8 ms·

Timekeeping Before Clocks

140 points by orcul 2y ago

johnlk 2y ago
Fascinating article. This has inspired me to make a sundial that works inside my NYC apartment. Ideally, there's some reflective device pointed outside and some warping that happens to allow the sundial to work inside.
- kjkjadksj 2y ago
  Why not just install one on the outside window sill?
- yencabulator 2y ago
  Maybe you can use a window? https://www.flickr.com/photos/jlcarmichael/albums/72157680483616690/with/31317734306 https://www.flickr.com/photos/jlcarmichael/albums/7215768048...
keiferski 2y ago
Another interesting thing is how Western clock technology was adapted to fit traditional Japanese notions of time, in the pre-Meiji era (after which, Japan adopted Western time.) A Japanese clock (和時計, wadokei) is a mechanical clock that has been made to tell traditional Japanese time, a system in which daytime and nighttime are always divided into six periods whose lengths consequently change with the season. Mechanical clocks were introduced into Japan by Jesuit missionaries (in the 16th century) or Dutch merchants (in the 17th century). https://en.wikipedia.org/wiki/Japanese_clock https://en.wikipedia.org/wiki/Japanese_clock And on a related note, Lewis Mumford, a philosopher and writer, wrote quite a bit about how clocks were (in his view) the necessary invention for capitalism to flourish: The first phase of technically civilized life (AD 1000 to 1800) begins with the clock, to Mumford the most important basis for the development of capitalism because time thereby becomes fungible (thus transferable). The clock is the most important prototype for all other machines. https://en.wikipedia.org/wiki/Technics_and_Civilization https://en.wikipedia.org/wiki/Technics_and_Civilization
- loppink 2y ago
  There is a scene in that recent shogun series where a team performs a raid. The leader sends the team in in small waves and “times” each groups entrance by counting rhythmic taps on his shoulder. I thought it was such a great detail to include. Of course rhythm would be the measure of time without a watch to look at.
  - deleted 2y ago
    [deleted]
  - bombcar 2y ago
    One of the medieval time measurements were standard prayers - a Pater Noster is about the same amount of time each time, and a decade of a rosary for a given person will be pretty consistent.
    - yencabulator 2y ago
      Two more modern anecdotes of using songs for rhythm or timing: The ideal pace for CPR chest compressions is pretty much exactly Stayin' Alive by Bee Gees. Or if you like darker humor, Another One Bites the Dust by Queen. At the peak of COVID-19, the recommended duration for hand washing was Happy Birthday twice.
  - antognini 2y ago
    Reminds me of how the Pueblo leader Popé distributed ropes with knots tied in them to various groups across the region to coordinate his attack. Every day each group would untie one knot in their rope, and when all the knots were untied they were to attack the Spanish.
- sigil 2y ago
  > And on a related note, Lewis Mumford, a philosopher and writer, wrote quite a bit about how clocks were (in his view) the necessary invention for capitalism to flourish. Szabo also takes this up in his excellent essay "A Measure of Sacrifice": Fair broadcast and verification of time was thus of fundamental importance to the most common contractual relationship in the new European cities. In agricultural societies, including medieval Europe, serfdom and slavery had provided most of the labor. Most workers in a modern economy earn wages based on a time rate. Along with or following the rise of the time-rate institution – including the contracts themselves, the laws and regulations governing the contracts, and the technology to fairly measure the principal quantity – came the growth of related economic institutions, such as the joint stock company. These institutions enabled a boom in productivity and the spectacular rise of Europe from its darkest ages to the modern era. We will now chart the rise of the clocks and the institutions they supported. https://www.fon.hum.uva.nl/rob/Courses/InformationInSpeech/CDROM/Literature/LOTwinterschool2006/szabo.best.vwh.net/synch.html https://www.fon.hum.uva.nl/rob/Courses/InformationInSpeech/C...
kang 2y ago
Something one might like as a continuation of the article is digital sundials. Apart from types listed on wikipedia, there are 3D-printed versions etc.
fellerts 2y ago
Timekeeping leading up to the marine chronometer is also very interesting. Note that none of the timekeeping devices mentioned in the article would work very well at sea, making it impossible to accurately determine your longitude. Solving that proved to be extremely difficult. https://www.rmg.co.uk/stories/topics/harrisons-clocks-longitude-problem https://www.rmg.co.uk/stories/topics/harrisons-clocks-longit...
- vbezhenar 2y ago
  > John Harrison was a carpenter by trade who was self-taught in clock making. During the mid-1720s he designed a series of remarkable precision longcase clocks. These clocks achieved an accuracy of one second in a month, far better than any clocks of the time. Wow. I own Tissot and Casio hand clocks and both are significantly worse precision. Are there any available clocks with that precision? Of course with GPS, WiFi and other wireless ways to access atomic clocks that's not so important, but still interesting.
