Welcome to Stuff you should Know, a production of iHeartRadio.
Hey, and welcome to the podcast. I'm Josh and there's Chuck and this is stuff you should know. It's just Josh and Chuck today. Yeah, that's all right, don't freak out, Chuck. We're gonna make it. Just sorry.
I'm just glad we're recording. This is just a little inside baseball here. This is our third attempt at this recording. Sessh.
Yeah, well you diffuse my inside joke to you that I didn't have enough time to prepare for this episode.
So, yeah, my internet went out because of a windstorm last week, and then we were like, you were kind enough to be like, we'll just do it next Thursday. And then yesterday your internet had problems, and I said, well, let's just do it tomorrow morning, because you know, Friday morning at eight fifty five is when the voice is in perfect shape.
Right, which was also very kind of you. So we've been kind to one another throughout this ordeal.
At least you got to do that. People. If you want to stay married.
Yeah, definitely, you want the other person to hold your hand, you'd better be kind.
But I'm excited to finally and you know, probably it was probably good that I had a lot more time with this, because this is one of those sort of thought experimentee, get your brain in the right frame of mind kind of episodes, and we love doing these, and this is going to be a good one.
Yeah, for sure. So what we're talking about today, Chuck, is the Silurian hypothesis, which if I could do anything with this thing, I would rename it. I'd be like, guys, that was a terrible decision.
I keep listening everybody, so right, I promise is interesting.
So the whole thing came out of we'll explain in a second, but we should probably talk about where it came from and why we don't like this name. The whole thing came out of a meeting between a guy named Adam Frank who's an astrophysicist at the University of Rochester, and a guy named Gavin Schmidt, who's the big wig director for the Goddard Institute for Space Studies, a NASA joint. Yeah, and Adam Frank went to Gavin Schmidt and said, hey, I'm trying to figure out if we could find ancient
defunct civilizations elsewhere in you know, off of Earth. What would I look for? And the reason he was doing this. This is a it's an answer to the family paradox, where is everybody? Well, one answer is, well, they were here, but now they all died out. So Adam Frank is looking for evidence that they were there. And Gavin Schmidt said, let me just stop you right there and up the ante here.
Well, actually, you know what Gavin Schmidt said. What he said, let me tell you something, Professor Frank hey, and Professor Frank said, oh god, I had a dime for every time somebody did that, right, so so close. Yeah, Schmidt was like, hey, buddy, would you say I'll one.
Up, you'll up at okay, up.
The ante here? What if it's planet Earth? And what if there were ancient civilizations here? My friend? Yeah, and they said check please.
Yeah, Adam Frank just vomited directly all over Gavin Smith's desk, very famously.
Yeah. I mean, I think they sort of started chatting about this thing, and we should point out that, you know what we're gonna They wrote a paper. We'll get to that in a second, and they named it Silurian hypothesis. But neither one of them think like, oh I think this is what happened. It's more, you know, it's a thought experiment. It's what happens when two remarkably intelligent people get together sometimes and take LSD.
One of the other things about it that I think makes it worthwhile too. First of all, these guys are the first scientists to seriously explore the idea which you can apply science to anything like that, and sure they even though they don't think it's correct, they don't rule it out. Yeah, you can't rule it out. There's not enough information to rule it out right.
Yeah.
But the other thing that it does is that it provides kind of like a guide to see what we're doing now, what we're going to leave in the far future as well.
Yeah, absolutely so. I imagine they went to another venue, they went to a bar afterward to have a drink, keep this party going, and they were like, well, you know, there's been enough time for something like this to have happened, because when you look at the fossil record, the oldest thing that we know of is a cyanobacteria fossil that's about three and a half billion years old that was from the ocean. And if you're talking about complex life, then you only have to go back about five hundred
and forty million years ago to the Cambrian explosion. So like anything beyond that was you know, stuff like soundo bacteria that we know of at least, so any prior intelligent species wouldn't theoretically be older than that Cambrian explosion.
Yeah, they call it an explosion because everything went from single celled organisms like you were saying, to like basically all the types of animals on the planet today. Yeah, just like it exploded. It's just the best name for it. It really can't add to that. But there's another guy, another character we need to add here, and his name is Jason Wright.
I like this guy.
He's an astronomer at Penn State. And he said, whoa, whoa guys, And this is in a separate paper that I think even predated the Silurian hypothesis paper.
He was sitting next to them overhearing them at the bar.
Right, they were like covering their work while exactly so, Jason Wright says, not to them directly, but in general, he's like, Okay, we don't know that you have to stop at the Cambrian explosion to look for intelligent life on Earth. In the past. And the reason why is because we have a really like that's using a really limited definition of life. That's using the kind of life that has certain body plans with the cent nervous system.
