Lidar Reveals 650-Square-Mile Maya Site Hidden Beneath Guatemalan Rain Forest

107 points by andreshb 2 years ago | 56 comments
  • spaceman_2020 2 years ago
    If I was a billionaire, I’d commission a lidar survey of the entire planet.

    The amount of stuff that seems to be hidden beneath forest and snow and mud and ocean is absurd.

    • BoxOfRain 2 years ago
      If I was obscenely wealthy I'd do the same for the seas and oceans, there's got to be so many fascinating wrecks out there as well as natural formations we know nothing about yet that sonar could pick up. Shipwrecks often have a limited lifespan for things to be preserved too, for example there's very little left of Lusitania's wreck that resembles a ship any more just a rusty debris field.
      • rrival 2 years ago
        Saw Sarah Parcak speak on this at her book launch @ The Explorer's Club (https://www.amazon.com/Archaeology-Space-Future-Shapes-Past/...). The current, viable remote observation approach for shipwrecks is to use satellite photos of sand plume disturbances near beaches to hint at underwater features worth further exploration.
        • mcdonje 2 years ago
          If I were tetrazzinily wealthy, I'd lidar the solar system. There's no telling what we'd find in the asteroids alone.
        • bahador 2 years ago
          i think ted is overrated but i saw this recently: https://youtu.be/B6rIUxHZ9f4
          • speed_spread 2 years ago
            If you were to discover an alien spaceship laying under the ice in Antartica, for god's sake don't tell anyone and _don't dig it out_.
            • kcartlidge 2 years ago
              > If you were to discover an alien spaceship laying under the ice in Antartica

              A fair few things this could reference, but I'll use it as an opportunity to recommend reading the least likely option which is the book Ice Station by Matthew Reilly.

              • account42 2 years ago
                Resistance is futile.
              • GordonS 2 years ago
                Any napkin figures for how much that would cost, and how long it would take? The results could be incredible...
                • maxerickson 2 years ago
                  One way to sort of do it would be to poke at how much 3dep has cost so far and extrapolate from there. Hard to figure that though, with it being an aggregation of a bunch of other programs.
                • heliodor 2 years ago
                  Anyone know how much LIDAR surveys cost? Would love to hear some numbers!
                  • nopassrecover 2 years ago
                    What would it take to leverage Starlink?
                  • kristopolous 2 years ago
                    It's a shame to think of all the ancient literature and rich history we've lost from these civilizations.

                    I'm sure they had their Homers and Platos.

                    • DiscourseFan 2 years ago
                      Well, maybe. But people still speak Mayan today and they've retained the legends and stories which are depicted on the iconography and actually written in the script, that's how we were able to decipher and read it.

                      I don't mean to sound like a cultural darwinist, but Athens and the library of Alexandria were razed to the ground and yet we still have Plato today because everybody who got their hands on his writings decided to read, translate, and disseminate it--there was no reason for the Romans to preserve his philosophy, no reason for the Arabian and Persian peoples either, and yet here we are today with complete versions of these texts translated into myriad languages over thousands of years, whereas other cultural properties, perhaps even from civilizations far larger, have simply disappeared, like the Egyptian materials for over a thousand years.

                      I don't think its wise to be too excited about these potential discoveries, because the reason why these cities can even be recognized and named as such by peoples (namely, us) living and analyzing them hundreds or thousands of years later is because of certain shared psychological and therefore social contexts. They may manifest in different forms, but the parallel developments of civilization across time, in different places, in completely separate contexts, is only on account of the shared, basic psychology of all humans, and in the end there will never be a remarkable difference between the kinds of texts produced by a predominantly agrarian society in the Ancient near-east, like the Egyptians, and a predominantly agrarian society in Mesoamerica.

                      In any kind of scientific endeavour it is never a good idea to be over-confident, nevertheless I think I have to claim that at this point in time anthropologists have developed a pretty good map of how human civilizations develop, from the totemic cults of tribal cultures to the cosmopolitan sprawls of modern urban centers: no matter where you look or what you examine, material cultures appear to progress in a basically similar manner. And, as I said above, there is no sense in trying to "recover" a lost culture, Mayan or otherwise; those cultures are still alive and well today--cultures never die, they just change, all we can do is create a map of those changes, we can never actually go back and fully understand how a people lived and experienced the world and how they expressed that experience in literature and philosophy, since our interpretation of that data will always be tainted by modern experience. But the map, and the contact with the Other, in the form of a "lost" culture, can show us that our modern experience is not the end all be all of the world, there will always be something in these cultures that escapes modern understanding, and I think that in that encounter something fruitful can be born, and therein lies the value of these sorts of investigations.

