Age of the Earth, Part 2

groundwork for everything we're talking about today. In the last episode, we talked about why we're addressing this topic even though it's a topic that there is not legitimate scientific controversy about. There's no real scientific argument about whether the Earth is billions of years old or younger. Uh, it is billions of years old. But we are addressing it because we've we've frequently gotten mail from listeners asking us to help them sort out and understand the differences in claims about

the age of the Earth. So we're on that adventure now. Yeah, and if you listen to the first episode, I don't I do want to just tell everybody this one is is definitely worth listening to as well. It's not all gonna be elements and isotopes. There's gonna be some cool history in here. There's gonna be some some other dynamic geologic examples. So there's a there's a lot of cool

stuff in this episode. Even if you don't need convincing about the scientific consensus about the age of the Earth, or you don't need uh ammunition for arguments with people who do hold onto a some sort of a h a young Earth view. Uh, there's gonna be a lot of fun in this episode regardless. Robert, I say, we should meet a scientist named Claire c. Patterson, who I will hereafter call the Lord of Lead. Lord of lad does sound a lot more metal, I will say, well,

Claire Claire was a Lord of lad He. Claire Cameron Patterson lived nineteen twenty two to nineteen and he was a geochemist on the faculty at cal Tech and a

member of the National Academy of Sciences. According to his New York Times A Bitch Worry by William Dick, he had something of a reputation as sort of a rebel and an outlier in his field, and Barclay cam who was provost at Caltech in the nineteen eighties, once said that Patterson's thinking and imagination were quote so far ahead of the times that he has often gone misunderstood and unappreciated for years until his colleagues finally caught up and

realized he was right. Nothing to inflate your ego like somebody saying everybody will finally realize he's right. And speaking to an article in USA Today, the Caltech geologist John Eisler described him as fearless and said quote wherever the science took him, he would follow. And so Patterson was reportedly sometimes critical of colleagues who he might have referred to as ivory tower scientists. His research was definitely not

confined to arcane academic matters. He got down into the world, into stuff that that had an impact on human life and for one thing, much of Patterson's important, most important work focused on measuring and contrasting levels of lead in the atmosphere at various times in history, and as the Lord of Lead, Patterson, using a variety of methods, demonstrated that people in the twentieth century were taking in these enormous doses of lead contamination in their bodies, uh much

more than their prehistoric ancestors had consumed, and this exposure to lead has extreme consequences on the health of humans and other organisms. Lead gets in you. It effects everything from the brain to the kidneys. Um to quote from his New York Times obituary quote, he sampled snow from the ice caps of Greenland and Antarctica that had fallen hundreds or thousands of years earlier, showing there had been significant increases in lead in the northern Hemisphere when the

Greeks and Romans smelted lead in antiquity. He discovered that millions of years ago, the amount of lead stored in microscopic plant and animal life or plankton in ocean sediments was only one tenth to one on the amount now flowing into the oceans from the continents. And so Patterson's research helped form the basis of the case for the Clean Air Act of nineteen seventy and the elimination of leaded gasoline, which was the biggest single cause of lead

pollution in the environment at the time. All right, well, this is all, this is all well and good. I mean, this is great. Uh, but where does this where does he come into our discussion of the age of the Earth. Well, Patterson was also the first person to make an accurate estimate of the age of the Earth and the Solar System, which he published in the nineteen fifties based on the

accumulating body of knowledge about radioactive decay. Now, if you remember in the previous episode, one of the types of radiometric dating we talked about was uranium lead dating, and so that studies the decay of a radioactive isotope of uranium into lead over millions of years, and so specifically, in Patterson's case, the key was to look at the Solar system at law to find out how old the

Earth was. Since the evidence indicated that everything in the Solar System was formed around the same time, Patterson and others realized they could study the decay of uranium and thorium into daughter isotopes of lead in meteorites to determine the age of the Solar System objects, including the Earth, and so in the nineteen fifties, I think the late forties and early late forties and the fifties, Patterson used

mass spectrometry to study Earth based zircons. Those are these little crystals I talked about in the previous episode that are usually formed with zirconium atoms in them, but sometimes get radioactive uranium atoms lodged into them, and these the decay of these radioactive uranium atoms inside the zircon crystals

can be used to date the crystals. So he was studying Earth based zircons and uranium lead decay and meteorite material and ultimately Patterson was able to pin the date of the solar systems accretion including the Earth to about four point five billion years, which is still basically the accurate figure. And I love this link between his work on like environmental contaminants and and lead in human life, uh to to studying the very origin of the Earth.

That's that's some of the best stuff in science. When when knowledge gets applied in such different ways like that, it really gets my gears going right at the human level and right at the essentially the god level. So earlier I mentioned the quote from John Eiler talking to USA Today, UH and Eiler makes this case pretty well. He says, quote Patterson is a pretty clear example of the link between basic science that seems unrelated to everyday life, the age of the Earth, and science that makes a

crucial difference every moment in our everyday lives. There really isn't a difference between the skills the methods and the thinking that led him to both discoveries. And that's the story of science. And I love that quote because I feel like that's sort of the case we're trying to make in these episodes, right that there's sort of a coherent scientific approach to looking at the world around you.

And in order to reject the age of the Earth and say that the Earth is just a few thousand years old, you're not just arguing with a particular method of radiometric dating, as we will continue to explore throughout the rest of this episode, it's essentially a rebuke of the entire scientific way of looking at the world. Yeah, it would really force you to throw the trigonometry baby

into the ocean, and and you shouldn't have to do that. Um. So, there are a lot of difficulties Patterson had in his work, so he had to develop extremely stringent experimental procedures in order to get accurate results. That the Time's obituary talks about this. I've read about this elsewhere too, that he found that lead contamination was just everywhere. So scientific labs are full of lead contaminants because of all all kinds of lead pollution. And if you're trying to measure minute

ratios of lead isotopes inside a hunk of meteorite. You don't want to be taminating it with lead from I don't know, the car exhaust he walk through on the way to the lab, and all other kinds of ambient

