1: like the most precise radio carbon date anyone would have
24:27
Speaker 1: ever given. You'll be laughed out of the field if
24:30
Speaker 1: you do this instead. There's a couple of things that
24:33
Speaker 1: you have to do first. So radio carbon dates are
24:36
Speaker 1: given uh as a span of time, a bit of
24:40
Speaker 1: a range, right, so it'll say. And also because it's
24:44
Speaker 1: comparing to it's given not as a date like B
24:49
Speaker 1: C E or a D or C E or anything
24:51
Speaker 1: like that. It's BP before president years before president. So
24:56
Speaker 1: for that piece of wood, say, you would actually get
24:59
Speaker 1: something like twenty seven hundred and fifteen years before present
25:02
Speaker 1: plus or minus thirty years. So is it always thirty
25:06
Speaker 1: or is it no? No, it can can depend, it
25:08
Speaker 1: can it can range dramatically like Leotsie is there. They
25:14
Speaker 1: have them down to about three hundred or three hundred
25:16
Speaker 1: and fifty years, And you like the shorter the span
25:20
Speaker 1: of time, the plus or minus years or the window
25:24
Speaker 1: of years that you get, um, the less confidence you have.
25:28
Speaker 1: So maybe you'll have like twenty six percent confidence that
25:32
Speaker 1: it's from you know, uh, eight hundred forty five BC
25:38
Speaker 1: to eight hundred fifty five BC, but you have confidence
25:42
Speaker 1: that there's like this two hundred year span it's somewhere
25:45
Speaker 1: and there. That makes sense because I have a million
25:47
Speaker 1: percent confidence that it's somewhere within the last eighteen million
25:50
Speaker 1: years exactly exactly right. So it just keeps. The larger
25:53
Speaker 1: the window, the more confident you are. But I mean
25:56
Speaker 1: still you're talking a hundred two hundred years depending on
26:00
Speaker 1: how old the sample is, how good the sample is,
26:02
Speaker 1: so it's still pretty it's pretty um. They can zero
26:06
Speaker 1: it in pretty well. And that sciences job is to
26:09
Speaker 1: not say, well, let's just make a really big range
26:12
Speaker 1: and that will be good enough. They want a zero
26:14
Speaker 1: and as much as possible, Like you know, that's and
26:18
Speaker 1: still be accurate. So the thing is, though, is if
26:21
Speaker 1: you do the if you do the math, and you say, well,
26:23
Speaker 1: wait a minute, your example, Yeah, fifteen years before present
26:27
Speaker 1: plus or minus thirty years gives you a range of
26:30
Speaker 1: between seven hundred and twenty six and six sixty six BC.
26:34
Speaker 1: But that's not even close to what you said, yeah,
26:37
Speaker 1: which was before right, Yeah, so why wouldn't be in
26:42
Speaker 1: the sample? Chuck? Because uh, like we said in the
26:47
Speaker 1: very first sentence, radio carbon dating is uh not super
26:52
Speaker 1: I mean, it's accurate on a wide range, but it's
26:55
Speaker 1: a little clunky. It is. Part of it is because
26:58
Speaker 1: there's actual um problems, like known problems built in to
27:07
Speaker 1: the actual process of radio carbon dating and the results
27:09
Speaker 1: that they get back. I'll put that, I'll put that pause.
27:13
Speaker 1: I just had sounded really long in the replay, probably
27:17
Speaker 1: so I felt like it. But yeah, let's take a break, man,
27:19
Speaker 1: all right, We'll come right back and talk about more
27:21
Speaker 1: science right after this. So I thought this was was
27:38
Speaker 1: this from how stuff works and you in your brain
27:40
Speaker 1: and yeah and a bunch of other places too, and
27:43
Speaker 1: you in your brain. Okay, but there there's an interesting
27:48
Speaker 1: thing to note here, which is science makes a lot
27:51
Speaker 1: of assumptions when it comes to dating stuff. Uh, and
27:55
Speaker 1: this is the best way to say it. If you find,
27:57
Speaker 1: like if they find like a leather shield that they
28:00
Speaker 1: dig out of an archaeological site, they get super excited
28:04
Speaker 1: and they can date the shield and they can say,
28:07
Speaker 1: or they probably will say, well, whoever this heroic person
28:11
Speaker 1: was in the battlefield died on this around this date,
28:15
Speaker 1: because that's where the shield was dated from. But that
28:19
Speaker 1: is not necessarily true because they're dating the shield from
28:22
Speaker 1: the cow skin that's on the handle, let's say, and
28:26
Speaker 1: that just says when that cow is alive. Lass has
28:29
Speaker 1: nothing to do with when this person made the shield.
