7 ms·

Lidar reveals pre-Hispanic low-density urbanism in the Bolivian Amazon

167 points by bcaulfield 4y ago

oldstrangers 4y ago
Something I mentioned to my friends the other day is that I wish someone with the time, energy and resources would just start lidar-ing large swaths of Earth. And the seabed. Every day we inch closer to some profound realization about humans and where we came from, but no one seems in a rush to figure it out.
- roywiggins 4y ago
  Getting large swaths of the seabed is going to be beyond the resources of almost everyone. They spent like $200m hunting for MH370... and didn't find it. And on the scale of the ocean that was not a large swath by any means.
  - handmodel 4y ago
    I'm not going to pretend to be an expert but it seems like the hard/expensive part is probably building the underwater drone capable of taking the LIDAR? I would imagine at some point getting overhead satellite imagery by plane of the entire world seemed impossible - as did street view coverage of the entire US - but not the craziest expense once you have the ability to do it once.
    - chowells 4y ago
      The really hard part is the combination of the very short range of light transmission underwater and the very large size of the oceans. How many centuries are you willing to spend on the project?
      - roywiggins 4y ago
        The MH370 search used sonar, which works well underwater but has quite short range so it involved driving ships around on the surface dragging sonar arrays backwards and forwards for years. I think this is one of the systems used during the MH370 search, apparently it can scan 192km² per day. There are 161,000,000 km² of ocean, so you'd need at least a million days or 3,000 years to scan the whole thing, give or take. http://www.slhydrospheric.com/prosas60_spec.html http://www.slhydrospheric.com/prosas60_spec.html
        handmodel 4y ago
        That sounds extremely slow but presumably now that they've built one the cost to build 100 or 1000 would be achievable if someone (or some government) had the interest. I would think they would need a version that doesn't need the ship nearby to scale - but would still guess this is something that will be accomplished on the order of 30 years from now.
        narag 4y ago
        There are 161,000,000 km² of ocean... Sorry if you aren't the best choice, but I had to ask someone in the thread. Why? I mean why all the ocean? If the purpose is to find archeological sites, most will be on the continental platform.
        hetspookjee 4y ago
        _what if_ you find remains of a truly ancient civilisation on the abyssal plains. Now that would get the films rolling!
        ge96 4y ago
        Would be curious if those gliders were helpful or not/how much smaller.
    - bigDinosaur 4y ago
      There's twice as much sea as land, and from a brief glance LIDAR penetrates to 300m (whereas google informs me the average depth of the ocean is ~3600m) as well as presumably some weird topology which might make for interesting challenges. Certainly doesn't sound easy, but it'd be interesting to hear from anyone who works in this area.
  - irrational 4y ago
    Instead of SpaceX, couldn’t Elon musk have funded seaX and created teams to design and build autonomous scanning drones at scale?
  - VintageCool 4y ago
    For the purposes of studying human archaeology, I don't care about the deep sea. I want LIDAR surveys of shallow coastline waters. Global sea levels 20,000 years ago were 125 meters lower than they were today. Our ancestors could have been living on shorelines that are now deep under water. There could be extensive archaeological sites that are undiscovered because they are buried under 60 meters of ocean water. Ancient human tools have been found by fishing boats in Doggerland, the portion of the North Sea that used to be a land bridge between Europe and England. I bet there's a whole lot more discoveries to made just a few miles offshore.
    - roywiggins 4y ago
      Yeah, for sure. Doggerland would be top of my list too.
      - yread 4y ago
        Persian Gulf would be a trove
- gedy 4y ago
  One day, but I have to confess I like that there's still mysteries below us. Vs everything being known already.
- AlotOfReading 4y ago
  As someone who used to do academic archaeology, there are plenty of people with both the time, energy, and ideas out there. The main thing that's missing is money. Funding is tight to a degree that I don't think people from the traditional STEM disciplines realize. The average grant size is far lower than the average NSF grant despite much greater fieldwork costs [1]. The financial restrictions mean you're constantly weighing how important it really is to do basic checks like carbon dating, or whether you can afford imagery (vs just using a printout of google maps). I remember being heartbroken at losing a drone because the money spent buying it, and having to camp in fields and eat fish for long periods because I couldn't afford lodging/other food. [1] https://dougsarchaeology.wordpress.com/2014/03/12/does-the-size-of-your-nsf-grant-request-matter/ https://dougsarchaeology.wordpress.com/2014/03/12/does-the-s...