  - dgacmu 2y ago
    A cheap watch or clock will use an off-the-shelf crystal oscillator, where you'll be lucky if it's accurate to 20 seconds in a month. A temperature compensated crystal oscillator (TCXO) can do better than one second per month, but probably not better than a second every 2 months. An oven controlled crystal oscillator (OCXO) or a double ovenized crystal oscillator can get an order of magnitude better than that, But they start costing between $50 and $1,000. Beyond that you get into funky stuff like rubidium or cesium atomic clocks. There are, notably, miniaturized atomic clocks these days - about 2" x 2" - So you could technically put one into a wall clock, although they cost about $2,000. These days it's usually cheaper to use GPS to control a temperature compensated oscillator, which we call a GPSDO (gps disciplined oscillator).
    - WalterBright 2y ago
      I used a wall "atomic" clock for a couple decades. It would synchronize itself with a government radio signal.
complaintdept 2y ago
I'd just like to throw out a recommendation here for the book Longitude by Dava Sobel. It's about the invention of the marine chronometer by a self-taught carpenter. Fascinating read, and a real page turner too.
- kej 2y ago
  Seconding this, and I'd add that Sobel's Galileo's Daughter was also a good read for anyone interested in the history of science.
  - zen_of_prog 2y ago
    I’m reading and so far enjoying “A Brief History of Timekeeping” by Chad Orzel. Not to discount Harrison’s achievements, but there are other interesting navigational approaches - using Tobias Mayer’s Lunar tables: > Mayer is far less celebrated than Harrison, but his method was in many ways the more immediately successful of the two Or, if society were to collapse and rebuild, Lewis Dartnell proposes a radio in “The Knowledge”, since a radio transmitter is probably simpler to build than an accurate chronometer.
russfink 2y ago
Often we wonder what distinguishes humans from other animals. Measurement and optimization. Do other species measure, and optimize? Others use tools, but do they optimize?
- sandworm101 2y ago
  >> Do other species measure, and optimize? Others use tools, but do they optimize? They all do. Think of locomotion. Most every animal that can move has a few different ways of doing it. We can walk, or run. An eagle can fly direct or take a circuitous route between updrafts. A whale has sprint mode or easy cruise mode. We are all constantly optimizing how we move in order to minimize expended energy to accomplish a given task.
- kjkjadksj 2y ago
  How would you define optimization? As in time management? Making some process take less effort perhaps? I’d say my cat fits the bill. She seems to have a better sense of time and keeping to her schedule than I do. She has also figured out many optimizations for her life that make sense to her. For example her path routing ability while running full speed is pretty amazing, she manages to figure out routes that keep her on a vector enabling full tilt acceleration vs turning and walking around furniture like us humans do with our poorly optimize walking.
  - shagie 2y ago
    > I’d say my cat fits the bill. She seems to have a better sense of time and keeping to her schedule than I do. https://www.tiktok.com/@donna.aka.donna/video/7214251381807385899?lang=en https://www.tiktok.com/@donna.aka.donna/video/72142513818073...
- shagie 2y ago
  I wonder why we limit measurement and optimization to animals when examples of it have been observed in plants. https://en.wikipedia.org/wiki/Plant_arithmetic https://en.wikipedia.org/wiki/Plant_arithmetic > When an insect or spider crawling along the leaves contacts a hair, the trap prepares to close, snapping shut only if a second contact occurs within approximately twenty seconds of the first strike. > ... > The mechanism is so highly specialized that it can distinguish between living prey and non-prey stimuli, such as falling raindrops; two trigger hairs must be touched in succession within 20 seconds of each other or one hair touched twice in rapid succession, whereupon the lobes of the trap will snap shut, typically in about one-tenth of a second. > ... > Most plants accumulate starch by day, then metabolize it at a fixed rate during night time. However, if the onset of darkness is unusually early, Arabidopsis thaliana reduces its use of starch by an amount that effectively requires division. wever, there are alternative explanations, such as feedback control by sensing the amount of soluble sugars left. As of 2015, open questions remain.
WalterBright 2y ago
I sometimes watch those TV shows about ancient civilizations. They often talk about "astonishing" astronomy they used. In reality, all they did was track the sun. This can be done simply by putting a vertical stick in the ground, and marking the path the tip of the stick traces in the ground. This way, the calendar and solstices can be accurately determined. The shows will also talk about the "amazing" technology that enabled, say, a hole in a wall to shine on a statue for one special day a year. Again, rather simple to do using the same idea as the stick in the ground. The third thing that annoyed me was their "incredible" astronomical knowledge in predicting eclipses. All that is is collecting observations over decades and then recognizing the pattern. There is no astronomical knowledge involved. They still had no idea what the sun, moon, and planets were, nor even the layout of the solar system.
