From wikipedia: The book presents recent research findings in different fields that suggest human populations in the Western Hemisphere—that is, the indigenous peoples of the Americas—were more numerous, had arrived earlier, were more sophisticated culturally, and controlled and shaped the natural landscape to a greater extent than scholars had previously thought.
This is not my field of expertise, but why wouldn't we just run LIDAR scans of as much of the earth's surface as possible?
Is it prohibitively expensive at this point? Is the computation [relatively] expensive? Is there a sound reason we don't race to do more?
I get the feeling this kind of data could inspire generations of new archaeologists and historians.
There are also some pseudo-archeological and pseudo-historical claims that might be put to rest (or less likely, cause a revolution in human self-knowledge). Eg: https://en.wikipedia.org/wiki/Bosnian_pyramid_claims
LiDAR collection is pretty dense from a data perspective. When I was working with helicopter collection teams we would regularly collect 1TB of point data per day at around 120 points per square meter. Based on the density of the canopy in Central America, the teams are probably using a density greater than that, and are using "multiple return" depth mapping so that they can see through the forest.
Processing LiDAR data is also quite expensive in terms of the hardware required and expertise of the people needed to correct the data back at the office. Typically LiDAR processing workstations have around 128-256 GB of RAM and a large RAID array of SSDs to quickly perform corrections interactively.
After the initial correction, most of the data is thrown out or "filtered" down to just the points of interest to save on space. Since it's quite easy to end up with hundreds of TBs worth of point data within a few months of collection. If the team is using colorized LiDAR, orthographic, and oblique images then that can take up even more space.
So the short answer to why more of the world hasn't been mapped with LiDAR techniques is money, time, and storage space. But with self driving cars now making LiDAR more prevalent, and storage space becoming more affordable every year, mapping whole regions with LiDAR is a more reasonable task.
NOTE: One of my former jobs was working with aerial LiDAR collection teams to manage the data and processing of the collected assets. This was around 2012 so some of the numbers may have changed since then.
Thanks, this is the kind of information I was curious about receiving in a concise digest.
So ultimately it sounds like I have to wait a decade or so before we can really proliferate, and to speed it up need a few more eccentric billionaires to get into funding some cool projects.
I'll use your information as jumping points to find out more.
My hopes lie with the open sourcing of in-vehicle processing hardware and software that is being used within self driving cars. As of today my understanding is much of that is part of the "secret sauce" of companies like Waymo and others.
If it were possible to apply kinematic geo-correction along with point filtering and feature detection during collection then a lot of the "heavy" data could be reduced down to what is just needed for human verification.
If you want to start your investigation with existing projects you could have a look at what the United Kingdom is doing with their government LiDAR data sets[0][1].
I like the tech because of its ability to prevent the destruction of archaeological sites while still allowing for discovery that would otherwise require an immense amount of digging and other labours.
If my hasty math is in the ballpark, the raw data for 500 trillion square meters would be a few hundred petabytes. Not cheap, but cheap enough that I would guess the cost and logistics of acquiring the data are much more of an obstacle.
Yes that is true, logistical support and processing have considerable costs. For aerial LiDAR collection via helicopter you're looking at about $20,000 per day of onsite collection including the helicopter team, insurance, and support. That gets you high density low altitude assets, not including the processing and storage costs.
It's cheaper to fly with a fixed wing aircraft, but you will typically get lower density assets and the possibility of obscured imagery due to cloud coverage because of the higher collection altitude. However the advantage is you're able to cover a wider collection swath with each pass, and it's a lot easier to fly a fixed wing vs. helicopter so the pilots are cheaper.
That depends a lot on the density of point coverage you need. Most LiDAR receptors weighed between 100-300lbs five years ago. They have become much smaller now, again due to self driving cars. However I am not sure that the hardware which is suitable for self driving applications would be "survey grade" appropriate for forest canopy and ground truth mapping. I'm also not sure what the power requirements of the newer LiDAR arrays are, but the weight for batteries is significant as it directly impacts your time "in the air" between ground support stations. In a helicopter you can power all the instruments off a DC power supply from the turbine.
