Space Archaeology with Sarah Parcak

Who really built the pyramids? Neil deGrasse Tyson and Chuck Nice learn about space archaeology, LIDAR, and discovering tombs, pyramids, and new Nazca lines with space archaeologist Sarah Parcak.

Speaker names marked ? are inferred from speaking time and the show’s known hosts — they are not voice-verified.

• 0:00Neil deGrasse Tyson?

  Chuck, I think everyone should have their own personal archaeologist.

• 0:03Chuck Nice?

  Is it Indiana Jones? Yeah, I'll take that.

• 0:05Neil deGrasse Tyson?

  You just never know when you need one.

• 0:07Chuck Nice?

  That's true. Exactly. You never know where you're gonna end up on a dig and be and and just be curious.

• 0:12Neil deGrasse Tyson?

  Just be curious.

• 0:13Chuck Nice?

  What's buried here?

• 0:14Neil deGrasse Tyson?

  What is that and why?

• 0:15Chuck Nice?

  Yes, exactly. I I need an emotional archaeologist is what I need.

• 0:20Neil deGrasse Tyson?

  Dig into your mind.

• 0:21Chuck Nice?

  I've just been burying so much over the years.

• 0:25Neil deGrasse Tyson?

  All right, a little bit of space archaeology and more coming right up.

• 0:31Neil deGrasse Tyson?

  Welcome to StarTalk, your place in the universe where science and pop culture collide. StarTalk begins right now.

• 0:44Neil deGrasse Tyson?

  This is StarTalk. Neil deGrasse Tyson here, your personal astrophysicist. Guy with me Chuck Nice. Chuck, baby, how you doing?

• 0:51Chuck Nice?

  What's happening, Neil? How's it going?

• 0:53Neil deGrasse Tyson?

  All right, we got a topic today we've never covered before.

• 0:56Chuck Nice?

  Yes, that's correct.

• 0:57Neil deGrasse Tyson?

  We've been doing this for more than a dozen years.

• 0:59Chuck Nice?

  More than a dozen.

• 1:00Neil deGrasse Tyson?

  It's never come up. Today, we are devoting to space archaeology.

• 1:05Chuck Nice?

  Oh, look at that.

• 1:07Neil deGrasse Tyson?

  Okay, just to be clear, it's not going to the moon digging up fossils.

• 1:11Chuck Nice?

  Because there's none there.

• 1:12Neil deGrasse Tyson?

  Well, well, no, there's there could be a reason for that, but we'll get to that later. This is specifically using space assets to help the archaeologists do their job.

• 1:24Chuck Nice?

  Oh, okay, so basically, they just hijacked your field. That's what they did. They jacked your equipment. It's just jet, the satellite jacked you.

• 1:38Neil deGrasse Tyson?

  I think they had permission. It was not a gunpoint. So we we combed the world and there are people who are experts in this. And we found Sarah Parcak. Sarah, welcome to StarTalk.

• 1:50Speaker 02

  Thank you. Thank you so much for having me. I'm thrilled to be here.

• 1:53Neil deGrasse Tyson?

  And I pronounce your last name correctly, Hard C, Parcak.

• 1:56Speaker 02

  Parcak, correct.

• 1:58Neil deGrasse Tyson?

  Sarah Parcak, archaeologist, Egyptologist. Egyptologist, that always sounds so cool. You're a PhD in this from University of Cambridge back in '05, and now you're Professor of Anthropology, University of Alabama Birmingham. And I love this.

• 2:14Speaker 02

  Right.

• 2:14Neil deGrasse Tyson?

  Founding Director for the Laboratory for Global Observation at that university. And recently you have a book sensibly titled Archaeology from Space: How the Future Shapes Our Past. Henry Holt, we share publishers in that name.

• 2:32Speaker 02

  Oh, cool.

• 2:33Neil deGrasse Tyson?

  One of my recent books is from Henry Holt. And is this true? You wrote a textbook, the first textbook on satellite archaeology, which means you wrote the book on the subject.

• 2:47Speaker 02

  I actually legit wrote the book. I did.

• 2:50Neil deGrasse Tyson?

  Wow.

• 2:52Neil deGrasse Tyson?

  Okay, subtitle Satellite Remote Sensing for Archaeology, published by Rutledge, a good academic publisher there. And you're founder and president of Global Explorer, E X spelled just with an X, a not-for-profit company using tech to protect and preserve cultural heritage. I want to learn more about that at a moment. And you've also collaborated with NASA and the US State Department. So you are the right person for any question we might have on the subject. So let's get right in. Since you did write the book on this, what is space archaeology? Just put us on the same page here.

• 3:29Speaker 02

  Sure. So space archaeology is the use of sort of the general fun description or term for any use of space-based assets to map archaeological sites, whether it's, you know, NASA satellites, commercial satellites, drone imagery, data taken from airplanes. It's any kind of remote information that you might use. Um, to locate, whether it's a whole ancient archaeological site, whether it's a specific feature on a site, or whether it's looking for things like, you know, buried ancient river channels that may show how and why ancient settlements moved over time. Um, and you know,

• 4:11Speaker 02

  that can be called satellite archaeology, remote sensing for archaeology, but actually NASA has a space archaeology program that funds scientists to do exactly what I do. So I figure if NASA calls it space archaeology, then it's a legit name.

• 4:26Neil deGrasse Tyson?

  Okay. So Sarah, you need some more convincing for me of what you do, only because when we use NASA to look at other planets, their surfaces and the like, it's because we can't go to the planet. So we need space assets to zoom in in places we cannot go. And so now you're telling me that a satellite either parked at 23,000 miles up or orbiting hundreds of miles up is somehow going to serve you better than you just putting your ass on location with a trowel? So tell me why one is better than the other.

• 5:05Speaker 02

  So, so that's really the fun part. And the, and the whole point is to get somewhere on the ground to do survey, to do mapping, to do excavation. But you know, anytime you're doing archaeology, you know, if everything were already visible, we wouldn't need to dig, right? So these are features, these are entire cities, these are pyramids, these are tombs that have been covered over time by sand or soil or dense rainforest. And so what the satellites allow us to do is whether, you know, whether we're using different parts of the light spectrum. So think of it like a space-based x-ray or MRI. We're able to look at an archaeological site and we see these subtle differences on the surface.