                      • badrabbit 2 years ago
                        > perhaps even from civilizations far larger, have simply disappeared, like the Egyptian materials for over a thousand years.

                        What you're missing is a history of conquest. Greece and Rome had a very intertwined cultural exchange. It wasn't just alexander that conquered land all over (all the way to india) and I am sure you know of how rome invaded it's way to the point they needed two emperors.

                        Civilizationd in america invaded each other but not the rest if the world. Same with Africa (outside of Egypt and few minor regionally invading countries). Even in asia, chinese never invaded india. Now Genghis obviously did more invading than alexander so I'd be interested in how much culture and history he spread but I think Rome is what made a difference in the western part of the old world. They built roads and encouraged people from different parts of the empire to travel and trade. Genghis had a habit of killing everyone that resisted but the romans kept them alive as slaves.

                        American culture and literature for example, I am sure will last many centtiries in other cultures.

                        • DiscourseFan 2 years ago
                          >American culture and literature for example, I am sure will last many centuries in other cultures.

                          Who can say?

                          You're right that Greece and Rome had very intertwined cultural exchange, but that was only after Greece had been conquered; again, that doesn't explain why Platonic philosophy was so influential outside of Greece and Rome.

                          And yes, the American civilizations didn't invade people from other parts of the world, but to them they did, because their immediate area was the world, and I'm sure if the Mayan civilization never collapsed they would be a colonizing force not unlike the Europeans. Appropriating land and labor for use in capital exploitation is not a distinctly European phenomenon.

                        • JoeAltmaier 2 years ago
                          Didn't the Maya civilization suffer from systematic erasure? Monks collected their books and had bonfires, called them devil-worshippers and threatened them to abandon their scripts and legends.
                          • musicale 2 years ago
                            Unfortunately, yes.

                            The few surviving ones are amazing though. I always hope that someday a hidden cache of preserved codices that somehow escaped destruction will be discovered, but it seems unlikely.

                            https://en.wikipedia.org/wiki/Maya_codices

                        • pjmlp 2 years ago
                          The worse part of it, compared with other lost civilizations is that we Europeans were responsible for it, in the process to make them "civilized".

                          How it could have turned much differently if there was a pacific coexistence with the conquistadores.

                          • hypertele-Xii 2 years ago
                            Wikipedia disagrees with you:

                            > The Classic Maya collapse is one of the greatest unsolved mysteries in archaeology. [...] Over 80 different theories or variations of theories attempting to explain the Classic Maya collapse have been identified. From climate change to deforestation to lack of action by Maya kings, there is no universally accepted collapse theory, [...]

                            What's your source or authority for claiming it was definitively the conquistadores?

                            • makomk 2 years ago
                              If the dating estimates in the article are right, I think this might even have been caused by the prior Preclassic Collapse a few centuries before that. Remember, the dates given are a full two millenia before colonialism and a lot can happen to cause societies to change and history and knowledge to be lost over that timescale; our historical knowledge of much of Europe during this time period isn't exactly great either.
                              • 2 years ago
                              • wageslave99 2 years ago
                                I know it is not an excuse but the European conquerors did the same other cultures have been doing to them for centuries. The "barbaric way of doing things" was common and was pretty extended for much part of the history.

                                European nations had been plagued by poverty, wars, killing, totalitarianism, witch hunting... For centuries, so when they reach the New World they continue to behave the same way they have been behaving until that point.

                                The only good part is that some countries were conquered and dominated by cultures that did not exterminated them. There was some mixing between peoples and the culture was enriched by that exchange.

                            • mydriasis 2 years ago
                              So exciting! The number of buildings in the images is insane. I wonder what they'll find if they go down and poke around a bit?
                              • d--b 2 years ago
                                Is there some kind of openstreetmap layer where lidar-surveyed sites are aggregated?

                                It'd be nice

                                • maxerickson 2 years ago
                                  The US has 3dep, which is a USGS program to aggregate and publish various federal and state data.

                                  Not really the same thing you are talking about, and not global, but it can be fascinating to look at. You can see old logging railroads and things like that in Michigan, and trace them to where they collected and dumped into rivers.

                                  • heliodor 2 years ago
                                    Catalog map is at:

                                    https://apps.nationalmap.gov/lidar-explorer/

                                    Click on a covered area, click one of the green icons listed next to each data set, then click on Potree Viewer in order to get to the 3D viewer (Potree in this case; I haven't tried the other one much).