lead that are currently poisoning your body. So he established clean room procedures, including like washing your hands and distilled water and putting on all the you know, all the what are the when people go and work on the chips in the laboratories, Those suits and all of this should help us notice that radiometric dating has all kinds of important caveats, Like pretty much all types of chemical measurement. It can be subject to sample contamination, to equipment malfunction,

to user error, and so forth. And this is why it's really important to corroborate any radiometrically generated date with multiple tests and if possible, with multiple methods. Also, when possible, I think it's better to think about radiometric dating instead of giving us a date, giving us sort of confidence

ratings for different ranges of dates. So, just as an example, a radiometric test or series of tests might tell us that we're sure that the thing is between four and five billion years old, and seventy percent sure that it's between four point five and five points or four point six billion years old, and that kind of thing, right, Yeah, I mean there is there is a certain amount of uncertainty baked into the process, right, But it will tell

you bigger ranges with greater certainty. But what about rocks from the Earth itself? This can be more difficult since the Earth is just frequently eating and barfing up its own crust. It's part of how Earth is. Yeah, it's it's it's dynamic. Yeah uh, and this this can be more difficult. So rocks from billions of years ago often tend to disappear into the bowels of the Earth. They get gobbled up in one way or another, they get subducted or something like that. But sometimes we can find them.

And it's pretty common to read about discoveries of increasingly ancient rocks found on Earth. Just I was looking at a few articles from recent years. One is that um rocks from the Acosta Knife in the Northwest territories of Canada. And that's nice g N E I S S. That's a geological term, not not like, oh, nice um that those have been dated to more than four billion years old. In September two thousand eight, there was a National Science

Foundation press release. I was reading about a piece of Canadian bedrock from the and I'm sorry if I mispronounced this, the Neuvo Agatuck Greenstone Belt, which was dated to between three point eight and four point to eight billion years old. And then also there is a zircon from the jack Hills of Western Australia that's been dated to over four billion years I think about four point four billion years old.

So here and there we find little bits of the surface of the Earth that seemed to go almost all the way back to the beginning and certainly back before say that's six thousand year point. Yeah, I mean they're they're not just quibbling with the six thousand year point. They're saying it is so many orders of magnitude off. As we said that, they just of confidence intervals. They

don't tell you an exact date. So you know, you could quibble here or there with calibrating the correct date of these rocks, but they're not going to calibrate orders of magnitude down. It just comes back to what I said in the last episode about the difference between the scale of human history and the scale of geologic history, religion and myth with with a with some notable exceptions tend to take place within human history because it is

a product of human understanding. That's a good point. Our our minds are just not made to contemplate time scales like this. It's not I would argue, actually, it's not just theological beliefs that drive people to want to imagine a younger Earth. I think. I mean, it's also like, if you want to wrap your brain around the history of the Earth, you're not going to be able to do it with a four point five billion year old Earth.

You're not really picturing that time. You're just sort of condensing it into a representation of a timeline you can kind of picture, right, I mean they I mean, how

do you put that into a perspective of generations? Right, and and and so and so begot so and so, you know, I mean it doesn't work right, I mean, And I mean and I'm not just you know, harping on you know, books of the Bible or anything here, but just the human perspective, the human shape of things, Like we just have a tendency to understand those better, to understand those stories better. Again, the the appeal of storytelling versus the kind of data that is involved in

in rigorous scientific understanding. Yeah, and I mean we are always vulnerable to this. Stories are more compelling. Stories are more compelling than data. They shouldn't be. I mean, the data are actually more reliable. But what are people going to remember better a story? What's going to connect better with people emotionally is a story. Even even people who try to be scientifically minded are highly vulnerable to stories. I think about the most if effective science communication books

try to be story based. Like in in our last episode, you know, there was a point where we had to talk about radioisotopes and stuff like that in order to explain how how radioactive decay works. But talking about how radioisotopes decay is not as compelling as like telling the story of the Lord of Lead anyway, I mean to derail the conversation. I can I can talk all day about you know, science and religion and where and where and when they can line up and and um and

and support each other. Really, you mean like we need to create new religious narratives that that that help people confirm scientific knowledge, or I mean part of it is realizing what kind of answers religion can provide versus what kind of answers uh science can provide. Um. It's been pointed out, for instance, that uh, you can take the question why and they're they're essentially two different versions of why.

There's a causal why, and there's a teleological why. There's the why like why is this, Why did this happen? What is the thing uh that preceded it? What was the process physical chain of events that caused it? Right? And then on the other hand that the telological why is for what reason is this as it is? For what reason? Am I? What I am? And so um I mean, broadly speaking, you can say that religion can

provide the teleological and science provides the causal Um. Religion is very good at providing a sense of narrative, as we were just talking about narratives and stories, a sense of narrative or story that that makes sense of things. But again, I don't mean to derail the conversation. I could talk about that all day. Well, yeah, but I guess I guess we've got to get back to the idea of what we're setting out to talk about we

have a lot of impersonal geology to unpack here. No, we'll try to make it as personal it's and it's exciting stuff. It is dynamic. We're talking about the stuff of of you know, earthquakes and volcanoes here. So so you might be thinking, you you've heard us talk about radio isotope decay, about radiometric dating, about Claire Patterson, and you think, yeah, but how do we know these methods of dating the Earth actually work? Like are we just taking some scientist's word for it? Like what if a

scientist is lying and saying it works but it doesn't. Really, that's not really a plausible critique because like the yes, but what if it wasn't response? I can explain why it's not a plausible critique. And one strong line of evidence is when multiple independent tests with different methods produce results that are in agreement with each other. The simple version of this is, um, how do you know when eyewitness testimony is good? Right? You know? And eyewitness can

get all kinds of stuff wrong. We explore that on the podcast all the time. So say you you know, you arrive at the scene of a crime, you pull up at the video store, and uh, and somebody has just sped away stealing a priceless copy of Highlander. To the quickening, I mean, especially if you're an orthodox Highlander tooth than as except no director's cut, except no renegade cut unacceptable. You've got to get the original version on VHS that's got all the bad scenes. It's the only

way to feel the quickening. But yeah, so you get on the scene a copy of Highlander two has been stolen, and you want to find out who did it. Fortunately,

