Speaker 1: Welcome to Stuff to Blow your Mind from how Stuffworks
Speaker 1: dot com. Hey, are you welcome to step to Blow
Speaker 1: your Mind. My name is Robert Lamb and I'm Joe McCormick.
Speaker 1: And this is part two of our two part exploration
Speaker 1: of the Age of the Earth. If you have not
Speaker 1: heard part one of this episode, you should go back
Speaker 1: and listen to that first. That's really gonna lay the
Speaker 1: groundwork for everything we're talking about today. In the last episode,
Speaker 1: we talked about why we're addressing this topic even though
Speaker 1: it's a topic that there is not legitimate scientific controversy about.
Speaker 1: There's no real scientific argument about whether the Earth is
Speaker 1: billions of years old or younger. Uh, it is billions
Speaker 1: of years old. But we are addressing it because we've
Speaker 1: we've frequently gotten mail from listeners asking us to help
Speaker 1: them sort out and understand the differences in claims about
Speaker 1: the age of the Earth. So we're on that adventure now. Yeah,
Speaker 1: and if you listen to the first episode, I don't
Speaker 1: I do want to just tell everybody this one is
Speaker 1: is definitely worth listening to as well. It's not all
Speaker 1: gonna be elements and isotopes. There's gonna be some cool
Speaker 1: history in here. There's gonna be some some other dynamic
Speaker 1: geologic examples. So there's a there's a lot of cool
Speaker 1: stuff in this episode. Even if you don't need convincing
Speaker 1: about the scientific consensus about the age of the Earth,
Speaker 1: or you don't need uh ammunition for arguments with people
Speaker 1: who do hold onto a some sort of a h
Speaker 1: a young Earth view. Uh, there's gonna be a lot
Speaker 1: of fun in this episode regardless. Robert, I say, we
Speaker 1: should meet a scientist named Claire c. Patterson, who I
Speaker 1: will hereafter call the Lord of Lead. Lord of lad
Speaker 1: does sound a lot more metal, I will say, well,
Speaker 1: Claire Claire was a Lord of lad He. Claire Cameron
Speaker 1: Patterson lived nineteen twenty two to nineteen and he was
Speaker 1: a geochemist on the faculty at cal Tech and a
Speaker 1: member of the National Academy of Sciences. According to his
Speaker 1: New York Times A Bitch Worry by William Dick, he
Speaker 1: had something of a reputation as sort of a rebel
Speaker 1: and an outlier in his field, and Barclay cam who
Speaker 1: was provost at Caltech in the nineteen eighties, once said
Speaker 1: that Patterson's thinking and imagination were quote so far ahead
Speaker 1: of the times that he has often gone misunderstood and
Speaker 1: unappreciated for years until his colleagues finally caught up and
Speaker 1: realized he was right. Nothing to inflate your ego like
Speaker 1: somebody saying everybody will finally realize he's right. And speaking
Speaker 1: to an article in USA Today, the Caltech geologist John
Speaker 1: Eisler described him as fearless and said quote wherever the
Speaker 1: science took him, he would follow. And so Patterson was
Speaker 1: reportedly sometimes critical of colleagues who he might have referred
Speaker 1: to as ivory tower scientists. His research was definitely not
Speaker 1: confined to arcane academic matters. He got down into the world,
Speaker 1: into stuff that that had an impact on human life
Speaker 1: and for one thing, much of Patterson's important, most important
Speaker 1: work focused on measuring and contrasting levels of lead in
Speaker 1: the atmosphere at various times in history, and as the
Speaker 1: Lord of Lead, Patterson, using a variety of methods, demonstrated
Speaker 1: that people in the twentieth century were taking in these
Speaker 1: enormous doses of lead contamination in their bodies, uh much
Speaker 1: more than their prehistoric ancestors had consumed, and this exposure
Speaker 1: to lead has extreme consequences on the health of humans
Speaker 1: and other organisms. Lead gets in you. It effects everything
Speaker 1: from the brain to the kidneys. Um to quote from
Speaker 1: his New York Times obituary quote, he sampled snow from
Speaker 1: the ice caps of Greenland and Antarctica that had fallen
Speaker 1: hundreds or thousands of years earlier, showing there had been
Speaker 1: significant increases in lead in the northern Hemisphere when the
Speaker 1: Greeks and Romans smelted lead in antiquity. He discovered that
Speaker 1: millions of years ago, the amount of lead stored in
Speaker 1: microscopic plant and animal life or plankton in ocean sediments
Speaker 1: was only one tenth to one on the amount now
Speaker 1: flowing into the oceans from the continents. And so Patterson's
Speaker 1: research helped form the basis of the case for the
Speaker 1: Clean Air Act of nineteen seventy and the elimination of
Speaker 1: leaded gasoline, which was the biggest single cause of lead
Speaker 1: pollution in the environment at the time. All right, well,
Speaker 1: this is all, this is all well and good. I mean,
Speaker 1: this is great. Uh, but where does this where does
Speaker 1: he come into our discussion of the age of the Earth. Well,
Speaker 1: Patterson was also the first person to make an accurate
Speaker 1: estimate of the age of the Earth and the Solar System,
Speaker 1: which he published in the nineteen fifties based on the
Speaker 1: accumulating body of knowledge about radioactive decay. Now, if you
Speaker 1: remember in the previous episode, one of the types of
Speaker 1: radiometric dating we talked about was uranium lead dating, and
Speaker 1: so that studies the decay of a radioactive isotope of
Speaker 1: uranium into lead over millions of years, and so specifically,
Speaker 1: in Patterson's case, the key was to look at the
Speaker 1: Solar system at law to find out how old the
Speaker 1: Earth was. Since the evidence indicated that everything in the
Speaker 1: Solar System was formed around the same time, Patterson and
Speaker 1: others realized they could study the decay of uranium and
Speaker 1: thorium into daughter isotopes of lead in meteorites to determine
Speaker 1: the age of the Solar System objects, including the Earth,
Speaker 1: and so in the nineteen fifties, I think the late
Speaker 1: forties and early late forties and the fifties, Patterson used
Speaker 1: mass spectrometry to study Earth based zircons. Those are these
Speaker 1: little crystals I talked about in the previous episode that
Speaker 1: are usually formed with zirconium atoms in them, but sometimes
Speaker 1: get radioactive uranium atoms lodged into them, and these the
Speaker 1: decay of these radioactive uranium atoms inside the zircon crystals
Speaker 1: can be used to date the crystals. So he was
Speaker 1: studying Earth based zircons and uranium lead decay and meteorite
Speaker 1: material and ultimately Patterson was able to pin the date
Speaker 1: of the solar systems accretion including the Earth to about
Speaker 1: four point five billion years, which is still basically the
Speaker 1: accurate figure. And I love this link between his work
Speaker 1: on like environmental contaminants and and lead in human life,
Speaker 1: uh to to studying the very origin of the Earth.
Speaker 1: That's that's some of the best stuff in science. When
Speaker 1: when knowledge gets applied in such different ways like that,
Speaker 1: it really gets my gears going right at the human
Speaker 1: level and right at the essentially the god level. So
Speaker 1: earlier I mentioned the quote from John Eiler talking to
Speaker 1: USA Today, UH and Eiler makes this case pretty well.
Speaker 1: He says, quote Patterson is a pretty clear example of
Speaker 1: the link between basic science that seems unrelated to everyday life,
Speaker 1: the age of the Earth, and science that makes a
Speaker 1: crucial difference every moment in our everyday lives. There really
Speaker 1: isn't a difference between the skills the methods and the
Speaker 1: thinking that led him to both discoveries. And that's the
Speaker 1: story of science. And I love that quote because I
Speaker 1: feel like that's sort of the case we're trying to
Speaker 1: make in these episodes, right that there's sort of a
Speaker 1: coherent scientific approach to looking at the world around you.
Speaker 1: And in order to reject the age of the Earth
Speaker 1: and say that the Earth is just a few thousand
Speaker 1: years old, you're not just arguing with a particular method
Speaker 1: of radiometric dating, as we will continue to explore throughout
Speaker 1: the rest of this episode, it's essentially a rebuke of
Speaker 1: the entire scientific way of looking at the world. Yeah,
Speaker 1: it would really force you to throw the trigonometry baby
Speaker 1: into the ocean, and and you shouldn't have to do that. Um. So,
Speaker 1: there are a lot of difficulties Patterson had in his work,
Speaker 1: so he had to develop extremely stringent experimental procedures in
Speaker 1: order to get accurate results. That the Time's obituary talks
Speaker 1: about this. I've read about this elsewhere too, that he
Speaker 1: found that lead contamination was just everywhere. So scientific labs
Speaker 1: are full of lead contaminants because of all all kinds
Speaker 1: of lead pollution. And if you're trying to measure minute
Speaker 1: ratios of lead isotopes inside a hunk of meteorite. You
Speaker 1: don't want to be taminating it with lead from I
Speaker 1: don't know, the car exhaust he walk through on the
Speaker 1: way to the lab, and all other kinds of ambient
Speaker 1: lead that are currently poisoning your body. So he established
Speaker 1: clean room procedures, including like washing your hands and distilled
Speaker 1: water and putting on all the you know, all the
Speaker 1: what are the when people go and work on the
Speaker 1: chips in the laboratories, Those suits and all of this
Speaker 1: should help us notice that radiometric dating has all kinds
Speaker 1: of important caveats, Like pretty much all types of chemical measurement.
