Let’s recap the history of science so far:
systematic knowledge-making has probably occurred
as long as humans have been around.
Unfortunately, historians rely primarily on
written records, and those are only a few
thousand years old.
Although ancient Egyptian, Sumerian, and Chinese
cultures had writing and useful sciences,
we started with classical Greek and Indian
cultures that developed systems for understanding
the cosmos and all the stuff in it.
Today, we’re going to jump through space
to see how other cultures made knowledge at
roughly the same time without any contact
with the peoples of Africa, Asia, or Europe.
This is a story about the planet Venus, breathtaking
pyramids,
and most of all the question “when are we?”
What is time, and how do you measure it?
[Intro Music Plays]
The classical civilizations of Mesoamerica,
or what is now Mexico and Central America,
didn’t “leave behind” as many paper
sources as those of the Indian or Greco-Roman
linguistic worlds…
Because after CE 1500, Spanish imperialists
destroyed those records.
Of all the Mayan books made of folded-up bark
cloth—called codies—only four survive
today.
Luckily, stone tends to stick around.
There are thousands of Mayan stone engravings.
Archaeologists are still working to learn
what role monumental stone works served in
ancient Mesoamerican society.
And linguists have only recently decoded many
hieroglyphs found on Mayan engravings.
But stone carvings mostly concern gods and
wars.
Historians struggle to understand what daily
life was like and—in the case of science—how
ancient Mesoamericans produced knowledge unrelated
to the divine stars.
To paraphrase archaeologist Michael Coe, imagine
that everything we knew about English came
from only three prayer books…
The earliest Mesoamerican writing comes from
the Olmecs, who lived in what is today southern
Mexico from 1500 to 400 BCE.
Their carvings included human–jaguar hybrids.
But the Olmecs are best known for their colossal
human heads cut from volcanic stone.
From an early date, Mesoamerican cultures
traded goods and knowledge.
Over time, sites elsewhere took on Olmec features.
In addition to an art style and a writing
system, the Olmecs invented a mathematics,
including the number zero, and a calendar
system that influenced later Mesoamerican
civilizations.
Ancient Mesoamerican civilization reached
a height of astronomical knowledge under the
Maya.
They ruled over what is now all of Belize
and Guatemala, western El Salvador and Honduras,
and southern Mexico from 2000 BCE until the
1600s, in the common era.
The Maya built great step pyramids.
These were temples devoted to kings as well
as sites for making astronomical observations.
The Caracol or Observatory of Chichén Itzá,
for example, was built
to align with the extremes of Venus’s rising
and setting in the year CE 1000.
That's cool!
The Maya had a base-twenty or vigesimal mathematical
system that included zero, but no fractions.
And they created very large tables for calculations.
These tables came in handy because one of
the principal cultural obsessions of the Maya
priesthood was calculating future calendar
dates—and we’re talking very far future.
You may have heard a sort of history of science
urban legend—that the Maya thought the world
would end when their calendar calculations
ran out on December 23, 2012…
Which, I think we can confirm, didn’t happen.
We aren’t sure what the ancient Maya thought,
but it’s true that they made of lot of calculations
about time for religious purposes.
To understand Mayan time-keeping, let’s
head to the ThoughtBubble:
“When are we?”
To answer this question, the Maya used an
extraordinarily complicated system of five
interlocking calendars of different lengths.
This provided them with very accurate timing
regarding both the solar and lunar years…
and the Venusian year.
Because, to the Maya, Venus was the most important
heavenly body.
The primary calendars were the tzolkin,
a 260-day sacred cycle that developed by CE
200, and the “Vague Year” solar calendar.
The Vague Year has eighteen 20-day months
with a period of five unlucky corrective days
to bring the year to 365 days total.
But vaguely.
The tzolkin and Vague Year together made the
Calendar Round, which repeated every 52 years.
Also, the 260-day tzolkin was made up of two
smaller calendars, marking a 13-day numbered
and 20-day named cycle of days.
But also the Maya kept track of the “Long
Count”—a calendar made of different units
ranging from one day to sixty-three thousand
years.
Using the Long Count, the Maya reckoned time
in the millions of years.
Thus every single day of the Maya year served
a specific sacred function defined in relation
to Venus, which mattered in Mayan astrology
and medicine; and gave the average person
a useful sense of time, for example in relation
to the harvest; and also answered the question
“when are we?”
accurately across literally millions of years.
Perhaps no other people in human history have
cultivated such a complete understanding of time.
And this isn’t just history.
In Guatemala, there are Mayan priests called
Day Keepers who still keep the sacred calendar.
And you can buy tzolkins in your local mini-mart.
Thanks Thought Bubble.
The Maya developed a writing system of hundreds
of square glyphs depicting natural elements
such as jaguars, fish, and people.
These carry both symbolic and phonetic meanings.
That is, they can indicate sounds and directly
represent ideas.
The complexity of the system points to a priest–scribe
caste.
And there was an academy for them at Mayapán.
From the few Mayan codices that remain, we
know that the scribes determined the lunar
month to three decimal places and predicted
eclipses.
They also actively undertook research to improve
the accuracy of their tables, improving their
understanding of Venus’s movements over
time.
They may have worked on astronomical tables
for Mars, Mercury, and Jupiter as well.
Why did the Maya undertake a long-term research
program about the planets?
We don’t know for sure, but we know they
had a complex astrological system that generated
prophecies by correlating the positions of
Venus and other heavenly bodies with historical events.
With this system, the Maya coordinated military
campaigns and how your individual daily life
would work out… and what would happen millions
of years in the future.
You know, small stuff.
