11 ms·

How the Mayans were able to accurately predict solar eclipses for centuries

134 points by pseudolus 1y ago

uvaursi 1y ago
Whenever I see these backwards-applied math models I think of the “wet streets cause rain” expression.
pavinjoseph 1y ago
The original RDB!
photon_garden 1y ago
> The Maya Civilization, from Central America, was one of the most advanced ancient civilizations The Maya are still around! I spent a few months in the Guatemalan highlands last year and all the kids in the village spoke Kaqchikel, one of the Mayan languages, at home. (Young people speaking the language is key to language health.)
- throwup238 1y ago
  I was surprised to find out that there are still many indigenous groups with populations in the millions. My California public education made it seem like they were all pretty much wiped out save for those who survived to the various reservation systems. My favorite group is the Mapuche who managed to hold out against the Spaniards until they were conquered by Chile and Argentina in the late 19th century. They managed to thwart the conquistadors for centuries! It wasn’t until the modern era where military logistics got good enough to unseat them and overcome the advantages they had.
  - gausswho 1y ago
    The Mapuche even expanded their territorial control, in large part to their acquisition and mastery of Spanish horses.
    - pjbk 1y ago
      They also mainly continued to be loyal to the Spanish crown after Argentina and Chile went through their independence, and carried out the final pacification of the Mapuche territories in the 19th century. By then only a very small part of the population had not mingled with Europeans.
  - WalterBright 1y ago
    The Commanche also held out until after the Civil War.
    - beerandt 1y ago
      Was always weird to me how "the French and Indian War" had Indian involvement almost over emphasized to pretend like it wasn't the extension of a European war... While all the other American conflicts with tons of Indian involvement (both sides, esp civil war) had it downplayed. One of my first realizations of slant put on history.
      - tdeck 1y ago
        It's more properly a campaign of the Seven Years War, which was almost a world war of its time.
        beerandt 1y ago
        >like it wasn't the extension of a European war...
        pqtyw 1y ago
        The French and Indian war began 2 years before the war in Europe. So in a way it was the other way around (of course there were much more important factors than what was effectively an ongoing proxy war in faraway colonies)
        tdeck 1y ago
        My comment wasn't intended as a "correction", just adding that historians seem to refer to this war by a different name these days. At least in the textbooks I learned from, it was discussed in the context of the Seven Years War.
  - jcranmer 1y ago
    Even in the US, the Indian Wars weren't finished until the 1890s. In fact, most of the big wars against the Native Americans took place after the American Civil War. One of the big faults I have with US history in the education system is that it tends to front-load the depiction of Native Americans in the Precolonial portion of history, with an echo in the Trail of Tears and forced migration in the 1830s, and largely edits them out of the history of the settling of the west, despite this process requiring a very violent dispossession of the existing inhabitants.
    - t1E9mE7JTRjf 1y ago
      > most of the big wars against the Native Americans As I learned it, most of the conflicts were between not against. Native Americans, became a term as a general catch all but those peoples saw themselves as quite diverse, and as such is something of a misnomer.
      - sethammons 1y ago
        Look up the american bison. The US government's official policy was to eliminate bison to eliminate Indians/First Peoples. Mountains of skulls. In under a decade, the bison population was pushed down from 30-60M to approximately 500 individuals. Did tribes fight and war and capture slaves? Yes. They did that for forever. Then colonization and disease and westward expansion. Look up the Trail of Tears, the genocide and/or ethnic cleansing. Your education may align with propaganda. Even today, first people nations are actively having their history taken. Pete Hegseth, sec of def/war, has pushed to close the door on the massacre of wounded knee, enshrining the medals earned for slaughtering woman and children. https://www.nytimes.com/2025/09/27/us/hegseth-wounded-knee.html https://www.nytimes.com/2025/09/27/us/hegseth-wounded-knee.h.... Look up how the US government stole native kids and sent them catholic schools to have the Indian taught out of them. A system that was purpose built to stop their way of life. Or forced, non-consented sterilization of native woman that was happening in the 60s and 70s. If you somehow didn't know the US government's history of conflict and abuse of Native Americans, you should question your formal education. And you should do some light research.