Also typically you want an absolute vertical accuracy of +/- 5cm during flight in order to confidently map the surface features below foliated vegetation cover. This requires quite specialized differential GPS equipment as well as a radio/cellular connection to a commercial GPS ground station network. With the improvements in GLONASS/GALILEO constellations maybe the ground networks are not as critical anymore.
A few hints from the article: 810 sq miles mapped, a three year project and lidar flying by helicopter. Another giveaway is the search for MH370. In some dimensions Earth is still huge!
In a straight line, it’s smaller than we might expect: People can (and do) walk across continents, sail across oceans in one-person boats, fly all the way around in 2 days, visit every country at least once during their life, etc.
But of course the surface is two-dimensional, we can’t see very far at a time. The land surface is about 150 million square kilometers. (For reference, New York’s Central Park is about 3.4 square kilometers.)
It’s also “fractal”, in the sense that as we look at smaller and smaller pieces, we keep noticing more and more details. Every little patch of soil is teeming with tiny animals, plants, fungi, and bacteria.
Or if you like, there are probably at least 10 million restaurants in the world (maybe an order of magnitude more, it’s hard to guess). If you eat at 3 different restaurants every day for your whole life, it will take more than 100 lifetimes to eat at all of them. Then there are the 150 million books to read. Etc.
To me, fears of overpopulation have less to do with how much of the earth serves as living space, but how much human activity currently impacts nearly every corner of the planet. I think it's plausible that we can lessen human impact without actually decreasing population. Not sure it's likely, though.
I recall a letter to Science from the mid 70s, rebutting The Limits to Growth. I have tried to find it more-or-less lately, with no luck. As I recall, its author argued that the Earth could support well over 10^8 people in Trantor style. He assumed unlimited energy from fusion, and substantial food synthesis. Only humans, pets, crops, livestock, and requisite insects and microorganisms would survive. The planetary surface would support a building ~16 km high. At that height, the surface would be in thermal equilibrium at ~1500°C.
But hey, if that were doable, why not just build space habitat's?
In other words 100 billion to 1 trillion. The world’s land area, excluding Antarctica, is about 50 million sq. miles. With a comfortable population density of 1000 ppl/sqm (like in South Korea, Holland, Israel, or the state of New Jersey) you would get to 50 billion (same as Trantor). The population density of Singapore is close to 20k ppl/sqm, that would give you 1 trillion.
If you are willing to pad the Earth with buildings 16 km high, you could pack at least 1000 times more people, more likely 1 million times more.
I don't remember the number. What I recall is just that it was an absurdly huge estimate. And I'd love to have a copy of that ~1975 letter, if anyone has access to requisite tools.
And, in case it's not obvious, it's not a world that I'd care to live in.
A private small-aircraft flight over any populated area (other than the biggest cities) reveals just how sparse most towns are. Travel almost any direction away from a main highway and in a minute or two you'll be looking at trees, trees, trees (or desert/mountains/fields).
It helps give one an entirely new perspective when we're used to traveling along roads and seeing unyielding flows of civilization, when the reality is those are mere ribbons of development criss-crossing what is still mostly empty, disinterested nature.
Overpopulation at a certain level of consumption is a valid concern.
If all 7.4 billion people on the planet all consume 3 burger patties a day, all drive internal combustion powered vehicles, and all have a new iphone each, that would very quickly require an extreme amount of resource consumption - it is unsustainable.
Of course, if you just want "as high a population at any cost" the earth can probably sustain trillions of humans, but the bulk of those humans would have no clean water to drink, with no access to clean air, no access to a livable wage, no reasonable access to hospital and emergency services, etc.
You could have a trillion slaves, all pampering the lives of a the select few hundred billionaires who own everything. That's the real fear of overpopulation.
I guess I'll just have to study up on the tech. IIRC there was a fairly quick LIDAR demo put on by a team at MIT that scanned the campus and surrounding areas in a relatively brief amount of time using a drone, I think.
My ignorance on the subject of LIDAR has me wondering why we can't use a faster traveling vehicle, or would it be possible to do perform scans with something like a fleet of balloons that stream the data back vs one static device.