there are several people standing around it just happened. So you separate all the people and they can't talk to each other, and you interview them one at a time, And the first witness tells you that it was a man wearing a kilt with a bagpipe on his back and a katana sword hanging from his hip, and he ran into the store and he yelled, there can be

only one and he grabbed the tape and he ran out. Now, as we've said, I witness testimony can be very faulty sometimes people they are all kinds of issues with perception and memory. But if you talk to the second witness

and they independently mentioned all the same stuff. They kill, the bagpipe, the katana, and you talk to a third witness they mentioned all the same stuff again, you really have to think, Okay, if they haven't talked to each other and they're all telling me all the same details, what are the odds that three people are getting all this different stuff wrong in the same way. And that's

how corroboration of dating methods works. It's like having a second witness or a third witness on the scene who independently tells you they saw the same thing that the other witnesses did. It's possible they could be all they could all be wrong, But if they haven't talked to each other, why would they all be wrong the same way? All right, Well, on that note, let's take a quick break and we come back. We'll jump right back into

the discussion. Thank alright, we're back, alright. So I wanted to talk about a really great article that I read on this subject about how to corroborate the dating methods that are used in h in radiometric dating and establishing the Age of the Earth, and the articles by the American geologist Brent Dalrymple, who worked for the U S Geological Survey and was a professor at Oregon State University, and he published a book on the Age of the

Earth called The Age of the Earth with Stanford University Press in And so he's got this really excellent article hosted on the National Center for Science Education website and which he picks out four different examples, basically four studies that he had personal experience with in which radiometric date ranges were corroborated by multiple kinds of tests, multiple labs

that showed them to be accurate. Um, So it's again not just that we do one test and assume it's the answer is right, but we test multiple samples, multiple methods, multiple labs and get agreement on the results. So, first example, he gives the Manson meteorite impact site and the Pierre Shale the Manson the Manson meteorite. There's got to be a metal band for this one. And also this has nothing to do with Charlie though right as I don't know,

uh it's Manson Iowa. Does Manson Iowa have anything to do with Charlie does? But it's still hard to shake that possible connection. Okay, well, this is a look at argon argon dating, argne orgon dating is a method that's a derivative of the classic potassium argone dating method, but it's now considered a more accurate version of that decay series test. It helps detect errors protect against an accurate results.

And so during the Cretaceous period, we know that there was a big old meteorite the hit part of what is now Iowa in the United States, near Manson, Iowa and uh. The hot impact melted a bunch of feldspar crystals and the granite rockley are near the surface of the time, and when these crystals are melted, their internal radiometric clocks get reset to zero. So if you use argon argon dating to date these melted crystals, you'll get

an age of about seventy four point one million years. However, when the Manson media write hit, it also created what's known as shocked quartz crystals that exploded up into the air. They came down west of the impact and what's what was then an inland see and now you can find the shocked quarts from this impact in a thing in layer that's known as the Crow Creek member, and that's been within this larger sedimentary rock formation called the Pierre Shale.

The Pierre Shale also contains marine fossils like ammonites and ash from volcanic eruptions. These ash beds from the volcanic eruptions, they've also got minerals in them like sanity and feldspar and biotite which have been independently dated using the argon argon method. And so there there's a study that that the Dalrymple sites from Isaac Koban Dalrymple and Obradovich in n in the Geological Society of America bulletin. And what

did they find. So they found more than a half dozen dates of biotite and sanitine surrounding the Crow Creek member where the where the evidence of this impact near Manson was and interesting, so remember that the melted feldspar crystals from the impact were dated to seventy four point one million years old. The minerals found right below the impact layer, so that means they should be a little bit older, came up with dates about seventy four to

seventy five million years old. The minerals found right above the impact layer, which should be a little bit younger, got results indicating they were about seventy three to seventy four million years old. So these dates for each mineral we're all corroborated with multiple sample tests to make sure they all agreed, and they tested with different kinds of minerals,

and the results agreed. The biggest discrepancy and results came from comparing the biotite and the sanity and from the layer right below the impact, but this was less than a one percent difference. Also, the dates generated by the argon argne tests generally agree with how old these layers of rock are supposed to be and with the kinds

of fossils we'd expect to find in them. So if the dating method is not reliable, why do so many different tests of different minerals from different time periods agree with each other and fit together in the correct plausible geological order. And this is another thing we haven't even talked about much yet, is the the idea of geologic stratification, like that there are layers of deposition of sedimentary that happened over time and volcanic deposits from volcanic eruptions that

you can see going back through time. And you know, there were paleontologists who were looking at fossil layers in rock formations going down this uh stratigraphic column looking at the history of the Earth's surface. Before there was anything like radiometric dating, we didn't have any dates, but they were still saying, here are the ages that came earlier and the ages that came before that, and identifying what

these layers looked like. Yeah, I mean, and if you wanted a really impressive vision of this, I mean, simply look at an image of or or better yet, a visit say the Grand Canyon and uh, and you are just I mean, there's no denying the these these geological layers. I mean, it is a visual presentation of geologic time. I have not seen the Grand Canyon walls up close. What does it look like? Well, I mean up close it looks well, yeah, but I mean just like the

grand scheme of things. And there there's a lot of uh, you know edgrigal educational material at the park as well that really talks about the different layers and what you're looking at and really the time that you're looking into one. In fact, there is a there is a little walk you can do right at the like the major area of like the in Innocence kind of like the high tourist area of the Grand Canyon. There is a walk through time you can take and it like just talks

about the different the different geologic ages. Do you remember what time you were at when a squirrel tried to steal food out of your hand? That was? That was a little further into the king Um I want to say, it was like, what what is it? Angelhead trail one of one of those. Yeah, it's a creepy name. I may have that wrong. I don't have that in my notes,

but yeah, squirrel attack trail. Now, we mentioned earlier that one of the ways that say uh Patterson, the Lord of Lead identified the age of the Earth was by identifying the ages of meteorites that we think were formed around the same time. And meteorites are often subject to radiometric dating because it can help us understand the origins

of the Solar system. So, given our current best model of how the Solar system formed out of a solar nebula and accretion disc it seems likely that the oldest meteorites are probably pretty close to the same age as the Earth itself. And Dalrymple writes about different tests on