  - treis 4y ago
    How reliable are these LIDAR scans? They seem pretty speculative to me and the way they label features doesn't always make sense. Like page 10 of the PDF has a causeway intersecting with a canal and merging. That doesn't seem likely or possible given what I know about canals and roads.
- irrational 4y ago
  If billionaires have to spend their money on vanity projects, I wish they would spend it on something like this.
  - puranjay 4y ago
    I'm surprised more billionaires are interested in going to space but not exploring earth itself
- sammalloy 4y ago
  Avi Loeb is planning a project to search the ocean floor near Papua New Guinea for interstellar meteor fragments from CNEOS-2014-01-08. https://en.wikipedia.org/wiki/CNEOS_2014-01-08 https://en.wikipedia.org/wiki/CNEOS_2014-01-08
- jimmySixDOF 4y ago
  A better fit is Ground Penetrating Radar or at least do it with LiDAR - there is much more archeology below the surface than above.
  - AlotOfReading 4y ago
    The issues of GPR in rocky or variable soils and the difficulty of interpretation end up being very limiting to actual usage in my experience. It's pretty difficult to scale in the same way LIDAR can. It's also common for there to be surface expressions of sites, as long as your signal filtering and sensors are good enough. Even the 1m data the UK publishes has been amazingly useful. With the data I've seen from modern high end sensors, whew.
frankfrankfrank 4y ago
I am reluctantly not at all a fan of these kinds of publications of unknown historical sites. All it does is expose to thieves where untold archeological sites are to be found.
- warent 4y ago
  Aren't these areas densely covered in hostile impassible terrain? Even knowing the location it would take a miracle or a ton of resources to have any hopes of getting there
  - markdown 4y ago
    No harder than getting on a boat and starting the engine.
    - gotmedium 4y ago
      I believe you have never been to the Amazon. It is not like taking a water cab in Amsterdam or a ferry in nyc. The sheer complexity of canals[1], [2] tides, [3] seasonality influences a great deal on who will have the guts, time and money to visit the region. [1] https://onlinelibrary.wiley.com/doi/abs/10.1002/eco.1863 https://onlinelibrary.wiley.com/doi/abs/10.1002/eco.1863 [2] https://www.tide-forecast.com/locations/Macapa-Amazon-River-Brazil/tides/latest https://www.tide-forecast.com/locations/Macapa-Amazon-River-...
      - ge96 4y ago
        Also all the critters/way to get poisoned by something.
      - is_true 4y ago
        For people that live there is like taking a cab in a canal.
        chucksta 4y ago
alsaaro 4y ago
Its a good thing that books like 1491 are increasingly validated with archeology. The previous prevailing wisdom held that outside of the Aztecs and the Inca sophisticated urban settlement didn't prevail in the Amazon due to the "Green Desert" hypothesis and primitive tools. This research confirms early Spanish chronicles, previously derided as fanciful, that vast urban settlements existed along rivers for many miles and would stretch continuously for hours as they travelled down river.
- NelsonMinar 4y ago
  1491 was reporting on archeology, cutting edge archeology for when it was written in 2005. It's nice to see the field progressing but it wasn't like Mann was guessing! I'm just eager for a new book updated with all the findings since that book was written.
  - mooreds 4y ago
    I'd buy that book for sure. 1491 was eye opening for me in the same way that few books are. Others that come to mind: Guns Germs and Steel Godel Escher Bach
    - jfengel 4y ago
      Guns Germs and Steel is widely considered discredited by anthropologists. It introduces a lot of concepts that were previously unfamiliar to the layman (not unlike Godel, Escher, Bach), but it has a lot of weaknesses and is much too strong in its conclusions. It's worth reading the quick overview in Wikipedia: https://en.wikipedia.org/wiki/Guns,_Germs,_and_Steel#Criticism https://en.wikipedia.org/wiki/Guns,_Germs,_and_Steel#Critici... I'm not saying it shouldn't be eye-opening, but just that you should take it with a large grain of salt. It's not as definitive as is commonly thought.
      - MichaelZuo 4y ago