28:32
Speaker 1: How long that leather had been around before they went
28:35
Speaker 1: out onto the battlefield and took an arrow to the forehead. Yeah,
28:38
Speaker 1: maybe they were like super into vintage leather to use
28:41
Speaker 1: on their shield handle here. It's it's sounds ridiculous, but
28:44
Speaker 1: it's also possible. But the thing is is archaeological or
28:49
Speaker 1: archaeology is based on making assumptions and presumptions based on
28:53
Speaker 1: the context. And it's like, this is totally fine, this
28:57
Speaker 1: is widely accepted. This is not new or scandalous at all,
28:59
Speaker 1: but like that is part of archaeology's job. As you say,
29:02
Speaker 1: here's the context of this find. And based on this
29:05
Speaker 1: radiocarbon date of this, it's a pretty good guess that
29:08
Speaker 1: they killed the cow, made the leather, made the shield,
29:11
Speaker 1: and the guy died probably within a ten fifteen year window.
29:15
Speaker 1: And I mean the idea it would be an even
29:18
Speaker 1: weirder assumption to think that it was an ancient hipster
29:21
Speaker 1: who collected old hold leathers. Right, check out my new
29:25
Speaker 1: that's right. And then the other part of it too
29:28
Speaker 1: is they also use it to compare to other stuff.
29:30
Speaker 1: Like if they're in a pit filled with other um
29:33
Speaker 1: soldiers of a certain you know, from a certain nation
29:37
Speaker 1: or clan or whatever, um, and they knew of a
29:40
Speaker 1: lost grade, they may have found that if it kind
29:43
Speaker 1: of roughly correlates to the date. They were thinking, Like,
29:45
Speaker 1: there's a lot of a lot of stuff that they
29:47
Speaker 1: put together. They don't just say, here's what the radio
29:49
Speaker 1: carbon date says, so this is what it is. That's right.
29:52
Speaker 1: So because science does this, Libby was certainly doing this.
29:55
Speaker 1: The wild man was doing this, and he was making
29:58
Speaker 1: assumptions and he was and hey, we're not knocking the
30:01
Speaker 1: guy because he want a Nobel prize for this, but
30:04
Speaker 1: he assumed a couple of things that were not correct. Uh,
30:08
Speaker 1: One of which was he got the half life wrong. Yeah,
30:10
Speaker 1: he said the half life of carbon fourteen was five thousand,
30:13
Speaker 1: five D sixty eight years. We actually know it's fifty
30:17
Speaker 1: thirty like we said. And he also presumed that carbon
30:23
Speaker 1: fourteen in the atmosphere is very steady over time and
30:28
Speaker 1: it's something we can really depend on, being like they're
30:31
Speaker 1: being a certain amount. And that's not really the case either. No,
30:34
Speaker 1: it's not that second one is a big one. Like
30:36
Speaker 1: the first one. You can just mess around with some
30:38
Speaker 1: math and be like, okay, well this is the actual
30:40
Speaker 1: half life. Well, but it's interesting. That's what we've had
30:43
Speaker 1: to do because that's another thing we didn't go back
30:46
Speaker 1: and change because it was all done on the basis
30:49
Speaker 1: of right. Right. So the initial stuff, the initial dates
30:54
Speaker 1: that were done when Libby invented it, were based on
30:56
Speaker 1: a half life from right but from uh, I don't
31:03
Speaker 1: I don't know exactly when they figured it out, but
31:05
Speaker 1: at some point in the ensuing decades they figured out, no,
31:08
Speaker 1: the half life is actually fifty thirty and rather than
31:11
Speaker 1: just go back and re read um uh analyze the
31:16
Speaker 1: old samples which actually may have been destroyed by this time. Uh,
31:19
Speaker 1: they said, we're just going to stick with this convention
31:22
Speaker 1: and follow it, and we could just do the math
31:25
Speaker 1: and just say, actually, this is the real half life
31:28
Speaker 1: converted to the libyhalf life, and then have a radiocarbon date. Yeah.
31:32
Speaker 1: But the other thing he got wrong, like you said,
31:34
Speaker 1: is is the bigger problem because it can't just be
31:37
Speaker 1: solved with math, and that is his presumption that uh,
31:42
Speaker 1: carbon fourteen in the upper atmosphere is produced at a
31:45
Speaker 1: steady rate. We know now that they are all kinds
31:48
Speaker 1: of things that can and have affected that rate over
31:51
Speaker 1: the years, everything from ocean currents to super volcanoes, two
31:56
Speaker 1: solar flares, to the Earth's magnetic field. It is fluctuated
32:00
Speaker 1: a lot over time. Yeah, but I mean from year
32:03
Speaker 1: to year, we're starting to find that it's not at
32:05
Speaker 1: all study. And that's a big one because one of
32:09
Speaker 1: the foundations of radiocarbon dating is this idea that that
32:13
Speaker 1: it's like a reliable clock that just starts clicking backwards.