  - tdeck 1y ago
    This is also a difference in outcomes between traditional colonialism (where indigenous people were viewed as a source of labor) and settler colonialism (where indigenous people are viewed simply as "in the way"). That's not to say that traditional colonialism is in any way acceptable, however.
  - pqtyw 1y ago
    Relatively (adjusted by area and duration) not that many people from Spain moved to the Americas between 1500 and ~1800, especially compared to the British colonies in North America. So they couldn't murder/expel (unlike the British/American colonists) most of the native population (especially considering that North America was much less densely inhabited to begin with) if they wanted someone to work in the mines and plantation (again relatively not that many slaves were imported to the mainland colonies as well). France was similar (except they struggled even more with getting enough people to move to the colonies).
- tdeck 1y ago
  The Maya are still around, but the Maya civilization's institutions were all destroyed. And the Spanish made a point of seeking out all the Maya books [1] they could find and burning them. So a lot of knowledge was lost. [1] https://en.wikipedia.org/wiki/Maya_codices https://en.wikipedia.org/wiki/Maya_codices
  - Cantinflas 1y ago
    The link doesn't mention "seeking out" those books, in fact it mentions catholic priests both burning and lamenting the burn.
    - wudangmonk 1y ago
      I guess that is implied since these things always happen this way, its not like book burners are just having a nice campfire and the books they dislike just happen to be close by.
    - jacobolus 1y ago
      They hunted down all of the libraries, collected all of the books inside, and burned them in massive bonfires, accidentally saving a total of like 3 books which had already been shipped back to Europe as trophies. I think there are also some remaining fragments of a few others. One Spaniard wrote about it: > We found a large number of books in these characters and, as they contained nothing in which there were not to be seen superstition and lies of the devil, we burned them all, which they regretted to an amazing degree, and which caused them much affliction.
      - antognini 1y ago
        It is worth noting that the friar who organized this book burning was recalled to Spain to stand trial on account of his actions.
        Larrikin 1y ago
        Why is that worth noting?
- bboygravity 1y ago
  I've been in towns in Mexico where the kids ONLY speak a Mayan language. No Spanish or English. I asked for directions and just got blank stares until someone who spoke Spanish in the village explained, lol.
  - xandrius 1y ago
    Where for example? I'm curious!
- piokoch 1y ago
  That is not that simple. They never invented the wheel, the Maya calendar cycled over 5128, which is not really convenient, numeric system was also rather uncomfortable, strange numerals working in 19-base system (but they have invented zero). In addition to that they've invented sadistic religion with human sacrifices and their culture was very aggressive, what finally put Maya civilization to an end, as everyone around happily joined European conquerors to get rid of Mayans ASAP.
  - alephnerd 1y ago
    > In addition to that they've invented sadistic religion with human sacrifices and their culture was very aggressive, what finally put Maya civilization to an end, as everyone around happily joined European conquerors to get rid of Mayans ASAP That was the Aztec, an entirely different culture from the Mayans. The Mayan Kingdoms lasted until 1697.
    - selimthegrim 1y ago
      Mayans also did sacrifice, but it was mainly PoWs/losers in battle or of ballgames
  - AngryData 1y ago
    They had the wheel, they just didn't find many practical uses for it without having either beasts of burden or nice relatively flat paved roads. Wheels are great if you have something stronger than a human to pull it, or you only have to move it a short distance, or if you have a hard paved road. But pulling carts or wagons or wheelbarrows through rough terrain or muddy roads with just human power is absolute trash and not worth the effort, and moving things over small short distances alone isn't worth the specialized labor and cost of making decent wheel and axle systems without machine tools. If you are still unsure, ask yourself why hikers and campers don't pull a cart or push a wheelbarrow everywhere they go instead of using a backpack even though they can have ultra light aluminum construction with pneumatic tires and ball bearing axles. All the effort you would save by using a wheelbarrow on smooth parts of your path would be undone by just a handful of random sticks or rocks you run into with it along the way.