LIDAR data requires precise location-information of the scanning-device, otherwise the data you collect is at best useless, and at-most wildly skewed. This is because all the points are in-reference to the location of the device. A faster traveling vehicle inherently means less-accurate location measurements.
> In that Empire, the Art of Cartography attained such Perfection that the map of a single Province occupied the entirety of a City, and the map of the Empire, the entirety of a Province. In time, those Unconscionable Maps no longer satisfied, and the Cartographers Guilds struck a Map of the Empire whose size was that of the Empire, and which coincided point for point with it. The following Generations, who were not so fond of the Study of Cartography as their Forebears had been, saw that that vast map was Useless, and not without some Pitilessness was it, that they delivered it up to the Inclemencies of Sun and Winters. In the Deserts of the West, still today, there are Tattered Ruins of that Map, inhabited by Animals and Beggars; in all the Land there is no other Relic of the Disciplines of Geography.
""On Exactitude in Science" or "On Rigor in Science" (the original Spanish-language title is "Del rigor en la ciencia") is a one-paragraph short story by Jorge Luis Borges, about the map-territory relation, written in the form of a literary forgery."
In addition to what everyone else has said: even if we did we wouldn't necessarily know what to look for. I have a friend who's PHD is trying to figure out what ancient dams look like in order to find sites of ancient agriculture. But that's the thing "what does a 500 year old dam look like" is a lifetime worth of study and is only just now possible.
"Just scan the fuck out of it and look for wierd stuff" is the dream but at the moment (as the other comments point out) we can't just scan everything but ALSO we don't know what's wierd.
I'm reading this now and it's excellent. It has the important characteristic so many popular revisionist histories lack, restraint. Later day American archaeology practically oozes with opportunities to speculate. Actual physical discoveries beg to be contextualized by our modern imaginations. Mann does visit some of these tangents of the imagination but he is also very careful to bracket these with explanations of what is known for a fact and what is not.
Mann does pick the most optimistic ranges of estimates to try to paint a particular narrative, but he is also very frank that he is doing that, and he repeats this fact several times throughout the book. It would be wonderful if more books were willing to do that sort of guarding to emphasize how much the evidence really supports the thesis. Considering that pre-Columbian America tends to get the short-end of the stick in history, I'm willing to tolerate the constant pushing on the narrative to help emphasize that the popular view of pre-Columbian American is more often incorrect to correct.
I appreciate the efforts and tech used to map the area and create the graphics but I've been to Guatemala and I suspect that these scientists didn't "discover" near as much as they claim here.
Mayans still live there, and they know every nook and cranny and tree and rock in those forests. If you ask them, and then shut up and listen, they'll tell you all about it and answer any questions you might have.
I did ask one about what was hidden in the forests below us that I met on the top of a pyramid in Belize. He pointed out the locations of about a dozen pyramids in Guatemala that we could see in the distance and told me about the roads and platforms and other structures hidden in the forests around us. I was astounded with what I learned from that man. He was a Forest Ranger who grew up there. His family had been living in the area forever.
I also asked him what they thought about scientists from foreign countries who come there and then announce to the world they've "discovered" something. Suffice it to say this piece would probably irk him because it pretends none of them knew anything about most of what scientists claim to have "discovered". He also opined a bit on how their culture has been depicted as being violent and bloodthirsty and offered a much more tempered version.
But, it is nice to know that Guatemala funded the project and have the data. That part is cool as can be and I look forward to hearing more about what they learn from it.
Most professional archaeologists/anthropologists do ask the indigenous people and do listen. Sure there are always some people who are attention seekers, but the majority do good science and leverage indigenous knowledge. That said, you overestimate how much the people can know. They don’t have ground penetrating memory, and the Maya people have always been far from one united nation but closer to a collection of city-states with some shared cultural traits.
Furthermore, most of the classic Mayan sites were long ago abandoned so it isn’t like there are indigenous people hanging out around Ti’kal or Calak’mul that can just spill the entire history.
Any competent Mayanist would have told you the same as that person in Belize. It is no secret the landscape is dotted with unexcavated ruins, but the scope is unclear which is exactly why this research is so useful.