Some have like backbones, some don't, some are jellyfish. Doesn't matter, Like, what if there's other kinds of life out there? What if some of those single celled organisms had gotten together and formed like a hive mind colony, right that was capable of intelligent industrialization. We wouldn't know that, like think out of the box, guys.
Yeah, exactly, because you know, it's hard to wrap your head around all we know is us and what happened with the development of how we got to now. Yeah, So he's like, you know, turn that off, everybody, because that could have happened what Josh Clark just said. And
they were like, who's Josh Clark? And they said, you'll find out sooner enough, he said, Or maybe there was another like Cambrian like explosion that happened like way way back before that, and maybe it's maybe they didn't leave any fossils behind, or so few that we didn't find them, or maybe you know, that was a cataclysm that destroyed everything,
like there was this complex life. It destroyed everything, and it kind of just rebooted the system with these single celled organisms, and that's what we know is the start, right, Yeah, And they yeah, whoa buddy.
I know it's pretty cool.
Can I pay for this guy's drink?
Yeah? Can I buy you a beer? So Gavin Schmidt and Adam Frank are like, we think we're onto something here. Let's let's kind of flush this out a little more. And I think it was Gavin Schmidt who suggested they call it the Silurian hypothesis. And the reason we call it the Silurian that's a I think a period or an epoch or something in Earth's history five hundred something million years ago. But they weren't naming it after that.
They were naming it after a race of lizard people who are characters on Doctor Who.
Yeah, do you watch Do you have any doctor who experience?
None? I feel like it's like this whole thing out there that's waiting for me to meet it, and I'm like, I don't know.
I mean, I've never I don't know anything about it. But I just caveat that because there may be emails coming in that are like they're not lizard like people. They are this like, I have no idea. I looked at pictures of them like you did, and they look like lizard reptilian type creatures.
They do. So that I mean for all INtime process is if you're not super into Doctor Who, they're.
Lizard people, I really really hope.
So the reason that they named it after this race of lizard people and Doctor Who is that on the in the Doctor Who universe, they lived about three hundred million years ago, which would actually make them place them in the Carboniferous period, not the Silurian and apparently all Doctor Who fans are aware.
Of that because they're all Doctor Frank's right.
But they supposedly survived a bunch of cataclysms here on Earth by moving underground hibernating until things cooled off a little bit. And now they're back in the Doctor Who universe, so they would like the ancient civilization. And so there's two reasons why I find the unfortunate that they named it after that. One it just makes the whole thing silly to a degree. Apologies to Doctor Who fans, but it it like this is an actual, like academic exercise.
They're engaged in. It has a silly thing out of the gates.
It's a tea. I mean again, we're not saying doctor who is silly, but it'd be like us coming up with like the Family Ties hypothesis or something right right, Like it's named after a TV show.
It says like before you even read the abstract, don't take this seriously. But it's meant to be taken seriously. It's not tongue in cheek at all. The paper isn't at least or the hypothesis. The other reason why is because every single author who wrote any piece or article about this hypothesis afterward uses a hypothetical lizard race to discuss what we would be looking for. And it's so obnoxious, man, So we're not going to do that. We're not even going to try to guess what they would be like
or look like. They're just the hypothetical ancient industrialized civilization that we're looking for. So if we're looking for something like that here on earth, Chuck, what would we start to look for?
Well? And I mean those are sort of the questions these guys started. I guess they went to another bar and started asking. They're pretty sloshed at this point, that's gonna say, and they start asking even more questions. I guess after they got over the I mean, hopefully they didn't have to argue about Silurian. I'm praying they were both Doctor Who fans and that doctor Frank didn't have to convince Oh Gavin, you know, I think it might.
Have been the other way around, and based on titles, I think Frank would have had to go along with it.
Okay, Well, either way, they started to sort of ask these big questions, and what it really comes down to are two main questions, what should we be looking for? And in order to think about what should we be looking for, a good place to start art is well, what are we leaving behind that a future archaeologist or geologist might look for?
Mm hmm.
And when they started poking around a little bit, they found that, you know, there's some stuff here that that does bear a resemblance to like possible signals that something could have happened as far as an ancient industrialized civilization that just went away.
Like you can't hear it, but my jaw just dropped.
All right, Josh's jaws on the floor. We're going to seek some medical attention, and we'll take a little break and we'll be right back.
Definitely, child.
Y s K.
Stucks.
I don't know that you know it stuck and sucks that.
It's a great name.
I could remember.
That's the name of it. It's a great name. All right, stucks net with an X.