- amypetrik8 1y ago
  I was just in Silver Spring MD, just outside of Washington, DC, and I noticed that all those kids moved from Guatamala to DC! The American dream! All the kids in Silver Spring spoke Kaqchikel, one of the Mayan languages, at home. We need more Kaqchikel-speaking children in the Silver Spring area to add to diversity, so that it's not just a primarily Spanish-speaking-only area, but a Spanish-and-Kaqchikel speaking area.
NooneAtAll3 1y ago
How does one even come up with 260 day year? Is the weather in the tropics so similar that year-on-year mismatch stops mattering?
- antognini 1y ago
  The origins of the 260 day ritual year are not known for certain, but there are a couple of hypotheses: 1. Pregnancy. 260 days is roughly the gestation period of a baby, so this may have been the inspiration for tracking this duration. (For what it is worth, modern Maya timekeepers cite this as being the reason for the length of the 260 day ritual calendar.) 2. In the tropics there are two days of the year when the Sun passes through the zenith and objects cast no shadows. In the latitude where the earliest Mesoamerican civilizations emerged, the length of time between these two days of the year is about 260 days. 3. Numerology. 260 is the product of 20 and 13. 20 was significant in Mesoamerican culture because it was the base of their numbering system and was associated with the human body (given that we have 20 fingers and toes). And the number 13 was associated with the cosmos. So the number 260 represented a kind of interlocking between the human and the cosmic. It's also worth noting that the Maya also tracked a 365 solar cycle, so they did have a concept of a more standard kind of "year." The 365 cycle was used for civil purposes. The 260 day ritual cycle was used more for divination. (Shameless plug, but if you want to learn more about Mesoamerican astronomy I have a podcast about the history of astronomy and I talked about it on the last episode: https://songofurania.com/episode/047 https://songofurania.com/episode/047)
  - behnamoh 1y ago
    > And the number 13 was associated with the cosmos. Any reason number 13, of all numbers, has been so significant in different parts of the world, sometimes associated with completely opposite meanings (e.g., between Jews and Persians/Europeans)?
    - NooneAtAll3 1y ago
      generally, 7 and 13 get a lot of attention because a)they are prime b)1/7 and 1/13 have long period when written as decimal fraction - so you keep stumbling in your calculations every time you encounter them 1/7 in base 20 takes surprisingly short form of 0.(1h) (h is 17), unlike 1/9 or 1/11 - so I wonder if there's Mayan prejudice on those instead
ranger_danger 1y ago
The sad thing is that for all their advanced ways of the time, they succumbed to the same thing we are experiencing now... being too comfortable to fix what's broken. The Mayans did not want to give up their lifestyles even in the face of crippling population growth and surrounding natural resource depletion... which led to their downfall.
- t1E9mE7JTRjf 1y ago
  Sounds like the opposite no? Since we are going through population collapse in a time of abundance. Does make me wonder what the political dynamics were at the time, whether some could see problems but weren't in power to change things. Or maybe they couldn't understand or figure out solutions to the problems. What I'd give to be a multilingual fly on the wall throughout history.
  - asacrowflies 1y ago
    We don't really have abundance tho.... We have massive over consumption that feels like abundance. Like a gambler
- sethammons 1y ago
  This should be upvoted. A lot. The downvotes are ill-informed. https://www.earthobservatory.nasa.gov/images/77060/mayan-deforestation-and-drought https://www.earthobservatory.nasa.gov/images/77060/mayan-def... From newish imaging. We can see the impressions of vast jungle swaths cut down and way made for planting food and houses. This looks to have disrupted the water cycle enough to cause cinotes (underground water systems and only source of drinking water) to deplete. We see sacrificial remnants below the modern water line. Their water disappeared and so did their civilization. By the time the Spanish arrived, the local people had no knowledge of how to build nor maintain their now ancient cities, the jungles regrew, water came back, and sacrificial artifacts were covered by replenished water levels. They are an example of man made effects on local weather leading to the downfall of an advanced civilization.
  - b112 1y ago
da02 1y ago
They used past historical data to make predictions without having the need for a helio-centric model?
- cwmoore 1y ago
  Is this the answer?