• 5:46Speaker 02

  Because of how the surface soils or sand or vegetation is being impacted by what's buried below, we're able to get maps of what's there. And so, you know, think of like a dense rainforest that's covering an amazing site like an Angkor Wat, where you go there on the ground and it looks like the site is, you know, pretty big. But when you map it using lasers and you can do point cloud data and remove all the overlaying vegetation just by using laser data collected from airplanes, you're able to see the site is two, three, four, five times as large as you previously saw it. So, so really, that's the strength of satellites. They allow us to see size, scale, and extent of sites and better plan our seasons that when we go there, we know

• 6:30Speaker 02

  exactly what we're looking for.

• 6:32Neil deGrasse Tyson?

  What you're saying is, not to put words in your mouth, you have vegetation penetrating bands of light. Because obviously, if you're there, you have to, you have to cut through the brush and bramble, but certain forms of electromagnetic spectrum cut right through that, saving you that effort.

• 6:48Speaker 02

  Right. So, so we use different technologies in different places. So, for example, you know, where I work in Egypt, or any kind of open area, whether it's Morocco, or Peru.

• 6:59Neil deGrasse Tyson?

  Yeah, there's no jungle covering Egypt, last I checked.

• 7:03Speaker 02

  No, no jungle. So, most of the archaeological sites are open and exposed, but the sand is covering, you know, the foundations of a temple, or a tomb, or a pyramid. And so, what the satellites allow us to do is looking at, you know, for example, let's just say it's a large settlement and it's made of mud brick. That mud brick, even if it's foundation, is going to hold moisture differently than the surrounding soils. And what the satellites allow us to do using the near infrared is map these subtle differences that are completely invisible to us with our, you know, normal visual eyesight.

• 7:41Neil deGrasse Tyson?

  And so just go near infrared, so we have the visible spectrum, and then there's this big band of infrared off to the side of red. And I'm fascinated that we use these sort of proximal words, near infrared and far infrared. That's, it's a weird fact, but near would be like closer to the red, and far infrared would be farther away. But what does near infrared do for you that far infrared does not?

• 8:05Speaker 02

  So, near infrared is the best part of the light spectrum to map. Uh, differences in vegetation and vegetation health. You know, when I'm explaining the light spectrum to my students, you know, it's so important because vegetation health can be impacted by what's buried beneath it. So it can be healthy or unhealthy, depending on if the roots are going into, you know, mud brick or dense stone, or maybe it's in a ditch.

• 8:32Neil deGrasse Tyson?

  Or even I've heard about some, some soil contamination can be uptaken into this plants. And then you'd see, and you can see regions of plants that are just simply different from other surrounding regions. Right.

• 8:44Chuck Nice?

  I believe they call that Monsanto.

• 8:48Chuck Nice?

  I'm joking Monsanto, I know you're listening, I'm joking.

• 8:51Neil deGrasse Tyson?

  They're now owned by Bayer, so you're, you're fine.

• 8:53Chuck Nice?

  Okay.

• 8:55Speaker 02

  So we're able to see leaves, right, in the green part of the light spectrum? Because that's the information that is transmitted from them. That's, that's what we, from the light. Um, but it absorbs. The sunlight, right, from the sunlight. But it absorbs the infrared. That also is important, right? Because we, we have to use computer programs to discern these differences that we can't otherwise see.

• 9:22Chuck Nice?

  So when you're looking at that from, you know, from a satellite, uh, in the infrared, if you see like brighter leaves, does that mean they're healthier? Or if they're dimmer, they're not as healthy, does what?

• 9:35Speaker 02

  Right.

• 9:35Chuck Nice?

  Is that how that would work?

• 9:36Speaker 02

  So, so we, yeah, so that's exactly right. So healthier vegetation, um, we see a brighter response. So it's going to have a higher value. And that's what we look for. And less healthy vegetation, we don't see the same information.

• 9:49Neil deGrasse Tyson?

  But, but actually, Sarah, isn't it true? You're not there to value judge it, you're just trying to find differences.

• 9:55Speaker 02

  Right, yeah, I mean, it's, it could indicate a wall, it could indicate a, you know, an underground water source. We don't know, right? And, but if it's a linear, so it's, it's interesting though, like. You know, thinking about what we see and what we don't see and false positives. There was one time where I was convinced there was nothing there. And it was actually a real positive that I thought was a false positive. That there was a very strong signature of healthy vegetation that was found in someone's backyard on this little island called Papastor in Scotland. And they'd been finding Viking objects in their garden for years and years and years. And so this very strong signature showed up.

• 10:38Speaker 02

  And I said, it's in alignment with their house. And typically, when you see that, it's like a buried water pipe or a gas pipe. And I dismissed it. I said to the team, we're not going to check that out, right? It's modern. But the team didn't listen to me. I was collaborating with local archaeologists. They're like, I think you found the Viking structure. I think that's what it is. I'm like, no, it's not there. Could you listen to me? I'm the expert. So when I showed up, they're like, yeah, so why don't you check it out? And it was this massive Viking hall that was inhabited over hundreds of years by royalty and a king may have visited. So I was happily wrong to be wrong.

• 11:22Speaker 02

  You know, and this is science, right? Sometimes we're really cautious. Sometimes we need to throw caution to the wind and go with a super positive, healthy vegetation signature that turns out was a Viking wall.

• 11:33Neil deGrasse Tyson?

  Tell me about LIDAR. We've all heard LIDAR. We know radar, right? Which is, of course, an acronym. Or how you get a ticket.

• 11:44Neil deGrasse Tyson?

  It's one of the earliest ever acronyms. Ra- radio ranging, radio detection and ranging. Radar and radio, radio waves, but the smallest versions of those radio waves are microwaves.

• 11:59Neil deGrasse Tyson?

  And that's what the police use for your, it's still, it's still collectively radar. So LiDAR, is that just visible light?

• 12:06Speaker 02

  So LiDAR stands for Light Detection and Ranging. And it sounds like, you know, something you might see in a Marvel movie. So a sensor system is flown on, whether it's a helicopter or an airplane or a drone, and it sends down millions of pulse beams of light. And if you imagine you're in a dense rainforest, you know, you're in the middle of the heart of, whether it's Cambodia or Brazil, anywhere in the world that has this dense vegetation.

• 12:33Neil deGrasse Tyson?