        Some of those critiques introduce additional assumptions that Diamond's arguments don't rely on: "has almost no role for human agency—the ability people have to make decisions and influence outcomes. Europeans become inadvertent, accidental conquerors. Natives succumb passively to their fate." Assumes a conquest due to technological and other disparities implies a lack of human agency on both sides. Why wouldn't the level of human agency everywhere remain roughly constant pre and post colonization regardless of what happened? The only way I can make sense of this is if the writer assumes 'human agency' is some magical force that can overcome every other factor. "Diamond's account makes all the factors of European domination a product of a distant and accidental history" Assumes all 'factors' arose as a result of events in the distant past. Gunpowder, which was spread from China via the silk road, clearly and immediately was put to use fairly soon after the Spanish got hold of it, within a few generations. etc.
TheAceOfHearts 4y ago
This seems like a huge opportunity to gather up a bunch of natives that are familiar with navigating the land, professional archeologists, a camera crew, and just let the story unfold itself. Why isn't the entertainment industry more interested in creating exploratory content like this?
- deleted 4y ago
  [deleted]
- AlotOfReading 4y ago
  Imagine watching a series about a bunch of people sitting in muddy pits doing paperwork for 3 months, or counting charcoal/pollen on a microscope in a lab. That's 'real archaeology'. There's a very limited amount of information known about what's uncovered while people are onsite and film crews would be prohibited from filming most of the spectacular things that might be found for ethical reasons. Moreover, it usually takes 1-2 years after excavations are completed to organize everything to a degree of public presentability. All of that is a really bad fit for typical production schedules and TV drama, so what popular media does is go to people who have opinions about sites that are already long excavated and find the ones that give them the most 'interesting' soundbites and perspectives post-editing. It's entertainment rather than education.
  - multjoy 4y ago
    Have I got the show for you... https://g.co/kgs/KhN9J9 https://g.co/kgs/KhN9J9
    - piceas 4y ago
      A Google search link for time team. https://en.m.wikipedia.org/wiki/Time_Team https://en.m.wikipedia.org/wiki/Time_Team
      - Accacin 4y ago
        Oh, I absolutely loved this when I was a kid. We'd all sit down together as a family every Sunday to watch it. I've always had a love for archeaology and history, and I think I have that show to thank for it :) For anyone curious, the whole series is available on YouTube :) It's really not the most exciting show though.
metadat 4y ago
Where are the pictures? EDIT: They're only in the PDF: https://www.nature.com/articles/s41586-022-04780-4.pdf https://www.nature.com/articles/s41586-022-04780-4.pdf From the VUX-1 LIDAR product specs, it seems they flew over the area no with an airplane at > 2,460 ft. to collect the data. http://www.riegl.com/products/unmanned-scanning/riegl-vux-1uav/ http://www.riegl.com/products/unmanned-scanning/riegl-vux-1u...
- thrdbndndn 4y ago
  > They're only in the PDF I can see all the figures on the webpage version just fine. Just click the interlink or scroll in the figure sidebar.
mark336 4y ago
I'm a Native-American from the Andean region. And I had some idea that there were settlements, from a few articles I read some time ago. For example, the Inca and other Pre-Hispanic cultures were known to have traded parrot feathers. There had to be networks in the jungle. This is by far a more comprehensive report.
- soapdog 4y ago
  Hello fellow South American :D you might enjoy the 1941 book by Charles Mann. A lot there will already be known to you, but it is still a very good book.
  - ch4s3 4y ago
    I can second that. You may also enjoy The Dawn of Everything: A New History of Humanity[1] which goes into a ton of detail about the sate archeology regarding pre-Colombian peoples in the Americas. I learned that Teotihuacan had abandoned the pyramid temples and pulled down many of it's palaces and rebuilt the city with apartment blocks hundreds of years before being abandoned. [1] https://www.amazon.com/Dawn-Everything-New-History-Humanity/dp/0374157359 https://www.amazon.com/Dawn-Everything-New-History-Humanity/...
    - adolph 4y ago
      I recommend the above too and add David Reich’s “Who we are and how we got here” which speaks to aspects of human biology and migration through genetics. https://www.goodreads.com/book/show/35749414-who-we-are-and-how-we-got-here https://www.goodreads.com/book/show/35749414-who-we-are-and-...
      - ch4s3 4y ago
        After reading this review[1], I'm now really interested to read his book. [1] https://www.goodreads.com/review/show/2376793572?book_show_action=true&from_review_page=1 https://www.goodreads.com/review/show/2376793572?book_show_a...