134 points by pseudolus 1y ago

uvaursi 1y ago

Whenever I see these backwards-applied math models I think of the “wet streets cause rain” expression.

pavinjoseph 1y ago

The original RDB!

photon_garden 1y ago

> The Maya Civilization, from Central America, was one of the most advanced ancient civilizations The Maya are still around! I spent a few months in the Guatemalan highlands last year and all the kids in the village spoke Kaqchikel, one of the Mayan languages, at home. (Young people speaking the language is key to language health.)

throwup238 1y ago
I was surprised to find out that there are still many indigenous groups with populations in the millions. My California public education made it seem like they were all pretty much wiped out save for those who survived to the various reservation systems. My favorite group is the Mapuche who managed to hold out against the Spaniards until they were conquered by Chile and Argentina in the late 19th century. They managed to thwart the conquistadors for centuries! It wasn’t until the modern era where military logistics got good enough to unseat them and overcome the advantages they had.
- gausswho 1y ago
  The Mapuche even expanded their territorial control, in large part to their acquisition and mastery of Spanish horses.
  - pjbk 1y ago
    They also mainly continued to be loyal to the Spanish crown after Argentina and Chile went through their independence, and carried out the final pacification of the Mapuche territories in the 19th century. By then only a very small part of the population had not mingled with Europeans.
- WalterBright 1y ago
  The Commanche also held out until after the Civil War.
  - beerandt 1y ago
    Was always weird to me how "the French and Indian War" had Indian involvement almost over emphasized to pretend like it wasn't the extension of a European war... While all the other American conflicts with tons of Indian involvement (both sides, esp civil war) had it downplayed. One of my first realizations of slant put on history.
    - tdeck 1y ago
      It's more properly a campaign of the Seven Years War, which was almost a world war of its time.
      - beerandt 1y ago
        >like it wasn't the extension of a European war...
        pqtyw 1y ago
        The French and Indian war began 2 years before the war in Europe. So in a way it was the other way around (of course there were much more important factors than what was effectively an ongoing proxy war in faraway colonies)
        tdeck 1y ago
        My comment wasn't intended as a "correction", just adding that historians seem to refer to this war by a different name these days. At least in the textbooks I learned from, it was discussed in the context of the Seven Years War.
- jcranmer 1y ago
  Even in the US, the Indian Wars weren't finished until the 1890s. In fact, most of the big wars against the Native Americans took place after the American Civil War. One of the big faults I have with US history in the education system is that it tends to front-load the depiction of Native Americans in the Precolonial portion of history, with an echo in the Trail of Tears and forced migration in the 1830s, and largely edits them out of the history of the settling of the west, despite this process requiring a very violent dispossession of the existing inhabitants.
  - t1E9mE7JTRjf 1y ago
    > most of the big wars against the Native Americans As I learned it, most of the conflicts were between not against. Native Americans, became a term as a general catch all but those peoples saw themselves as quite diverse, and as such is something of a misnomer.
    - sethammons 1y ago
      Look up the american bison. The US government's official policy was to eliminate bison to eliminate Indians/First Peoples. Mountains of skulls. In under a decade, the bison population was pushed down from 30-60M to approximately 500 individuals. Did tribes fight and war and capture slaves? Yes. They did that for forever. Then colonization and disease and westward expansion. Look up the Trail of Tears, the genocide and/or ethnic cleansing. Your education may align with propaganda. Even today, first people nations are actively having their history taken. Pete Hegseth, sec of def/war, has pushed to close the door on the massacre of wounded knee, enshrining the medals earned for slaughtering woman and children. https://www.nytimes.com/2025/09/27/us/hegseth-wounded-knee.html https://www.nytimes.com/2025/09/27/us/hegseth-wounded-knee.h.... Look up how the US government stole native kids and sent them catholic schools to have the Indian taught out of them. A system that was purpose built to stop their way of life. Or forced, non-consented sterilization of native woman that was happening in the 60s and 70s. If you somehow didn't know the US government's history of conflict and abuse of Native Americans, you should question your formal education. And you should do some light research.
- tdeck 1y ago