Similar thing in the lower parts of Mexico. As told to me by some locals on a stop while riding through the country on my motorcycle, there are plenty of locally known, overgrown ruins that are yet undeveloped as visitor sites simply due to lack of funds or renovation resources.
Which in turn reminds me of Richard Feynman describing the Mayan Calendar in his famous lectures on quantum mechanics, as an example of how the Mayans understood how the planets moved by looking, that they even figured out a number of patterns and predictions, but that they still did not know why the planets moved as they did, his point being that current understanding of quantum mechanics is very similar to this[0].
At the end, he tangentially mentions that we only know about this calendar because it is described in one of the three surviving books of their culture, out of thousands[1]
> "Just imagine our civilization reduced to three books, just the particular ones left by accident, which ones... So eh.. anyway, I get off the subject..."
The genocide of Native Americans is of course horrible by itself, but somehow this remark made me realize what "genocide" means beyond people being killed en masse. So much culture and knowledge was lost.
And the reason that there are only a few surviving books is that the Spanish conquerors plucked those out to send back to Europe as curios before they burned down all the libraries.
This stuff drives me so nuts. It also seems to be something that I've only ever noticed being done by religious people who follow done monotheistic believe. Does anyone know if any destruction of a culture and its artifacts had happened by someone not motivated by monotheistic delusions?
This was a honest question. With so many atrocities going on it's hard to differentiate which ones don't only seek out to kill all members of a given culture but also their cultural artifacts. Thank you for listing several that fit the bill.
There was a interesting discussion somewhere (can't remember where) that called communism the first techno religion. The idea was that everything is build around the expectation that labor will become less important and owning means of production becomes paramount because of automation. Very relevant thoughts nowadays. Nice to look in the mirror of the past.
I highly recommend Eric Hoffer's The True Believer if you're interested this topic at all. It's a short book full of major ideas.
Hoffer's treatment of the phenomenon is just as fresh and relevant today as it was when he wrote the book in the 1950s.
I got downvoted for suggesting that Maoism was a religion, but it quite clearly had more commonalities than differences with the more extremist religious cults (as did Stalinism, Nazism, etc.)
It was common in the ancient world -- "we won because our god(s) are greater than your god(s)."
Look at the (pagan/polytheist) Romans' actions in the seige and destruction of (monotheist) Jerusalem, for one example. Or (pagan) Viking raids on English/Welsh/Irish Christian monasteries for another.
That’s exactly what I just said... the Spaniards burned all of the books except for a small handful which were sent back to Europe as curios.
> We found a large number of books in these characters and, as they contained nothing in which were not to be seen as superstition and lies of the devil, we burned them all, which they regretted to an amazing degree, and which caused them much affliction. – Bishop De Landa
Once again someone many have accused of tinfoil battery being shown to be onto some nugget of truth. He had a medical scare recently, anyone know how he's doing?
This is why liberals are sometimes using the term genocide more broadly in a way conservatives don’t like. They reference things like “black genocide” and conservatives get mad because the actual slayings are too few to be considered “genocide”.
Yet in terms of lost culture, putting a high enough percentage of individuals in prison, and confining enough of the others to ghettos, while driving them out of historical cultural centers, has an equivalent result to genocide in some ways.
Essentially, a percentage of the people can be alive while also having “the culture” be as dead as dead can be.
Of course the culture is born again in a different form, as Native American culture endures today, despite “genocide”. And rendering that invisible is just a continuation of that genocide so I certainly don’t want to intimate that such culture is truly gone.
> Of course the culture is born again in a different form, as Native American culture endures today
Well, a culture is born again; culture just tends to happen if you put people together, it's in our blood. The question is whether it flourishes. I am from Europe so cannot say this for certain, but I get the impression that all over both American continents, Native Americans are still very much an ethnic minority whose rights are being trampled over.
You can't take HN threads into pure ideological warfare like this. It isn't what this site is for, and it's toxic to what it is for, namely intellectual curiosity. Since we've warned you before, and you obviously don't want to use the site as intended, I've banned this account.