167 points by bcaulfield 4y ago

Something I mentioned to my friends the other day is that I wish someone with the time, energy and resources would just start lidar-ing large swaths of Earth. And the seabed. Every day we inch closer to some profound realization about humans and where we came from, but no one seems in a rush to figure it out.

roywiggins 4y ago
Getting large swaths of the seabed is going to be beyond the resources of almost everyone. They spent like $200m hunting for MH370... and didn't find it. And on the scale of the ocean that was not a large swath by any means.
- handmodel 4y ago
  I'm not going to pretend to be an expert but it seems like the hard/expensive part is probably building the underwater drone capable of taking the LIDAR? I would imagine at some point getting overhead satellite imagery by plane of the entire world seemed impossible - as did street view coverage of the entire US - but not the craziest expense once you have the ability to do it once.
  - chowells 4y ago
    The really hard part is the combination of the very short range of light transmission underwater and the very large size of the oceans. How many centuries are you willing to spend on the project?
    - roywiggins 4y ago
      The MH370 search used sonar, which works well underwater but has quite short range so it involved driving ships around on the surface dragging sonar arrays backwards and forwards for years. I think this is one of the systems used during the MH370 search, apparently it can scan 192km² per day. There are 161,000,000 km² of ocean, so you'd need at least a million days or 3,000 years to scan the whole thing, give or take. http://www.slhydrospheric.com/prosas60_spec.html http://www.slhydrospheric.com/prosas60_spec.html
      - handmodel 4y ago
        That sounds extremely slow but presumably now that they've built one the cost to build 100 or 1000 would be achievable if someone (or some government) had the interest. I would think they would need a version that doesn't need the ship nearby to scale - but would still guess this is something that will be accomplished on the order of 30 years from now.
      - narag 4y ago
        There are 161,000,000 km² of ocean... Sorry if you aren't the best choice, but I had to ask someone in the thread. Why? I mean why all the ocean? If the purpose is to find archeological sites, most will be on the continental platform.
        hetspookjee 4y ago
        _what if_ you find remains of a truly ancient civilisation on the abyssal plains. Now that would get the films rolling!
      - ge96 4y ago
        Would be curious if those gliders were helpful or not/how much smaller.
  - bigDinosaur 4y ago
    There's twice as much sea as land, and from a brief glance LIDAR penetrates to 300m (whereas google informs me the average depth of the ocean is ~3600m) as well as presumably some weird topology which might make for interesting challenges. Certainly doesn't sound easy, but it'd be interesting to hear from anyone who works in this area.
- irrational 4y ago
  Instead of SpaceX, couldn’t Elon musk have funded seaX and created teams to design and build autonomous scanning drones at scale?
- VintageCool 4y ago
  For the purposes of studying human archaeology, I don't care about the deep sea. I want LIDAR surveys of shallow coastline waters. Global sea levels 20,000 years ago were 125 meters lower than they were today. Our ancestors could have been living on shorelines that are now deep under water. There could be extensive archaeological sites that are undiscovered because they are buried under 60 meters of ocean water. Ancient human tools have been found by fishing boats in Doggerland, the portion of the North Sea that used to be a land bridge between Europe and England. I bet there's a whole lot more discoveries to made just a few miles offshore.
  - roywiggins 4y ago
    Yeah, for sure. Doggerland would be top of my list too.
    - yread 4y ago
      Persian Gulf would be a trove
gedy 4y ago
One day, but I have to confess I like that there's still mysteries below us. Vs everything being known already.
AlotOfReading 4y ago
As someone who used to do academic archaeology, there are plenty of people with both the time, energy, and ideas out there. The main thing that's missing is money. Funding is tight to a degree that I don't think people from the traditional STEM disciplines realize. The average grant size is far lower than the average NSF grant despite much greater fieldwork costs [1]. The financial restrictions mean you're constantly weighing how important it really is to do basic checks like carbon dating, or whether you can afford imagery (vs just using a printout of google maps). I remember being heartbroken at losing a drone because the money spent buying it, and having to camp in fields and eat fish for long periods because I couldn't afford lodging/other food. [1] https://dougsarchaeology.wordpress.com/2014/03/12/does-the-size-of-your-nsf-grant-request-matter/ https://dougsarchaeology.wordpress.com/2014/03/12/does-the-s...
- treis 4y ago
  How reliable are these LIDAR scans? They seem pretty speculative to me and the way they label features doesn't always make sense. Like page 10 of the PDF has a causeway intersecting with a canal and merging. That doesn't seem likely or possible given what I know about canals and roads.
irrational 4y ago
If billionaires have to spend their money on vanity projects, I wish they would spend it on something like this.
- puranjay 4y ago
  I'm surprised more billionaires are interested in going to space but not exploring earth itself
sammalloy 4y ago
Avi Loeb is planning a project to search the ocean floor near Papua New Guinea for interstellar meteor fragments from CNEOS-2014-01-08. https://en.wikipedia.org/wiki/CNEOS_2014-01-08 https://en.wikipedia.org/wiki/CNEOS_2014-01-08
jimmySixDOF 4y ago
A better fit is Ground Penetrating Radar or at least do it with LiDAR - there is much more archeology below the surface than above.
- AlotOfReading 4y ago
  The issues of GPR in rocky or variable soils and the difficulty of interpretation end up being very limiting to actual usage in my experience. It's pretty difficult to scale in the same way LIDAR can. It's also common for there to be surface expressions of sites, as long as your signal filtering and sensors are good enough. Even the 1m data the UK publishes has been amazingly useful. With the data I've seen from modern high end sensors, whew.