  This is also a difference in outcomes between traditional colonialism (where indigenous people were viewed as a source of labor) and settler colonialism (where indigenous people are viewed simply as "in the way"). That's not to say that traditional colonialism is in any way acceptable, however.
- pqtyw 1y ago
  Relatively (adjusted by area and duration) not that many people from Spain moved to the Americas between 1500 and ~1800, especially compared to the British colonies in North America. So they couldn't murder/expel (unlike the British/American colonists) most of the native population (especially considering that North America was much less densely inhabited to begin with) if they wanted someone to work in the mines and plantation (again relatively not that many slaves were imported to the mainland colonies as well). France was similar (except they struggled even more with getting enough people to move to the colonies).
tdeck 1y ago
The Maya are still around, but the Maya civilization's institutions were all destroyed. And the Spanish made a point of seeking out all the Maya books [1] they could find and burning them. So a lot of knowledge was lost. [1] https://en.wikipedia.org/wiki/Maya_codices https://en.wikipedia.org/wiki/Maya_codices
- Cantinflas 1y ago
  The link doesn't mention "seeking out" those books, in fact it mentions catholic priests both burning and lamenting the burn.
  - wudangmonk 1y ago
    I guess that is implied since these things always happen this way, its not like book burners are just having a nice campfire and the books they dislike just happen to be close by.
  - jacobolus 1y ago
    They hunted down all of the libraries, collected all of the books inside, and burned them in massive bonfires, accidentally saving a total of like 3 books which had already been shipped back to Europe as trophies. I think there are also some remaining fragments of a few others. One Spaniard wrote about it: > We found a large number of books in these characters and, as they contained nothing in which there were not to be seen superstition and lies of the devil, we burned them all, which they regretted to an amazing degree, and which caused them much affliction.
    - antognini 1y ago
      It is worth noting that the friar who organized this book burning was recalled to Spain to stand trial on account of his actions.
      - Larrikin 1y ago
        Why is that worth noting?
bboygravity 1y ago
I've been in towns in Mexico where the kids ONLY speak a Mayan language. No Spanish or English. I asked for directions and just got blank stares until someone who spoke Spanish in the village explained, lol.
- xandrius 1y ago
  Where for example? I'm curious!
piokoch 1y ago
That is not that simple. They never invented the wheel, the Maya calendar cycled over 5128, which is not really convenient, numeric system was also rather uncomfortable, strange numerals working in 19-base system (but they have invented zero). In addition to that they've invented sadistic religion with human sacrifices and their culture was very aggressive, what finally put Maya civilization to an end, as everyone around happily joined European conquerors to get rid of Mayans ASAP.
- alephnerd 1y ago
  > In addition to that they've invented sadistic religion with human sacrifices and their culture was very aggressive, what finally put Maya civilization to an end, as everyone around happily joined European conquerors to get rid of Mayans ASAP That was the Aztec, an entirely different culture from the Mayans. The Mayan Kingdoms lasted until 1697.
  - selimthegrim 1y ago
    Mayans also did sacrifice, but it was mainly PoWs/losers in battle or of ballgames
- AngryData 1y ago
  They had the wheel, they just didn't find many practical uses for it without having either beasts of burden or nice relatively flat paved roads. Wheels are great if you have something stronger than a human to pull it, or you only have to move it a short distance, or if you have a hard paved road. But pulling carts or wagons or wheelbarrows through rough terrain or muddy roads with just human power is absolute trash and not worth the effort, and moving things over small short distances alone isn't worth the specialized labor and cost of making decent wheel and axle systems without machine tools. If you are still unsure, ask yourself why hikers and campers don't pull a cart or push a wheelbarrow everywhere they go instead of using a backpack even though they can have ultra light aluminum construction with pneumatic tires and ball bearing axles. All the effort you would save by using a wheelbarrow on smooth parts of your path would be undone by just a handful of random sticks or rocks you run into with it along the way.
amypetrik8 1y ago
I was just in Silver Spring MD, just outside of Washington, DC, and I noticed that all those kids moved from Guatamala to DC! The American dream! All the kids in Silver Spring spoke Kaqchikel, one of the Mayan languages, at home. We need more Kaqchikel-speaking children in the Silver Spring area to add to diversity, so that it's not just a primarily Spanish-speaking-only area, but a Spanish-and-Kaqchikel speaking area.