  It sounds like you get around.

• 12:35Speaker 02

  Yeah, man. I, I do get around. I do get around. It's a good thing my husband's upstairs, so, but yeah, he could confirm, I do get around. And you're in the heart of this dark.

• 12:47Speaker 02

  I make a lot of jokes.

• 12:50Chuck Nice?

  Just let it go, Sarah. I was like, I'm gonna, I'm gonna, I'm not gonna respond.

• 12:54Neil deGrasse Tyson?

  So we gotta let go, Chuck.

• 12:55Chuck Nice?

  I'm gonna let that happen, you know?

• 12:57Speaker 02

  So you're in the heart of dense rainforest, but even when you're in the densest part of the rainforest, you still see light coming through. And what the LiDAR does is, you know, maybe hundreds of thousands of pulse beams of light hit the uppermost parts of vegetation, you know, hundreds of thousands hit the middle. Hundreds of thousands ultimately will hit the rainforest floor and you end up with a 3D point cloud model of the entire landscape. And what software allows you to do is to remove all the dots that are above the ground and you're left with what's known as a bare earth model or a digital elevation model.

• 13:37Speaker 02

  And if there's a pyramid or canals or terracing, any kind of structures that indicate ancient settlement in that area, they are going to be obvious. And clear in a way that isn't even when you're walking through the rainforest. Or, or maybe you might say, okay, I can see the hint. Maybe there's a structure here, but you're not going to know exactly what it is. And that's, that's what the light are doing. You know, there's really this light are revolution.

• 14:03Neil deGrasse Tyson?

  But does, don't you need that at different angles through the vegetation? Because if you just go from one direction down and up.

• 14:11Chuck Nice?

  You just maybe get in the canopy. You're not getting.

• 14:13Neil deGrasse Tyson?

  Get the canopy. Right.

• 14:14Chuck Nice?

  Getting penetration.

• 14:15Neil deGrasse Tyson?

  For a different angle.

• 14:15Speaker 02

  Yeah, you're catching it at different angles as it goes along. And so you end up with millions and millions of points.

• 14:21Neil deGrasse Tyson?

  Oh, I see because it's passing overhead. And so if you constantly get the data, then I see.

• 14:27Speaker 02

  And, and, and the point is to use a sensitive enough system, a powerful enough system to actually go through and get a certain number of points per square meter on the ground. You actually need, you know, between five and 12 points per square meter on the ground. And then you have very high resolution data.

• 14:44Neil deGrasse Tyson?

  Topographic data.

• 14:46Speaker 02

  Yeah, for topographic data. And then you can create these models. And, you know, for example, my, my colleagues at Tulane University just used LiDAR.

• 14:54Neil deGrasse Tyson?

  Lane in Norrlands, Norrlands.

• 14:55Speaker 02

  Norrlands, correct. Yes. They just used LiDAR data and they found 80,000 previously unknown structures and features around Tikal. It was in science, it was huge paper in science.

• 15:07Neil deGrasse Tyson?

  In the Science Magazine, yes.

• 15:18Speaker 03

  Hi, I'm Ernie Carducci from Columbus, Ohio. I'm here with my son, Ernie, because we listen to StarTalk every night and support StarTalk on Patreon.

• 15:28Neil deGrasse Tyson?

  This is StarTalk with Neil deGrasse Tyson.

• 15:39Chuck Nice?

  How do you get below ground, like a tomb? Or, or if you're talking about pyramids, you know, a lot of the pyramid for the burial parts are underground. So how do you get that?

• 15:51Speaker 02

  So to what Neil brought up earlier, so depending on what features you're looking for and how deeply they're buried, we can use a couple of different kinds of data. So we can use radar data, so that will pass through.

• 16:04Chuck Nice?

  That penetrates, right.

• 16:05Speaker 02

  That penetrates not very far, not as far as you think, maybe a couple of meters.

• 16:09Chuck Nice?

  Oh.

• 16:10Speaker 02

  It has to be in dry environment. So it works really, really well for detecting things like buried rivercourses where you're looking for old settlements from maybe 10,000 years ago, deep in the Sahara. You can also use thermal infrared data. So this is the next part of the light spectrum. So you've got the near middle, far infrared, and then you've got the thermal infrared, and that measures heat differences. So for example, let's just say you have a buried chamber or a buried tomb where the temperature is different, you're going to see that void that has a slight temperature difference and know.

• 16:45Chuck Nice?

  You'll know that there's an opening there or there's a space.

• 16:48Neil deGrasse Tyson?

  Right. I think generally when we think of infrared, we only ever typically think of temperature.

• 16:53Chuck Nice?

  I'm Predator.

• 16:54Neil deGrasse Tyson?

  Yeah, but infrared is light just like any other part of the spectrum. And if you know in advance, you're trying to find subtle temperature differences, then infrared's your, that's your choice, right?

• 17:05Speaker 02

  And the other thing that we use is what I was talking about earlier, which is what's known as active satellite data. So you have, well, so you have active and then you have passive, excuse me. So passive is the, most of the satellite data that I use. So it's receiving light that's reflected off the earth's surface. It's not sending data down like lidar or radar. It's receiving that information. So that's where we're using different parts of the light spectrum, so the, the near middle and far infrared to look at things like vegetation differences, soil differences, water differences. And then we're using pretty standard off the shelf, remote sensing software, so.

• 17:45Neil deGrasse Tyson?

  We can just get it anywhere. We can get it.

• 17:47Speaker 02

  Yeah, get it anywhere.

• 17:49Chuck Nice?

  Like TurboTax.

• 17:52Neil deGrasse Tyson?

  Yeah, just all over the place.

• 17:55Speaker 02

  And the great part about so much of the data that I use and my colleagues use, it's free. You know, NASA has put millions, tens of millions now of their satellite imagery data sets online. And that's for kind of, you know, larger areas. But the commercial satellite data, you know, you can easily get a satellite image of an archaeological site in the surrounding area for a couple hundred dollars. So it's not free, but also it's not going to break the bank either.

• 18:22Neil deGrasse Tyson?

  You know, Sarah, in my day, we had to actually go to the sites. I just want to say, you know, you, you, you young.

• 18:29Chuck Nice?

  You can't, you can't hate on the fact that they found a smarter way to work.