- antognini 2y ago
  Those kinds of shows can be sensationalized and shallow, but if you're interested in learning more in depth about ancient astronomy (shameless plug) I have been doing a podcast on the subject. So far I've covered the astronomy of the Babylon, Greece, Rome, India, prehistoric Europe, Subsaharan Africa, and am currently five episodes into the astronomy of premodern China. https://songofurania.com https://songofurania.com
  - n1b0m 2y ago
    Thanks for sharing. Just started listening
- HelloMcFly 2y ago
  I think you're underselling the accomplishment of determining some of these things, particularly predicting eclipses. And I think there's quite a bit to be said about novel applications that emerge out of tracking the sun, like announcing seasons for citizens to help know when to plant, reap, store, etc. to manage agriculture across empire. Often they amazing thing was taking a small thing and spinning into a massive, society-impacting solution.
  - 2y ago
antognini 2y ago
There is a really nice surviving water clock from the early Imperial era in China that was discovered in the 1970s [1]. The Imperial bureaucracy was sophisticated enough at this point that official timekeeping equipment like this was carefully tracked. The water clock has an inscription that details where it was made (Qianzhang), when it was made (27 BC), and how heavy it is 32 "Jin"). There is a text written a few decades after this water clock was made that provides enough detail to approximately reconstruct how astronomers used it for their measurements. In essence they would calibrate the water clock against the motion of the Sun so that they could correspond some volume of water to a 24 hour period. Then they would measure the amount of water that flowed from the transit of one star to another to figure out the separation of those stars in right ascension. The measurements were sophisticated enough that they apparently took into account factors like humidity and temperature when using the water clock. [1]: https://www.reddit.com/r/ArtefactPorn/comments/150024l/the_zhongyang_water_clock_with_inscriptions/ https://www.reddit.com/r/ArtefactPorn/comments/150024l/the_z...
dekhn 2y ago
Just build a digital sundial: https://www.thingiverse.com/thing:1068443 https://www.thingiverse.com/thing:1068443
renlo 2y ago
Not to be pedantic but I was genuinely confused by this statement: > He lived and wrote in the late 200s and early 100s BCE Shouldn't this instead be phrased as: > He lived and wrote in the early 200s and late 100s BCE He was born in 254 BCE and died in 184 BCE, he lived from the mid 200s BCE, started writing in the _early_ 200s BCE, and died in the _late_ 100s BCE.
- crdrost 2y ago
  No. The English terms "earlier" and "later" refer to the progression of time from the past (earlier) towards the present and future (later); they do not refer to the number itself being larger except incidentally. (The etymologies here are that "earlier" comes from "ere" meaning "before" or "soon", "later" comes from various "lat-" roots meaning "sluggish" or "lazy" hence starting after their appointed time.) So for example the Wikipedia article on Hellenistic Palestine contains the opening line, > The region came first under Ptolemaic rule beginning in the late 4th century BCE with Ptolemy I Soter, followed by Seleucid rule beginning in the early 2nd century BCE with Antiochus III the Great. It then clarifies that the events of the late 4th century BCE include events in ~320 BCE, and that the early 2nd century stuff happened in ~198 BCE. This is a standard usage of those terms "early" and "late" as applied to those centuries, the 4th (400 BCE - 301 BCE) and 2nd (200 BCE - 101 BCE).
  - renlo 2y ago
    I think the issue primarily is that there are two frames of reference used: "earlier" / "later" terms use the absolute frame of reference (time progressing forward), the numerical terms ("100s" / "4th century") are relative to the common era (higher BCE numbers mean further back in time). To me it is confusing that they've mixed the two, even though it is convention to do so.
hammock 2y ago
Court of the Lions (14th c.) in the Alhambra palace is my favorite water clock. A large pool of water is surrounded by 12 lions that would spout water from their mouths and depending on the hour of the day (1 o'clock, 2 o'clock, etc), the water comes from Lion 1, Lion 2, Lion 3, etc. https://en.wikipedia.org/wiki/Court_of_the_Lions https://en.wikipedia.org/wiki/Court_of_the_Lions
hammock 2y ago
Also worth noting that some early timekeepers used the burning of incense to count down the time.
foreigner 2y ago
I want a wrist-mounted sundial "watch" that automatically calibrates itself using my phone's GPS.
nvader 2y ago
> get the time the way people had been since the dawn of civilization. I nearly applauded, what a great way to end the article!
jes5199 2y ago
what, no astrolabe? astrolabes are the direct precursor to mechanical clocks, you can think of them as a slide rules with a inclinometer and a star map, and their primary application was to convert the altitude of visible stars or the sun into the current time