All Right, So we're back, and we were talking about where you might or what you might look for if you're looking for a previous advanced civilization and sort of the obvious first place. You know, we're going to start
easy and get a little more complex here. It's just like all the all the physical stuff, Like if you're an industrialized, intelligent civilization, you're going to have industry and cities and factories and things and skyscrapers and buildings, and it's hard to wrap your head around all that stuff being gone one day when you're living amongst it. But like the life of a skyscraper is about fifty years
without human intervention to you know start. You know, that's why when you go to New York, every building has scaffolding on it practically, because you have to keep those buildings up. They start falling apart because of corrosion and erosion. So without that, even though it's hard to imagine, everything will eventually be gone. And we're talking about in the grand scheme of the big, big timeline, so like hundreds of millions of years.
Yeah, yeah, but for a city itself, I mean, apparently water intrusion is a big problem for all of those tall buildings as well as erosion and corrosion and all that. They're like, it's not going to take millions of years for them to go away. We're talking thousands to tens of thousands of years.
Yeah, and our.
Cities will be just completely rubble, especially ones that are built on like solid ground or rocky ground well above sea level, because those are the ones that are most like open and left vulnerable to the processes of erosion that sweep across Earth's surface and wipe the whole thing clean.
And yeah, it wouldn't take very long. The stuff that's underground might be a little more easily preserved, like they're you know, any under any city, there's a huge network of infrastructure of pipes and cables and tunnels and hard hats and stuff like that that conceivably, even after the city above is long gone, that stuff could could be preserved to a certain degree.
Yeah, for sure. And we should shout out this guy that did you dig him up? Or was that Livia I think found him. Yeah. His name is it starts with the J, but as yan Zeala Schevitz, and he's a paleontologist at the University of Lester. Nice work, oh boy in the UK. And we shout him out because he, you know, he sort of let us down this path of looking underground, potentially looking underwater because things would just deteriorate a lot slower down there. But he's just a guy.
I just want to recommend if you're if you want to get into some heady sort of YouTube stuff, just google yan Zella Schevitz. It's z A l A s I E V I c Z. Because I went down a little because we had so much extra time, just a little bit of a rabbit hole. This guy, he has a bunch of YouTube where he speaking to the university groups and classrooms and things, and he's just super smart and interesting.
Yeah, the stuff he's into is super cool too. But yeah, he himself gets it across really well.
I like it.
Yeah, so he points out he was the one he I think he chose San Francisco. Like San Francisco's a goner. It's not gonna be around very long once we're gone. And by the way, I keep saying once we're gone. Remember that amazing two thousand and seven book The World Without Us by Alan Weisman.
Never heard of it?
Oh, yes you have. It was like all the thing back in two thousand and seven. They made like TV shows about it and all that. So this guy basically went to the trouble of figuring out in five years, ten years, fifty years, one hundred years, thousand and so on. That sounds familiar what the planet would be like, yeaf if humans just suddenly vanished, And like he goes into detail of like the processes of erosion and crosion, what effects it's going to happen. It's just so fascinating.
That's super cool.
Yeah, it is super cool. Like the series, at least one series I think on like Science Channel or something like that was what was worth watching too. But that's I mean, that has a lot to do with what we're talking about. So the top side city's gone, the stuff underneath might be preserved, but the cities that are built along water and there's a lot of cities that are built along water. Yeah, they like say New Orleans
is actually built below sea level. When people are gone from New Orleans, New Orleans is gonna go away really quick, but it will probably get preserved or at least covered over, if not preserved by a lot of the muck, the delta muck that's brought down the Mississippi River, and that will could conceivably create the conditions to preserve the whole city in some form of fashion.
Totally. But and you know, a lot of the thought experiment is like introducing things and poking holes in it. There's not a lot, like you know, if you lived in an urban area. It's kind of hard to think that there's not much urban area in the world, but there really isn't. I think the liberal estimates have it at about a little less than three percent, like two point seven two point eight percent of the world has been urbanized. Some people put it as low as one percent.
So there's there's a lot of just land out there still. So you're looking if you're looking for an ancient civilization, I mean, who's not to say that it could have been like fifty percent of the earth, But chances are it would be something a little more like what we're doing.