NooneAtAll3 1y ago

How does one even come up with 260 day year? Is the weather in the tropics so similar that year-on-year mismatch stops mattering?

antognini 1y ago
The origins of the 260 day ritual year are not known for certain, but there are a couple of hypotheses: 1. Pregnancy. 260 days is roughly the gestation period of a baby, so this may have been the inspiration for tracking this duration. (For what it is worth, modern Maya timekeepers cite this as being the reason for the length of the 260 day ritual calendar.) 2. In the tropics there are two days of the year when the Sun passes through the zenith and objects cast no shadows. In the latitude where the earliest Mesoamerican civilizations emerged, the length of time between these two days of the year is about 260 days. 3. Numerology. 260 is the product of 20 and 13. 20 was significant in Mesoamerican culture because it was the base of their numbering system and was associated with the human body (given that we have 20 fingers and toes). And the number 13 was associated with the cosmos. So the number 260 represented a kind of interlocking between the human and the cosmic. It's also worth noting that the Maya also tracked a 365 solar cycle, so they did have a concept of a more standard kind of "year." The 365 cycle was used for civil purposes. The 260 day ritual cycle was used more for divination. (Shameless plug, but if you want to learn more about Mesoamerican astronomy I have a podcast about the history of astronomy and I talked about it on the last episode: https://songofurania.com/episode/047 https://songofurania.com/episode/047)
- behnamoh 1y ago
  > And the number 13 was associated with the cosmos. Any reason number 13, of all numbers, has been so significant in different parts of the world, sometimes associated with completely opposite meanings (e.g., between Jews and Persians/Europeans)?
  - NooneAtAll3 1y ago
    generally, 7 and 13 get a lot of attention because a)they are prime b)1/7 and 1/13 have long period when written as decimal fraction - so you keep stumbling in your calculations every time you encounter them 1/7 in base 20 takes surprisingly short form of 0.(1h) (h is 17), unlike 1/9 or 1/11 - so I wonder if there's Mayan prejudice on those instead

ranger_danger 1y ago

The sad thing is that for all their advanced ways of the time, they succumbed to the same thing we are experiencing now... being too comfortable to fix what's broken. The Mayans did not want to give up their lifestyles even in the face of crippling population growth and surrounding natural resource depletion... which led to their downfall.

t1E9mE7JTRjf 1y ago
Sounds like the opposite no? Since we are going through population collapse in a time of abundance. Does make me wonder what the political dynamics were at the time, whether some could see problems but weren't in power to change things. Or maybe they couldn't understand or figure out solutions to the problems. What I'd give to be a multilingual fly on the wall throughout history.
- asacrowflies 1y ago
  We don't really have abundance tho.... We have massive over consumption that feels like abundance. Like a gambler
sethammons 1y ago
This should be upvoted. A lot. The downvotes are ill-informed. https://www.earthobservatory.nasa.gov/images/77060/mayan-deforestation-and-drought https://www.earthobservatory.nasa.gov/images/77060/mayan-def... From newish imaging. We can see the impressions of vast jungle swaths cut down and way made for planting food and houses. This looks to have disrupted the water cycle enough to cause cinotes (underground water systems and only source of drinking water) to deplete. We see sacrificial remnants below the modern water line. Their water disappeared and so did their civilization. By the time the Spanish arrived, the local people had no knowledge of how to build nor maintain their now ancient cities, the jungles regrew, water came back, and sacrificial artifacts were covered by replenished water levels. They are an example of man made effects on local weather leading to the downfall of an advanced civilization.
- b112 1y ago

da02 1y ago

They used past historical data to make predictions without having the need for a helio-centric model?

cwmoore 1y ago
Is this the answer?