Speaker 1: It can be subject to sample contamination, to equipment malfunction,
Speaker 1: to user error, and so forth. And this is why
Speaker 1: it's really important to corroborate any radiometrically generated date with
Speaker 1: multiple tests and if possible, with multiple methods. Also, when possible,
Speaker 1: I think it's better to think about radiometric dating instead
Speaker 1: of giving us a date, giving us sort of confidence
Speaker 1: ratings for different ranges of dates. So, just as an example,
Speaker 1: a radiometric test or series of tests might tell us
Speaker 1: that we're sure that the thing is between four and
Speaker 1: five billion years old, and seventy percent sure that it's
Speaker 1: between four point five and five points or four point
Speaker 1: six billion years old, and that kind of thing, right, Yeah,
Speaker 1: I mean there is there is a certain amount of
Speaker 1: uncertainty baked into the process, right, But it will tell
Speaker 1: you bigger ranges with greater certainty. But what about rocks
Speaker 1: from the Earth itself? This can be more difficult since
Speaker 1: the Earth is just frequently eating and barfing up its
Speaker 1: own crust. It's part of how Earth is. Yeah, it's
Speaker 1: it's it's dynamic. Yeah uh, and this this can be
Speaker 1: more difficult. So rocks from billions of years ago often
Speaker 1: tend to disappear into the bowels of the Earth. They
Speaker 1: get gobbled up in one way or another, they get
Speaker 1: subducted or something like that. But sometimes we can find them.
Speaker 1: And it's pretty common to read about discoveries of increasingly
Speaker 1: ancient rocks found on Earth. Just I was looking at
Speaker 1: a few articles from recent years. One is that um
Speaker 1: rocks from the Acosta Knife in the Northwest territories of Canada.
Speaker 1: And that's nice g N E I S S. That's
Speaker 1: a geological term, not not like, oh, nice um that
Speaker 1: those have been dated to more than four billion years old.
Speaker 1: In September two thousand eight, there was a National Science
Speaker 1: Foundation press release. I was reading about a piece of
Speaker 1: Canadian bedrock from the and I'm sorry if I mispronounced this,
Speaker 1: the Neuvo Agatuck Greenstone Belt, which was dated to between
Speaker 1: three point eight and four point to eight billion years old.
Speaker 1: And then also there is a zircon from the jack
Speaker 1: Hills of Western Australia that's been dated to over four
Speaker 1: billion years I think about four point four billion years old.
Speaker 1: So here and there we find little bits of the
Speaker 1: surface of the Earth that seemed to go almost all
Speaker 1: the way back to the beginning and certainly back before
Speaker 1: say that's six thousand year point. Yeah, I mean they're
Speaker 1: they're not just quibbling with the six thousand year point.
Speaker 1: They're saying it is so many orders of magnitude off.
Speaker 1: As we said that, they just of confidence intervals. They
Speaker 1: don't tell you an exact date. So you know, you
Speaker 1: could quibble here or there with calibrating the correct date
Speaker 1: of these rocks, but they're not going to calibrate orders
Speaker 1: of magnitude down. It just comes back to what I
Speaker 1: said in the last episode about the difference between the
Speaker 1: scale of human history and the scale of geologic history,
Speaker 1: religion and myth with with a with some notable exceptions
Speaker 1: tend to take place within human history because it is
Speaker 1: a product of human understanding. That's a good point. Our
Speaker 1: our minds are just not made to contemplate time scales
Speaker 1: like this. It's not I would argue, actually, it's not
Speaker 1: just theological beliefs that drive people to want to imagine
Speaker 1: a younger Earth. I think. I mean, it's also like,
Speaker 1: if you want to wrap your brain around the history
Speaker 1: of the Earth, you're not going to be able to
Speaker 1: do it with a four point five billion year old Earth.
Speaker 1: You're not really picturing that time. You're just sort of
Speaker 1: condensing it into a representation of a timeline you can
Speaker 1: kind of picture, right, I mean they I mean, how
Speaker 1: do you put that into a perspective of generations? Right,
Speaker 1: and and and so and so begot so and so,
Speaker 1: you know, I mean it doesn't work right, I mean,
Speaker 1: And I mean and I'm not just you know, harping
Speaker 1: on you know, books of the Bible or anything here,
Speaker 1: but just the human perspective, the human shape of things,
Speaker 1: Like we just have a tendency to understand those better,
Speaker 1: to understand those stories better. Again, the the appeal of
Speaker 1: storytelling versus the kind of data that is involved in
Speaker 1: in rigorous scientific understanding. Yeah, and I mean we are
Speaker 1: always vulnerable to this. Stories are more compelling. Stories are
Speaker 1: more compelling than data. They shouldn't be. I mean, the
Speaker 1: data are actually more reliable. But what are people going
Speaker 1: to remember better a story? What's going to connect better
Speaker 1: with people emotionally is a story. Even even people who
Speaker 1: try to be scientifically minded are highly vulnerable to stories.
Speaker 1: I think about the most if effective science communication books
Speaker 1: try to be story based. Like in in our last episode,
Speaker 1: you know, there was a point where we had to
Speaker 1: talk about radioisotopes and stuff like that in order to
Speaker 1: explain how how radioactive decay works. But talking about how
Speaker 1: radioisotopes decay is not as compelling as like telling the
Speaker 1: story of the Lord of Lead anyway, I mean to
Speaker 1: derail the conversation. I can I can talk all day
Speaker 1: about you know, science and religion and where and where
Speaker 1: and when they can line up and and um and
Speaker 1: and support each other. Really, you mean like we need
Speaker 1: to create new religious narratives that that that help people
Speaker 1: confirm scientific knowledge, or I mean part of it is
Speaker 1: realizing what kind of answers religion can provide versus what
Speaker 1: kind of answers uh science can provide. Um. It's been
Speaker 1: pointed out, for instance, that uh, you can take the
Speaker 1: question why and they're they're essentially two different versions of why.
Speaker 1: There's a causal why, and there's a teleological why. There's
Speaker 1: the why like why is this, Why did this happen?
Speaker 1: What is the thing uh that preceded it? What was
Speaker 1: the process physical chain of events that caused it? Right?
Speaker 1: And then on the other hand that the telological why
Speaker 1: is for what reason is this as it is? For
Speaker 1: what reason? Am I? What I am? And so um
Speaker 1: I mean, broadly speaking, you can say that religion can
Speaker 1: provide the teleological and science provides the causal Um. Religion
Speaker 1: is very good at providing a sense of narrative, as
Speaker 1: we were just talking about narratives and stories, a sense
Speaker 1: of narrative or story that that makes sense of things.
Speaker 1: But again, I don't mean to derail the conversation. I
Speaker 1: could talk about that all day. Well, yeah, but I
Speaker 1: guess I guess we've got to get back to the
Speaker 1: idea of what we're setting out to talk about we
Speaker 1: have a lot of impersonal geology to unpack here. No,
Speaker 1: we'll try to make it as personal it's and it's
Speaker 1: exciting stuff. It is dynamic. We're talking about the stuff
Speaker 1: of of you know, earthquakes and volcanoes here. So so
Speaker 1: you might be thinking, you you've heard us talk about
Speaker 1: radio isotope decay, about radiometric dating, about Claire Patterson, and
Speaker 1: you think, yeah, but how do we know these methods
Speaker 1: of dating the Earth actually work? Like are we just
Speaker 1: taking some scientist's word for it? Like what if a
Speaker 1: scientist is lying and saying it works but it doesn't. Really,
Speaker 1: that's not really a plausible critique because like the yes,
Speaker 1: but what if it wasn't response? I can explain why
Speaker 1: it's not a plausible critique. And one strong line of
Speaker 1: evidence is when multiple independent tests with different methods produce
Speaker 1: results that are in agreement with each other. The simple
Speaker 1: version of this is, um, how do you know when
Speaker 1: eyewitness testimony is good? Right? You know? And eyewitness can
Speaker 1: get all kinds of stuff wrong. We explore that on
Speaker 1: the podcast all the time. So say you you know,
Speaker 1: you arrive at the scene of a crime, you pull
Speaker 1: up at the video store, and uh, and somebody has
Speaker 1: just sped away stealing a priceless copy of Highlander. To
Speaker 1: the quickening, I mean, especially if you're an orthodox Highlander
Speaker 1: tooth than as except no director's cut, except no renegade
Speaker 1: cut unacceptable. You've got to get the original version on
Speaker 1: VHS that's got all the bad scenes. It's the only
Speaker 1: way to feel the quickening. But yeah, so you get
Speaker 1: on the scene a copy of Highlander two has been stolen,
Speaker 1: and you want to find out who did it. Fortunately,
Speaker 1: there are several people standing around it just happened. So
Speaker 1: you separate all the people and they can't talk to
Speaker 1: each other, and you interview them one at a time,
Speaker 1: And the first witness tells you that it was a
Speaker 1: man wearing a kilt with a bagpipe on his back
Speaker 1: and a katana sword hanging from his hip, and he
Speaker 1: ran into the store and he yelled, there can be
Speaker 1: only one and he grabbed the tape and he ran out. Now,
Speaker 1: as we've said, I witness testimony can be very faulty
Speaker 1: sometimes people they are all kinds of issues with perception
Speaker 1: and memory. But if you talk to the second witness
Speaker 1: and they independently mentioned all the same stuff. They kill,
Speaker 1: the bagpipe, the katana, and you talk to a third
Speaker 1: witness they mentioned all the same stuff again, you really
Speaker 1: have to think, Okay, if they haven't talked to each
Speaker 1: other and they're all telling me all the same details,
Speaker 1: what are the odds that three people are getting all
Speaker 1: this different stuff wrong in the same way. And that's
Speaker 1: how corroboration of dating methods works. It's like having a
Speaker 1: second witness or a third witness on the scene who
Speaker 1: independently tells you they saw the same thing that the
Speaker 1: other witnesses did. It's possible they could be all they
Speaker 1: could all be wrong, But if they haven't talked to
Speaker 1: each other, why would they all be wrong the same way?