• 18:35Speaker 02

  Right? Like, so, so, so, once we have all this data, right? You know, whether you have, you know, your area that you've mapped, there's 100 potential archaeological sites, or maybe there are features on the site, we then have to do the really fun part, which is called ground truthing. So we then go to these sites, we go to these places. And instead of spending, you know, six months in the field hacking through rainforest, or months and months of looking for things and hoping we find something, we're able to have a very targeted approach. We know exactly where we're going. You know, today we are going to check out these 10 places. And with government, you know, cuts to funding, with having to, to, to really optimize our time in the field, it's an enormous time saver.

• 19:17Chuck Nice?

  That's like playing poker with a marked deck. That's kind of what you're doing.

• 19:23Neil deGrasse Tyson?

  A lot of people crash, Chuck. This is a, this is noble work here, computer poker game. Plus, just the concept of a ground truth, I think, has its origins in the military, where you would fly over some region, and you'd think something was the troop movement or, or enemy movement. And you'd have someone on the ground verifying that, who was right up close.

• 19:44Chuck Nice?

  Would radio you back and say, you can't handle the ground truth.

• 19:50Speaker 02

  And you know, it's interesting, too. Did you know that, that aerial archaeology is the reason that we have all aerial reconnaissance in the military? It started in World War I, when the first military planes were flying over Syria, there were amateur photographers from France and England, and they would take pictures. Of archaeological sites because they were archaeologists and hobbyists. They showed these to their commanders and they went, wait a minute, you can map things from the air? Oh, thank you very much.

• 20:29Neil deGrasse Tyson?

  Then the funding flowed like rivers.

• 20:31Chuck Nice?

  Right, yeah.

• 20:34Neil deGrasse Tyson?

  So Sarah, if light are uses light, it seems to me lasers would be a very good source of light for this because you need the intensity and you see the reflected signal. I've used three different color lasers in my life, a blue or green and a red.

• 20:48Chuck Nice?

  All illegal.

• 20:51Chuck Nice?

  Every single one of them.

• 20:51Neil deGrasse Tyson?

  Just because Chuck, don't tell people.

• 20:57Neil deGrasse Tyson?

  So I would imagine that different color lasers, because lasers is monochromatic light, would serve different questions that you might have for the terrain.

• 21:06Speaker 02

  You know, as far as I'm aware, the lasers that are used for light are pretty standard. So the data we get from the lasers is the point cloud data. So there's no specific spectral information that's contained within that.

• 21:20Neil deGrasse Tyson?

  You're only using it for the topography.

• 21:22Speaker 02

  Correct, correct.

• 21:23Chuck Nice?

  And when you go to the site, so you've identified it from the air and you say, okay, we have these 10 sites. When you go to them, are you trying to establish that you're going to now move on to excavation? Or are you just trying to figure out if there's something viable?

• 21:39Neil deGrasse Tyson?

  You think she's just going to stay home? You think, you think, really?

• 21:43Chuck Nice?

  Really? I'm just saying, is there any, do you ever come up with a dud? It's like, you know, when you're drilling for oil, there are a lot of times you think that you have found an actual viable site to drill and nothing's there.

• 21:56Neil deGrasse Tyson?

  In the old days, that was much more common, Chuck.

• 21:58Chuck Nice?

  Of course.

• 21:59Neil deGrasse Tyson?

  Now, the geophysics is way better today. So Wildcat drills is way more efficient than.

• 22:06Chuck Nice?

  Because of her. That's why it's more efficient. They're actually using the exact same technology that Sarah's talking about. But I'm saying for your purposes, do you ever come up with a dud?

• 22:18Speaker 02

  When I first started, when I did this as part of my PhD, you know, it's science, right? We have to be critical about what works and what doesn't work. And when we go into the field to check. You know, maybe eighty-five to ninety percent of the time, there's a thing there. There's an archaeological site and maybe one out of ten, oh, I thought it was a site, but there's this thing here instead. Okay, why am I getting a false positive? And then we refine our methodology and go back, but it's come a long way, you know, in in twenty, twenty-five years. And so the, you know, when I was doing my thesis, high resolution satellite data was five to ten thousand dollars for a single image. I had to rely on the cheaper, lower resolution NASA data.

• 23:01Chuck Nice?

  And now we have Google Maps.

• 23:05Chuck Nice?

  You were spending ten grand a picture.

• 23:07Speaker 02

  Yeah, no.

• 23:09Chuck Nice?

  Now it's six, pulls it up on their iPad.

• 23:11Speaker 02

  Yeah, I know. My son's like, mommy, you missed one. But I wish I were lying, but he's done that to me before. But, you know, this means that data is, there's this great democratization of of information now. And we have so much more to go through and whether we're identifying something visually or identifying something using algorithms, using different parts of the light spectrum. Um, it means we have to go back and reanalyze all of our data because of what we missed. So sometimes when we go into the field and you say, okay, I think what I have found looks like pyramid, right? It's the same size and shape and extent. But maybe when we excavated, okay, it's not a pyramid. It's a huge tomb. That's not an L. Like, that's still a W.

• 23:54Chuck Nice?

  L for loss, W for win.

• 23:56Speaker 02

  Yes, yes.

• 23:57Chuck Nice?

  Okay, to get the lingo here.

• 23:59Speaker 02

  I speak an eleven-year-old now. My son tells me, take the L, mom, take the L.

• 24:04Chuck Nice?

  The W column. Took an L, but today I bounced back. Okay.

• 24:10Speaker 02

  So, but but the other nice thing about satellite imagery, you know, especially high resolution imagery, if you're working in an area like Egypt where maybe you're in Saqqara, it's pretty well excavated. There are hundreds of known tombs. And you've got, you know, 300 discrete features that the satellite image has helped you to identify that don't look like there are any previous excavation reports. We have all this data. So in archaeology, we go from the known to the unknown. And so we look at the tombs from the third dynasty, fourth dynasty, fifth dynasty, you know, the pyramid age, the age of the pyramids at Giza. And we look at their size and shape and orientation and relationship to one another. And we're able to make pretty

• 24:49Speaker 02

  good guesses as to what the things are that we have found. So maybe our grant from, you know, the National Science Foundation is to explore economic mobility of upper class individuals in the late Old Kingdom. And so we want to excavate tombs from Dynasty VI only. So that satellite data helps us to target what areas to excavate.