32:17
Speaker 1: You know, at any point in time, whatever year you
32:20
Speaker 1: come in on you're going to be able to compare
32:22
Speaker 1: it to a modern sample and get a coherent UM
32:26
Speaker 1: radiocarbon date that will make sense. That's just absolutely not
32:30
Speaker 1: the case because of all of those fluctuations, Right, That's
32:33
Speaker 1: something that this field is definitely grappling with, which uh
32:37
Speaker 1: it will it will be able to overcome and largely
32:40
Speaker 1: has already because they use other types of dating to
32:43
Speaker 1: calibrate their radiocarbon dates. Yeah, which is really cool. We
32:47
Speaker 1: were talking about the um relative dating of carbon fourteen dating.
32:54
Speaker 1: What they're now trying to do, who not now they've
32:56
Speaker 1: been doing it for a while is absolute dating, like
32:58
Speaker 1: what you're talking about, comparing it to own quantities. And
33:02
Speaker 1: one of those is tree rings. And I'm surprised we've
33:05
Speaker 1: talked about tree rings a little bit here and there,
33:07
Speaker 1: but I wonder if it could be a shorty on
33:09
Speaker 1: its own at least Yeah, maybe more. We'll just start
33:14
Speaker 1: wrapping on it and whether if it turns into a
33:18
Speaker 1: real deal episode we'll go with, we'll just cancel our
33:20
Speaker 1: dinner plans keep going. But tree ring dating is called
33:26
Speaker 1: dendo chronology counting tree rings, and not all trees have
33:32
Speaker 1: tree rings. Will get to that, which can be a problem,
33:35
Speaker 1: but a lot of them do and some of them
33:37
Speaker 1: grow every year, just like you learned, and everyone probably
33:40
Speaker 1: thinks it's true from like kids science class. It's like
33:43
Speaker 1: once a year a tree has a ring, so if
33:45
Speaker 1: you cut a tree down, you can just count the
33:46
Speaker 1: rings and know how old it is, which is I
33:48
Speaker 1: mean basically right, depending on the tree is exactly. But
33:52
Speaker 1: here's the thing is, trees absorbed that carbon fourteen just
33:56
Speaker 1: like everything else, but those tree rings don't. Once they
33:59
Speaker 1: have completed a tree ring cycle, that tree ring is
34:03
Speaker 1: essentially dead inside the tree and is not accepting any
34:06
Speaker 1: more carbon fourteen. Yeah, it's like a fossil. It's like
34:09
Speaker 1: if you look at the outside of a tree, that's
34:12
Speaker 1: the living part. Like as big as a tree is
34:14
Speaker 1: and enormous as it is, the actual living part of
34:17
Speaker 1: it is just this outside veneer and like the leaves
34:19
Speaker 1: and everything. Right, yeah, everything inside is what used to
34:23
Speaker 1: be outside but is now inside because a new ring
34:26
Speaker 1: of growth grew around it. So um, since it's not
34:28
Speaker 1: taking in any more carbon, it's like a snapshot of
34:31
Speaker 1: the carbon fourteen that was in the atmosphere the year
34:36
Speaker 1: that tree ring grew. Yes, and we know this, and
34:39
Speaker 1: now we have something to compare against those Carbon fourteen
34:42
Speaker 1: data results. Yeah, because if you chop the tree down today,
34:46
Speaker 1: you would say thank you father tree, mother tree, um,
34:50
Speaker 1: for sacrificing your life for for science. That's what you
34:54
Speaker 1: have to say first. Um, And you start counting the
34:57
Speaker 1: tree rings backwards. If you it to another tree that's
35:01
Speaker 1: much older, but that lived that the lifetime of which
35:05
Speaker 1: overlapped with the tree you just cut down, you can
35:08
Speaker 1: eventually jump over from the tree you just cut down
35:12
Speaker 1: to this older tree and keep counting backwards and then
35:15
Speaker 1: just keep if you find enough old trees, keep leaping
35:19
Speaker 1: from tree to tree, counting tree rings as if it
35:21
Speaker 1: was one big old tree. That's really cool. It is,
35:25
Speaker 1: and there are very very old trees that do exist
35:27
Speaker 1: on Earth that you can count backwards from over very
35:32
Speaker 1: long spans of time. But you can also use multiple trees. Yeah.
35:36
Speaker 1: And like if you're sitting at home or in your car, thinking, well,
35:39
Speaker 1: why don't they just find the oldest tree and go there,
35:42
Speaker 1: Like you want that overlap because you want a complete
35:44
Speaker 1: record because stuff you're dating might fall. You know in
35:47
Speaker 1: that that they need everything to fall in that range, right,
35:51
Speaker 1: And so this has been extremely helpful for radio carbon
35:55
Speaker 1: dating because they have managed to compile basically a library
36:00
Speaker 1: of tree ring data UM going back like fourteen thousand,
36:03
Speaker 1: five hundred years. It's amazing. It's called the Holocene tree record,
36:07
Speaker 1: and it's one of the I didn't even know it existed.