How about you instead engage with that individual if you disagree? I don't find his comment unwelcoming to discussion. Now, whether he is correct or wrong is entirely separate, but from my point of view all I'm seeing is discussion being shutdown in the name of feelings and prevailing opinion.
"It should be noted - this definition as genocide as destruction of a culture (instead of physical murder of a people) also supports the idea of "white genocide":
A targeted effort by people with power to liquidate white peoples' group identity ("abolish whiteness") and to marginalize and obscure their traditional cultural touchstones ("don't teach books by dead white men" and related efforts to avoid teaching Shakespeare, the Bible, old white philosophers, etc), efforts to bring in many immigrants to make whites minorities in areas where they were previously a majority (and gleeful anticipation of this outcome), etc."
In his defense, it's difficult to want to waste time debating with this line of reasoning. There are some huge unfounded assumptions being made right here in a well thought out way. A nugget of possible truth, mixed with a lot of personal opinion. With that said, doesnt seem like it would lead to a productive conversation.
I'm not sure why the need to insert white males into the equation. That argument is based on you believing there is a secret organized attack against white men going on. I think thats open to interpretation depending on who you are. If anything, I, as a minority, see a balancing of power. Im also aware that whitw males still dominate the economical and political spectrum, so its even harder to agree with this logic. Is thus attack being perpetuated by other white males? To what gain? It seems to me that it appears as an attack on white males, when white males are no longer allowed to dominate culturally, economically, or in numbers in certain areas. They arent being excluded, others are being allowed to the table. That means more chairs need to be pulled up and you cant have the entire meal to yourself. I can't call that "cultural genocide". The role of white male in society remains much the same. This argument makes me think of the people who complain about AA hires, while ignoring the fact that the company is comprised of 85% white hires.
I'm reading "Lost City of the Monkey God" by Douglas Preston right now. It's been a highly entertaining first-hand account of (what I think was) the first use of LIDAR for archaeology in the jungles of Central America, and the ground exploration that followed. I'd definitely recommend it to anyone who's interested in this story.
I just started reading this book last night (my wife listened to the audiobook version several months ago, which caught my interest). Strange how these things "come together"...
The is one thing I don't understand. The article reports the use of lasers to map the ground, yet they mention the presence of foliage in situ. Assuming that they use optical or infrared lasers, foliage should be completely opaque at these wavelengths. How did they manage to map the asperities and characteristics of the ground?
LiDAR wavelengths are returned at various depths from within the forest canopy. In order to get a return on the ground you simply filter the returns down to the last value.
Sometimes however you want to keep the other returns and so you filter the values down to say 10% of all returns from a given depth, with a constraint between the depths of say 10cm so that you can see the density of the layers.
This is an astonishing thing to witness. Many people are familiar with the well known sites, they have seen the temples in pictures or on a TV show, for example Tikal. These sites are commonly depicted after they have been painstakingly reclaimed from the jungle, the structures are stone colored and the paths among them are dirt brown.
What's not commonly seen is the view out from atop one of these tall structures - the chaotic green sea of the jungle canopy is punctuated by tidy triangular mounds as far as the eye can see. The landscape is littered with these structures that were once upon a time built and maintained by many generations. Weep ye mighty!
This is something that has always fascinated me - just how do the processes which cover a landscape with, say, layers and layers of sediment - or jungle cover - really work?
I mean, I get it - you leave something out, a few weeks later its going to get covered in a layer of dust/sediment. But how is it that entire cities get buried under 10's of meters of dirt? I'm sure geologists have this all figured out, but it always amazes me that our world changes like this so rapidly.
In this case, I'm sure the answer is 'the jungle eats everything' .. but there are places in the world, buried under meters of sand and sediment, that I just wonder .. how does this happen ..
Leaf litter accumulates and breaks down and becomes new soil, mountains and hills erode and that sediment accumulates in lower areas, wind move lots of sand and fine sediment around, All of that piles up in places until things once on top of the soil are now buried.
It's a little more complicated than that, but that's part of the process.