• 25:14Neil deGrasse Tyson?

  Are there satellites that will help you find the lost city of gold? Because that's what's truly important here, Sarah. No, no, Atlantis, Atlantis. Or Atlantis, yeah. So Sarah, I wanted to pivot to Egypt because that's one of your specialties. I have to ask a very blunt question.

• 25:32Speaker 02

  Please.

• 25:33Neil deGrasse Tyson?

  What hasn't been excavated there? What is still there to learn? It's been there for thousands, what? What's taking you guys so long? Why isn't everything known? What's, what is going on here? Plus, it's not like Egypt was lost and buried and then discovered like Pompeii, all right? Egypt was always sitting there. Ancient Egypt was always there. So what does it mean to have a new discovery when we have a continuum of occupation and presence and awareness of that archaeological site?

• 26:07Speaker 02

  If you think about how long ancient Egypt lasted. So we're talking about a civilization that at its height lasted for approximately 3,000 years. But it of course continued after with the Roman Empire and then Muslim invasion and then, you know, medieval period and so on. But, but it came before then too. You know, Egypt had its origins deep in the Western Desert. So you have 7,000 plus years of occupation. But in the Nell Valley, if you think, you know, generally speaking, there were around two to three million people who lived there over that. Three thousand year period and the Nile is continuously depositing silt every year,

• 26:50Speaker 02

  which is, you know, causing the landscape to rise. So imagine cities and villages and towns and tombs and temples and pyramids for two million people over a three thousand or more year period of time. That's a lot of places to find. So

• 27:09Neil deGrasse Tyson?

  A lot. Okay. All right. I hadn't I hadn't appreciated that would be that many people.

• 27:14Chuck Nice?

  So yeah, so can I ask you this from what you just said? And it's always puzzled me. It's one thing when you talk about waterways that are shifting and depositing silt and creating layers upon layers. But then you see these dig sites that are in the heart of the city where people are still living and buried beneath that city is a whole nother city. How does that happen? What did they just go? Look, we get, we need dirt because we are tired of like, let's just bury this and build on top. What happens to create? And then like when they uncover it's full, you know, structures that are intact and their

• 27:57Chuck Nice?

  interiors are intact. What happens? Is it tragedy? Is it a, a, a some kind of disaster? What causes that to happen?

• 28:06Speaker 02

  So some cities in the world, you know, you both have have traveled all over the place and they there are these magical cities that have these old vibes, you know, whether it's Athens, whether it's Istanbul, whether it's Paris, whether it's Cairo, ancient Rome, right?

• 28:22Neil deGrasse Tyson?

  Yeah, Rome itself, yeah.

• 28:23Chuck Nice?

  Ancient Rome, I'm walking in a building and so, oh, by the way, over here, the floor is glass, so you can see crypts that happen to be

• 28:29Speaker 02

  Right.

• 28:30Chuck Nice?

  Meanwhile, I'm just trying to get a donut from the

• 28:34Speaker 02

  That was, that was the OG crypto, right?

• 28:38Speaker 02

  So you have these, I call them layered cities. They're places that were great to live thousands of years ago and they're great to live today. They're everywhere, right? Like, look at what happened during the Olympics in Athens. They had to construct the subway and they it took them years longer. They barely finished it in time because the whole process was an archaeological excavation. So we as humans like to live In the same places, right? So we call them palimpsests, so these layers and layers and layers of occupation.

• 29:07Neil deGrasse Tyson?

  Presumably because like the climate was good or the water supply was good or there's some feature that you're not going to go into the hills to escape just because somebody lived there before you.

• 29:17Speaker 02

  Or a place like Istanbul, which is perfectly located, it separates Europe and Asia, trade, commerce, access.

• 29:26Chuck Nice?

  Always a crossroads.

• 29:27Speaker 02

  Yeah, a crossroads, right? These crossroads, places that are magical. And it speaks to the great continuity of humanity. And you know, I so I wondered, I got asked that question all the time, Neil, that you asked me a couple of minutes ago, like, how much is left? How can we possibly be sure? So I took all the sites that I found as part of my PhD, so hundreds of sites across the Delta.

• 29:51Neil deGrasse Tyson?

  The Nile Delta.

• 29:52Speaker 02

  Nile Delta, Nile Delta, right.

• 29:54Neil deGrasse Tyson?

  The hairlines.

• 29:55Speaker 02

  No, not Delta. And I combined them with the hundreds of known archaeological sites in the Egyptian Delta. I then looked at all the known excavation data for all the sites and I calculated their area and volume. And as it turns out, in the Egyptian Delta alone, we have excavated one one thousandth of one percent of the site.

• 30:20Neil deGrasse Tyson?

  That's the answer. Wow. That's the answer.

• 30:22Speaker 02

  We know this much. And look, Egypt, we know nothing. This is why, this is why all over the world, all the time, we keep making these amazing discoveries.

• 30:30Neil deGrasse Tyson?

  All right, Sarah, get back to work. What are you doing on this show?

• 30:34Speaker 02

  I'm slacking. I only found a hundred sites this morning. I know. I gotta go. I gotta pick it up.

• 30:58Neil deGrasse Tyson?

  Does my next question dovetail into your global explorer project? And let me just see if it does. So if archaeology is no longer the province of professional archaeologists because you are accessing the same data on the cheap as anybody else can access with a computer. Has that turned the world into a raging circus of amateur archaeologists, each sure that they've made a new discovery?

• 31:32Speaker 02

  So, yes, to your question.

• 31:35Neil deGrasse Tyson?

  That's the answer.

• 31:37Speaker 02

  So, you know, anyone with a computer can look at Google Earth. You know, it's on everyone's phones, if you want it. Everyone from the age of four, five, six, you know, whether they want to find mummies or pyramids or dig up dinosaurs, everyone grows up with a passion for the past, which is awesome.

• 31:53Neil deGrasse Tyson?

  It's a compliment to your field, right?

• 31:55Speaker 02

  Right, yeah, there's nothing like, I want everyone excited about archaeology, because let's face it, massive cuts to the National Endowment for the Humanities, National Science Foundation, you know, museums are undergoing funding cuts, anthropology departments are closing in the US and other parts of the world. If the public is interested and passionate and understands the role that the past can have today for helping us to understand climate change and war and, you know, give us some hope, which we need more of, then that's only good. We want people participating, but participating in a guided way. So, this is one of the reasons that I started my not-for-profit Global Explorers. So, back in 2016, we built an online citizen archaeology crowdsourcing platform.