36:09
Speaker 1: Now I'm just I love it. Yeah, it's pretty cool.
36:11
Speaker 1: I want to I like wanta a bound copy of
36:16
Speaker 1: it for the coffee table or something and lay in
36:19
Speaker 1: a hammock in the middle of Pando and read it
36:22
Speaker 1: and read it and be like, oh, look at this year, Pando,
36:24
Speaker 1: what do you think what happened this year? And Panda
36:27
Speaker 1: would hug you. Uh so I was trying to think
36:30
Speaker 1: of something you would do back to Pando, but I
36:33
Speaker 1: would go glow and Panda's leaves. But that feels good. Sure.
36:39
Speaker 1: So there are other places in nature that have the
36:41
Speaker 1: same kind of snapshots. Uh, if you wanted more than
36:45
Speaker 1: because you need more just than the Holocene tree record. Uh,
36:49
Speaker 1: they can use coral reef because there's clearly carbon in
36:51
Speaker 1: the ocean um still actites and stillagmites, which are called
36:55
Speaker 1: spelio thembs through whenever busts out out at a party,
36:59
Speaker 1: you'll know they're talking about. Yeah, you probably should, because
37:03
Speaker 1: everyone else is just going to be talking about I
37:05
Speaker 1: can never remember which ones are exactly. Oh you mean,
37:09
Speaker 1: just let me educate you. Goodbye. Uh. They are made
37:13
Speaker 1: of carbon and they are deposited in layers, just like
37:16
Speaker 1: the tree rings in the coral uh. In fact, they
37:19
Speaker 1: have found some in China kind of recently. They go
37:22
Speaker 1: back fifty four thousand years. Yeah. I think they really
37:26
Speaker 1: recently found this so much so that hasn't been like
37:28
Speaker 1: fully vetted, but they were super excited about it. That
37:31
Speaker 1: the idea that it gave a basically a long mineral
37:37
Speaker 1: rich tree ring library of fifty four thousand years of
37:41
Speaker 1: the carbon fourteen concentrations in the atmosphere. If they if
37:46
Speaker 1: it does pan out, that would be amazing. And what's
37:48
Speaker 1: the deal with the lake in Japan? It reliably puts
37:52
Speaker 1: down a new layer of sediment every six months. That's
37:54
Speaker 1: pretty cool. Yeah. And so they've taken core samples and
37:58
Speaker 1: in these core samples they've turned up like leaves trapped
38:02
Speaker 1: in single layers and something like six hundred and fifty
38:05
Speaker 1: different spots. So all they have to do is count backwards,
38:11
Speaker 1: find you know, the and they'll know the year that
38:14
Speaker 1: this UM leaf is trapped in and then test the
38:20
Speaker 1: carbon fourteen and the leaf and you've got like a
38:22
Speaker 1: picture right there. And that is called what we'll call
38:26
Speaker 1: a library of atmospheric carbon fourteen concentrations. Yeah, they should
38:31
Speaker 1: have a name. It does. It's called ink COW I
38:34
Speaker 1: N T C A and UM. There's different programs that
38:37
Speaker 1: you can run all this through like before, back in
38:40
Speaker 1: the forties and fifties, like they were, I guess, using
38:43
Speaker 1: slide rules and stuff like this to come up with these.
38:46
Speaker 1: Now we have basically machine learning algorithms running these these
38:51
Speaker 1: computations for us. But UM, they have programs that use
38:54
Speaker 1: this calibration library to basically say, here's the what the
38:59
Speaker 1: radio harbon date is saying. What does this library of
39:03
Speaker 1: absolute dates say? And then what they do is they actually, well,
39:07
Speaker 1: the computer I should say, overlaps what's called the wiggles.
39:10
Speaker 1: They hold it up to the light yea, and they
39:13
Speaker 1: find like where these kind of wiggles overlap, which are
39:16
Speaker 1: UM confidence intervals I guess, uh, and where it's most
39:21
Speaker 1: confident that you have a pretty good idea of what
39:25
Speaker 1: the range is for the age of this sample. And
39:28
Speaker 1: that means we know exactly how old everything is always
39:32
Speaker 1: all right precisely to the day. That is not true
39:35
Speaker 1: because all the things we just mentioned, the spile, thems,
39:40
Speaker 1: the coral, everything has its own individual problems, right. Um.