Speaker 1: All right, Well, on that note, let's take a quick
Speaker 1: break and we come back. We'll jump right back into
Speaker 1: the discussion. Thank alright, we're back, alright. So I wanted
Speaker 1: to talk about a really great article that I read
Speaker 1: on this subject about how to corroborate the dating methods
Speaker 1: that are used in h in radiometric dating and establishing
Speaker 1: the Age of the Earth, and the articles by the
Speaker 1: American geologist Brent Dalrymple, who worked for the U S
Speaker 1: Geological Survey and was a professor at Oregon State University,
Speaker 1: and he published a book on the Age of the
Speaker 1: Earth called The Age of the Earth with Stanford University
Speaker 1: Press in And so he's got this really excellent article
Speaker 1: hosted on the National Center for Science Education website and
Speaker 1: which he picks out four different examples, basically four studies
Speaker 1: that he had personal experience with in which radiometric date
Speaker 1: ranges were corroborated by multiple kinds of tests, multiple labs
Speaker 1: that showed them to be accurate. Um, So it's again
Speaker 1: not just that we do one test and assume it's
Speaker 1: the answer is right, but we test multiple samples, multiple methods,
Speaker 1: multiple labs and get agreement on the results. So, first example,
Speaker 1: he gives the Manson meteorite impact site and the Pierre
Speaker 1: Shale the Manson the Manson meteorite. There's got to be
Speaker 1: a metal band for this one. And also this has
Speaker 1: nothing to do with Charlie though right as I don't know,
Speaker 1: uh it's Manson Iowa. Does Manson Iowa have anything to
Speaker 1: do with Charlie does? But it's still hard to shake
Speaker 1: that possible connection. Okay, well, this is a look at
Speaker 1: argon argon dating, argne orgon dating is a method that's
Speaker 1: a derivative of the classic potassium argone dating method, but
Speaker 1: it's now considered a more accurate version of that decay
Speaker 1: series test. It helps detect errors protect against an accurate results.
Speaker 1: And so during the Cretaceous period, we know that there
Speaker 1: was a big old meteorite the hit part of what
Speaker 1: is now Iowa in the United States, near Manson, Iowa
Speaker 1: and uh. The hot impact melted a bunch of feldspar
Speaker 1: crystals and the granite rockley are near the surface of
Speaker 1: the time, and when these crystals are melted, their internal
Speaker 1: radiometric clocks get reset to zero. So if you use
Speaker 1: argon argon dating to date these melted crystals, you'll get
Speaker 1: an age of about seventy four point one million years. However,
Speaker 1: when the Manson media write hit, it also created what's
Speaker 1: known as shocked quartz crystals that exploded up into the air.
Speaker 1: They came down west of the impact and what's what
Speaker 1: was then an inland see and now you can find
Speaker 1: the shocked quarts from this impact in a thing in
Speaker 1: layer that's known as the Crow Creek member, and that's
Speaker 1: been within this larger sedimentary rock formation called the Pierre Shale.
Speaker 1: The Pierre Shale also contains marine fossils like ammonites and
Speaker 1: ash from volcanic eruptions. These ash beds from the volcanic eruptions,
Speaker 1: they've also got minerals in them like sanity and feldspar
Speaker 1: and biotite which have been independently dated using the argon
Speaker 1: argon method. And so there there's a study that that
Speaker 1: the Dalrymple sites from Isaac Koban Dalrymple and Obradovich in
Speaker 1: n in the Geological Society of America bulletin. And what
Speaker 1: did they find. So they found more than a half
Speaker 1: dozen dates of biotite and sanitine surrounding the Crow Creek
Speaker 1: member where the where the evidence of this impact near
Speaker 1: Manson was and interesting, so remember that the melted feldspar
Speaker 1: crystals from the impact were dated to seventy four point
Speaker 1: one million years old. The minerals found right below the
Speaker 1: impact layer, so that means they should be a little
Speaker 1: bit older, came up with dates about seventy four to
Speaker 1: seventy five million years old. The minerals found right above
Speaker 1: the impact layer, which should be a little bit younger,
Speaker 1: got results indicating they were about seventy three to seventy
Speaker 1: four million years old. So these dates for each mineral
Speaker 1: we're all corroborated with multiple sample tests to make sure
Speaker 1: they all agreed, and they tested with different kinds of minerals,
Speaker 1: and the results agreed. The biggest discrepancy and results came
Speaker 1: from comparing the biotite and the sanity and from the
Speaker 1: layer right below the impact, but this was less than
Speaker 1: a one percent difference. Also, the dates generated by the
Speaker 1: argon argne tests generally agree with how old these layers
Speaker 1: of rock are supposed to be and with the kinds
Speaker 1: of fossils we'd expect to find in them. So if
Speaker 1: the dating method is not reliable, why do so many
Speaker 1: different tests of different minerals from different time periods agree
Speaker 1: with each other and fit together in the correct plausible
Speaker 1: geological order. And this is another thing we haven't even
Speaker 1: talked about much yet, is the the idea of geologic stratification,
Speaker 1: like that there are layers of deposition of sedimentary that
Speaker 1: happened over time and volcanic deposits from volcanic eruptions that
Speaker 1: you can see going back through time. And you know,
Speaker 1: there were paleontologists who were looking at fossil layers in
Speaker 1: rock formations going down this uh stratigraphic column looking at
Speaker 1: the history of the Earth's surface. Before there was anything
Speaker 1: like radiometric dating, we didn't have any dates, but they
Speaker 1: were still saying, here are the ages that came earlier
Speaker 1: and the ages that came before that, and identifying what
Speaker 1: these layers looked like. Yeah, I mean, and if you
Speaker 1: wanted a really impressive vision of this, I mean, simply
Speaker 1: look at an image of or or better yet, a
Speaker 1: visit say the Grand Canyon and uh, and you are
Speaker 1: just I mean, there's no denying the these these geological layers.
Speaker 1: I mean, it is a visual presentation of geologic time.
Speaker 1: I have not seen the Grand Canyon walls up close.
Speaker 1: What does it look like? Well, I mean up close
Speaker 1: it looks well, yeah, but I mean just like the
Speaker 1: grand scheme of things. And there there's a lot of uh,
Speaker 1: you know edgrigal educational material at the park as well
Speaker 1: that really talks about the different layers and what you're
Speaker 1: looking at and really the time that you're looking into one.