How do you build all of those temples to Venus?
You need a lot of people.
In pre-industrial times, that meant you needed
good farmers.
In addition to swidden or shifting agriculture,
the Maya also practiced intensive cultivation
of crops
such as maize, sunflower, cotton, chiles,
chocolate, and vanilla using irrigation.
They domesticated dogs and ducks, and penned
up wild turkeys and deer.
Is agriculture a science?
It definitely encompasses lots of knowledge-work,
including crop improvement and the management
of large-scale production systems involving
canals and multiple harvests.
In fact, historians are only today coming
to understand just how densely populated the
Mayan world was.
Central America is tropical, so many Mayan
ruins lie buried underneath the forest.
But recent archaeological evidence uncovered
using LiDAR—light detection and ranging—at
the metropolis of Tikal, in what is now Guatemala,
has shown that Mayan civilization was perhaps
three times as populous as previously thought.
By the way, LiDAR a good example of how modern
science can help us understand history, including
the history of science.
Without the wheel or the horse, the Maya cities
were for a while united in a true hydraulic
empire.
Maya civilization was not only much larger
than, say, the equivalent one in medieval
England, but on the same scale as the great
dynasties of medieval China.
Mayan culture came under stress in CE 800,
and the Long Count fell into disuse after 1200.
The fragility of the Mayan food system probably
played a role in collapse.
Deforestation to make lime for stucco, or
plaster for decoration, may have played a
role in changing rainfall patterns, leading
to famines.
Then, after 1500, Spanish genocide definitively
crushed high Mayan culture.
The 260-day sacred tzolkin persisted, but
the Maya didn’t maintain a class of astronomer–priests.
After the decline of the Mayan states but
before the arrival of the Spanish, tribes
from what is now northern Mexico moved south
and established new kingdoms.
The largest group of peoples who settled in
central Mexico were the Nahuas.
The Nahuas called the Aztecs were the great
builders of central Mexico.
They planned the great capital of Tenochtitlán in 1325, on Lake Texcoco,
and this city is still around: you might know
it as Ciudad de México, or Mexico City.
Building a big stone city on top of a lake
and growing enough food for its citizens involved
a lot of hydraulic engineering.
The Aztecs created a system of canals, floodgates,
and aqueducts.
They used dikes to separate fresh and saltwater.
This allowed them to practice intensive lake-marsh
agriculture, growing maize, amaranth, fish,
and ducks.
In this way, Tenochtitlán supported a population
of maybe three hundred thousand.
Here, the Aztecs supported a full-time priest
caste, as well as a large army and many merchants.
Aztec bureaucracy included tax collection,
judiciary system, and censuses.
The Aztecs used the 52-year Mayan Calendar
Round but aligned their great temple with
the setting sun, not Venus.
And the Aztecs built other buildings on equinoctial
lines—or the lines along which the plane
of Earth’s equator passes through the center
of the Sun’s disk, once in the spring and
once in the fall.
The Aztecs collected a wealth of botanical
and medical knowledge, maintained by priests
who also served as astrologers.
They believed in a complicated humoral system
that linked plants, the human body, and the
heavens.
Which was oddly similar to the Greco-Roman-Islamicate
one we’ll talk about in a few episodes.
Aztec healers seem to have been specialists,
focusing either on surgery, bloodletting,
childbirth, creating herbal drugs, or treating
sick turkeys.
Aztec physicians had an extensive anatomical
lexicon.
They even treated dandruff!
No wonder Aztec life expectancy exceeded that
of the Spanish colonizers.
Like the Mesoamericans, the people of South
America traded widely.
Very widely: a new genetic study of sweet
potatoes shows that Polynesians traveled to
the Americas around CE 1000 at least once,
traded for these vegetables, and then possibly
came back.
They may have also introduced chickens to
the Americas ahead of the Europeans.
The South Americans forged empires, featuring
monumental stonework and carefully planned
agriculture.
The Inka developed an empire in the Andes
Mountains from roughly CE 1100 until the Spanish
conquest.
The most famous Inkan site is Machu Pichu,
in what is now Peru.
This city of polished, carefully fitted stone
was built around 1450… on the top of a mountain.
The Inkan state involved tax and census records,
standard measures, medical specialists, and
astronomical and calendric data recorded into
the very architecture of their cities.
But, unlike the other original empires, no writing system. This makes the story of Incan knowledge making,
difficult to recover.
The Inka did, however, use a sophisticated
system of tying strings of knots, called khipu
to keep records.
Khipu used a decimal system and allowed the
Inka to share data related to taxes, the census,
the calendar, and military organization…
And the khipu might have worked a bit like
a writing system, too, at least some of the
time.
Just as linguists are still decoding the hieroglyphs
of the Maya, researchers are still trying
to understand just what the khipu mean.
In fact, the latest breakthrough, linking
khipu record-keeping to a colonial-era Spanish
census, was made by an undergraduate!
The Spanish and other colonizers devastated cultures native to the Americas.
Reducing the complexity of thousands of years of history into a small number of paper sources and a
few dozen monumental stone buildings and artworks.
Nature reclaimed entire cities, and historians
are left to scratch their heads.
Many people of Mayan, Aztec, and Inkan heritage
are alive today, but the Spanish genocide
created a decisive break with ancient Mayan,
Aztec, and Inkan civilizations, distinct from
those of Europe and elsewhere.
Next time—we’ll explore the infrastructural
engineering with the ancient Romans.
Crash Course History of Science is filmed
in the Dr. Cheryl C. Kinney studio in Missoula,
Montana and it’s made with the help of all
this nice people and our animation team is
Thought Cafe.
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