devindotcom 2y ago
I was thinking about this while watching an amazing Chinese historical drama, "Longest Day in Chang'an," which has a "24"-like real-time structure. But instead of the beep... beep... beep... you have this one guy in an official building intently watching a water clock and pretty much every episode he bangs a drum on the hour and yells out the exact time and a kind of proverb, like "1 o clock!! The shadows reappear!" Great show and there are lots of interesting historical details like this. Good post too.
gumby 2y ago
A few footnotes: The “stick” of the sundial is called a gnomon. Early hours were not uniform in length (they couldn’t be, really, with a sundial). The Babylonians (and the Egyptians after them) divided day (daylight) into twelve equal regions and night (between sunset and dawn) into twelve equal periods, but day and night hours were not the same length, nor were those of successive days or nights. Parasite was a kind of job: if you were rich you had a parasite or two who would accompany you when you were out and about. You paid for their food and upkeep and in exchange everyone could see how rich and generous you were.
0xcg 2y ago
Great article that covers some fantastic examples of sun-based time. If you want to read about two more, Seiko has a great article [1] about a traditional Japanese clock (Wadokei) which had moving indices based on the seasons. The local time we keep today is supremely useful for global synchronization, but is disconnected from the natural world. I came across this example (Wadokei) after making an app for myself to track the moon above and below the horizon and doing some research after creating a similar style clock which uses the sun as the anchor of the clock (high noon is the top of the clock, instead of 12 noon). This one is a full-day clock that shows the hours of the “local time” day as well as the positioning of the sun and moon. The hours shift dramatically during the peak of summer and depths of winter, especially at extreme latitudes [2]. You can really get a sense of the length of the daylight and how it changes by using any of these sun-based clocks. [1] https://museum.seiko.co.jp/en/knowledge/relation_15/ https://museum.seiko.co.jp/en/knowledge/relation_15/ [2] https://apps.apple.com/us/app/moontime-lunar-clock-widget/id6448401297 https://apps.apple.com/us/app/moontime-lunar-clock-widget/id...
StanislavPetrov 2y ago
The poem by the Hungary Parasite reminded me of the 1960 J.G. Ballard short story, "Chronopolis".
teleforce 2y ago
Toward the end of the article there are descriptions of Al-Jazari water clocks but did not mention about the infamous Alhambra Palace lions water clock, and most likely it was based on Al-Jazari inventions. Since Alhambra Palace construction was started in the same century of Al-Jazari death (13th century AD) it's very plausible that it's based on his work. Al-Jazari invented hundreds of inventions including mechanical robots that were said to be copied by later scientist and engineers including Leonardo da Vinci, and we know that good artists copy but great artists steal [1]. During a visit to Alhambra Spain it was claimed the water will gush out from each of the lion figure's mouth fountain for every hour, in sequence of turns not unlike our clock now but it all based on water. Perhaps this is possible due to the Al-Jazari water clock invention but no one know how it was originally working [2]. It's a shame that indispensable knowledge like this has been lost forever and this also happened to the earliest earthquake sensor instrument invented by Zhang Heng back in 132 A.D. He called his seismoscope Houfeng Didong Yi, meaning an "instrument for measuring the seasonal winds and the movements of the Earth." Now the working replica has been recreated but only until very recently they had managed to recreate the functioning replica but knowledge regarding the actual original working mechanism has been lost forever [3]. Ironically after more than 2000 years later and USD1 Billion spent for the earthquake sensors system installations, the latest system with 15K sensor stations throughout China, it still cannot predict the earthquakes but only provide alerts to the authority after the main earthquake has happened somewhere in China [4],[5]. [1] The Relation between Al-Jazari of the East and Leonardo da Vinci of the West: https://dergipark.org.tr/en/pub/oad/issue/78379/1264652 https://dergipark.org.tr/en/pub/oad/issue/78379/1264652 [2] Invention or Solving the Mystery of Water Clock of the Lion Court Fountain in Alhambra palace (Granada): https://ijisrt.com/assets/upload/files/IJISRT22JAN498.pdf https://ijisrt.com/assets/upload/files/IJISRT22JAN498.pdf [3] The ancient earthquake detector that puzzled modern historians: https://www.engadget.com/2018-09-28-backlog-zhang-heng-seismoscope.html https://www.engadget.com/2018-09-28-backlog-zhang-heng-seism... [4] Innovative earthquake alarm system in China: https://ibtekr.org/en/cases/innovative-earthquake-alarm-system-in-china/ https://ibtekr.org/en/cases/innovative-earthquake-alarm-syst... [5] Chinese Nationwide Earthquake Early Warning System and Its Performance in the 2022 Lushan M6.1 Earthquake: https://www.mdpi.com/2072-4292/14/17/4269 https://www.mdpi.com/2072-4292/14/17/4269