the ages of meteorites. So he talks about how the earliest types of meteorites are called chondrites because they contain these tiny spheres of crystals known as con d rules and meteorites are often radiometrically dated, and when their mineral composition allows it, they're often dated by more than one

different type of radioisotope de K series test. So a few examples heat sites are the i end A meteorite which got argon argon lead, lead, and both methods agreed the date is about four point five something billion years old, the Warina meteorite, which got argon argon spectrum rubidium strontium is acron both methods agreeing with an age of a little less than four point five billion years, and the Saint Severin meteorite, which got argon ar gone rubidium, strontium's

samariam neodymium, lead lead, all agreeing with roughly four point five billion years, give or take a hundred million years or so. So lots of different labs, different methods, using different radioactive clocks, all converging on answers within about a one percent difference of each other. So again it all adds up. You don't just have one eye witness, you have multiple eyewitnesses that are independently telling you more or less the same thing, all telling you about the kilt,

all telling you the Katana. Another example, he cites the Katie tech tites, So we know about the the Oh my god, I can never say this right. The cheek shalub Um. I've whenever I've had to do it for a video or something, I've had to look it up. I'm gonna say cheek shalub and and hope it's right. So the cheek shalhoub impact, Robert, we know. Around night scientists discovered there's this huge crater spanning the code to the Yucatan Peninsula in Mexico. Its center is near a

village or a town known as cheek Schlub. And this is the site of the cheek Schalub impact event, which in the village was not there, no occurred to certainly not no. This happened about sixty six million years ago. Uh. And it's the the event which many paleontologists point to as the main factor or one of the main factors, in the last great extinction before the present, the Cretaceous Paleogene extinction, also known as the KPg extinction or the

kt extinction, which killed off the non avian dinosaurs. Of course, we've still got birds, which are dinosaurs, the chi but not just them. It killed something like seventy five percent of the plant and animal species on Earth and basically killed all the large animals. Was a real reboot, you might say. Yeah. The object itself was about ten kilometers in diameter. And when an object like that hits the earth,

it it creates a ruckus. It throws up tons of geologically weird material into the atmosphere, which comes down all over the place and becomes an easily recognizable layer within the geological strata that we were just talking about. So you can pretty easily look at geological layers and see where this impact happened once you know what to look for, because the sedimentary rocks below it contain Cretaceous fossils and dinosaurs and stuff, and the rocks above it do not.

But also because there's a thin layer of these weird impact byproducts, things like shocked quartz irridium, which is found in asteroids and these things called tech tits, So dinosaurs and then a layer of weird stuff and then a layer of no dinosaurs. Uh, it tells a story, right, And so tech tits are tech tits are sacred crystal shop stuff. If you look these up, you know, you think, you look at this and this is what will cure

your fear of the dark or something. Really, they are these black glassy blobs that are found only in the most unusual of circumstance. So when you've got a high energy impact that occurs and instantaneously melts rock, you'll get these tech tights and at the cheek schloub impact, these little glass fules, these tech tits got ejected up into the atmosphere and distributed all over the place, and they

can be found in Haiti and Mexico. And so tech tights from this layer corresponding to the KPg impact found in modern day Haiti have been dated radiometrically by different

labs at different times different methods. UH scientists from the U S Geological Survey, from Berkeley, from Stanford, from places in Canada and France all separately measured dates for these glassy little impact blobs and then for volcanic ash beds that are just a few centimeters above the KPg impact layer using different methods like are gone ar gone potassium argone, rubidium strontium and uranium lead, and all the results fell

within sixty four to sixty six million years ago. So yet again everybody's doing different tests, different stuff, and they're all getting the same answers. One last example that Dalrymple gives is dating something that we actually have historical records of. We know when it happened because humans were alive and they were there to see it happen and make records of it. And this would be the Mount Vesuvious eruption. Ah, yes,

the very explosive moment, very dramatic moment. Uh there. So this, the Mount Vesuvious eruption, happened on auguste and this was in the first century CE, and we actually have a first hand description of it from Plenty of the younger writing in a letter to Cornelius Tacitus, describing what happened. Just to read a short part of the letter with a couple of abridgements. Plenty rights, the sea seemed to roll back upon itself and to be driven from its

banks by the convulsive motion of the earth. It is certain at least the shore was considerably enlarged, and several sea animals were left upon it. On the other side. A black and dreadful cloud broken with rapid zigzag flashes, revealed behind it variously shaped masses of flame. These last were like sheet lightning, but much larger. Soon afterwards, the cloud began to descend and cover the sea it had already surrounded and concealed the island of Capri and the

promontory of Missenum. The ashes now began to fall upon us, though in no great quantity. I looked back. A dark a dense, dark mist seemed to be following us, spreading itself over the country like a cloud. And he goes on to talk about what all the people were doing as they were fleeing. It's great, we should maybe revisit the eruption of a Suko time. Yeah, let us know if you would like to hear an episode devoted to this, because we could have we could have a lot of

fun with it. I mean, tragic and destructive and apocalyptic as it is, but it's it's a great description that

that planny has here. But anyway, so how does this come into corroborating radiometric gates, Well, this is a historical event that can be used to calibrate radiometric meth It's not every method is appropriate for this kind of time scale, but scientists said the Berkeley Geochronology Center in the University of Naples, they wanted to see how well are Gone are Gone dating could do here, so they got twelve samples of sanitine from the ash flows from the vesuvious eruption,

and Dalrymple says that the dating method generated an estimate of about one thousand, nine hundred and twenty five years. This was in and the actual age of the time was one thousand, nine hundred and eighteen years, so about seven years off. And that's amazingly close for especially for young rock like this, which that which was assumed to be more difficult to date accurately. Absolutely, because again we're

zeroing in on seventy nine. Yeah. So one of the things I wanted to mention is that in one of the emails we got, like the the email from c J I think that we read at the beginning of the first episode, c J mentioned maybe like looking at creationist critiques of radiometric dating methods, and I don't think it really makes sense to try to focus on any one of these because they are myriad, So like it just seems like, there are thousands of them as many

as there are creationists books and pamphlets, so obviously we don't have time to address them all, and none stand out is particularly good when I've looked at them before.