Speaker 1: In fact, there is a there is a little walk
Speaker 1: you can do right at the like the major area
Speaker 1: of like the in Innocence kind of like the high
Speaker 1: tourist area of the Grand Canyon. There is a walk
Speaker 1: through time you can take and it like just talks
Speaker 1: about the different the different geologic ages. Do you remember
Speaker 1: what time you were at when a squirrel tried to
Speaker 1: steal food out of your hand? That was? That was
Speaker 1: a little further into the king Um I want to say,
Speaker 1: it was like, what what is it? Angelhead trail one
Speaker 1: of one of those. Yeah, it's a creepy name. I
Speaker 1: may have that wrong. I don't have that in my notes,
Speaker 1: but yeah, squirrel attack trail. Now, we mentioned earlier that
Speaker 1: one of the ways that say uh Patterson, the Lord
Speaker 1: of Lead identified the age of the Earth was by
Speaker 1: identifying the ages of meteorites that we think were formed
Speaker 1: around the same time. And meteorites are often subject to
Speaker 1: radiometric dating because it can help us understand the origins
Speaker 1: of the Solar system. So, given our current best model
Speaker 1: of how the Solar system formed out of a solar
Speaker 1: nebula and accretion disc it seems likely that the oldest
Speaker 1: meteorites are probably pretty close to the same age as
Speaker 1: the Earth itself. And Dalrymple writes about different tests on
Speaker 1: the ages of meteorites. So he talks about how the
Speaker 1: earliest types of meteorites are called chondrites because they contain
Speaker 1: these tiny spheres of crystals known as con d rules
Speaker 1: and meteorites are often radiometrically dated, and when their mineral
Speaker 1: composition allows it, they're often dated by more than one
Speaker 1: different type of radioisotope de K series test. So a
Speaker 1: few examples heat sites are the i end A meteorite
Speaker 1: which got argon argon lead, lead, and both methods agreed
Speaker 1: the date is about four point five something billion years old,
Speaker 1: the Warina meteorite, which got argon argon spectrum rubidium strontium
Speaker 1: is acron both methods agreeing with an age of a
Speaker 1: little less than four point five billion years, and the
Speaker 1: Saint Severin meteorite, which got argon ar gone rubidium, strontium's
Speaker 1: samariam neodymium, lead lead, all agreeing with roughly four point
Speaker 1: five billion years, give or take a hundred million years
Speaker 1: or so. So lots of different labs, different methods, using
Speaker 1: different radioactive clocks, all converging on answers within about a
Speaker 1: one percent difference of each other. So again it all
Speaker 1: adds up. You don't just have one eye witness, you
Speaker 1: have multiple eyewitnesses that are independently telling you more or
Speaker 1: less the same thing, all telling you about the kilt,
Speaker 1: all telling you the Katana. Another example, he cites the
Speaker 1: Katie tech tites, So we know about the the Oh
Speaker 1: my god, I can never say this right. The cheek
Speaker 1: shalub Um. I've whenever I've had to do it for
Speaker 1: a video or something, I've had to look it up.
Speaker 1: I'm gonna say cheek shalub and and hope it's right.
Speaker 1: So the cheek shalhoub impact, Robert, we know. Around night
Speaker 1: scientists discovered there's this huge crater spanning the code to
Speaker 1: the Yucatan Peninsula in Mexico. Its center is near a
Speaker 1: village or a town known as cheek Schlub. And this
Speaker 1: is the site of the cheek Schalub impact event, which
Speaker 1: in the village was not there, no occurred to certainly
Speaker 1: not no. This happened about sixty six million years ago. Uh.
Speaker 1: And it's the the event which many paleontologists point to
Speaker 1: as the main factor or one of the main factors,
Speaker 1: in the last great extinction before the present, the Cretaceous
Speaker 1: Paleogene extinction, also known as the KPg extinction or the
Speaker 1: kt extinction, which killed off the non avian dinosaurs. Of course,
Speaker 1: we've still got birds, which are dinosaurs, the chi but
Speaker 1: not just them. It killed something like seventy five percent
Speaker 1: of the plant and animal species on Earth and basically
Speaker 1: killed all the large animals. Was a real reboot, you
Speaker 1: might say. Yeah. The object itself was about ten kilometers
Speaker 1: in diameter. And when an object like that hits the earth,
Speaker 1: it it creates a ruckus. It throws up tons of
Speaker 1: geologically weird material into the atmosphere, which comes down all
Speaker 1: over the place and becomes an easily recognizable layer within
Speaker 1: the geological strata that we were just talking about. So
Speaker 1: you can pretty easily look at geological layers and see
Speaker 1: where this impact happened once you know what to look for,
Speaker 1: because the sedimentary rocks below it contain Cretaceous fossils and
Speaker 1: dinosaurs and stuff, and the rocks above it do not.
Speaker 1: But also because there's a thin layer of these weird
Speaker 1: impact byproducts, things like shocked quartz irridium, which is found
Speaker 1: in asteroids and these things called tech tits, So dinosaurs
Speaker 1: and then a layer of weird stuff and then a
Speaker 1: layer of no dinosaurs. Uh, it tells a story, right,
Speaker 1: And so tech tits are tech tits are sacred crystal
Speaker 1: shop stuff. If you look these up, you know, you think,
Speaker 1: you look at this and this is what will cure
Speaker 1: your fear of the dark or something. Really, they are
Speaker 1: these black glassy blobs that are found only in the
Speaker 1: most unusual of circumstance. So when you've got a high
Speaker 1: energy impact that occurs and instantaneously melts rock, you'll get
Speaker 1: these tech tights and at the cheek schloub impact, these
Speaker 1: little glass fules, these tech tits got ejected up into
Speaker 1: the atmosphere and distributed all over the place, and they
Speaker 1: can be found in Haiti and Mexico. And so tech
Speaker 1: tights from this layer corresponding to the KPg impact found
Speaker 1: in modern day Haiti have been dated radiometrically by different
Speaker 1: labs at different times different methods. UH scientists from the
Speaker 1: U S Geological Survey, from Berkeley, from Stanford, from places
Speaker 1: in Canada and France all separately measured dates for these
Speaker 1: glassy little impact blobs and then for volcanic ash beds
Speaker 1: that are just a few centimeters above the KPg impact
Speaker 1: layer using different methods like are gone ar gone potassium argone,
Speaker 1: rubidium strontium and uranium lead, and all the results fell
Speaker 1: within sixty four to sixty six million years ago. So
Speaker 1: yet again everybody's doing different tests, different stuff, and they're
Speaker 1: all getting the same answers. One last example that Dalrymple
Speaker 1: gives is dating something that we actually have historical records of.
Speaker 1: We know when it happened because humans were alive and
Speaker 1: they were there to see it happen and make records
Speaker 1: of it. And this would be the Mount Vesuvious eruption. Ah, yes,
Speaker 1: the very explosive moment, very dramatic moment. Uh there. So this,
Speaker 1: the Mount Vesuvious eruption, happened on auguste and this was
Speaker 1: in the first century CE, and we actually have a
Speaker 1: first hand description of it from Plenty of the younger
Speaker 1: writing in a letter to Cornelius Tacitus, describing what happened.
Speaker 1: Just to read a short part of the letter with
Speaker 1: a couple of abridgements. Plenty rights, the sea seemed to
Speaker 1: roll back upon itself and to be driven from its
Speaker 1: banks by the convulsive motion of the earth. It is
Speaker 1: certain at least the shore was considerably enlarged, and several
Speaker 1: sea animals were left upon it. On the other side.
Speaker 1: A black and dreadful cloud broken with rapid zigzag flashes,
Speaker 1: revealed behind it variously shaped masses of flame. These last
Speaker 1: were like sheet lightning, but much larger. Soon afterwards, the
Speaker 1: cloud began to descend and cover the sea it had
Speaker 1: already surrounded and concealed the island of Capri and the
Speaker 1: promontory of Missenum. The ashes now began to fall upon us,
Speaker 1: though in no great quantity. I looked back. A dark
Speaker 1: a dense, dark mist seemed to be following us, spreading
Speaker 1: itself over the country like a cloud. And he goes
Speaker 1: on to talk about what all the people were doing
Speaker 1: as they were fleeing. It's great, we should maybe revisit
Speaker 1: the eruption of a Suko time. Yeah, let us know
Speaker 1: if you would like to hear an episode devoted to this,
Speaker 1: because we could have we could have a lot of
Speaker 1: fun with it. I mean, tragic and destructive and apocalyptic
Speaker 1: as it is, but it's it's a great description that
Speaker 1: that planny has here. But anyway, so how does this
Speaker 1: come into corroborating radiometric gates, Well, this is a historical
Speaker 1: event that can be used to calibrate radiometric meth It's
Speaker 1: not every method is appropriate for this kind of time scale,
Speaker 1: but scientists said the Berkeley Geochronology Center in the University
Speaker 1: of Naples, they wanted to see how well are Gone
Speaker 1: are Gone dating could do here, so they got twelve
Speaker 1: samples of sanitine from the ash flows from the vesuvious eruption,
Speaker 1: and Dalrymple says that the dating method generated an estimate
Speaker 1: of about one thousand, nine hundred and twenty five years.
Speaker 1: This was in and the actual age of the time
Speaker 1: was one thousand, nine hundred and eighteen years, so about
Speaker 1: seven years off. And that's amazingly close for especially for
Speaker 1: young rock like this, which that which was assumed to
Speaker 1: be more difficult to date accurately. Absolutely, because again we're
Speaker 1: zeroing in on seventy nine. Yeah. So one of the
Speaker 1: things I wanted to mention is that in one of
Speaker 1: the emails we got, like the the email from c
Speaker 1: J I think that we read at the beginning of
Speaker 1: the first episode, c J mentioned maybe like looking at
Speaker 1: creationist critiques of radiometric dating methods, and I don't think
Speaker 1: it really makes sense to try to focus on any
Speaker 1: one of these because they are myriad, So like it
Speaker 1: just seems like, there are thousands of them as many
Speaker 1: as there are creationists books and pamphlets, so obviously we
Speaker 1: don't have time to address them all, and none stand
Speaker 1: out is particularly good when I've looked at them before.