frankfrankfrank 4y ago

I am reluctantly not at all a fan of these kinds of publications of unknown historical sites. All it does is expose to thieves where untold archeological sites are to be found.

warent 4y ago
Aren't these areas densely covered in hostile impassible terrain? Even knowing the location it would take a miracle or a ton of resources to have any hopes of getting there
- markdown 4y ago
  No harder than getting on a boat and starting the engine.
  - gotmedium 4y ago
    I believe you have never been to the Amazon. It is not like taking a water cab in Amsterdam or a ferry in nyc. The sheer complexity of canals[1], [2] tides, [3] seasonality influences a great deal on who will have the guts, time and money to visit the region. [1] https://onlinelibrary.wiley.com/doi/abs/10.1002/eco.1863 https://onlinelibrary.wiley.com/doi/abs/10.1002/eco.1863 [2] https://www.tide-forecast.com/locations/Macapa-Amazon-River-Brazil/tides/latest https://www.tide-forecast.com/locations/Macapa-Amazon-River-...
    - ge96 4y ago
      Also all the critters/way to get poisoned by something.
    - is_true 4y ago
      For people that live there is like taking a cab in a canal.
      - chucksta 4y ago

alsaaro 4y ago

Its a good thing that books like 1491 are increasingly validated with archeology. The previous prevailing wisdom held that outside of the Aztecs and the Inca sophisticated urban settlement didn't prevail in the Amazon due to the "Green Desert" hypothesis and primitive tools. This research confirms early Spanish chronicles, previously derided as fanciful, that vast urban settlements existed along rivers for many miles and would stretch continuously for hours as they travelled down river.

NelsonMinar 4y ago
1491 was reporting on archeology, cutting edge archeology for when it was written in 2005. It's nice to see the field progressing but it wasn't like Mann was guessing! I'm just eager for a new book updated with all the findings since that book was written.
- mooreds 4y ago
  I'd buy that book for sure. 1491 was eye opening for me in the same way that few books are. Others that come to mind: Guns Germs and Steel Godel Escher Bach
  - jfengel 4y ago
    Guns Germs and Steel is widely considered discredited by anthropologists. It introduces a lot of concepts that were previously unfamiliar to the layman (not unlike Godel, Escher, Bach), but it has a lot of weaknesses and is much too strong in its conclusions. It's worth reading the quick overview in Wikipedia: https://en.wikipedia.org/wiki/Guns,_Germs,_and_Steel#Criticism https://en.wikipedia.org/wiki/Guns,_Germs,_and_Steel#Critici... I'm not saying it shouldn't be eye-opening, but just that you should take it with a large grain of salt. It's not as definitive as is commonly thought.
    - MichaelZuo 4y ago
      Some of those critiques introduce additional assumptions that Diamond's arguments don't rely on: "has almost no role for human agency—the ability people have to make decisions and influence outcomes. Europeans become inadvertent, accidental conquerors. Natives succumb passively to their fate." Assumes a conquest due to technological and other disparities implies a lack of human agency on both sides. Why wouldn't the level of human agency everywhere remain roughly constant pre and post colonization regardless of what happened? The only way I can make sense of this is if the writer assumes 'human agency' is some magical force that can overcome every other factor. "Diamond's account makes all the factors of European domination a product of a distant and accidental history" Assumes all 'factors' arose as a result of events in the distant past. Gunpowder, which was spread from China via the silk road, clearly and immediately was put to use fairly soon after the Spanish got hold of it, within a few generations. etc.

