
Sprawling Mayan network discovered under Guatemala jungle - rbanffy
http://www.bbc.com/news/world-latin-america-42916261
======
brett40324
This highly corroborates Charles C Mann's book 1491:
[https://en.m.wikipedia.org/wiki/1491:_New_Revelations_of_the...](https://en.m.wikipedia.org/wiki/1491:_New_Revelations_of_the_Americas_Before_Columbus)

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.

~~~
52-6F-62
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](https://en.wikipedia.org/wiki/Bosnian_pyramid_claims)

I would also love to see plots like Cahokia (and others like it) scanned:
[https://en.wikipedia.org/wiki/Cahokia](https://en.wikipedia.org/wiki/Cahokia)

~~~
Dangeranger
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.

~~~
52-6F-62
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.

~~~
Dangeranger
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].

[0] [https://www.gov.uk/government/news/environment-agency-
uncove...](https://www.gov.uk/government/news/environment-agency-uncovers-
landscape-with-laser-mapping)

[1] [http://vterrain.org/Locations/uk/](http://vterrain.org/Locations/uk/)

~~~
52-6F-62
Brilliant! Thank you. I wonder now if Canada has any projects remotely similar
occuring

------
oblib
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.

~~~
36bydesignBL
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.

~~~
oblib
"They don’t have ground penetrating memory,"

No, they don't.

I'll point out that the article mentions they "remove the dense tree canopy to
create a 3D map". It does not say "they used ground penetrating Lidar".

Seems to me you underestimate what they know and overestimate what you know
and that is exactly what I was saying they found irksome.

------
danans
Reminds me of the recent finding that the Amazon River basin was much more
cultivated in the ancient past than was thought:

[https://www.theatlantic.com/science/archive/2017/03/its-
now-...](https://www.theatlantic.com/science/archive/2017/03/its-now-clear-
that-ancient-humans-helped-enrich-the-amazon/518439/)

~~~
vanderZwan
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.

[0]
[https://www.youtube.com/watch?v=xdZMXWmlp9g&t=25m28s](https://www.youtube.com/watch?v=xdZMXWmlp9g&t=25m28s)

[1]
[https://www.youtube.com/watch?v=xdZMXWmlp9g&t=32m26s](https://www.youtube.com/watch?v=xdZMXWmlp9g&t=32m26s)

~~~
erikpukinskis
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.

~~~
vanderZwan
> _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.

~~~
empath75
In Guatemala, they’re an ethnic majority whose rights are still being trampled
over.

------
vosper
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.

[https://smile.amazon.com/dp/B01G1K1RTA](https://smile.amazon.com/dp/B01G1K1RTA)

~~~
defen
You might also be interested in "Breaking the Maya Code" which is a great
historical account of the decipherment of Maya script.

[https://www.amazon.com/Breaking-Maya-Code-Third-
Michael/dp/0...](https://www.amazon.com/Breaking-Maya-Code-Third-
Michael/dp/0500289557)

~~~
jpm_sd
I loved this book! I think any software engineer would enjoy it.

------
ziotom78
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?

~~~
Dangeranger
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.

------
empath75
You see overgrown mounds all over central america, and not all of them are
volcanic. There's an immense amount of undiscovered history there.

~~~
digi_owl
Yeah i think we are heavily underestimating how quickly nature can retake
cultivated land.

~~~
mmjaa
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 ..

~~~
InclinedPlane
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.

~~~
mturmon
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...](https://en.m.wikipedia.org/wiki/Ogallala_Aquifer#General_characteristics)).

The greater part of the LA Basin is a floodplain which consists of hundreds of
feet of sediment from the San Gabriel mountains.

------
twooclock
There are two NY articles worth reading:
[https://www.newyorker.com/magazine/2013/05/06/the-el-
dorado-...](https://www.newyorker.com/magazine/2013/05/06/the-el-dorado-
machine) and [https://www.newyorker.com/tech/elements/an-ancient-city-
emer...](https://www.newyorker.com/tech/elements/an-ancient-city-emerges-in-a-
remote-rain-forest)

------
rjurney
The better link for Americans is here on National Geographic:
[https://news.nationalgeographic.com/2018/02/maya-laser-
lidar...](https://news.nationalgeographic.com/2018/02/maya-laser-lidar-
guatemala-pacunam/) It lists a special including the Lidar discoveries on Feb
6 on National Geographic.

------
melling
The NatGeo submission was a good read too:

[https://news.ycombinator.com/item?id=16286230](https://news.ycombinator.com/item?id=16286230)

Direct link:

[https://news.nationalgeographic.com/2018/02/maya-laser-
lidar...](https://news.nationalgeographic.com/2018/02/maya-laser-lidar-
guatemala-pacunam/)

------
grafelic
Is that possibly a meteor crater seen on the right of the second LiDAR
picture?

~~~
naikrovek
You mean the left side?

------
utefan001
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.

[https://en.wikipedia.org/wiki/Archaeology_and_the_Book_of_Mo...](https://en.wikipedia.org/wiki/Archaeology_and_the_Book_of_Mormon)

~~~
mholt
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.

~~~
ga_golfnut
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.

~~~
dragonwriter
> 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.

~~~
ga_golfnut
I should have qualified that with "during the Book of Mormon timeline".

~~~
dragonwriter
3kya is just about at the Book of Mormon timeline.

~~~
ga_golfnut
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]

[1]
[https://www.lds.org/scriptures/bofm/ether/9.19?lang=eng&clan...](https://www.lds.org/scriptures/bofm/ether/9.19?lang=eng&clang=eng#p18)