Speaker 1: They take the form of One of the things we
Speaker 1: talked about in the last episode is like pointing out
Speaker 1: ways that radiometric dating could be missupplied or could be flawed,
Speaker 1: which scientists know about and they take steps to correct,
Speaker 1: including corroborating with multiple methods, um or using using you know,
Speaker 1: careful types of calibration to eliminate errors and to increase
Speaker 1: accuracy in their tests. Some of it's just pointing out
Speaker 1: ways that measurements could go wrong, which scientists already know
Speaker 1: about and take into account, and using that as an
Speaker 1: excuse to just throw the whole method out. Yeah, it's
Speaker 1: kind of like saying, you know, there are lots of
Speaker 1: ways that watches can be wrong, therefore your watch you
Speaker 1: can't trust what time it says. Other methods that I
Speaker 1: think are common are like isolating examples of when a
Speaker 1: radiometric dating method has generated a incorrect result, and these
Speaker 1: are often highlighted in order to show ways that you
Speaker 1: can make the tests more accurate and eliminate errors. So
Speaker 1: like scientists are aware of the fact that it's possible
Speaker 1: to generate an incorrect result with the radiometric test, part
Speaker 1: of what they do is learning the circumstances in which
Speaker 1: these errors arise and trying to avoid them. And then
Speaker 1: others are just theoretical critiques, which I think are simply
Speaker 1: misunderstandings of the underlying science. But I it has never
Speaker 1: seemed very productive to me to just play whack a
Speaker 1: mole with the various uh, you know, misunderstandings and critiques
Speaker 1: as they arise. Yeah, I agree, I don't think that's
Speaker 1: a constructive exercise at all. But what we wanted to
Speaker 1: finish on today was to talk about ways in which
Speaker 1: the age of the Earth is not just confirmed by
Speaker 1: direct measurement methods that say, look at meteorites or look
Speaker 1: at rocks on the Earth and say this is how
Speaker 1: old it is, and then and then as if the
Speaker 1: age of the Earth rests entirely on those results. The
Speaker 1: fact that the Earth is old, that it is older
Speaker 1: than a few thousand years is something that is so
Speaker 1: thoroughly incorporated in pretty much every branch of science that
Speaker 1: if the Earth were only a few thousand years old,
Speaker 1: we would have to throw out essentially all of science.
Speaker 1: It touches everything. And so for the rest of the
Speaker 1: today's episode, we just wanted to explore other ways of
Speaker 1: looking at time and and the history of the Earth
Speaker 1: and the universe, the additional examples of of of just
Speaker 1: how interconnected all of this is, and additional examples of
Speaker 1: things you would have to throw out if you were
Speaker 1: to adhere to say, a six thousand year old model
Speaker 1: for the Earth. Do you want to take a quick
Speaker 1: break and then deal with this when we come back,
Speaker 1: Let's do it. Thank alright, we're back. Okay, So we're
Speaker 1: gonna talk about ways of corroborating the fact that the
Speaker 1: Earth is old, which essentially becomes everything else in science,
Speaker 1: right and we're gonna jump around a little bit in here.
Speaker 1: But you know, we can do some geological science, uh
Speaker 1: some some some some, some astronomy as well. Um, some
Speaker 1: of these examples we're gonna spend just a few sentences on.
Speaker 1: Others we're gonna go into a little more depth right now.
Speaker 1: Not every method will help give us an estimate of
Speaker 1: the exact age of the Earth, like radiometric dating MTE,
Speaker 1: but there are at least dozens of other lines of
Speaker 1: evidence that we can talk about that the Earth, the
Speaker 1: solar system in the universe must be older than X time,
Speaker 1: with X always being much longer than the proponents of
Speaker 1: a several thousand year old Earth would would grant. Yeah,
Speaker 1: like evidence, you're gonna we're gonna see this over and
Speaker 1: over again, Like here's evidence of something that it only
Speaker 1: makes sense if it's eight thousand years old. It only
Speaker 1: makes sense if it's ten thousand years old. So let's
Speaker 1: look at some other stuff about what's in the Earth,
Speaker 1: like geochemistry and geology. Yeah, if we enter into the
Speaker 1: realm of petroleum geology, um uh, we have we know
Speaker 1: that biomass requires far are more than six thousand years
Speaker 1: to become cold or petroleum like hundreds of thousands to
Speaker 1: millions of years. Uh, and then it takes roughly twenty
Speaker 1: five million years for it to reach the surface in
Speaker 1: a natural oil seep. Right, oil coal doesn't make sense
Speaker 1: in a young earth, right, So yeah, if you're gonna
Speaker 1: have that six thousand year old Earth, you don't get
Speaker 1: to use any of the petroleum. So they're also if
Speaker 1: you just look at the formations of individual like rocks
Speaker 1: and crystals and stuff. They're they're slow forming crystals. Yeah,
Speaker 1: take the take the diamond for instance. By radioactively dating
Speaker 1: minerals inside diamonds, because you can't date the diamond itself,
Speaker 1: we can tell that most diamonds probably formed in the
Speaker 1: Earth's first two billion years or so, and even younger
Speaker 1: diamonds are still tens of hundreds of millions of years old. Uh.
Speaker 1: This according to diamond expert Jeffrey Post, who was quoted
Speaker 1: in a Smithsonian magazine piece. Wait, tens of hundreds of millions,
Speaker 1: wouldn't that be billions? He has attributed as saying, tens
Speaker 1: of hundreds of millions of years old. I I you
Speaker 1: run into this occasionally, people who are generally, you know,
Speaker 1: experts in the field that are hesitant to use the
Speaker 1: word billions. I feel like I've seen that too. That
Speaker 1: is weird. It's like they don't like it. It doesn't
Speaker 1: sound right billions. I feel like there's probably a good
Speaker 1: reason for that, but still like the numbers are still
Speaker 1: the same, so there's nothing yet inaccurate in in this statement.
Speaker 1: They all have somebody they don't like named bill that
Speaker 1: they don't want an order of magnitude named after him. Hey,
Speaker 1: here's another one. When you look at the earth caves, Now,
Speaker 1: there are quick forming caves, for example, like lava tubes.
Speaker 1: Lava tubes are wonderful, fascinating thing we could look at
Speaker 1: some time. But we know that there are other kinds
Speaker 1: of caves, and we know what these other kinds of
Speaker 1: caves look like that take a very long time to form,
Speaker 1: and that formations within them take a very long time
Speaker 1: to to assume the shape we see them in now. Yeah,
Speaker 1: stalactites and stalagmites are great examples to look at. You know,
Speaker 1: we're talking about calcite stone formations created by the gradual
Speaker 1: dripping of water in cave environments, and the process is
Speaker 1: often still taking place right before our eyes, and the
Speaker 1: resulting formations are often quite old. So the exact rate
Speaker 1: of stalactite and stalagmite formation varies. Of course. Limestone stalactites
Speaker 1: and stalag mights generally take thousands of years. Those in
Speaker 1: lava tubes, as you mentioned, those may take hours to form.
Speaker 1: You know. Um, but like let's let's imagine a limestone
Speaker 1: cave or you know, and again some kind of sedimentary cave.
Speaker 1: What do the stalactites and stalagmites look like they're I mean,
Speaker 1: there's some wonderful examples of just enormous stalactites stalagmites. If
Speaker 1: you've ever visited a cave, uh, you know, I'm thinking
Speaker 1: of some of like the more touristic caves, especially in
Speaker 1: the United States, like say Mammoth Cave, h Cumberland Caverns,
Speaker 1: that sort of thing. Then you've you've probably seen some
Speaker 1: of these examples. They're enormous. And again it's like looking
Speaker 1: at the Grand Canyon. You're looking at time right there
Speaker 1: in front of you. UM. Just a few examples that
Speaker 1: I picked out here that that I think speak to this.
Speaker 1: For instance, in two thousand seventeen, a stalac might growing
Speaker 1: quote unquote out of the hip bone of a prehistoric
Speaker 1: human skeleton helped date a Yucatan Peninsula skeleton to at
Speaker 1: least thirteen thousand years old. So, in other words, they
Speaker 1: were looking at these bones, and they were looking at this, uh,
Speaker 1: this this stalaga mte that seemed to be growing up
Speaker 1: out of it, and uh and this was the the
Speaker 1: age range they were dealing with. Another example, in France's
Speaker 1: Brunoquil Cave, we have evidence of Neanderthals having broken off
Speaker 1: four hundred stalagmites to a range into two rings, and
Speaker 1: supporting evidence, including carbon dating of a burnt bare bone
Speaker 1: from the location, indicate that the rings were roughly forty
Speaker 1: seven thousand, six hundred years old, older than any cave painting.