TheAceOfHearts 4y ago

This seems like a huge opportunity to gather up a bunch of natives that are familiar with navigating the land, professional archeologists, a camera crew, and just let the story unfold itself. Why isn't the entertainment industry more interested in creating exploratory content like this?

deleted 4y ago
[deleted]
AlotOfReading 4y ago
Imagine watching a series about a bunch of people sitting in muddy pits doing paperwork for 3 months, or counting charcoal/pollen on a microscope in a lab. That's 'real archaeology'. There's a very limited amount of information known about what's uncovered while people are onsite and film crews would be prohibited from filming most of the spectacular things that might be found for ethical reasons. Moreover, it usually takes 1-2 years after excavations are completed to organize everything to a degree of public presentability. All of that is a really bad fit for typical production schedules and TV drama, so what popular media does is go to people who have opinions about sites that are already long excavated and find the ones that give them the most 'interesting' soundbites and perspectives post-editing. It's entertainment rather than education.
- multjoy 4y ago
  Have I got the show for you... https://g.co/kgs/KhN9J9 https://g.co/kgs/KhN9J9
  - piceas 4y ago
    A Google search link for time team. https://en.m.wikipedia.org/wiki/Time_Team https://en.m.wikipedia.org/wiki/Time_Team
    - Accacin 4y ago
      Oh, I absolutely loved this when I was a kid. We'd all sit down together as a family every Sunday to watch it. I've always had a love for archeaology and history, and I think I have that show to thank for it :) For anyone curious, the whole series is available on YouTube :) It's really not the most exciting show though.

metadat 4y ago

Where are the pictures? EDIT: They're only in the PDF: https://www.nature.com/articles/s41586-022-04780-4.pdf https://www.nature.com/articles/s41586-022-04780-4.pdf From the VUX-1 LIDAR product specs, it seems they flew over the area no with an airplane at > 2,460 ft. to collect the data. http://www.riegl.com/products/unmanned-scanning/riegl-vux-1uav/ http://www.riegl.com/products/unmanned-scanning/riegl-vux-1u...

thrdbndndn 4y ago
> They're only in the PDF I can see all the figures on the webpage version just fine. Just click the interlink or scroll in the figure sidebar.

mark336 4y ago

I'm a Native-American from the Andean region. And I had some idea that there were settlements, from a few articles I read some time ago. For example, the Inca and other Pre-Hispanic cultures were known to have traded parrot feathers. There had to be networks in the jungle. This is by far a more comprehensive report.

soapdog 4y ago
Hello fellow South American :D you might enjoy the 1941 book by Charles Mann. A lot there will already be known to you, but it is still a very good book.
- ch4s3 4y ago
  I can second that. You may also enjoy The Dawn of Everything: A New History of Humanity[1] which goes into a ton of detail about the sate archeology regarding pre-Colombian peoples in the Americas. I learned that Teotihuacan had abandoned the pyramid temples and pulled down many of it's palaces and rebuilt the city with apartment blocks hundreds of years before being abandoned. [1] https://www.amazon.com/Dawn-Everything-New-History-Humanity/dp/0374157359 https://www.amazon.com/Dawn-Everything-New-History-Humanity/...
  - adolph 4y ago
    I recommend the above too and add David Reich’s “Who we are and how we got here” which speaks to aspects of human biology and migration through genetics. https://www.goodreads.com/book/show/35749414-who-we-are-and-how-we-got-here https://www.goodreads.com/book/show/35749414-who-we-are-and-...
    - ch4s3 4y ago
      After reading this review[1], I'm now really interested to read his book. [1] https://www.goodreads.com/review/show/2376793572?book_show_action=true&from_review_page=1 https://www.goodreads.com/review/show/2376793572?book_show_a...