39:46
Speaker 1: Coral turns out isn't a great material for calibrating this
39:51
Speaker 1: stuff because ocean concentrations of carbon are not the same
39:56
Speaker 1: as in the atmosphere. So that kind of throws it
39:59
Speaker 1: off right there. It So if you're comparing like something
40:02
Speaker 1: that lived on land to coral in the library in
40:06
Speaker 1: cal library, yeah, it's not gonna it's not gonna calibrate
40:09
Speaker 1: very well. Um. Tree rings are a problem too, because
40:12
Speaker 1: they figured out that depending on the hemisphere that the
40:17
Speaker 1: tree grew in, it will give you a different atmospheric
40:19
Speaker 1: concentration because the southern atmosphere has more oceans and those
40:24
Speaker 1: oceans absorb more carbon dioxide. So there's actually less carbon
40:28
Speaker 1: fourteen on the land in the southern hemisphere than there
40:32
Speaker 1: is in the northern hemisphere. So if you checked out
40:35
Speaker 1: a water logged oak that grew in Ireland and two
40:39
Speaker 1: c e if you found a cody tree the Cody
40:47
Speaker 1: tree in New Zealand that grew that same year, they
40:50
Speaker 1: would have different radio carbon dates because they have different
40:53
Speaker 1: carbon radiocarbon concentrations. So it's just there's a lot of
40:57
Speaker 1: things confounding this stuff that's keeping it and being less precise,
41:02
Speaker 1: that's right. And it gets even worse because there have
41:05
Speaker 1: been long stretches of time on Earth in our history
41:09
Speaker 1: where carbon fourteen production really increased every year over you know,
41:15
Speaker 1: hundreds of thousands of years or tens of thousands. Yeah,
41:18
Speaker 1: well there's stretches that. So all over the radio carbon calendar,
41:24
Speaker 1: there are these things called plateaus, and I think the
41:27
Speaker 1: longest that they've ever found is a few hundred years.
41:30
Speaker 1: When I said tens of thousands, just like a radio
41:33
Speaker 1: carbon date, all right, it feel so bad. They found
41:36
Speaker 1: this thing called the Hallstock plateau, more like the Hallstat disaster. Yeah,
41:41
Speaker 1: that's what some people call them, all right, I'm sure
41:43
Speaker 1: that's what Willard Libby called that. Sure, But basically there
41:46
Speaker 1: were periods during Earth's history, This one in particular goes
41:50
Speaker 1: from seven sixty four b C where the the production
41:56
Speaker 1: of carbon fourteen in the atmosphere just in priest basically
42:01
Speaker 1: steadily steadily every year, so nothing ever got older relative
42:05
Speaker 1: to new stuff, right, which means that if you radio
42:10
Speaker 1: carbon date something at the in seven sixty b C
42:14
Speaker 1: and something in four twenty BC, they're going to give
42:17
Speaker 1: you the same exact radio carbon date. Does that make
42:21
Speaker 1: sense for that was your response. Hey, there's people out
42:29
Speaker 1: there thinking it to the Hallstad disaster. All right, Willard
42:33
Speaker 1: Libby would be proud. He was the wild Man. So
42:37
Speaker 1: this is why old this is important. It's not just
42:40
Speaker 1: to put a date on something so we know how
42:43
Speaker 1: old it is and we can just put it down
42:45
Speaker 1: in a museum or a history book or whatever. Right. Um,
42:48
Speaker 1: it really opens up all of science and all of
42:52
Speaker 1: ancient history to interpretation and kind of rock to the
42:56
Speaker 1: world about a lot of things that we thought were
42:58
Speaker 1: true that are true. Yeah. They call it the radio
43:01
Speaker 1: carbon revolution, and like, well, one good example is in
43:06
Speaker 1: the UK there we talked about Stonehenge. They used to
43:09
Speaker 1: think that Stonehenge was the result of the how do
43:14
Speaker 1: you pronounce that missini myceney? I don't know mycen A.
43:20
Speaker 1: You'd think I know mice sna. I think it's the
43:24
Speaker 1: mycen A civilization in Greece, But the A and the
43:27
Speaker 1: E on the end. It's got to do something more
43:29
Speaker 1: than like why not just add a Y instead of
43:33
Speaker 1: an e. I'm with you, and you know sometimes you
43:35
Speaker 1: see the A and the E together conjoined, like Ronnie
43:39
Speaker 1: and Donnie Galleon. You know. So what is that? It's
43:45
Speaker 1: its own thing. So we used to think that came
43:48
Speaker 1: from an ancient Greek civilization, but because of radio carbon dating,
43:54
Speaker 1: they said no, no, no, no no, no, this is uh,
43:56
Speaker 1: we had the age all wrong. And Stonehenge came before
43:59
Speaker 1: that ever, happened before the civilization was even there. So
44:03
Speaker 1: it really helps clear up a picture of everything from
44:06
Speaker 1: Otsy the ice Man to knowing uh that the shroud
44:09
Speaker 1: of Turin was only seven years old. Uh. It so
44:13
Speaker 1: it can confirm things and it can quh other things.