For sure, And so like you were saying, like, that's one of the cool things about this as a thought experiment, Like you raise this point and then you like poke holes in it, then sometimes you can kind of support it instead. And so, like a legitimate question would be, like, why are we assuming that an ancient civilization from millions of years ago in Earth's history had cities? Yea, and
point the reason why if they have any kind of intelligence. Typically, the more of an intelligent organiz you put together, the more advanced it becomes. Like twelve thousand years ago, there was something like fifteen million people across all of planet Earth tops. But then as we started to grow in density thanks to agriculture and animal domestication, all of a sudden, our technology started to develop at a really rapid pace geologically speaking,
and now here we are. So we could assume that there'd be some form of density, because you need x number of intelligent organisms to advance to an industrialized civilization, one would imagine, So there's actually a legitimate reason to think that they would have cities that we could look for the problem is this, Chuck, and you know this as well as I do. We'll see the Earth does not like things like cities and ruins or fossils. Let's talk about fossils.
Yeah, I mean that seems to be the next best place to start looking. If let's say the buildings are gone, fossils are or how we know what happened in our distant past. But fossils are tough, just because of how rare they are and how hard it is to make one, and how sort of lucky it is that they happen to begin with, and that we find them. The t rex is a great example, just a little like back
in the envelope math. Some estimates say that somewhere in the neighborhood of twenty thousand t rexes at any given time during their run, we're walking stomping around planet Earth with their tiny little baby arms. They were around for about two and a half million years. That comes out to roughly one hundred and twenty seven thousand generations on
the lifespan of a t rex. So we're talking total, roughly, of course, about two and a half billion individual t rexes that lived and died at any point in their history, and we only found fifty fossilized skeletons, which is about two millions of one percent of the total population.
Yeah, I should forewarn you that two millions of one percent is my math personally, but I did use an online percentage calculator like three different times to make sure so it's it's accurate.
My friend, Oh, I know the math people are always checking checking you. I was about say, getting your back, but really trying to.
Prove you're getting I got a target on my back, that's what they're trying to get.
Uh. But you know the movie Jurassic Park, as silly as some of that stuff was with great movie, don't get me wrong, but you know the the mosquito being covered in amber, Like if you if you look at that movie, like that one mosquito got trapped in amber.
And that's kind of what we're talking about here, is just sort of the dumb luck of the fossil happening to begin with a and then that fossil that's buried eventually getting pushed up to the Earth's surface where we can find it, right but within the window between it popping up and it being findable to it eroding to where it's not findable anymore. It's like it's it's all.
I mean, that's why we don't have, you know, billions and billions of fossils, is because it's just really rare to make one and find one.
Yeah, not just making one, but yes, finding one. It's all a product of time and space and a really complex formula. And I saw an article called how Can I Become a Fossil? By John Pickerel from twenty eighteen on BBC really well worth reading.
Did it start listening to the Doobie Brothers.
Nice, Oh yeah, rip Dicky Bets.
Huh well not Almond brothers, but sure, well yeah, I know I knew that, but yeah, okay, I mean they're both brothers. Yeah yeah, same time period, Rip Dicky Bets. That was that was a tough one.
If you had been in my brain, it would have been no, I got yeah, of course.
And it's also nine twenty.
So John Pickerell cited an estimate that one tenth of one percent of all the species that have ever existed has had one of their individuals fossilized. Oh wow, so just really tiny, tiny percentages of fossils are ever created. But and also I got to just say this quote too. There's another article called the scene as a joke.
Yeah, I thought you were going to skip this one. This is great.
Yeah. A guy named Peter Brannan who's a science writer, wrote it, and basically he's explaining like just how insignificant humans have been on Earth, even as much as we've affected Earth. It's just how insignificant it actually is, and how easily Earthball shake our our stuff off. Yeah, but he had this great quote. I think you should say it.
Oh, okay, do you know where he's from so I can prepare.
No, let's say Austria, Cherk.
I mean, I guess that's sort of German. I'm just going to read him as American. This is this is a great quote. Each fossil was its own miracles, sampled randomly from almost two hundred million years of history. A few stray, wind blown pages of a library.
Isn't that great?
Yeah? That really drives it home.
It really does. So hats off to Peter Brandon and John Pickerel. Definitely go read those and also go watch youtubes of Yon Zelhevich, z Lushevich.
Right, Zela Schevitz kind of likevitz.
Right but with a Z.
Yeah.
So all of that said, though, we have discovered really really old fossils. The oldest hominid our ancestor, the oldest indisputable ancestor to humans, Australipithecus and amensis, was walking around four and a half almost four and a half million years ago, and we have a skeleton of that guy. So as miraculous as fossilization and discovery of fossils is, it does happen.
Yeah, absolutely, And that's hominids are our old buddy. Yan Zelisovitch is like, you know what else could happen is we're creating a bunch of potential techno fossils as we advance, Like somebody could find a smartphone one day, somebody could find a grocery bag that's been fossilized. Sure, the more likely thing that's going to be found is not some smartphone that you could plug in and then reboot.