Another aspect is that cities used to literally rise as they deposited waste in situ and had to build up as 1st floors became basements. This is partially the source of mounds.
It's not that complicated. Humans tend to build in flat areas. Flat areas tend to be flood plains. When flood plains flood they leave behind sediment. There are additional ways that sediment builds up such as airborne deposits and importantly from growing plants leaving behind biomatter, but in a lot of cases flooding explains the substantial depth of sediment deposited.
It’s one of those overlooked facets of Nature. Much of the Great Plains sits on the Ogallala Aquifer. This is an underlying terrain, to depths of hundreds of meters, filled in by sediment from the Rockies (https://en.m.wikipedia.org/wiki/Ogallala_Aquifer#General_cha...).
The greater part of the LA Basin is a floodplain which consists of hundreds of feet of sediment from the San Gabriel mountains.
There are lots of depositional (and erosive) processes happening. They're all subject to local conditions. But the most common (in no particular order) are: accumulation of plant matter, flood deposits, human-generated organic and building debris, and earthworm casts. You can also see other things, like volcanic activity and wind-blown material, in fewer places.
Definitely. It's a common sight in tropical countries to see modern buildings covered in random growth foliage (gutters, roofs, pavement cracks, window sills, etc.). I'd hazard a guess that even 20 years would probably be enough to significantly hide most low-rise buildings.
The link below may be interesting to look at (or laugh at?) since the LDS church's famous book claims to be about 3 civilizations that lived somewhere in north,central or south america. As far as I understand, one or more LDS leaders years ago decided (for arguably valid reasons) that all of the Book of Mormon events occurred between 600 BC to about AD 400.
This has made it more difficult for the church to say "look, we were right!" when discoveries like this are made because the timeline in several cases doesn't align with 600 BC to AD 400.
The Book of Mormon never claims that everyone died in the Americas at AD ~400. Nor does it claim that its account of the peoples there is comprehensive. In fact, it says the opposite: that splinter groups settled elsewhere, that there were other bands of people in the land, and that after the destruction of the Nephites, the millions of remaining Lamanites continued to sprawl over the land.
And it also says things like horses, chariots, steel, and other anachronistic things existed in the pre-Columbian Americas. There is no evidence (to date) to support any of those claims. You might want to look into the history of NWAF and Thomas Ferguson. Michael Coe, a renowned expert in this field and also mentioned on this post, was friends with Ferguson. It's an interesting history.
> And it also says things like horses, chariots, steel, and other anachronistic things existed in the pre-Columbian Americas. There is no evidence (to date) to support any of those claims.
Horses definitively existed in (far enough) precolumbian America. The dominant belief seems to be that they died out (perhaps due to human hunting) at or shortly after the end of the Pleistocene, ca. 10-12kya, but there is some evidence there may have been some populations around as late as ca. 3kya, IIRC.
EDIT: of course, one must keep in mind that the horses of precolumbian America were much smaller than Old World horses, so it's not really plausible that they'd be being ridden, pulling chariots, or generally being used like Old World horses even if it is (just barely) plausible that they were around at the right time.
Just about is fair but still short by ~400 years, unless you count the Jaredites. They purportedly fled the Old World around the time of the Tower of Babel (~2000 BCE IIRC?).
EDIT: I wasn't sure if the Book of Ether even mentioned horses, but it did, along with elephants. [1]
Could it be that maybe some things were lost in translation? Maybe a “chariot” isn’t exactly the way we think of a chariot now. Maybe it was just a saddle?
> While the evidence for horses in pre-Columbian America is encouraging, it still requires some caution. Additional C-14 dating from other samples will be needed to change the prevailing view. Until then, this evidence should be considered provisional, but promising.
Not being critical, only pointing out every time their is a big discovery like this, some level of time and effort is spent trying to align the discovery with the BOM. The wiki article has a lot of references in it that are related to the topic.
From wikipedia: The book presents recent research findings in different fields that suggest human populations in the Western Hemisphere—that is, the indigenous peoples of the Americas—were more numerous, had arrived earlier, were more sophisticated culturally, and controlled and shaped the natural landscape to a greater extent than scholars had previously thought.