44:16
Speaker 1: Right and then, and the way that they used to
44:19
Speaker 1: do it before was they would just kind of dig
44:23
Speaker 1: in the earth and turn up artifacts. And because an
44:26
Speaker 1: artifact was closer to the ground than another one, it
44:30
Speaker 1: just meant it was more recent. That's like as precise
44:33
Speaker 1: as they could get. Radio carbon was like, not only
44:35
Speaker 1: are we going to do with that, but get this
44:37
Speaker 1: pal here's a date and a pretty good estimate of
44:41
Speaker 1: a date that this thing existed. That's how much it
44:45
Speaker 1: changed things. They used to be like this is older
44:47
Speaker 1: than this. Now it's this. Let's see the ice man
44:49
Speaker 1: was running around, you know, in and in doing that,
44:55
Speaker 1: it also changes everything and that they're saying, oh well,
44:58
Speaker 1: Letsie was also ound with tattoos on him that seemed
45:02
Speaker 1: to suggest acupuncture, which apparently they didn't think anymore. But
45:05
Speaker 1: but that changed our idea of how old acupuncture was.
45:10
Speaker 1: And then he had certain tools on him. We didn't
45:12
Speaker 1: know that they were making these tools back then, but
45:14
Speaker 1: now that we've reliably dated Utsie, we know that the
45:17
Speaker 1: the this, this toolmaking complex is much older. People had
45:21
Speaker 1: professions much sooner than we thought. It just opens up
45:25
Speaker 1: everything when you have a date for one thing. Yeah,
45:27
Speaker 1: the tender rols are far reaching, right, exactly a broad
45:30
Speaker 1: and it happened actually here in the United States to
45:33
Speaker 1: ur in North America. You know, we did a whole
45:35
Speaker 1: episode on the Clovis Police. Sure the idea that the
45:40
Speaker 1: Clovis people were the first Americans and they came over
45:43
Speaker 1: from crossing over the I guess the bearing Land Bridge
45:46
Speaker 1: when the ice sheet receded, and so Willard Libby did
45:50
Speaker 1: uh a test that showed there's no way that the
45:54
Speaker 1: ice sheet was open anywhere before twelve thousand to five
46:01
Speaker 1: fifteen thousand years ago. So he actually said a baseline,
46:05
Speaker 1: this is when the earliest people possibly could have been here. Well,
46:08
Speaker 1: we've been finding and radiocarbon dating settlements that are older
46:13
Speaker 1: than that. They found one in Idaho on the Snake River.
46:16
Speaker 1: I can't remember the name of the island. Um, that's
46:19
Speaker 1: like almost sixteen thousand years old, and it shows definitively
46:23
Speaker 1: that since the ice sheet was there, they couldn't have
46:26
Speaker 1: come around the burying language. So now we think the
46:28
Speaker 1: first Americans came over by boat, all because of radiocarbon dating. Amazing,
46:33
Speaker 1: But we're screwing it all up for the future because
46:37
Speaker 1: of human activity. Um that you know, we're burning a
46:40
Speaker 1: lot of fossil fuels and we were releasing a lot
46:44
Speaker 1: of carbon into the atmosphere, and so much so that
46:48
Speaker 1: that that consistent, previously reliable ratio of carbon twelve to
46:54
Speaker 1: carbon fourteen has been knocked all out of whack because
46:57
Speaker 1: of us. And in the next what uh years, Yeah,
47:02
Speaker 1: thirty to forty years. Uh, we may not be able
47:05
Speaker 1: to date things accurately using this method anymore. Yeah. Yeah,
47:08
Speaker 1: Because when you know, when they say, well you burn
47:10
Speaker 1: fossil fuels, you release a lot of carbon dioxide. Well,
47:14
Speaker 1: those fuels used to be alive, so they used to
47:17
Speaker 1: have carbon fourteen in them, but they're so old there
47:19
Speaker 1: isn't any carbon fourteen now, it's all just carbon twelve.
47:22
Speaker 1: And we're releasing tons of carbon twelve into the atmosphere
47:25
Speaker 1: that wouldn't normally be there. That's right. And uh, nuclear
47:29
Speaker 1: tests that we conducted UM had a big actually had
47:32
Speaker 1: the opposite effect. Between nineteen fifty five and nineteen sixty three,
47:36
Speaker 1: the common concentration of carbon fourteen in the atmosphere doubled,
47:40
Speaker 1: almost doubled. Yeah, so there's all screwy now. It is
47:44
Speaker 1: a very screw so much so that now they have
47:46
Speaker 1: modern samples. They have a beat harvest from the seventies
47:51
Speaker 1: that they used to replace a beat from France from
47:53
Speaker 1: nineteen fifty that they used to be like, this is
47:55
Speaker 1: the baseline now for modern This is what we're reduced
47:58
Speaker 1: to is sampling beats for God's say. That's how much
48:01
Speaker 1: it screwed things up. But they have figured out how
48:05
Speaker 1: to um use this kind of modern screw nous to
48:10
Speaker 1: also date UM recent remains, which everyone thought was just
48:14
Speaker 1: impossible Um, that you couldn't you couldn't tell when a
48:17
Speaker 1: body lived or died if it were just a you know,
48:20
Speaker 1: a decade or so dead or less. But we have
48:24
Speaker 1: historical records for all this stuff. I know it's a
48:27
Speaker 1: big deal, but like, and we're screwing stuff up to
48:30
Speaker 1: the future. But isn't the the utility of carbon fourteen
48:33
Speaker 1: dating because it was pre history? Yeah, that that certainly helps.