Right, they'd be like, let's see what pictures this guy.
But it might be something like a brick or a glass bottle that's you know, that clearly human made, that's like artificial in shape, and it may be stamped with like a company name or something like that. Like something like that is more probable for a future anthropology archaeologist to find as a techno fossil. Yeah, so, or plastic, right.
Plastic is another good one. We actually don't know how long it takes plastic to break down to its constituent parts. We know that it breaks down into really really small particles, but there's still like microparticles of plastic. It's like intact particles of plastic. Right, And if a future like race discovered our plastic, they'd be like, this is really bizarre. Yeah,
because by definition, the plastic we make is artificial. There are like polymers in nature like cellulose that are an analog to our plastic, but all the plastic we make is not found in nature. So if they found that, they'd be like, this is kind of weird, what's going on with this?
Yeah, for sure.
And then chicken bones too, chuck, hmmm.
Have you ever seen there was an Instagram account it may have been called Atlantic Chicken Bones that we're just these great pictures of chicken bones in parking lots and sidewalks all over Atlanta.
Right, So that's a really great point. There's the people who are like all bully on the anthroposceine, the idea that the humans are creating our own geological era or epoch, say, like chicken bones are probably a pretty good bet for
like fossilized evidence of our presence. Because we raise and kill so many chickens at Box the Mine, their bones get everywhere, and they are anatomically different from all other kinds of chickens because we've bred them to be different, like have huge breasts and not be able to walk in all sorts of terrible stuff. So if you found other chicken bones in the fossil record, and then you found our broiler chicken bones, you'd be like, what is this? And also why are they in Antarctica?
Right? I also want to point out, since I brought up Atlanta chicken bones, I am a lover of fried chicken, as you know. Yeah, it's probably my favorite food. And I have been known to have car chicken.
As long as there's no shower chicken, I'm still that's still fine on the sand that.
No, you want to keep it crispy, you don't want any humidity in there. But I've always resisted the urge to toss my chicken bones because I have dogs, and I walk dogs, and if you're not paying attention, that dog can snap up at chicken bone on the sidewalk pretty easily. So just a psa there, try and keep those chicken bones in the box.
Yeah, and chicken bones can splinter so readily that it can really hurt your dog's throat stomach. You don't want a dog eating chicken bones.
Okay, Yeah, did I ever tell you this will be quick about when my deceased dog Buckley ate an entire drummet that fell off the grill. No, it popped off many years ago Buckley left us, But I looked down. I was like, oh, shoot, chicken bone or chicken drummet, and it was just gone. And it was gone so fast, and Buckley was there, but I was like, he wasn't chewing or evening. I was like, what happened to that thing? Ten minutes later? Oh no, he barfs up a hole.
He swallowed it whole, a whole chicken drummet that was still steaming from the heat of the grill.
So good.
So it was like, I mean, thank god he did that, because that would not have been good.
No.
Yeah, he swallowed that thing like a pill, and then.
When he threw up, he wiped his mouth.
He's like, totally right, yeah, I think he thought it was worth it.
So I said something earlier, Chuck, we were talking about ruins, fossils, all that stuff. I said that Earth doesn't really like that kind of stuff, and I was right.
Are you setting me up?
Yeah?
Yeah, Well, because here on Earth we have plate tectonics, we have a situation where if you're talking about the ocean crust, it subducts below the lighter continental crust and it's going to push everything down, down, down toward the mantle where it melts and then eventually comes back up via like a land volcano, maybe an undersea volcano, to form a new crust. And it's just like this this giant, super super slow recycling conveyor belt.
Yeah, it takes I think, on average, about two hundred and fifty million years for new crust to go through that whole cycle. That's just on average. It can take hundreds of millions of years longer. Yeah, take less, but that's just kind of generally how slow it is. The point is is that after X number of millions of years, that crust is what and everything attached to it is totally gone. Once it hits that mantle, it doesn't discriminate
everything gets melted. Everything gets melted in the middle. What about on land, Well, land is not subject to the forces of like subduction, right, but it does have that erosion through wind and water, and everything just kind of gets recycled in its own way. Plus also the plates that do collide with one another, and there's you know, continental fault lines obviously too, that produce earthquakes when they collide. The stuff anywhere near those edges gets all kinds of
messed up. Yeah, and that's how a lot of mountain ranges form. And then there's the Himalayas. The thing is is that erosion, that process of erosion that completely recycles Earth's surface over X number of years. An eighty eight million year, the Himalayas will be gone. It'll just be a meadow where they's.