Speaker 1: In Spain's Moraine Cave, for instance, you'll find a stalagmite
Speaker 1: that's estimated to be uh nine thousand and fifty five,
Speaker 1: give or take nine fifteen years old. I want to
Speaker 1: point out that you you also do see examples, small
Speaker 1: examples of stalagmites forming in concrete structures, and this is
Speaker 1: something that you occasionally see pointed out on some of
Speaker 1: these websites saying how can you believe in the age
Speaker 1: of stalagmites, because look, if you go to the parking deck,
Speaker 1: there's a little stalagmite. They're clearly the earth is only
Speaker 1: as old as this, uh this parking deck. Well, here's
Speaker 1: how what's going on. Concrete derives. Stalagmites are sometimes observed
Speaker 1: in concrete structures, and these again are quite small, and
Speaker 1: they form more rapidly than natural cave structures. Uh. There
Speaker 1: by no means a gotcha point for discreting geologic science.
Speaker 1: I've never seen a parking garage sale. What you need
Speaker 1: to get into. They're around. If you hang out in
Speaker 1: some of the subterranean concrete zones around our own city
Speaker 1: of Atlanta, you will encounter them. Robert, what's your favorite
Speaker 1: parking garage to hang out in? Oh? I don't know.
Speaker 1: I do actually enjoy like a significant, a creepy parking
Speaker 1: garage environment. It feels act like the morlocks are going
Speaker 1: to show up in any moment, right well, I always
Speaker 1: think of like Escape from New York and kind of
Speaker 1: seventies Carpenter, seventies eighties Carpenter. When I when there's a
Speaker 1: good abandoned parking garage, it's got that kind of that
Speaker 1: echoe creepiness of the early scenes and Escape from New York.
Speaker 1: Yeah yeah, um, but but even then you're not going
Speaker 1: to find any huge stalactites are still like mites now. Um,
Speaker 1: as far as the age of caves go, um, you
Speaker 1: get into you know, much deeper time when you're just
Speaker 1: talking about those, You're not talking about the formations within,
Speaker 1: but just the cave systems themselves. Consider Mammoth Cave National Park,
Speaker 1: UH major tourist attraction as far as caves go. Geologists
Speaker 1: estimate that the oldest part of the sprawling cave complex
Speaker 1: formed ten million years ago. And if you're in Australia
Speaker 1: and you happen to visit gen Olan caves, I believe
Speaker 1: I'm saying that that ride perhaps it's gen Olan. I'm
Speaker 1: sure our our Awestlee listeners will correct me on this.
Speaker 1: Oh I'm still I still can't live it down from
Speaker 1: when I said, what did I say Canberra or something? Oh? Yes,
Speaker 1: I think it's Canberra. Well, anyway, if you visit this
Speaker 1: particular cave, you will be visiting some caves that are
Speaker 1: thought to be three forty million years old. And there's
Speaker 1: a lot more here we can talk about geologically. I mean,
Speaker 1: you can look at the formation of mountains, rock layering
Speaker 1: through sedimentation, which we've touched on already. Uh, there's a
Speaker 1: reason we speak of geologic time, and the Earth is
Speaker 1: written in geologic time. Young Earth views enforced human time, uh,
Speaker 1: or the timeline of human civilization upon a thing that
Speaker 1: dwarfs our brief period of cultural as sentence. You know,
Speaker 1: one way you can actually make geologic time feel a
Speaker 1: little bit more intuitive that you can try to internalize
Speaker 1: it is visiting fossil beds. I know that was a feeling.
Speaker 1: I One of the coolest things I've ever gotten to
Speaker 1: do I've talked about on the show before, was visiting
Speaker 1: the Trialobyte beds Burgess Shale National Park in Canada, which
Speaker 1: is Cambrian fossils trial bites everywhere Anomala carreras fossils, and
Speaker 1: you're just walking around on them, but you get to
Speaker 1: see the massive vertical face of the shale that's made
Speaker 1: by sedimentary deposition over millions, billions of years that's broken
Speaker 1: off into all these flakes that you're walking around, and
Speaker 1: you just realize, like the depth of time required to
Speaker 1: lay down this sediment, fossilize all these creatures, and then
Speaker 1: drive it up, make it into the side of a
Speaker 1: mountain near the top of the mountain, and then break
Speaker 1: it all off as it erodes into these beds along
Speaker 1: the mountain side. It's humbling. It's a humbling amount of
Speaker 1: time that you that is required to see this happen.
Speaker 1: And it's all extinct organisms too. Yeah. Now, and now
Speaker 1: this is great though that we brought up the fossils here,
Speaker 1: because the next area I want to touch on has
Speaker 1: to do with with the sea floor spreading and continental drift,
Speaker 1: and indeed the distribution of fossils ecs. This is a
Speaker 1: really interesting one. Yeah, and I feel it's it's particularly
Speaker 1: interesting because I feel, on one hand, most of us
Speaker 1: are at least dimly aware that the continents are not
Speaker 1: in the in the position they were they were always in.
Speaker 1: I mean, if nothing else has been pointed out to
Speaker 1: you on a world map, how Africa and South America
Speaker 1: wants spooned, or perhaps you've seen an epic animation detailing
Speaker 1: the breaking up of Pangaea and the end of the
Speaker 1: super Ocean. But wait a minute, what if I were
Speaker 1: to say, well, I think it's just a coincidence that
Speaker 1: South America has shaped like it used to fit into
Speaker 1: the underside of the part of Africa. Well, this is
Speaker 1: this was is a valid um um critique of of
Speaker 1: just this argument on on the face of it, because
Speaker 1: it's really only been fairly recently that we've we've known
Speaker 1: about this, and it's been accepted before roughly a hundred
Speaker 1: years ago. We just assumed that the continents were basically
Speaker 1: in the same position that they've always been in. Uh.
Speaker 1: The evidence that led to the revelation, uh here was
Speaker 1: the distribution of fossil speed seas. And that's where German
Speaker 1: scientists Alfred uh Wegner comes in, who lived eighteen eighty
Speaker 1: through nineteen thirty, and indeed he came up against the
Speaker 1: same criticism it's just a coincidence, yeah, saying well, they're saying, well,
Speaker 1: that's interesting, but I don't know if that's really uh
Speaker 1: that it's really solid evidence for what you're talking about.
Speaker 1: Because he he noted the presence of similar plan and
Speaker 1: animal fossils in South America and Africa. How did they
Speaker 1: get there? Well, that that's that's what he was he
Speaker 1: was trying to answer. He noted the similar geologic formations
Speaker 1: on both continents, and uh and also the whole spooning thing.
Speaker 1: He said, how how else, though, could we possibly have
Speaker 1: these these examples on these separate continents unless they were
Speaker 1: once part of the same land mass. Okay, so South
Speaker 1: America and Africa look like they used to fit together.
Speaker 1: Weirdly enough, we find that the same species used to
Speaker 1: sort of cross boundaries between them. That's kind of odd.
Speaker 1: But how could they have actually been split apart? That
Speaker 1: doesn't make any sense. And that's the thing they said, Well,
Speaker 1: we need we need a more robust idea of how
Speaker 1: this could possibly work. Otherwise we're just not going to
Speaker 1: buy it. So it wasn't until the fifties and sixties
Speaker 1: that marine geologists identified the ocean ridges that wound about
Speaker 1: the Earth as well as the mid ocean ridges formed
Speaker 1: by sea floor volcanoes. And this was backed up by
Speaker 1: magnetometer data as well. So this is the basic seafloor
Speaker 1: spreading hypothesis proposed by petrologist Harry Hess and oceanographer Robert Deats.
Speaker 1: In sixty five, geophysicist J. Tuzo Wilson used continental drift
Speaker 1: and seafloor spreading to propose the theory of plate tectonics.
Speaker 1: This theory is now universally accepted by geoscientists. Yeah, that's
Speaker 1: one of those great scientific theory success stories. We could
Speaker 1: tell that story sometime, because that was something that was
Speaker 1: ridiculed at first. The idea that the continents are moving
Speaker 1: around and it is it is a crazy mind blowing
Speaker 1: thing to try and uh and think about, because it
Speaker 1: is it just is existing on a time scale far
Speaker 1: beyond uh we've evolved to really comprehend. But it is
Speaker 1: amazing how an animation like I described earlier can give
Speaker 1: it life and and make sense of it for you. Now,
Speaker 1: let's try to imagine a model where South America and
Speaker 1: Africa split up and they were split apart by a
Speaker 1: spreading ocean ridge, and that happened just a few thousand
Speaker 1: years ago. That is a that is a messed up world. Yeah,
Speaker 1: it it doesn't hold up. Yeah, it simply doesn't work
Speaker 1: with a model of Earth that's less than two million
Speaker 1: years old. You cannot have a younger Earth and bring
Speaker 1: the geosciences with you. You have to cast out all
Speaker 1: of the twentieth centuries evidence and clinging to essentially a
Speaker 1: pre vaga or understanding of the position of the continents.