48:38
Speaker 1: And yeah, I guess you're right that having a record
48:40
Speaker 1: would definitely help quite a bit. And I'm not you know,
48:43
Speaker 1: saying like who cares then? But at least we have
48:46
Speaker 1: that going for us. That's a good point. It'd be like, well,
48:49
Speaker 1: the leather seat from this automobile is the same age
48:52
Speaker 1: as this leather shoe from three thousand years before, which
48:55
Speaker 1: is which? Um, But yeah, they have figured out how
48:58
Speaker 1: to how to use it for forensics based on your
49:02
Speaker 1: teeth enamel, which are like tree rings, and then based
49:05
Speaker 1: on your soft tissues. But your soft tissues degrade, so
49:08
Speaker 1: they figured out that they can actually test the casings
49:12
Speaker 1: from the larva that eat your soft tissues as you're decomposing.
49:15
Speaker 1: So the soft tissue is the carbon fourteen in the scenario. Yeah,
49:19
Speaker 1: which you're constantly remaking, and then as you die, it
49:22
Speaker 1: gets it stops being um taken in, and then starts decaying.
49:27
Speaker 1: And as you're being eaten by these you know, bug larva,
49:31
Speaker 1: they shed their casings, and the casings don't degrade. So
49:35
Speaker 1: you can come along and test the casings and they
49:37
Speaker 1: ate your carbon fourteen and you can figure out when
49:41
Speaker 1: that person that body last lived based on the casings
49:45
Speaker 1: of the bugs that ate it. And in a million years,
49:48
Speaker 1: if I were not to get cremated and they were
49:50
Speaker 1: to bury me into the ground, the only thing that
49:53
Speaker 1: would remain of me are the three titanium screws holding
49:56
Speaker 1: in my three fake teeth. That's Nate. A million years,
50:00
Speaker 1: who'd have thought, Yeah, there he is. Yeah, there's Chuck one.
50:06
Speaker 1: You got anything else? There may be more than that
50:08
Speaker 1: by then too, it might be four or five. Any so,
50:11
Speaker 1: anything else you want to keep going that we can
50:13
Speaker 1: keep talking about this. I have no dinner plans, Okay, Um, well,
50:17
Speaker 1: I think we're gonna stop with Carbon four team. We
50:18
Speaker 1: don't want to press our luck. It did go pretty well, Chuck,
50:21
Speaker 1: I told you I think so. And since I said
50:23
Speaker 1: it went pretty well, it's time for listener mail all right,
50:28
Speaker 1: and I was preparing for the next episode. Yeah, we
50:30
Speaker 1: got a listener mail for look at me? All right.
50:34
Speaker 1: I'm gonna call this uh soup follow up. If you remember,
50:39
Speaker 1: we talked about cam soup in a previous episode on
50:44
Speaker 1: what Else Augmented Reality? Right, And I think we were
50:48
Speaker 1: pegged as a progressive guys because you you spoke up first.
50:53
Speaker 1: It's yeah with a name brand. I'm a Campbell's man. Hey,
50:57
Speaker 1: I don't discriminate. I like Campbell's Chunky two. I just
51:00
Speaker 1: kind of went along with it. I didn't want to
51:01
Speaker 1: ruffle any feathers. I didn't speak up, but this is
51:04
Speaker 1: about that. Hey, guys, there are no words to describe
51:07
Speaker 1: how much I enjoy your podcast. I've listened to every
51:10
Speaker 1: single episode and continue to do so each and every week.
51:13
Speaker 1: Thank you for bringing wonderful science, exploration, for knowledge and
51:16
Speaker 1: laughs to my days. So far, so good. I listened
51:19
Speaker 1: to the latest episode on Augmented Reality while on a
51:22
Speaker 1: plane to Boston, and I could not stop laughing. When
51:25
Speaker 1: you got to a full on sant tangent about can Soup.
51:28
Speaker 1: I thought, this is my moment, this is my chance
51:31
Speaker 1: to write in I've been two Stars struck before. But
51:33
Speaker 1: here we go. I know can Soup all too well.
51:36
Speaker 1: I spent seven years right out of college working for
51:38
Speaker 1: General Mills. Yes, they make the serial, but they also
51:43
Speaker 1: owned Progresso. I worked in sales, managing our businesses with
51:47
Speaker 1: our East Coast and national accounts. Three years ago, I
51:50
Speaker 1: left General Mills and went to work for Campbell Soup.