• 32:40Neil deGrasse Tyson?

  So, this gave some structure and an umbrella under which this activity can unfold. So, it's not just random at this point?

• 32:47Speaker 02

  No, I mean, we, so we started the platform with archaeological site data from Peru. So, we had the full buy-in from the Ministry of Culture in Peru. We were collaborating with a number of Peruvian archaeologists and specialists.

• 33:01Neil deGrasse Tyson?

  That means you have the Nazca Lines and the Nazca Patterns on the plains of Peru, right?

• 33:07Speaker 02

  Correct.

• 33:08Neil deGrasse Tyson?

  Yeah.

• 33:09Speaker 02

  So, the data that the crowd used and the data that the crowd generated, so the crowd ended up finding almost 30,000 potential, we called them anthropogenic features, so suggestive, we were very careful. So, we then looked through all the data and over 800 of them were determined to be significant previously unknown discoveries.

• 33:32Neil deGrasse Tyson?

  So, these are sculptures or structures or paintings or some surface features on earth?

• 33:39Speaker 02

  So, four settlements, potential tombs, suggestive structures that are on the earth's surface. And we then gave that data to colleagues in the region of Nazca. And in looking for the sites that the crowd found, they found new Nazca lines. So this collaborative project helped to support great local archaeological work and gave them a new perspective and allowed new discoveries to be made. So that's, that's what we want the data to do. We want this, we want to harness the power of the crowd and everyone's passion. And some people got really, really good at finding sites and features. We had some super users that found hundreds of features. And then that can help people on the ground who have the qualifications to go out and excavate and map.

• 34:26Neil deGrasse Tyson?

  But there's still renegades out there for sure. And what do you do about people who just, whose imagination is put forth as a substitute for science?

• 34:36Chuck Nice?

  I believe that's called America. I believe you just described the entire country.

• 34:43Neil deGrasse Tyson?

  That was a damn good sentence. I don't even know if I can repeat that.

• 34:46Speaker 02

  So we're having, we're having a moment right now in our country where the value of experts and expertise is coming under fire. It was exacerbated, of course, by the pandemic. There's that famous, there's that famous, I think it was a New Yorker cartoon, some guy's on an airplane and he's like, come on, you know, we can pilot better than the pilot. Let's go. And you're like, what? And so, so archaeology, that's not real. I can dig. Digging, like digging is what my toddler does. What are they? So people don't understand or appreciate, you know, that it takes years and years, decades of training. I'm still learning. Every time I go into the field, I've been doing this for 25 years. I'm still learning.

• 35:27Neil deGrasse Tyson?

  Right. You regress. If you're not learning every day, you might as well move backwards.

• 35:33Speaker 02

  And, and I, you know, people like me get accused of gatekeeping. Oh, you think you're better than everyone else just because you know how to dig. It's like, if I have a problem with my heart, I want a qualified heart surgeon. I don't want Aunt Edna on Facebook to tell me to take herbs.

• 35:47Neil deGrasse Tyson?

  Video that you can just operate on your own heart. I saw.

• 35:50Chuck Nice?

  And who needs a YouTube video? I like to feel my way through these things.

• 35:55Speaker 02

  I have a feeling.

• 35:56Chuck Nice?

  I've got the right cardiology vibes right now.

• 35:59Speaker 02

  Yeah, I just have a knife. I have some rubbing alcohol. I don't want to discredit people's passion, right? There are so many great people online who are excited. They're enthusiastic. They have good ideas. They just don't have the training. They don't have the framework. And I wish more of them would take archaeology classes because I, I think they could all make real contributions to the field that are valid.

• 36:23Chuck Nice?

  The problem is that your archaeology classes, they don't support the fact that everything you dig up was put there by aliens.

• 36:33Chuck Nice?

  Sarah, I don't know if you know this, but everything that you guys dig up was put there by aliens.

• 36:41Neil deGrasse Tyson?

  The previous civilization.

• 36:43Chuck Nice?

  Right, exactly.

• 36:44Speaker 02

  And isn't it interesting Egypt, Central America, Peru, great Zimbabwe, India, it's all aliens. But Rome, Stonehenge, I don't know what that could be.

• 36:58Neil deGrasse Tyson?

  As much as I love the movie Stargate Atlantis, it still had the pyramids built by aliens.

• 37:04Chuck Nice?

  Right.

• 37:04Neil deGrasse Tyson?

  Right? Yeah. The Africans somehow didn't have that ability. You need to be aliens. Right.

• 37:10Speaker 02

  And what I tell people, I, I was at a lunch years ago with some interesting people. And they all, all said like, well, come on aliens, right? You can't, can't go to the pyramids and look at the pyramids and be like, how is that now? How is this done by humans? I'm like, okay, fine. You, you give me three minutes. Give me three minutes. I will prove that the pyramids were not built by aliens.

• 37:32Chuck Nice?

  Oh, please, can you do that?

• 37:34Speaker 02

  Okay, so I pull out my phone. I pull up my, my.

• 37:37Neil deGrasse Tyson?

  First you have to punch him in the face.

• 37:38Speaker 02

  Well, yeah, victory dance. So, so I, I hold up my phone. I'm like, so is this built by aliens? They're like, what do you know? You know, Steve Jobs and the iPhone. And so I said, so you know, you go back, whatever, 5,000, 6,000 years in Egypt. And first steps, you know, they put the dead, they put their dead in the ground. Is that aliens? We're like, no, that's normal. You bury your dead underground. I'm like, okay, well, then like dogs dig them up and start eating them and that's gross. So you start putting stones on top of them to protect them from dogs. Is that aliens? They're like, no, that's again, normal. I'm like, right. So things develop and there's social stratification. And soon, you know, the wealthier people, the leaders, you bury them with pots and goodies and they're and and but still there's stones and aliens. No, still no aliens.