140 points by orcul 2y ago

Fascinating article. This has inspired me to make a sundial that works inside my NYC apartment. Ideally, there's some reflective device pointed outside and some warping that happens to allow the sundial to work inside.

kjkjadksj 2y ago
Why not just install one on the outside window sill?
yencabulator 2y ago
Maybe you can use a window? https://www.flickr.com/photos/jlcarmichael/albums/72157680483616690/with/31317734306 https://www.flickr.com/photos/jlcarmichael/albums/7215768048...

keiferski 2y ago

Another interesting thing is how Western clock technology was adapted to fit traditional Japanese notions of time, in the pre-Meiji era (after which, Japan adopted Western time.) A Japanese clock (和時計, wadokei) is a mechanical clock that has been made to tell traditional Japanese time, a system in which daytime and nighttime are always divided into six periods whose lengths consequently change with the season. Mechanical clocks were introduced into Japan by Jesuit missionaries (in the 16th century) or Dutch merchants (in the 17th century). https://en.wikipedia.org/wiki/Japanese_clock https://en.wikipedia.org/wiki/Japanese_clock And on a related note, Lewis Mumford, a philosopher and writer, wrote quite a bit about how clocks were (in his view) the necessary invention for capitalism to flourish: The first phase of technically civilized life (AD 1000 to 1800) begins with the clock, to Mumford the most important basis for the development of capitalism because time thereby becomes fungible (thus transferable). The clock is the most important prototype for all other machines. https://en.wikipedia.org/wiki/Technics_and_Civilization https://en.wikipedia.org/wiki/Technics_and_Civilization

loppink 2y ago
There is a scene in that recent shogun series where a team performs a raid. The leader sends the team in in small waves and “times” each groups entrance by counting rhythmic taps on his shoulder. I thought it was such a great detail to include. Of course rhythm would be the measure of time without a watch to look at.
- deleted 2y ago
  [deleted]
- bombcar 2y ago
  One of the medieval time measurements were standard prayers - a Pater Noster is about the same amount of time each time, and a decade of a rosary for a given person will be pretty consistent.
  - yencabulator 2y ago
    Two more modern anecdotes of using songs for rhythm or timing: The ideal pace for CPR chest compressions is pretty much exactly Stayin' Alive by Bee Gees. Or if you like darker humor, Another One Bites the Dust by Queen. At the peak of COVID-19, the recommended duration for hand washing was Happy Birthday twice.
- antognini 2y ago
  Reminds me of how the Pueblo leader Popé distributed ropes with knots tied in them to various groups across the region to coordinate his attack. Every day each group would untie one knot in their rope, and when all the knots were untied they were to attack the Spanish.
sigil 2y ago
> And on a related note, Lewis Mumford, a philosopher and writer, wrote quite a bit about how clocks were (in his view) the necessary invention for capitalism to flourish. Szabo also takes this up in his excellent essay "A Measure of Sacrifice": Fair broadcast and verification of time was thus of fundamental importance to the most common contractual relationship in the new European cities. In agricultural societies, including medieval Europe, serfdom and slavery had provided most of the labor. Most workers in a modern economy earn wages based on a time rate. Along with or following the rise of the time-rate institution – including the contracts themselves, the laws and regulations governing the contracts, and the technology to fairly measure the principal quantity – came the growth of related economic institutions, such as the joint stock company. These institutions enabled a boom in productivity and the spectacular rise of Europe from its darkest ages to the modern era. We will now chart the rise of the clocks and the institutions they supported. https://www.fon.hum.uva.nl/rob/Courses/InformationInSpeech/CDROM/Literature/LOTwinterschool2006/szabo.best.vwh.net/synch.html https://www.fon.hum.uva.nl/rob/Courses/InformationInSpeech/C...

kang 2y ago

Something one might like as a continuation of the article is digital sundials. Apart from types listed on wikipedia, there are 3D-printed versions etc.

fellerts 2y ago

Timekeeping leading up to the marine chronometer is also very interesting. Note that none of the timekeeping devices mentioned in the article would work very well at sea, making it impossible to accurately determine your longitude. Solving that proved to be extremely difficult. https://www.rmg.co.uk/stories/topics/harrisons-clocks-longitude-problem https://www.rmg.co.uk/stories/topics/harrisons-clocks-longit...