That's one of my favorite sort of facts of the show right there. Yeah, it's hard to imagine this stuff, but yeah, what is it eroding at like point one millimeter per year? And again we're talking these we're talking on timelines of hundreds of millions of years here, right, So eighty eight million years, Yeah, that's it just go romp in the meadow.
Yeah, because even if we're just going back to the Cambrian explosion. And you can argue that you can go back further like Jason Wright did. But even if you're just going back five hundred and forty million years, that means continental crusts have like reinvented themselves twice since then. Yeah, the Earth's surface has been recycled countless times. Apparently the oldest surface stretch of Earth is only is like less than two million years old.
Oh geez, that's really young. Yeah.
And the reason all this stuff is hard to imagine, like the Himalaya is going away, is because our sense of time is so limited to about the span of a lifetime, yeah, plus a couple of decades. Maybe that when we start to think a tens and in hundreds of millions of years into the future of the past, we just stop. It just doesn't It doesn't really make sense to us unless we really apply ourselves with episodes like this.
Yeah, exactly.
So you've got plates colliding, you've got glaciers do all sorts of They move entire regions around like bulldozers. But even something as humble as the movement of earthworms through the soil over enough time, that's going to erode fossils, ruins, subterranean networks of pipes, and essentially we're back to square one trying to figure out what to look for for an ancient civilization.
Are we done almost? All right? Maybe we should take a break and we'll come back and talk about why we're striking out and where we go next.
Definitely should also stuck.
You know what, Stuck.
That's a great name.
Yeah, that's the name of it.
It's a great name. All right, stucks net with with an X. Okay, chuck. So we've seen that we can dismiss the archaeologists, Thank you everybody, and bring in the geologists.
Yeah, like, take your take your whip, take your fedora, pack it all up, go take a break because the geologists are on the scene. You can doctor Jones, you can take a seat.
Right, So, I can't even like, what are the geologists like? They just they don't have a movie franchises like the archaeologists do.
Yeah, I mean they're not looking for grails, they're looking for residue. So it's not it's grabby.
Yeah, I guess they're the thing that you most associate with is like a slight coffin a really large, empty room.
Yeah, like there the would never be a movie called Indiana Jones and the Ancient Tree Ring. No, you know, no, unfortunately. But that's what we're talking about, is the fact that if we were to have a future geologists look back, that's what they would likely be looking for. Like, forget the fossils, They're gonna be looking for just little bits of residue by looking at these tiny little layers of sediment that we deposit every day all over the place
that eventually becomes rock. And this is how we know look back at our own past to learn things. That's how we knew that the dinosaurs were exploded basically because of that asteroid, and that Cambrian explosion happened because we have studied geology.
Yeah, we've learned to study those layers that get put down and put down. And the problem is on Earth's surface, as we've seen, there's the process of erosion, and there's an entire layer across the whole globe. It's not just in one spot, but there's a billion year stretch of the geological record that's just gone. It's missing this. Yeah, I hadn't either. It's called the Great Unconformity. And like we'll just never know what was there, what happened during
that time, because there's no record of it. They think that it was just a period where there wasn't a lot of sedimentation put down, but there was a lot of erosion.
Yeah.
So some people suggest that it was during Snowball Earth one of those periods where like ice sheets cover the entire globe three miles thick, and that they could erode stuff, you know, pretty cleanly across the globe. It's a pretty good, pretty good theory. But stuff like that happens. So when
we're looking on Earth's surface, you run into problems. But because that oceanic crust takes so much longer to recycle, we could look there and conceivably find something hundreds of millions of years old.
Yeah. I also got to say Snowball Earth is I mean, that's the next great Netflix show waiting to happen.
Maybe that's about an adventurous geologist.
Maybe, so I love it. So, Yeah, going back to underwater seems to be a better bet than because of stuff like the Great Unconformity. Going back underwater, where that process is of wearing stuff away is much much slower, is probably a better bet for us and a better bet for future geologists.
Yeah, because all the stuff that enters the ocean, or is born and lives and dies in the ocean, it becomes detritus that eventually tumbles down to the ocean floor and it gets locked in as sediment there, and it happens really really slowly, Like I think zero point eight centimeters every thousand years is about the average sedimentation. So that means that so far we have accumulated about point one six centimeters of ocean sediment that would bear our presence,
possibly even bear the signals that we ever lived. But we're doing we're adding to it every day thanks to things like nitrogen fertilizer that we overuse that enters the water sheds and eventually goes to the ocean and then goes and gets trapped in sediment. And so if you were a future archaeologist or geologist and you were looking at the layer where we existed, you'd be like, what is all this nitrogen suddenly doing here? And then also what are these weird polymers that used to be our plastic?