• 38:24Speaker 02

  Well, then they start getting fancy with the stones and they start like building superstructures and making a little more formalized and society gets more organized. That aliens? Well, no, that's normal. Okay. Well, things start getting bigger. We're able to see this in the archaeological records. Soon there's more chambers and more stuff. Is any of this aliens? No, still no aliens. All right. Well, so they get bigger and bigger and bigger over, you know, a 500 year period of time. And soon, you know, they're building huge structures out of mud brick. Aliens? No aliens. And I said, and then along comes Imhotep, the genius architect, the Steve Jobs of his time. And so he takes this very large stone-built tomb,

• 39:07Speaker 02

  where we see, you know, hundreds and hundreds of examples going back 500 plus years. And he looks at it. He's like, yeah, I'm not going to be extra. I'm going to stack them, one on top of the other. And I look at them. I'm like, what does your three-year-old do with blocks? Well, he stacks them. I'm like, right, just like Imhotep did. That was the start of pyramids. And then slowly over the next sort of 300 years, they get larger and more complex and eventually they get smooth sides.

• 39:34Neil deGrasse Tyson?

  Sure. Clearly Imhotep was the alien.

• 39:36Chuck Nice?

  That's what that's where it was going.

• 39:39Speaker 02

  So that's, that's it. It's, it's, it's, it's human genius. It's human innovation over hundreds and hundreds of years.

• 39:45Chuck Nice?

  And it's a progression that you see over a long period of time.

• 39:49Neil deGrasse Tyson?

  They didn't land from space. There was a prior story there. So Sarah, as in most branches of science and particularly where very precise tools, tactics and techniques arise, often they can be applied in other ways. And I, I can't help but think that everything you're doing here on earth can now be applied when we're mapping the moon or Mars or Venus. Oh, that makes us the aliens.

• 40:17Neil deGrasse Tyson?

  We are the aliens.

• 40:18Speaker 02

  We are the aliens.

• 40:19Neil deGrasse Tyson?

  Ah, the aliens. Stuping on other planets. So in what way have you has your field or the technologies of your field, satellite archaeology in particular, been co-opted the other way now?

• 40:32Speaker 02

  We're just starting to have more and more conversations with planetary scientists with NASA. I've been kicking around some ideas with our wonderful colleagues at SETI. And, you know, if you look at the Drake equation, right, when Frank Drake came up with it, we didn't know how many exoplanets there were capable of supporting life. And now, you know, there's, I don't know how many, I don't know how many there are hundreds.

• 40:57Neil deGrasse Tyson?

  Oh, capable of supporting life as we know it. Yeah, it'd be in the hundreds.

• 41:00Speaker 02

  Hundreds.

• 41:01Neil deGrasse Tyson?

  Out of the catalog of now, right now, rising through 6,000. So.

• 41:05Speaker 02

  So the question is, you know, as and when and if, but I think when I believe there's there's life out there. But the question is, if there's advanced life, what will it look like? How advanced will it be? And it could be that we find a planet where, you know, because of a catastrophe or whatever reason, you know, that civilization ceased to exist a million years ago. But it's still there. So what is it that we're doing and how we're mapping things on the ground? That could help us to unwrap, unshape.

• 41:36Neil deGrasse Tyson?

  Decode.

• 41:37Speaker 02

  And decode what these places could have been like. And archaeology is the way to do that, not necessarily through space archaeology that will help us map it. But archaeology provides us a framework to reconstruct how entire civilizations evolve.

• 41:52Neil deGrasse Tyson?

  The huge intellectual capital of invested brains thinking about that. In ways that the astrophysicist wouldn't. We don't think of civilizations in that way. Who needs civilization?

• 42:06Neil deGrasse Tyson?

  Yeah, we just don't have that training. I mean, we'd love to bring you on board for sure.

• 42:11Speaker 02

  I love jamming with other scientists because, you know, of course, everyone's got great ideas. And there's so much that I don't understand, appreciate, know about how and why things develop on planets. And the idea being like, where could we find this life, you know, could, could beings exist that have evolved to live in extreme temperatures, right? Which is why we're studying life around heat vents deep in the ocean. What are different ways that we could think about life? You know, octopuses, they make houses. Like, that's amazing. They construct their own little mini apartments, you know? Is that what an alien civilization would look like? Like a, an octopus condo? I don't know. But I think we could, we could create tools to help people think about ways of mapping them.

• 42:57Neil deGrasse Tyson?

  This is how science builds on science.

• 42:59Chuck Nice?

  Yeah.

• 43:00Neil deGrasse Tyson?

  Because not everyone can know everything going into a problem. Even Einstein, who laid the entire framework for the discovery of black holes, did not even predict their existence because it was outside of his thoughts. And it was even a denial of it for a while.

• 43:17Chuck Nice?

  I can't stop thinking about octopus house warmings now.

• 43:21Neil deGrasse Tyson?

  No, because he's got a house.

• 43:22Chuck Nice?

  Like, that's a little fact that you just threw out there that, you know, we kind of let it just fly. But like, wait a minute. Like, I have a completely different view of octopuses now, you know? Just like showing up to each other's house with a little bottle of vino, you know? Just like, hey, have a nice place you got here.

• 43:41Neil deGrasse Tyson?

  Selection of eight bottles from the case of war.

• 43:45Chuck Nice?

  Excellent. Well done. Well done.

• 43:47Neil deGrasse Tyson?

  So what does this say here about using archaeology to study the space station? Is that a thing?

• 43:52Speaker 02

  So that also is a form of space archaeology. I think, you know, I, the idea that we can use this technology to view how other places are inhabited and how and why it changes over time. You know, my colleagues who are studying the space station and moon artifacts, it's amazing work. And so essential to Understanding because for now, like that's all we have. We have the space station. We have to figure out what do people leave behind? What's the ephemeral evidence? What are things that we need to consider? And it's fascinating.

• 44:24Neil deGrasse Tyson?

  So it's a space version of your multiple civilizations. Because the ISS has been up for 25 years or 30 years or so. It was being assembled in the 90s. And different nationalities are there, they eat different foods. So are you referring to the run of human culture as it has been expressed in that space?

• 44:45Speaker 02

  Yeah, and changing technologies, innovations, breakages, additions. You know, studying how the space evolves, both on from the outside and also on the inside.

• 44:55Neil deGrasse Tyson?

  Right. Where did they put the 286 computer?

• 45:00Neil deGrasse Tyson?

  Did they bring it back to Earth? Did they just stick it outside so it's still floating by? Right. As times modernize, old things become obsolete. And what do you do with it? And it's all just contained there if not brought back.