vbezhenar 2y ago
> John Harrison was a carpenter by trade who was self-taught in clock making. During the mid-1720s he designed a series of remarkable precision longcase clocks. These clocks achieved an accuracy of one second in a month, far better than any clocks of the time. Wow. I own Tissot and Casio hand clocks and both are significantly worse precision. Are there any available clocks with that precision? Of course with GPS, WiFi and other wireless ways to access atomic clocks that's not so important, but still interesting.
- dgacmu 2y ago
  A cheap watch or clock will use an off-the-shelf crystal oscillator, where you'll be lucky if it's accurate to 20 seconds in a month. A temperature compensated crystal oscillator (TCXO) can do better than one second per month, but probably not better than a second every 2 months. An oven controlled crystal oscillator (OCXO) or a double ovenized crystal oscillator can get an order of magnitude better than that, But they start costing between $50 and $1,000. Beyond that you get into funky stuff like rubidium or cesium atomic clocks. There are, notably, miniaturized atomic clocks these days - about 2" x 2" - So you could technically put one into a wall clock, although they cost about $2,000. These days it's usually cheaper to use GPS to control a temperature compensated oscillator, which we call a GPSDO (gps disciplined oscillator).
  - WalterBright 2y ago
    I used a wall "atomic" clock for a couple decades. It would synchronize itself with a government radio signal.

complaintdept 2y ago

I'd just like to throw out a recommendation here for the book Longitude by Dava Sobel. It's about the invention of the marine chronometer by a self-taught carpenter. Fascinating read, and a real page turner too.

kej 2y ago
Seconding this, and I'd add that Sobel's Galileo's Daughter was also a good read for anyone interested in the history of science.
- zen_of_prog 2y ago
  I’m reading and so far enjoying “A Brief History of Timekeeping” by Chad Orzel. Not to discount Harrison’s achievements, but there are other interesting navigational approaches - using Tobias Mayer’s Lunar tables: > Mayer is far less celebrated than Harrison, but his method was in many ways the more immediately successful of the two Or, if society were to collapse and rebuild, Lewis Dartnell proposes a radio in “The Knowledge”, since a radio transmitter is probably simpler to build than an accurate chronometer.

russfink 2y ago

Often we wonder what distinguishes humans from other animals. Measurement and optimization. Do other species measure, and optimize? Others use tools, but do they optimize?

sandworm101 2y ago
>> Do other species measure, and optimize? Others use tools, but do they optimize? They all do. Think of locomotion. Most every animal that can move has a few different ways of doing it. We can walk, or run. An eagle can fly direct or take a circuitous route between updrafts. A whale has sprint mode or easy cruise mode. We are all constantly optimizing how we move in order to minimize expended energy to accomplish a given task.
kjkjadksj 2y ago
How would you define optimization? As in time management? Making some process take less effort perhaps? I’d say my cat fits the bill. She seems to have a better sense of time and keeping to her schedule than I do. She has also figured out many optimizations for her life that make sense to her. For example her path routing ability while running full speed is pretty amazing, she manages to figure out routes that keep her on a vector enabling full tilt acceleration vs turning and walking around furniture like us humans do with our poorly optimize walking.
- shagie 2y ago
  > I’d say my cat fits the bill. She seems to have a better sense of time and keeping to her schedule than I do. https://www.tiktok.com/@donna.aka.donna/video/7214251381807385899?lang=en https://www.tiktok.com/@donna.aka.donna/video/72142513818073...
shagie 2y ago
I wonder why we limit measurement and optimization to animals when examples of it have been observed in plants. https://en.wikipedia.org/wiki/Plant_arithmetic https://en.wikipedia.org/wiki/Plant_arithmetic > When an insect or spider crawling along the leaves contacts a hair, the trap prepares to close, snapping shut only if a second contact occurs within approximately twenty seconds of the first strike. > ... > The mechanism is so highly specialized that it can distinguish between living prey and non-prey stimuli, such as falling raindrops; two trigger hairs must be touched in succession within 20 seconds of each other or one hair touched twice in rapid succession, whereupon the lobes of the trap will snap shut, typically in about one-tenth of a second. > ... > Most plants accumulate starch by day, then metabolize it at a fixed rate during night time. However, if the onset of darkness is unusually early, Arabidopsis thaliana reduces its use of starch by an amount that effectively requires division. wever, there are alternative explanations, such as feedback control by sensing the amount of soluble sugars left. As of 2015, open questions remain.