51:53
Speaker 1: It's like, I guess, so just outside of Philadelphia. I
51:58
Speaker 1: guess you could say I too have a thing for
51:59
Speaker 1: Cance Soup. I currently manage our soup and pray go business,
52:04
Speaker 1: one of our largest East Coast grocery chains, and although
52:06
Speaker 1: it doesn't seem complicated, I can tell you a lot
52:08
Speaker 1: of work goes into you enjoying your can of red
52:12
Speaker 1: and white chicken noodle soup. I still love that Campbel's
52:15
Speaker 1: chicken noodle. Oh yeah, it's so good. It's like, how
52:18
Speaker 1: do you mess with a classic like that? Well, but
52:21
Speaker 1: there's also progressive creamy chicken noodles is the bomb. When
52:25
Speaker 1: you mentioned this episode brought to you by Progresso as
52:27
Speaker 1: a joke, I was just waiting for you to plug
52:29
Speaker 1: that you liked Campbell's as well and even more ha ha.
52:33
Speaker 1: Either way, I'm just glad you both enjoy eating our soups.
52:36
Speaker 1: I would be happy to give you a tour of
52:37
Speaker 1: Campbell's soup HQ if you're ever in Philly. Thanks to
52:41
Speaker 1: the entire team for all you do. You guys are
52:44
Speaker 1: a legend combined into a singular. That's from Kathleen and Kathleen.
52:50
Speaker 1: Uh no shade to progressive, But I'm a Campbell's man.
52:54
Speaker 1: I eat three soups a day. I eat Campbell's chicken noodle.
52:59
Speaker 1: I ate chicken corn chowder. I don't know. I fare
53:02
Speaker 1: that's and I eat their new England clam chowder. Yeah,
53:05
Speaker 1: that's good. Who who eats Manhattan clam chowder? I don't know,
53:10
Speaker 1: or I'm sorry, man, I had a clam chowder. No one,
53:13
Speaker 1: not even Manahaddan had nights. They're like, get this away,
53:16
Speaker 1: give me the real stuff, give me that creamy goodness.
53:18
Speaker 1: Do you ever have meatball alphabet? No? I don't know
53:23
Speaker 1: what we're in those meatballs, but I grew up on them,
53:25
Speaker 1: and look at me now. I know. That's all the
53:28
Speaker 1: soups I eat. Though it's weird. I have three soups. Yeah,
53:30
Speaker 1: and you gotta do the chunky stuff Campbell's chunky, I
53:34
Speaker 1: mean become in large cans, is like a hungry man. Well,
53:36
Speaker 1: that's the chicken corn chowder and the I have had
53:40
Speaker 1: that and it's good. Those are chunky. Have you heard
53:42
Speaker 1: the chicken pot pie? No? But I just made a
53:45
Speaker 1: homemade gluten free chicken pot pie biscuit topped. Well, how
53:49
Speaker 1: do you make a biscuit without gluten? You make it
53:52
Speaker 1: with one to one flower instead of wheat flower? What
53:57
Speaker 1: kind of flower is not wheat flour? What is like
54:01
Speaker 1: the white flower? Do you never luten free pasta? And
54:05
Speaker 1: I mean I've heard of it, I haven't eaten it.
54:07
Speaker 1: It's just made with flower without gluten. It's called one
54:10
Speaker 1: to one is in the ratio. So basically you buy
54:13
Speaker 1: the gluten free flower. Sometimes just rice flour, okay, tapioca,
54:17
Speaker 1: But have you had chicken flower? I don't think so
54:20
Speaker 1: it's not bad. I mean, I'm not gluten free. I
54:22
Speaker 1: did this so Emily get enjoyed chicken pope pie. But
54:25
Speaker 1: you know, you lay out you make the little chickenscu
54:27
Speaker 1: good little biscuits and you lay them on top of
54:30
Speaker 1: your pot pie, and then you brush it with egg yolk. Nice,
54:34
Speaker 1: and then that Bronze is up to a shiny brown
54:38
Speaker 1: top like people laying on the beach and so good.
54:41
Speaker 1: That is nice. Man, make a good chicken pop. Have
54:44
Speaker 1: you had it already but had like I haded this
54:46
Speaker 1: past weekend, but I have not had the soup, which
54:48
Speaker 1: is what led me to that danger. It's good, I
54:51
Speaker 1: won't I don't discriminate progressive Campbell's it's all good. Well,
54:55
Speaker 1: Chuck is checking his phone to see what time, and
54:57
Speaker 1: it's so I guess we should probably end this episode.
54:58
Speaker 1: If you want to get in touch a this to
55:00
Speaker 1: offer us a tour of where you work. That's always nice.
55:02
Speaker 1: Thank you. Um. You can go on to stuff you
55:05
Speaker 1: Should Know dot com, check out our social links, or
55:07
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55:16
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