From all this stuff, all the plastic that ends up in our oceans, those will eventually fall down to the bottom and become trapped in the sedimentary layer. Two.
Yeah, so that super soaker that your kid lost beyond the point where the waves would bring it back in is eventually going to end up at the or the trash that is floating around the ocean. All that stuff
is going to go down as well. And so this is going to lead behind like a trace, a sediment trace, where a future geologist might say, well, hey, I see that there was this specific time period one hundred million years ago where there was a spike in nitrogen, or a spike in these weird human made polymers, or maybe they didn't know that there were humans.
But either way, like we're lizards.
Yeah, something that doesn't jibe with what we have going on today. There are all these weird spikes, So there was clearly something going on in this time that we now think of as our time here on planet Earth.
Yeah, because that's how we we find mysterious signals in the geological record. You compare it to what's above and what's below it. And if something suddenly appears or disappears, you know, like it's like look here, look closer here. Now radioactivity will probably be a marker that will be behind two from all the nuclear tests, there'll be plutonium two forty four and iodine one nine, which have half
lives in the millions, tens of millions of years. If we end up going out in a massive nuclear war, you bet that will leave quite a signal in the geological record. And one of the other things about leaving like a record in oceanic crust is that the Earth goes through cycles of like cooling and warming and cooling and warming, and when it cools, the sea levels decline.
It gets sucked up into ice, and so what's under the ocean may end up hundreds of miles inland, right future archaeologists to find, probably more easily than they would if it were underwater at the time.
Yeah, for sure. So you know, sort of striking out all over the place such that our old astronomer friend Jason Wright is like, maybe Earth is not the place to look. Maybe you should be you know, we should be looking on a place like Mars that doesn't have plate tectonics and is probably a better, more hospitable place for some ancient thing to be discovered one day.
Yeah, and not necessarily a Martian civilization, but an intelligent Earth civilization that sent probes to Mars or something like that. The European Space Agency also points out that if anybody had been around to send like a probe out into geosynchronous orbit the furthest reaches of geosynchronous orbit around Earth, it would still be there. It's orbit wouldn't have collapsed yet. So you know, we need to look for sixty six
million year old probes spinning around Earth. That's a good good start too.
Yeah, so all of this sort of presents a paradox it's pretty interesting, which is that if you're going to be an industrialized civilization that lasts long enough to leave something behind for some future geologists to find, then that means that you found some sort of sustainable way to survive. And if you found a sustainable way to survive, that means you're not making as much of a findable im
packed on Earth. You're living more sustainably, and so you're not dumping plastics into the ocean or nitrogen into the ocean and sort of cleaning up your act and erasing your path a little bit better. If you're not doing that, then that means you haven't found a sustainable way to live. So that means you're going to as society die out much quicker, so you're going to be just a shorter blip. So either way, it's just going to make things more difficult.
Yeah, whether you're long lived or short lived, the record you leave is going to end up just being a blip in the geological record.
Right, Yeah, again on that huge timeline.
So like, I'm sure some people are pulling their hair out. They're like, how then, like it is even impossible to find signals that an ancient civilization existed or what signals will we leave too? And yes there are, And what you want to look for is not like traces of fossils or strange appearances of elements in the geological record
and sediments. Instead, you want to look at the impressions that the effects of those things had on Earth, because those get locked into geological records and they can stay around for a very very long time, so much so that we can look back into Earth's far, far far distant past. Yeah, and we see signals that were like, can't rule out that this some industrialized ancient civilization produced these effects on Earth because we don't know what.
Happened, yeah, exactly, And what we're talking about is something called a hyper thermal event where three things kind of line up, which is an abrupt extinction of maybe not everything, but many, many, many species. That's pretty obvious. That coincides with a build up of carbon in the atmosphere and
a lot of rapid coastal erosion. All of those three things happening at once is called a hyper thermal event, and it's a pretty good indication that something really really big happened to wipe out most.
Yes, and usually the hyperthermal events we found are caused by negative carbon isotope extrusions, which is basically just a different way of saying a ton of organic CO two was pumped into the atmosphere and it had all of these telltale marks, sea level rise leading to erosion, mass extinctions, dogs and cats living together, all that stuff, right, And so if we look in the past, there are events that coincide with this. One of them is the Paleocene
Eocene Thermal Maximum, the PETM. It took place about fifty six million years ago, so basically after the dinosaurs died out and right after mammals started to take over Earth, it got really hot. And I was trying to figure out how hot the surface tempts and the Arctic Sea were about seventy three degrees farrenheight twenty three degrees celsius. That's what you find today around the Panhandle in the
Gulf of Mexico. These are the Arctic seeds today. The global annual surface temperatures about fifty nine degrees farent height fifteen celsius. Yeah, back then it was ninety degrees farent hyder thirty two degrees celsius. Like, that's the global temperature, the average across all of the globe. So it was really really hot. And they have traced that to tons of carbon dioxide suddenly appearing in the atmosphere causing all these changes.