                                    Scroll down the sidebar and change the dropdown that says "intensity" to say "elevation". Right below that, tweak the slider bar to select the min and max elevations so that the landscape you're looking at gets colored with all the colors. At the very top, reduce the radius to 0 and increase the strength to 1.0. And if your hardware can handle it, increase the point budget to whatever is still responsive. Lastly, under filters, deselect everything except ground, if you want to see the ground instead of vegetation and buildings.

                                    Also worth mentioning is the shaded relief derived from all this data, which you can find at:

                                    https://apps.nationalmap.gov/3depdem/

                                    It's very detailed and is a great starting point for your exploration of an area before jumping into the 3D viewer.

                                    • colomon 2 years ago
                                      Ooo, I'll have to look into that. I had a fun couple of days a few years ago comparing Google Maps satellite images from St Clair County, MI with the old maps which showed where the Interurban ran. It was really impressive how much you could still see the routes from above, even though the tracks were torn up 80+ years ago...
                                      • maxerickson 2 years ago
                                        The resolution can vary a lot. Michigan tends to have a lot of very nice data because NOAA has recently been doing scans of the Great Lake shorelines.
                                  • comprambler 2 years ago
                                    • antiterra 2 years ago
                                      Check out Lost Cities with Albert Lin if you want to see some of this stuff being done and previous discoveries. It feels a little docu-dramatized but neat nonetheless.
                                    • zznzz 2 years ago
                                      what kind of lasers / lidar technology is this that is not reflected by trees?
                                      • defrost 2 years ago
                                        The usual kind.

                                        You know how light reaches the forrest floor? So does LIDAR.

                                        If you get raw data from a LIDAR device (as opposed to the usual commercial internally "processed and smoothed" relatively low frequency data stream) you get a high frequency noisy cloud.

                                        The HF cloud includes returns that bounced from the upper canopy and returns that bounced from the forrest floor.

                                        You write your filters to pick the features (tree tops, tree foor, canopy density estimates, etc) you're interested in.

                                        It's also possible to map recent snowfall depths with LIDAR | microwave RADAR tweaks.

                                        • unwind 2 years ago
                                          Good question!

                                          According to [1], they rely on finding holmes in the foliage:

                                          Lidar, of course, does not actually see through vegetation. Rather, it sees through holes in the foliage. Some of the multiple laser pulses it emits simply find openings between leaves and branches, in much the same way that sunlight filters through the forest canopy, continuing down to the ground.

                                          [1]: https://www.gislounge.com/next-generation-lidar-seeing-the-f....

                                          • geenew 2 years ago
                                            It’s a bit trickier than that; some of the photons from the pulse pass through the canopy to hit the ground. In other words, a single pulse can have multiple detected returns, some from the top of the canopy, some the middle, some the ground.

                                            It’s important to realize that the laser pulse doesn’t remain at the same diameter the whole time; it’s path looks like a cone, albeit a very narrow cone. By the time it hits the ground it can be a couple of metres in diameter.

                                            That two metre wide bunch of photons is what is travelling through the canopy. Some fraction hit the top of the canopy and are reflected; some fraction of the reflected photons travel back in a straight line to the detector, the rest are lost to the environment. The same process repeats until the pulse hits the ground, and whatever photons are left reflect back.

                                            The energy returned to the detector is a tiny fraction of the energy sent out.

                                            • unwind 2 years ago
                                              Uh, also, that should be "holes", they are not looking for a British fictional detective in the dense foliage of Central America's jungles. Thanks, phone. :|
                                            • 2 years ago
                                            • triyambakam 2 years ago
                                              This is exciting as someone who recently discovered Graham Hancock.
                                            • RaSoJo 2 years ago
                                              Let us bid adieu to that chunk of rain forest. First them archeologists will go scrounging, followed closely by the tourists.

                                              Do these 'historic' finds serve any purpose for our future generations? Or would those trees have served our children better?

                                              • hypertele-Xii 2 years ago
                                                Archeology studies past purpose, not future, and unless you're going to claim the entire science of history useless, better get used to the idea that some trees have to be sacrificed for science.

                                                Some 14120 square miles of Guatemala is forested. While the 650 square miles of this archeological site represents a not-insignificant 4.6% of its forests, I doubt the archeologists are going to fell every tree and dig up every stump.

                                                Since you care so much about trees, I have to ask, how many trees have you personally planted? How much money have you donated to tree-planting programs? Otherwise you're just virtue-signaling.

                                                • JoeAltmaier 2 years ago
                                                  When those civilizations were active, there were few trees. It's wrong to return that part of the world to a previous state?
                                                  • Rebelgecko 2 years ago
                                                    I don't think any of those things you fear came to pass after El Mirador was discovered. Why would this site be any different?