Speaker 1: And of course I know you'll say, keep your hands
Speaker 1: off the dinosaur, right, Yeah, you don't get off the
Speaker 1: dinosaurs either, And so no dinosaurs, no paleo art, stick
Speaker 1: to uh to draw in all the other cool stuff
Speaker 1: in those ancient texts. Now another now, just to leave
Speaker 1: we have an exhausted everything on the Earth that points
Speaker 1: to an old, old Earth, right because essentially the evidence
Speaker 1: here is all geoscience. Yeah, but we could also look
Speaker 1: beyond Earth. We can look to evidence from astronomy and astrophysics.
Speaker 1: And what you find when you look to astronomy and
Speaker 1: astrophysics is that everything in the universe agrees with a
Speaker 1: long billions of years timeline of the universe. That's right.
Speaker 1: And again part of the issue here is that world
Speaker 1: views that call for an absurdly young Earth are also
Speaker 1: calling for an absurdly young cosmos. And if you believe
Speaker 1: in a six thousand year old Earth, yeah, you don't
Speaker 1: get to keep modern astronomy. I mean, certainly we can
Speaker 1: speak to the probable time scale for the formation of
Speaker 1: our own solar system, but we also have to think
Speaker 1: to the stars. Now, nobody I think is going to
Speaker 1: be disputing the speed of light in a vacuum, right,
Speaker 1: But what does the speed of light and a vacuum
Speaker 1: tell us about the universe? We're looking at what gives
Speaker 1: you an idea of of not only the size of everything,
Speaker 1: but the but the vast time scale involved as well. So,
Speaker 1: for instance, with the naked human eye, uh, an individual
Speaker 1: on Earth can glimpse the light from the Andromeda galaxy,
Speaker 1: which will one day be the same as our galaxy.
Speaker 1: We're we're headed together, yeah, and again talking in distant
Speaker 1: time here, the big meet up yeah, but but currently
Speaker 1: the Andromeda galaxy that's two point six or I've also
Speaker 1: seen two point five four million light years from Earth
Speaker 1: and a light year will remind you is the distance
Speaker 1: traveled by a beam of light or or the photons
Speaker 1: technically in the space of a given year. So the
Speaker 1: light you see when you look to Andromeda, Uh, that
Speaker 1: left our sister galaxy two point six million years ago.
Speaker 1: So if we're to contend with this fact alone, the
Speaker 1: universe would have to at least be that old for
Speaker 1: light to have reached us at all. Uh, you know,
Speaker 1: given a magical finger snap creation of the cosmos. The
Speaker 1: thing about playing with with magic is that you can
Speaker 1: just make up additional Bologny answers of course and say, well,
Speaker 1: when the universe was created beams beams of light or
Speaker 1: photons created in transit to the destination. Well, if you're
Speaker 1: going to say stuff like that, I mean, you know,
Speaker 1: no no offense, you know, go in peace. But that
Speaker 1: you've just essentially surrendered having a conversation based on evidence.
Speaker 1: You've just said like, okay, well then I'm not interested
Speaker 1: in talking about what we can know based on what
Speaker 1: we observe. I just assume that magic is involved, and
Speaker 1: then in that case, why are we having the conversation? Right?
Speaker 1: But but I think it's fair to say that if
Speaker 1: you had a six thousand year old Earth within a
Speaker 1: six thousand year old cosmos, then then you would only
Speaker 1: be able to see things, You only be reachable by
Speaker 1: light within a six thousand light year radius. So there
Speaker 1: would be a six thousand light year visible universe. And uh,
Speaker 1: and we have a vaster visible universe than that, right,
Speaker 1: I mean, I wonder what if you are trying to
Speaker 1: imagine a younger universe and do astronomy, what do you
Speaker 1: make of the cosmic microwave background? What is it? What
Speaker 1: is that to you? Because of that, that's of course
Speaker 1: getting back to the very beginning. Um. But then there's
Speaker 1: other evidence as well. There there have been gamma ray
Speaker 1: bursts visible to the naked eye, UH that are further
Speaker 1: and older than, uh than what we were talking about
Speaker 1: with Andromeda and two thousand eight, astronomers clocked the stellar
Speaker 1: explosion RB zero eight zero three one nine B at
Speaker 1: seven point five billion light years away. And incidentally, this
Speaker 1: is one of five stellar explosions recorded on the day
Speaker 1: of author C. Clark's death on March nineteenth two thousand eight.
Speaker 1: Do you think he made it happen? Now? I think
Speaker 1: he would be mad if we thought that he did.
Speaker 1: Uh Hey, And if you drag the Hubble telescope into
Speaker 1: the fray, our limit takes takes us up to like
Speaker 1: what thirteen point four billion light years? You know again,
Speaker 1: that's light that that is that that can be at
Speaker 1: least technologically observed from our little corner of the cosmos.
Speaker 1: That's the radius of our view, not the diameter correct.
Speaker 1: So yeah, it's like we touched on before the astronomy.
Speaker 1: To to stare at the stars is to gaze into
Speaker 1: the past, a deep past, a past that dwarfs the
Speaker 1: entirety of human history, the entirety of of our our
Speaker 1: various stories about how the universe works and where it
Speaker 1: came from. But I mean, you can even extrapolate that
Speaker 1: back to the circumstance, the material circumstances of our own
Speaker 1: solar system. So it only takes light from our sun,
Speaker 1: you know, a number of minutes to reach us. But
Speaker 1: you can look at our sun and know that the
Speaker 1: universe is old. So one of the things is that
Speaker 1: the quality of our astronomical observation tools stellar astrophysics and
Speaker 1: computer modeling capabilities. Now let us know a lot about
Speaker 1: stars and how they form. And we know they form
Speaker 1: from clouds of dust and gas called nebulae that fall
Speaker 1: into gravitational collapse. They begin to coalesce and the heat
Speaker 1: up into what's known as a protostar. And we also
Speaker 1: know that this process of gas collapse takes a very
Speaker 1: long time. For instance, our Sun is a star that
Speaker 1: is obviously no longer a collapsing cloud of gas and dust.
Speaker 1: It's an adult star. It's a star that's performing fusion
Speaker 1: of hydrogen into helium. It's in its adult mature phase.
Speaker 1: And the time it takes for a star the size
Speaker 1: of our Sun to go from the beginning of collapse
Speaker 1: of the nebula into its adult phase. I was looking
Speaker 1: at some NASA materials on this that's somewhere around fifty
Speaker 1: million years. We can model that with the astrophysics knowledge
Speaker 1: we have, if the universe were not at least fifty
Speaker 1: million years old, our son could not be an adult star.
Speaker 1: But it gets worse because we also know that our
Speaker 1: son cannot be a first generation star. Our solar system
Speaker 1: is full of not just hydrogen. You know that, like
Speaker 1: the most abundant gas in the universe. It's full of
Speaker 1: heavy elements like iron. Where did all that come from?
Speaker 1: That's not primordial material. Heavy elements like that are forged
Speaker 1: in the deaths of other stars. So actually we know
Speaker 1: that not only did you know is our is our
Speaker 1: star an adult that had to grow up. Also, it
Speaker 1: can't have been a for generation star. It had to
Speaker 1: come from a previous generation of dead stars to create
Speaker 1: these heavy elements that make up things like the planets.
Speaker 1: And I have to say, you know, if this means
Speaker 1: that if if you if you cast aside this understanding,
Speaker 1: you can't have gold. And if you can't have gold,
Speaker 1: you can't have the Ark of the Covenant. And I
Speaker 1: and I have to say, like, how much cooler is
Speaker 1: the story of the Ark of the Covenant if if
Speaker 1: you factor in the fact that the Ark of the
Speaker 1: Covenant is made of this metal forged in the heart
Speaker 1: of a dying star. Oh, I think that's that's far
Speaker 1: more that that's far cooler, that's far more amazing. It
Speaker 1: is a radio for talking to God. But we can
Speaker 1: also I mean we talked about meteorites, so you can
Speaker 1: look at other objects in the Solar system and they
Speaker 1: also turn out to be quite old. They line up
Speaker 1: with our model of how old our solar system is.