They take the form of One of the things we talked about in the last episode is like pointing out ways that radiometric dating could be missupplied or could be flawed, which scientists know about and they take steps to correct, including corroborating with multiple methods, um or using using you know, careful types of calibration to eliminate errors and to increase

accuracy in their tests. Some of it's just pointing out ways that measurements could go wrong, which scientists already know about and take into account, and using that as an excuse to just throw the whole method out. Yeah, it's kind of like saying, you know, there are lots of ways that watches can be wrong, therefore your watch you

can't trust what time it says. Other methods that I think are common are like isolating examples of when a radiometric dating method has generated a incorrect result, and these are often highlighted in order to show ways that you can make the tests more accurate and eliminate errors. So like scientists are aware of the fact that it's possible to generate an incorrect result with the radiometric test, part of what they do is learning the circumstances in which

these errors arise and trying to avoid them. And then others are just theoretical critiques, which I think are simply misunderstandings of the underlying science. But I it has never seemed very productive to me to just play whack a mole with the various uh, you know, misunderstandings and critiques as they arise. Yeah, I agree, I don't think that's

a constructive exercise at all. But what we wanted to finish on today was to talk about ways in which the age of the Earth is not just confirmed by direct measurement methods that say, look at meteorites or look at rocks on the Earth and say this is how old it is, and then and then as if the

age of the Earth rests entirely on those results. The fact that the Earth is old, that it is older than a few thousand years is something that is so thoroughly incorporated in pretty much every branch of science that if the Earth were only a few thousand years old, we would have to throw out essentially all of science.

It touches everything. And so for the rest of the today's episode, we just wanted to explore other ways of looking at time and and the history of the Earth and the universe, the additional examples of of of just how interconnected all of this is, and additional examples of things you would have to throw out if you were to adhere to say, a six thousand year old model for the Earth. Do you want to take a quick break and then deal with this when we come back,

Let's do it. Thank alright, we're back. Okay, So we're gonna talk about ways of corroborating the fact that the Earth is old, which essentially becomes everything else in science, right and we're gonna jump around a little bit in here. But you know, we can do some geological science, uh some some some some, some astronomy as well. Um, some of these examples we're gonna spend just a few sentences on. Others we're gonna go into a little more depth right now.

Not every method will help give us an estimate of the exact age of the Earth, like radiometric dating MTE, but there are at least dozens of other lines of evidence that we can talk about that the Earth, the solar system in the universe must be older than X time, with X always being much longer than the proponents of a several thousand year old Earth would would grant. Yeah, like evidence, you're gonna we're gonna see this over and over again, Like here's evidence of something that it only

makes sense if it's eight thousand years old. It only makes sense if it's ten thousand years old. So let's look at some other stuff about what's in the Earth, like geochemistry and geology. Yeah, if we enter into the realm of petroleum geology, um uh, we have we know that biomass requires far are more than six thousand years to become cold or petroleum like hundreds of thousands to millions of years. Uh, and then it takes roughly twenty five million years for it to reach the surface in

a natural oil seep. Right, oil coal doesn't make sense in a young earth, right, So yeah, if you're gonna have that six thousand year old Earth, you don't get to use any of the petroleum. So they're also if you just look at the formations of individual like rocks and crystals and stuff. They're they're slow forming crystals. Yeah,

take the take the diamond for instance. By radioactively dating minerals inside diamonds, because you can't date the diamond itself, we can tell that most diamonds probably formed in the Earth's first two billion years or so, and even younger diamonds are still tens of hundreds of millions of years old. Uh. This according to diamond expert Jeffrey Post, who was quoted in a Smithsonian magazine piece. Wait, tens of hundreds of millions, wouldn't that be billions? He has attributed as saying, tens

of hundreds of millions of years old. I I you run into this occasionally, people who are generally, you know, experts in the field that are hesitant to use the word billions. I feel like I've seen that too. That is weird. It's like they don't like it. It doesn't sound right billions. I feel like there's probably a good reason for that, but still like the numbers are still the same, so there's nothing yet inaccurate in in this statement. They all have somebody they don't like named bill that

they don't want an order of magnitude named after him. Hey, here's another one. When you look at the earth caves, Now, there are quick forming caves, for example, like lava tubes. Lava tubes are wonderful, fascinating thing we could look at some time. But we know that there are other kinds of caves, and we know what these other kinds of caves look like that take a very long time to form, and that formations within them take a very long time to to assume the shape we see them in now. Yeah,

stalactites and stalagmites are great examples to look at. You know, we're talking about calcite stone formations created by the gradual dripping of water in cave environments, and the process is often still taking place right before our eyes, and the resulting formations are often quite old. So the exact rate of stalactite and stalagmite formation varies. Of course. Limestone stalactites

and stalag mights generally take thousands of years. Those in lava tubes, as you mentioned, those may take hours to form. You know. Um, but like let's let's imagine a limestone cave or you know, and again some kind of sedimentary cave. What do the stalactites and stalagmites look like they're I mean,

there's some wonderful examples of just enormous stalactites stalagmites. If you've ever visited a cave, uh, you know, I'm thinking of some of like the more touristic caves, especially in the United States, like say Mammoth Cave, h Cumberland Caverns, that sort of thing. Then you've you've probably seen some of these examples. They're enormous. And again it's like looking at the Grand Canyon. You're looking at time right there

in front of you. UM. Just a few examples that I picked out here that that I think speak to this. For instance, in two thousand seventeen, a stalac might growing quote unquote out of the hip bone of a prehistoric human skeleton helped date a Yucatan Peninsula skeleton to at least thirteen thousand years old. So, in other words, they were looking at these bones, and they were looking at this, uh, this this stalaga mte that seemed to be growing up out of it, and uh and this was the the

age range they were dealing with. Another example, in France's Brunoquil Cave, we have evidence of Neanderthals having broken off four hundred stalagmites to a range into two rings, and supporting evidence, including carbon dating of a burnt bare bone from the location, indicate that the rings were roughly forty seven thousand, six hundred years old, older than any cave painting.