WalterBright 2y ago

I sometimes watch those TV shows about ancient civilizations. They often talk about "astonishing" astronomy they used. In reality, all they did was track the sun. This can be done simply by putting a vertical stick in the ground, and marking the path the tip of the stick traces in the ground. This way, the calendar and solstices can be accurately determined. The shows will also talk about the "amazing" technology that enabled, say, a hole in a wall to shine on a statue for one special day a year. Again, rather simple to do using the same idea as the stick in the ground. The third thing that annoyed me was their "incredible" astronomical knowledge in predicting eclipses. All that is is collecting observations over decades and then recognizing the pattern. There is no astronomical knowledge involved. They still had no idea what the sun, moon, and planets were, nor even the layout of the solar system.

antognini 2y ago
Those kinds of shows can be sensationalized and shallow, but if you're interested in learning more in depth about ancient astronomy (shameless plug) I have been doing a podcast on the subject. So far I've covered the astronomy of the Babylon, Greece, Rome, India, prehistoric Europe, Subsaharan Africa, and am currently five episodes into the astronomy of premodern China. https://songofurania.com https://songofurania.com
- n1b0m 2y ago
  Thanks for sharing. Just started listening
HelloMcFly 2y ago
I think you're underselling the accomplishment of determining some of these things, particularly predicting eclipses. And I think there's quite a bit to be said about novel applications that emerge out of tracking the sun, like announcing seasons for citizens to help know when to plant, reap, store, etc. to manage agriculture across empire. Often they amazing thing was taking a small thing and spinning into a massive, society-impacting solution.
- 2y ago

antognini 2y ago

There is a really nice surviving water clock from the early Imperial era in China that was discovered in the 1970s [1]. The Imperial bureaucracy was sophisticated enough at this point that official timekeeping equipment like this was carefully tracked. The water clock has an inscription that details where it was made (Qianzhang), when it was made (27 BC), and how heavy it is 32 "Jin"). There is a text written a few decades after this water clock was made that provides enough detail to approximately reconstruct how astronomers used it for their measurements. In essence they would calibrate the water clock against the motion of the Sun so that they could correspond some volume of water to a 24 hour period. Then they would measure the amount of water that flowed from the transit of one star to another to figure out the separation of those stars in right ascension. The measurements were sophisticated enough that they apparently took into account factors like humidity and temperature when using the water clock. [1]: https://www.reddit.com/r/ArtefactPorn/comments/150024l/the_zhongyang_water_clock_with_inscriptions/ https://www.reddit.com/r/ArtefactPorn/comments/150024l/the_z...

dekhn 2y ago

Just build a digital sundial: https://www.thingiverse.com/thing:1068443 https://www.thingiverse.com/thing:1068443

renlo 2y ago

Not to be pedantic but I was genuinely confused by this statement: > He lived and wrote in the late 200s and early 100s BCE Shouldn't this instead be phrased as: > He lived and wrote in the early 200s and late 100s BCE He was born in 254 BCE and died in 184 BCE, he lived from the mid 200s BCE, started writing in the _early_ 200s BCE, and died in the _late_ 100s BCE.

crdrost 2y ago
No. The English terms "earlier" and "later" refer to the progression of time from the past (earlier) towards the present and future (later); they do not refer to the number itself being larger except incidentally. (The etymologies here are that "earlier" comes from "ere" meaning "before" or "soon", "later" comes from various "lat-" roots meaning "sluggish" or "lazy" hence starting after their appointed time.) So for example the Wikipedia article on Hellenistic Palestine contains the opening line, > The region came first under Ptolemaic rule beginning in the late 4th century BCE with Ptolemy I Soter, followed by Seleucid rule beginning in the early 2nd century BCE with Antiochus III the Great. It then clarifies that the events of the late 4th century BCE include events in ~320 BCE, and that the early 2nd century stuff happened in ~198 BCE. This is a standard usage of those terms "early" and "late" as applied to those centuries, the 4th (400 BCE - 301 BCE) and 2nd (200 BCE - 101 BCE).
- renlo 2y ago
  I think the issue primarily is that there are two frames of reference used: "earlier" / "later" terms use the absolute frame of reference (time progressing forward), the numerical terms ("100s" / "4th century") are relative to the common era (higher BCE numbers mean further back in time). To me it is confusing that they've mixed the two, even though it is convention to do so.

hammock 2y ago

Court of the Lions (14th c.) in the Alhambra palace is my favorite water clock. A large pool of water is surrounded by 12 lions that would spout water from their mouths and depending on the hour of the day (1 o'clock, 2 o'clock, etc), the water comes from Lion 1, Lion 2, Lion 3, etc. https://en.wikipedia.org/wiki/Court_of_the_Lions https://en.wikipedia.org/wiki/Court_of_the_Lions

hammock 2y ago

Also worth noting that some early timekeepers used the burning of incense to count down the time.

foreigner 2y ago

I want a wrist-mounted sundial "watch" that automatically calibrates itself using my phone's GPS.

nvader 2y ago

> get the time the way people had been since the dawn of civilization. I nearly applauded, what a great way to end the article!