• 45:13Speaker 02

  Right.

• 45:14Neil deGrasse Tyson?

  But that's pretty well. One thing I was going to mention earlier. People have considered looking for fossil remains of life on the moon from ejected rocks from asteroid impacts on Earth.

• 45:29Speaker 02

  Oh.

• 45:31Neil deGrasse Tyson?

  And then they would float through space because we have moon meteorites on Earth that we didn't have to go to the moon to get. Really, the moon has been hit before and so rocks get cast into space. Some arrive on Earth. So we have huge supplies of moon meteorites here on Earth. And if that's the case, presumably there would be Earth meteorites on the moon. And then you go there and look for any stowaway microbes, not thriving on the moon, of course. But there'd be evidence of them having once existed. So any of your people thinking about that, Sarah?

• 46:07Speaker 02

  No, I, I, wow, I mean, you, it's the first I've, I've heard of it just because it's, it's so outside.

• 46:13Neil deGrasse Tyson?

  Very inventive, yes.

• 46:14Speaker 02

  Yeah, it's awesome. It's super cool. I mean, I, you know, the question is like, what size would they be? I know that the moon is incredibly well mapped at a very high resolution. So, um, the question is, you know, where could they be? Are there places that they would, where we'd be more likely to find them?

• 46:34Neil deGrasse Tyson?

  Yeah. And how much of that meteorite would remain intact upon colliding with the moon? So there are other factors here, but I, once we learned that rocks move between planets, this became a, a very easy next thought to have about, and by the way, and the fossil record going back to the moon would, if it was preserved, would be intact over the thousands, millions, and even billions of years it's been sitting there. Because there's no erosion, there's no weather, there's no subduction, continental plates is just there. And so maybe that's another frontier.

• 47:08Speaker 02

  And the question I would have is, would, would those rocks, would they have a discreet spectral signature compared to the surrounding?

• 47:18Neil deGrasse Tyson?

  The rest of them, perfect.

• 47:19Speaker 02

  Right. And if they do.

• 47:20Neil deGrasse Tyson?

  Then they would pop out, then they would just reveal themselves. Right.

• 47:22Speaker 02

  So we, we just need one.

• 47:24Neil deGrasse Tyson?

  You are being lazy again. Let me just sit back and think. Smarter, not harder.

• 47:29Speaker 02

  But I think that's an amazing idea. Like, I, I would love to help with that kind of project.

• 47:35Neil deGrasse Tyson?

  Yeah. Cool. Very cool.

• 47:36Chuck Nice?

  Hey, is there a thread that as you span the globe, that is the most common thing amongst the cultures or civilizations that you dig up?

• 47:51Speaker 02

  So that's a wonderful question, and no one's ever asked me that before. And it's the subject of a book that I'm working on right now. So the book is sort of inverts the idea of collapse and is a very hopeful look at.

• 48:08Speaker 02

  How and why humanity lasts. So the thing I think that connects.

• 48:12Neil deGrasse Tyson?

  Humanity or civilizations, local civilizations.

• 48:16Speaker 02

  Humanity, humanity generally. The idea of continuity. That is the thing that connects so many of these sites and places that I and my colleagues have mapped all over the world, that wherever you go, people last. And, you know, kings may stop ruling. There may be environmental change, climate change, war, disease, but culture persists. People persist. And to me, the idea that so many of these places today, to the point earlier, that like so many cities are built on top of old cities. We last, we persist in spite of all of these awful things, some of which we have no control over, some of which we have great control over. And it makes, it makes me very hopeful

• 49:00Speaker 02

  in the face of all these awful things that we're staring down now with climate change, with war, with the rise of authoritarianism. So what the work I do gives me hope because of how long we've lasted and where we've lasted.

• 49:13Neil deGrasse Tyson?

  Wow, that's a tone to end the show on right there. Anything that gives us hope, I'm, I'm all in. Tell me about it.

• 49:22Neil deGrasse Tyson?

  Bring it on, bring on more hope, please. Give me some hope. My gosh.

• 49:29Speaker 02

  Anyway, it'll be out in a couple of years, so I'm working on it now.

• 49:32Neil deGrasse Tyson?

  All right. Well, good luck on that. Sometimes you need a little bit of luck when writing and publishing a book. Especially when it's about hope.

• 49:42Neil deGrasse Tyson?

  And your 2019 book with Henry Holt, Archaeology from Space, how the.

• 49:48Speaker 02

  Future shapes our past.

• 49:49Neil deGrasse Tyson?

  How the future shapes our past. That's a, that's a twist on the timeline right there. That's a Marty McFly moment for those of you who's listening. It's your kid, Marty. It's your kid, Marty.

• 50:04Neil deGrasse Tyson?

  Speaking of Back to the Future, I understand offline that you're a big sci-fi fan. We love sci-fi fans.

• 50:10Speaker 02

  Huge sci-fi fan.

• 50:12Neil deGrasse Tyson?

  Huge. What a note to end on. Let me see if I can take us out with a cosmic perspective. You know, when you're in school and you learn about the various sciences, no matter what course you take, there's a book and there's a book on that subject. And then you learn it and you do as best you can on the final and then you move on, often leaving the book behind or selling it on graduation. Whereas people who are deeply curious will know and recognize that we divided the science into these categories. Nature didn't do that. We did.

• 50:49Neil deGrasse Tyson?

  And if you look at the cross pollination of statistical tools, of mechanical tools, of electronic tools, of methods that overlap between one science and another, and then you realize we are all just curious children poking at what sits before us, what's under that rock, what's behind the tree, what's up in space. We're all the same species, those who ask questions and those who look up and down. These are two directions where there are frontiers that persist.

• 51:30Neil deGrasse Tyson?

  And so I'm delighted to learn that tactics, methods and tools of the archaeologist can be applied to space and vice versa. A reminder that maybe all the branches of science are not as far apart from one another as we might think, as we're struggling through them in school. And that is a cosmic perspective. This has been StarTalk. Sarah Parke, thanks for being on.

• 52:00Speaker 02

  Thank you. This has been so much fun. Thank you. Thank you.

• 52:04Neil deGrasse Tyson?

  And Chuck, always good to have you, man. Always a pleasure. This has been StarTalk. As always, I bid you be keep looking up.