In Spain's Moraine Cave, for instance, you'll find a stalagmite that's estimated to be uh nine thousand and fifty five, give or take nine fifteen years old. I want to point out that you you also do see examples, small examples of stalagmites forming in concrete structures, and this is something that you occasionally see pointed out on some of these websites saying how can you believe in the age of stalagmites, because look, if you go to the parking deck,

there's a little stalagmite. They're clearly the earth is only as old as this, uh this parking deck. Well, here's how what's going on. Concrete derives. Stalagmites are sometimes observed in concrete structures, and these again are quite small, and they form more rapidly than natural cave structures. Uh. There by no means a gotcha point for discreting geologic science. I've never seen a parking garage sale. What you need

to get into. They're around. If you hang out in some of the subterranean concrete zones around our own city of Atlanta, you will encounter them. Robert, what's your favorite parking garage to hang out in? Oh? I don't know. I do actually enjoy like a significant, a creepy parking garage environment. It feels act like the morlocks are going to show up in any moment, right well, I always think of like Escape from New York and kind of

seventies Carpenter, seventies eighties Carpenter. When I when there's a good abandoned parking garage, it's got that kind of that echoe creepiness of the early scenes and Escape from New York. Yeah yeah, um, but but even then you're not going to find any huge stalactites are still like mites now. Um, as far as the age of caves go, um, you get into you know, much deeper time when you're just talking about those, You're not talking about the formations within,

but just the cave systems themselves. Consider Mammoth Cave National Park, UH major tourist attraction as far as caves go. Geologists estimate that the oldest part of the sprawling cave complex formed ten million years ago. And if you're in Australia and you happen to visit gen Olan caves, I believe I'm saying that that ride perhaps it's gen Olan. I'm sure our our Awestlee listeners will correct me on this. Oh I'm still I still can't live it down from

when I said, what did I say Canberra or something? Oh? Yes, I think it's Canberra. Well, anyway, if you visit this particular cave, you will be visiting some caves that are thought to be three forty million years old. And there's a lot more here we can talk about geologically. I mean, you can look at the formation of mountains, rock layering through sedimentation, which we've touched on already. Uh, there's a reason we speak of geologic time, and the Earth is

written in geologic time. Young Earth views enforced human time, uh, or the timeline of human civilization upon a thing that dwarfs our brief period of cultural as sentence. You know, one way you can actually make geologic time feel a little bit more intuitive that you can try to internalize it is visiting fossil beds. I know that was a feeling.

I One of the coolest things I've ever gotten to do I've talked about on the show before, was visiting the Trialobyte beds Burgess Shale National Park in Canada, which is Cambrian fossils trial bites everywhere Anomala carreras fossils, and you're just walking around on them, but you get to see the massive vertical face of the shale that's made by sedimentary deposition over millions, billions of years that's broken off into all these flakes that you're walking around, and

you just realize, like the depth of time required to lay down this sediment, fossilize all these creatures, and then drive it up, make it into the side of a mountain near the top of the mountain, and then break it all off as it erodes into these beds along the mountain side. It's humbling. It's a humbling amount of time that you that is required to see this happen.

And it's all extinct organisms too. Yeah. Now, and now this is great though that we brought up the fossils here, because the next area I want to touch on has to do with with the sea floor spreading and continental drift, and indeed the distribution of fossils ecs. This is a really interesting one. Yeah, and I feel it's it's particularly interesting because I feel, on one hand, most of us are at least dimly aware that the continents are not in the in the position they were they were always in.

I mean, if nothing else has been pointed out to you on a world map, how Africa and South America wants spooned, or perhaps you've seen an epic animation detailing the breaking up of Pangaea and the end of the super Ocean. But wait a minute, what if I were to say, well, I think it's just a coincidence that South America has shaped like it used to fit into

the underside of the part of Africa. Well, this is this was is a valid um um critique of of just this argument on on the face of it, because it's really only been fairly recently that we've we've known about this, and it's been accepted before roughly a hundred years ago. We just assumed that the continents were basically in the same position that they've always been in. Uh. The evidence that led to the revelation, uh here was

the distribution of fossil speed seas. And that's where German scientists Alfred uh Wegner comes in, who lived eighteen eighty through nineteen thirty, and indeed he came up against the same criticism it's just a coincidence, yeah, saying well, they're saying, well, that's interesting, but I don't know if that's really uh that it's really solid evidence for what you're talking about. Because he he noted the presence of similar plan and animal fossils in South America and Africa. How did they

get there? Well, that that's that's what he was he was trying to answer. He noted the similar geologic formations on both continents, and uh and also the whole spooning thing. He said, how how else, though, could we possibly have these these examples on these separate continents unless they were once part of the same land mass. Okay, so South America and Africa look like they used to fit together. Weirdly enough, we find that the same species used to

sort of cross boundaries between them. That's kind of odd. But how could they have actually been split apart? That doesn't make any sense. And that's the thing they said, Well, we need we need a more robust idea of how this could possibly work. Otherwise we're just not going to buy it. So it wasn't until the fifties and sixties that marine geologists identified the ocean ridges that wound about the Earth as well as the mid ocean ridges formed by sea floor volcanoes. And this was backed up by

magnetometer data as well. So this is the basic seafloor spreading hypothesis proposed by petrologist Harry Hess and oceanographer Robert Deats. In sixty five, geophysicist J. Tuzo Wilson used continental drift and seafloor spreading to propose the theory of plate tectonics. This theory is now universally accepted by geoscientists. Yeah, that's one of those great scientific theory success stories. We could tell that story sometime, because that was something that was

ridiculed at first. The idea that the continents are moving around and it is it is a crazy mind blowing thing to try and uh and think about, because it is it just is existing on a time scale far beyond uh we've evolved to really comprehend. But it is amazing how an animation like I described earlier can give

it life and and make sense of it for you. Now, let's try to imagine a model where South America and Africa split up and they were split apart by a spreading ocean ridge, and that happened just a few thousand years ago. That is a that is a messed up world. Yeah, it it doesn't hold up. Yeah, it simply doesn't work with a model of Earth that's less than two million years old. You cannot have a younger Earth and bring

the geosciences with you. You have to cast out all of the twentieth centuries evidence and clinging to essentially a pre vaga or understanding of the position of the continents. And of course I know you'll say, keep your hands off the dinosaur, right, Yeah, you don't get off the dinosaurs either, And so no dinosaurs, no paleo art, stick to uh to draw in all the other cool stuff

in those ancient texts. Now another now, just to leave we have an exhausted everything on the Earth that points to an old, old Earth, right because essentially the evidence here is all geoscience. Yeah, but we could also look beyond Earth. We can look to evidence from astronomy and astrophysics. And what you find when you look to astronomy and astrophysics is that everything in the universe agrees with a long billions of years timeline of the universe. That's right.