jes5199 2y ago

what, no astrolabe? astrolabes are the direct precursor to mechanical clocks, you can think of them as a slide rules with a inclinometer and a star map, and their primary application was to convert the altitude of visible stars or the sun into the current time

devindotcom 2y ago

I was thinking about this while watching an amazing Chinese historical drama, "Longest Day in Chang'an," which has a "24"-like real-time structure. But instead of the beep... beep... beep... you have this one guy in an official building intently watching a water clock and pretty much every episode he bangs a drum on the hour and yells out the exact time and a kind of proverb, like "1 o clock!! The shadows reappear!" Great show and there are lots of interesting historical details like this. Good post too.

gumby 2y ago

A few footnotes: The “stick” of the sundial is called a gnomon. Early hours were not uniform in length (they couldn’t be, really, with a sundial). The Babylonians (and the Egyptians after them) divided day (daylight) into twelve equal regions and night (between sunset and dawn) into twelve equal periods, but day and night hours were not the same length, nor were those of successive days or nights. Parasite was a kind of job: if you were rich you had a parasite or two who would accompany you when you were out and about. You paid for their food and upkeep and in exchange everyone could see how rich and generous you were.

0xcg 2y ago

Great article that covers some fantastic examples of sun-based time. If you want to read about two more, Seiko has a great article [1] about a traditional Japanese clock (Wadokei) which had moving indices based on the seasons. The local time we keep today is supremely useful for global synchronization, but is disconnected from the natural world. I came across this example (Wadokei) after making an app for myself to track the moon above and below the horizon and doing some research after creating a similar style clock which uses the sun as the anchor of the clock (high noon is the top of the clock, instead of 12 noon). This one is a full-day clock that shows the hours of the “local time” day as well as the positioning of the sun and moon. The hours shift dramatically during the peak of summer and depths of winter, especially at extreme latitudes [2]. You can really get a sense of the length of the daylight and how it changes by using any of these sun-based clocks. [1] https://museum.seiko.co.jp/en/knowledge/relation_15/ https://museum.seiko.co.jp/en/knowledge/relation_15/ [2] https://apps.apple.com/us/app/moontime-lunar-clock-widget/id6448401297 https://apps.apple.com/us/app/moontime-lunar-clock-widget/id...

StanislavPetrov 2y ago

The poem by the Hungary Parasite reminded me of the 1960 J.G. Ballard short story, "Chronopolis".

teleforce 2y ago

Toward the end of the article there are descriptions of Al-Jazari water clocks but did not mention about the infamous Alhambra Palace lions water clock, and most likely it was based on Al-Jazari inventions. Since Alhambra Palace construction was started in the same century of Al-Jazari death (13th century AD) it's very plausible that it's based on his work. Al-Jazari invented hundreds of inventions including mechanical robots that were said to be copied by later scientist and engineers including Leonardo da Vinci, and we know that good artists copy but great artists steal [1]. During a visit to Alhambra Spain it was claimed the water will gush out from each of the lion figure's mouth fountain for every hour, in sequence of turns not unlike our clock now but it all based on water. Perhaps this is possible due to the Al-Jazari water clock invention but no one know how it was originally working [2]. It's a shame that indispensable knowledge like this has been lost forever and this also happened to the earliest earthquake sensor instrument invented by Zhang Heng back in 132 A.D. He called his seismoscope Houfeng Didong Yi, meaning an "instrument for measuring the seasonal winds and the movements of the Earth." Now the working replica has been recreated but only until very recently they had managed to recreate the functioning replica but knowledge regarding the actual original working mechanism has been lost forever [3]. Ironically after more than 2000 years later and USD1 Billion spent for the earthquake sensors system installations, the latest system with 15K sensor stations throughout China, it still cannot predict the earthquakes but only provide alerts to the authority after the main earthquake has happened somewhere in China [4],[5]. [1] The Relation between Al-Jazari of the East and Leonardo da Vinci of the West: https://dergipark.org.tr/en/pub/oad/issue/78379/1264652 https://dergipark.org.tr/en/pub/oad/issue/78379/1264652 [2] Invention or Solving the Mystery of Water Clock of the Lion Court Fountain in Alhambra palace (Granada): https://ijisrt.com/assets/upload/files/IJISRT22JAN498.pdf https://ijisrt.com/assets/upload/files/IJISRT22JAN498.pdf [3] The ancient earthquake detector that puzzled modern historians: https://www.engadget.com/2018-09-28-backlog-zhang-heng-seismoscope.html https://www.engadget.com/2018-09-28-backlog-zhang-heng-seism... [4] Innovative earthquake alarm system in China: https://ibtekr.org/en/cases/innovative-earthquake-alarm-system-in-china/ https://ibtekr.org/en/cases/innovative-earthquake-alarm-syst... [5] Chinese Nationwide Earthquake Early Warning System and Its Performance in the 2022 Lushan M6.1 Earthquake: https://www.mdpi.com/2072-4292/14/17/4269 https://www.mdpi.com/2072-4292/14/17/4269