Speaker 1: What about the Moon, Yeah, I mean there are there
Speaker 1: are a few different models for how the Moon came
Speaker 1: to be. The most popular scientific hypothesis is the giant
Speaker 1: impact or hypothesis. In this hypothesis, a Mars sized object
Speaker 1: hit the young, cooling Earth at an angle and this
Speaker 1: would have been This would have occurred about four point
Speaker 1: forty five billion years ago, and the impact or itself
Speaker 1: melted into the Earth, but debris from the impact went
Speaker 1: up and event eventually formed into the Moon. And this,
Speaker 1: according to the hypothesis, is why moon rocks are similar
Speaker 1: in composition to Earth's mantle and why the Moon has
Speaker 1: no iron core. Yeah, this makes sense. The the Moon
Speaker 1: looks like something that came off the Earth, but not
Speaker 1: from the core of the Earth. Right, It's an accretion
Speaker 1: of terrestrial shrapnel according to this hypothesis. You know, another
Speaker 1: totally different way of looking deep into the past that
Speaker 1: I've talked about before. I remember one time I did
Speaker 1: a guest episode of Tech Stuff with Jonathan Strickland about
Speaker 1: this is about ice core drilling. Oh yeah, yeah, So
Speaker 1: one way scientists study the atmosphere of the Earth long ago,
Speaker 1: like if you're trying to figure out what atmospheric composition
Speaker 1: was a long time ago. One way you can do
Speaker 1: this as you can drill down into ice sheets or
Speaker 1: into glaciers to pull up these cylinder shaped vertical columns
Speaker 1: of ice, and they will contain information interesting information like
Speaker 1: bubbles of gas trapped in ice layers from the distant past,
Speaker 1: or what the snow looked like as it was deposited
Speaker 1: each season in the past. And often these cylinder shaped
Speaker 1: ice cores come from Greenland or Antarctica, places where ice
Speaker 1: has been accumulating on top of itself for hundreds of
Speaker 1: thousands of years or more, and ice layers accumulate steadily
Speaker 1: year after year, giving you a very helpful map of
Speaker 1: past freezing seasons. And normally you can date this ice
Speaker 1: uh simply by counting the neatly ordered layers of yearly accumulation,
Speaker 1: especially near the top of an ice core. You can
Speaker 1: do that, though this method does become more difficult the
Speaker 1: deeper you go, because obviously you've got stuff like compression
Speaker 1: and stuff happening. So older samples can cross reference multiple
Speaker 1: dating methods to boost accuracy. Uh. These other methods can
Speaker 1: be things like correlating deeper layers of ice with known
Speaker 1: historical geological events like the deposition of volcanic ash or
Speaker 1: other geological markers. If you know when a volcano erupted
Speaker 1: and what that deposition layer looks like, you can see
Speaker 1: signs of that there. But there are some really old
Speaker 1: ice cores that we've that we've managed to pull up
Speaker 1: until last year. I think the oldest known ice core
Speaker 1: was about eight hundred thousand years old, and that came
Speaker 1: from a core drilled and Antarctica's dome c which was
Speaker 1: dated I believe using radiometric uranium decay. That's getting on
Speaker 1: down to that Lovecraftian city exactly, yeah, the Mountains of Madness.
Speaker 1: But in an extremely old ice core was drilled in
Speaker 1: a patch of what's known as Blue Ice and Alan
Speaker 1: Hills of East Antarctica. And in fact this was dated
Speaker 1: to two point seven million years old. Now, because of
Speaker 1: the nature of the blue ice patches where old ice
Speaker 1: formations are driven up from below, it couldn't be dated
Speaker 1: by like counting the layers, but it was dated by
Speaker 1: potassium or gone dating to two point seven million with
Speaker 1: a likely error tolerance. Of something like a hundred thousand years.
Speaker 1: So even just ice ice is not even rock. I mean,
Speaker 1: if you think about like ice should be melting and
Speaker 1: churning up all the time, we can find ice that
Speaker 1: goes back hundreds of thousands of years. So again, these
Speaker 1: are these are not like the only examples we could
Speaker 1: turn to. We could, it would be an exhaustive list,
Speaker 1: because virtually all the geosciences uh astronomical understanding, I mean,
Speaker 1: it all is based on this, and it all ties
Speaker 1: into this idea um of an old, much older Earth
Speaker 1: and a much older cosmos. Yeah, and so of course,
Speaker 1: as we were talking about a minute ago, a person
Speaker 1: whose theological beliefs to drive them toward believing in a
Speaker 1: young Earth can always simply say, well, none of that matters,
Speaker 1: because I have a supernatural explanation for the way things are.
Speaker 1: You know, there, it was just made to look that way.
Speaker 1: And if you believe that, as I've said, I mean that,
Speaker 1: I think that is the point where you may go
Speaker 1: in peace. Like you, it is possible you simply will
Speaker 1: not be convinced. But notice how much that type of
Speaker 1: explanation starts to resemble the invisible dragon in Carl Sagan's garage, Right, Like,
Speaker 1: if a belief is designed so that it can safely
Speaker 1: ignore all tests and all evidence to the contrary, why
Speaker 1: would you believe it? Yeah, And again I want to
Speaker 1: be clear, this is not aimed at religious beliefs in general.
Speaker 1: People have all kinds of ways of of being religious.
Speaker 1: And I'm talking about those specifically that make claims about
Speaker 1: physical reality and about history that encroach on territory for
Speaker 1: which we have good evidence about what actually happened. Yeah,
Speaker 1: areas where we're actually dealing with, um uh, the rejection
Speaker 1: of science or the twisting and replacement of science with
Speaker 1: a pseudoscience that supports a preconceived theological notion. Right. And
Speaker 1: so I guess maybe one question to end with is
Speaker 1: we started with these emails we've gotten from listeners asking
Speaker 1: for help sorting out these claims, and we get these
Speaker 1: emails else because people live in a world where they're
Speaker 1: competing claims against about the age of the Earth, and
Speaker 1: they don't know how to make sense of of the
Speaker 1: arguments coming from each side. And yeah, I've experienced this too.
Speaker 1: There are a bazillion Young Earth creationist arguments out there,
Speaker 1: and unless you literally devote your entire life to it.
Speaker 1: You're really not going to have time to investigate all
Speaker 1: of them for yourself and find out if they're correct. So,
Speaker 1: I mean, I think a fair question to ask is,
Speaker 1: how do you know when you can just consider an
Speaker 1: issue settled? How do you know when you can responsibly
Speaker 1: just start ignoring arguments that come from a certain perspective?
Speaker 1: You know what I mean? Robert? Yeah, yeah, Like, and
Speaker 1: we talk about it being the bedrock for person for
Speaker 1: a scientific understanding, but yeah, how can you know it's
Speaker 1: bed rock that you can build up up and on
Speaker 1: top of it, right, Because I mean, the scientific mindset,
Speaker 1: it doesn't say like, okay, now we've got a dogma
Speaker 1: and you just accept it forever and never question it.
Speaker 1: You know, you should always be open to evidence to
Speaker 1: the contrary. But how do you know when by paying
Speaker 1: attention to certain kinds of arguments you can be nine
Speaker 1: point nine sure that you are wasting your time? I mean,
Speaker 1: it's a great question because so much of the bedrock
Speaker 1: understanding of the natural world, you know, it's it's based
Speaker 1: on things that are technically theories. You know that we
Speaker 1: have theoretical understandings of things, and we have to proceed
Speaker 1: based upon those theories. Now, of course, we don't want
Speaker 1: to give the accidentally give the misimpression that a theory
Speaker 1: means a thing like is something we should not have
Speaker 1: good confidence in. No. No, you can have good confidence
Speaker 1: in a theory. Theory is above a hypothesis. Yeah, exactly.
Speaker 1: But I guess I'm trying to figure out where do
Speaker 1: you draw the line between. So here's one where most
Speaker 1: I think paleontologists think that the the we were talking
Speaker 1: about the cheek Schalube impact, right, that that was a
Speaker 1: major factor in the demise of the dinosaurs, right, But
Speaker 1: there are some who disagree. And so that seems like
Speaker 1: an issue where the evidence seems to be or at
Speaker 1: least the experts are largely on one side of the question,
Speaker 1: but there's maybe still legitimate controversy. Maybe we could find
Speaker 1: out the opposite is true. Maybe that impact was not
Speaker 1: the main factor in the dewise of the dinosaurs, And
Speaker 1: I can conceivably see that happening. The Young Earth does
Speaker 1: not feel that way to me, because it is it's
Speaker 1: so violates in such a fundamental way everything we know
Speaker 1: from every field that's you know, that's independently verified by
Speaker 1: the means of that field on its own. It seems
Speaker 1: like stuff that goes in the face of an old
Speaker 1: Earth is guaranteed to fail. Yeah, you're dealing with such
Speaker 1: drastically different ideas here. Yeah, again, just drastically different time scales.
Speaker 1: One matches up with our scientific understanding of the world
Speaker 1: and the other. As we have just been hammering home
Speaker 1: here in these two episodes, does not discovering that the
Speaker 1: Earth is young would be kind of like discovering that
Speaker 1: electricity not involve electrons. I would just want to just
Speaker 1: drive home. Like, if you're out there and you feel
Speaker 1: like your belief system keeps you from embracing science, um,
Speaker 1: I would encourage you to to look around and find
Speaker 1: and see if you can't find a version of your
Speaker 1: belief system that makes room for science and allows for science,
Speaker 1: because I can almost guarantee you that it's out there
Speaker 1: and there there are people out there who can hold
Speaker 1: on to the beliefs that you cherish and the culture
Speaker 1: that you cherish without rejecting science. All right, Well, on
Speaker 1: that note, we're gonna close this episode out, and we're
Speaker 1: just gonna remind everybody head on over to Stuff to
Speaker 1: Blow your mind dot com, because that is our mothership.
Speaker 1: That is where you will find all of our episodes,
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