And again part of the issue here is that world views that call for an absurdly young Earth are also calling for an absurdly young cosmos. And if you believe in a six thousand year old Earth, yeah, you don't get to keep modern astronomy. I mean, certainly we can speak to the probable time scale for the formation of our own solar system, but we also have to think

to the stars. Now, nobody I think is going to be disputing the speed of light in a vacuum, right, But what does the speed of light and a vacuum tell us about the universe? We're looking at what gives you an idea of of not only the size of everything, but the but the vast time scale involved as well. So, for instance, with the naked human eye, uh, an individual on Earth can glimpse the light from the Andromeda galaxy, which will one day be the same as our galaxy.

We're we're headed together, yeah, and again talking in distant time here, the big meet up yeah, but but currently the Andromeda galaxy that's two point six or I've also seen two point five four million light years from Earth and a light year will remind you is the distance traveled by a beam of light or or the photons technically in the space of a given year. So the light you see when you look to Andromeda, Uh, that left our sister galaxy two point six million years ago.

So if we're to contend with this fact alone, the universe would have to at least be that old for light to have reached us at all. Uh, you know, given a magical finger snap creation of the cosmos. The thing about playing with with magic is that you can just make up additional Bologny answers of course and say, well, when the universe was created beams beams of light or photons created in transit to the destination. Well, if you're going to say stuff like that, I mean, you know,

no no offense, you know, go in peace. But that you've just essentially surrendered having a conversation based on evidence. You've just said like, okay, well then I'm not interested in talking about what we can know based on what we observe. I just assume that magic is involved, and then in that case, why are we having the conversation? Right?

But but I think it's fair to say that if you had a six thousand year old Earth within a six thousand year old cosmos, then then you would only be able to see things, You only be reachable by light within a six thousand light year radius. So there would be a six thousand light year visible universe. And uh, and we have a vaster visible universe than that, right, I mean, I wonder what if you are trying to imagine a younger universe and do astronomy, what do you

make of the cosmic microwave background? What is it? What is that to you? Because of that, that's of course getting back to the very beginning. Um. But then there's other evidence as well. There there have been gamma ray bursts visible to the naked eye, UH that are further and older than, uh than what we were talking about with Andromeda and two thousand eight, astronomers clocked the stellar explosion RB zero eight zero three one nine B at

seven point five billion light years away. And incidentally, this is one of five stellar explosions recorded on the day of author C. Clark's death on March nineteenth two thousand eight. Do you think he made it happen? Now? I think he would be mad if we thought that he did. Uh Hey, And if you drag the Hubble telescope into the fray, our limit takes takes us up to like

what thirteen point four billion light years? You know again, that's light that that is that that can be at least technologically observed from our little corner of the cosmos. That's the radius of our view, not the diameter correct. So yeah, it's like we touched on before the astronomy. To to stare at the stars is to gaze into the past, a deep past, a past that dwarfs the entirety of human history, the entirety of of our our various stories about how the universe works and where it

came from. But I mean, you can even extrapolate that back to the circumstance, the material circumstances of our own solar system. So it only takes light from our sun, you know, a number of minutes to reach us. But you can look at our sun and know that the universe is old. So one of the things is that the quality of our astronomical observation tools stellar astrophysics and computer modeling capabilities. Now let us know a lot about

stars and how they form. And we know they form from clouds of dust and gas called nebulae that fall into gravitational collapse. They begin to coalesce and the heat up into what's known as a protostar. And we also know that this process of gas collapse takes a very long time. For instance, our Sun is a star that is obviously no longer a collapsing cloud of gas and dust. It's an adult star. It's a star that's performing fusion of hydrogen into helium. It's in its adult mature phase.

And the time it takes for a star the size of our Sun to go from the beginning of collapse of the nebula into its adult phase. I was looking at some NASA materials on this that's somewhere around fifty million years. We can model that with the astrophysics knowledge we have, if the universe were not at least fifty million years old, our son could not be an adult star. But it gets worse because we also know that our son cannot be a first generation star. Our solar system

is full of not just hydrogen. You know that, like the most abundant gas in the universe. It's full of heavy elements like iron. Where did all that come from? That's not primordial material. Heavy elements like that are forged in the deaths of other stars. So actually we know that not only did you know is our is our star an adult that had to grow up. Also, it

can't have been a for generation star. It had to come from a previous generation of dead stars to create these heavy elements that make up things like the planets. And I have to say, you know, if this means that if if you if you cast aside this understanding, you can't have gold. And if you can't have gold,

you can't have the Ark of the Covenant. And I and I have to say, like, how much cooler is the story of the Ark of the Covenant if if you factor in the fact that the Ark of the Covenant is made of this metal forged in the heart of a dying star. Oh, I think that's that's far more that that's far cooler, that's far more amazing. It is a radio for talking to God. But we can also I mean we talked about meteorites, so you can look at other objects in the Solar system and they

also turn out to be quite old. They line up with our model of how old our solar system is. What about the Moon, Yeah, I mean there are there are a few different models for how the Moon came to be. The most popular scientific hypothesis is the giant

impact or hypothesis. In this hypothesis, a Mars sized object hit the young, cooling Earth at an angle and this would have been This would have occurred about four point forty five billion years ago, and the impact or itself melted into the Earth, but debris from the impact went up and event eventually formed into the Moon. And this, according to the hypothesis, is why moon rocks are similar in composition to Earth's mantle and why the Moon has

no iron core. Yeah, this makes sense. The the Moon looks like something that came off the Earth, but not from the core of the Earth. Right, It's an accretion of terrestrial shrapnel according to this hypothesis. You know, another totally different way of looking deep into the past that I've talked about before. I remember one time I did a guest episode of Tech Stuff with Jonathan Strickland about