Yeah, and that lasted for about one hundred thousand years. But that's not the only one. There have been other events similar to that in the Cretaceous period, in the Jurassic period, in the Palaeozoic era, and then in the six million years since the PETM the Paleocene Eocene thermal Maximum, there were even more of those hyper thermal events. And again they sort of all bore the same similarities, right.
Yeah, because there's only so many ways that Earth responds to being messed with yeah, and so like all of these things kind of do bear a strike similarity, and there are things, there's natural things that you can point to that could have caused them, like massive volcanic activity across Earth, or a sudden huge depositive shale ended up in the mantle and got recycled very quickly, and all sorts of CO two was released in the air. Who knows. But what Schmidt and Frank basically point too is like,
and again they don't think this is correct. They say, like, you can't rule out, yeah, that this is a marker of an ancient civilization creating climate change in exactly the same way that we're creating climate change today, because we are laying down the foundations of a geological signal that will be detectable hundreds of millions of years in the future as a hyper thermal exactly like the ancient hyper thermals we've discovered in Earth's past.
Yeah, which is basically, if we do ourselves in with climate change.
Yeah, because they're predicting if we just keep going with fossil fuels just for the rest of the century, by the end of the century, will have increased the global temperature by about four point eight degrees celsius, which is huge. Is that qualifies as a hyper thermal maximum, and that PETM like the biggest hyper thermal maximum that ever happened all of a sudden, that took place over like one
thousand plus years. We're doing this in a couple hundred years, so it will really stick out in the geological record.
Yeah. I think the PETM had a five to seven celsius degree rise, and if we're looking at four point eight in that spend of time, that's trouble.
Yeah, and that's just by the end of the century. Who knows if we just keep going. We're not quite sure when the whole thing will study itself out and what the peaks will be when it does, you know.
Yeah.
So there's one other thing that I found really interesting is that the fossil fuels that we're using to create inadvertently this hyperthermal and Earth's geological record is create from the mass extinctions from the past. Those die offs turned into fossil fuels that we use today to essentially add all that carbon to the atmosphere, which is creating these
warmer conditions. Yeah. And then if you take it one step further, We're eventually going to create these mass extinctions that will create the fossil fuels for another industrialized civilization to come tens of millions of years in the future.
That's right. We're just insignificant, aren't we. Yeah, but also overly significant somehow.
That's right. If you really want to get that driven home, go read Peter Brandon's The Anthropistine as a joke. It really it almost made me feel like fine about climate change because it just in the grand scheme of things, it's so insignificant. I had to be like, no, no, it matters. It's important. Stop thinking like that. Yeah, uh so you got anything else?
I got nothing else. This is long a way did for us and a lot of fun.
Yeah, let's hope we remembered the press record.
Oh god, I would just retire.
Well, since Chuck said he would just retire, of course, that means he's triggered.
Listener mail, Yes, this is a story from Dylan. This is one that I know about or knew about, but I don't know if we ever talked about it. But it's a pretty interesting little thing. Okay, hey guys, I've been listening to you for about two years. Helps cut down on my commute and I often learn a lot
during the hitchhiking up. You were talking about the Curb Your Enthusiasm episode where Larry David picks up a sex worker so he can ride in the carpool lane to a Dodgers game, and I wanted to let you know something about that episode. Did you know this?
No? I thought this was amazing.
Yeah, that episode was actually used to help secure an alibi for a man, Juan Catalan, who is arrested for murder. They filmed the episode during an actual Dodgers game, and it just so happened that one and his family were sitting in the same section as Larry David when they were filming, and Wan's lawyer used the raw footage from the episode to help exonerate him. So they picked up this guy for murder. Yeah, and they proved him wrong thanks to this Curby Your Enthusiasm footage. He was like
he was at the Dodger game. He couldn't have done it.
God did not want one in jail.
Amazing. There's a short documentary on Netflix called long Shot, and it is truly one of the stories you can't believe is true. Thanks for the years of entertainment. I love sharing the knowledge with you guys, food Listener mail, Stay positive and keep testing negative. Dylan.
Awesome, Dylan, You're a cool cat we can tell. Thanks a lot for that great email. That was amazing and we will definitely go watch Long Shot very soon.
Totally.
Do you want to get in touch with this like Dylan did, You can send us an email. Send it off to stuff podcast at iHeartRadio dot com.
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MHM