this is about ice core drilling. Oh yeah, yeah, So one way scientists study the atmosphere of the Earth long ago, like if you're trying to figure out what atmospheric composition

was a long time ago. One way you can do this as you can drill down into ice sheets or into glaciers to pull up these cylinder shaped vertical columns of ice, and they will contain information interesting information like bubbles of gas trapped in ice layers from the distant past, or what the snow looked like as it was deposited

each season in the past. And often these cylinder shaped ice cores come from Greenland or Antarctica, places where ice has been accumulating on top of itself for hundreds of thousands of years or more, and ice layers accumulate steadily year after year, giving you a very helpful map of past freezing seasons. And normally you can date this ice uh simply by counting the neatly ordered layers of yearly accumulation,

especially near the top of an ice core. You can do that, though this method does become more difficult the deeper you go, because obviously you've got stuff like compression and stuff happening. So older samples can cross reference multiple dating methods to boost accuracy. Uh. These other methods can be things like correlating deeper layers of ice with known historical geological events like the deposition of volcanic ash or

other geological markers. If you know when a volcano erupted and what that deposition layer looks like, you can see signs of that there. But there are some really old ice cores that we've that we've managed to pull up until last year. I think the oldest known ice core was about eight hundred thousand years old, and that came from a core drilled and Antarctica's dome c which was

dated I believe using radiometric uranium decay. That's getting on down to that Lovecraftian city exactly, yeah, the Mountains of Madness. But in an extremely old ice core was drilled in a patch of what's known as Blue Ice and Alan Hills of East Antarctica. And in fact this was dated

to two point seven million years old. Now, because of the nature of the blue ice patches where old ice formations are driven up from below, it couldn't be dated by like counting the layers, but it was dated by potassium or gone dating to two point seven million with a likely error tolerance. Of something like a hundred thousand years. So even just ice ice is not even rock. I mean, if you think about like ice should be melting and churning up all the time, we can find ice that

goes back hundreds of thousands of years. So again, these are these are not like the only examples we could turn to. We could, it would be an exhaustive list, because virtually all the geosciences uh astronomical understanding, I mean, it all is based on this, and it all ties into this idea um of an old, much older Earth

and a much older cosmos. Yeah, and so of course, as we were talking about a minute ago, a person whose theological beliefs to drive them toward believing in a young Earth can always simply say, well, none of that matters, because I have a supernatural explanation for the way things are. You know, there, it was just made to look that way. And if you believe that, as I've said, I mean that, I think that is the point where you may go in peace. Like you, it is possible you simply will

not be convinced. But notice how much that type of explanation starts to resemble the invisible dragon in Carl Sagan's garage, Right, Like, if a belief is designed so that it can safely ignore all tests and all evidence to the contrary, why would you believe it? Yeah, And again I want to be clear, this is not aimed at religious beliefs in general. People have all kinds of ways of of being religious.

And I'm talking about those specifically that make claims about physical reality and about history that encroach on territory for which we have good evidence about what actually happened. Yeah, areas where we're actually dealing with, um uh, the rejection of science or the twisting and replacement of science with

a pseudoscience that supports a preconceived theological notion. Right. And so I guess maybe one question to end with is we started with these emails we've gotten from listeners asking for help sorting out these claims, and we get these emails else because people live in a world where they're competing claims against about the age of the Earth, and they don't know how to make sense of of the arguments coming from each side. And yeah, I've experienced this too.

There are a bazillion Young Earth creationist arguments out there, and unless you literally devote your entire life to it. You're really not going to have time to investigate all of them for yourself and find out if they're correct. So, I mean, I think a fair question to ask is, how do you know when you can just consider an issue settled? How do you know when you can responsibly just start ignoring arguments that come from a certain perspective?

You know what I mean? Robert? Yeah, yeah, Like, and we talk about it being the bedrock for person for a scientific understanding, but yeah, how can you know it's bed rock that you can build up up and on top of it, right, Because I mean, the scientific mindset, it doesn't say like, okay, now we've got a dogma and you just accept it forever and never question it. You know, you should always be open to evidence to

the contrary. But how do you know when by paying attention to certain kinds of arguments you can be nine point nine sure that you are wasting your time? I mean, it's a great question because so much of the bedrock understanding of the natural world, you know, it's it's based on things that are technically theories. You know that we have theoretical understandings of things, and we have to proceed

based upon those theories. Now, of course, we don't want to give the accidentally give the misimpression that a theory means a thing like is something we should not have good confidence in. No. No, you can have good confidence in a theory. Theory is above a hypothesis. Yeah, exactly. But I guess I'm trying to figure out where do

you draw the line between. So here's one where most I think paleontologists think that the the we were talking about the cheek Schalube impact, right, that that was a major factor in the demise of the dinosaurs, right, But there are some who disagree. And so that seems like an issue where the evidence seems to be or at least the experts are largely on one side of the question, but there's maybe still legitimate controversy. Maybe we could find

out the opposite is true. Maybe that impact was not the main factor in the dewise of the dinosaurs, And I can conceivably see that happening. The Young Earth does not feel that way to me, because it is it's so violates in such a fundamental way everything we know from every field that's you know, that's independently verified by the means of that field on its own. It seems like stuff that goes in the face of an old Earth is guaranteed to fail. Yeah, you're dealing with such

drastically different ideas here. Yeah, again, just drastically different time scales. One matches up with our scientific understanding of the world and the other. As we have just been hammering home here in these two episodes, does not discovering that the Earth is young would be kind of like discovering that electricity not involve electrons. I would just want to just

drive home. Like, if you're out there and you feel like your belief system keeps you from embracing science, um, I would encourage you to to look around and find and see if you can't find a version of your belief system that makes room for science and allows for science, because I can almost guarantee you that it's out there and there there are people out there who can hold on to the beliefs that you cherish and the culture

that you cherish without rejecting science. All right, Well, on that note, we're gonna close this episode out, and we're just gonna remind everybody head on over to Stuff to Blow your mind dot com, because that is our mothership. That is where you will find all of our episodes, you'll find blog posts, you'll find links to our various social media accounts, and you also find a tab for

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