[HN Gopher] Timekeeping Before Clocks
___________________________________________________________________
Timekeeping Before Clocks
Author : orcul
Score : 106 points
Date : 2024-05-13 07:14 UTC (1 days ago)
(HTM) web link (worldhistory.substack.com)
(TXT) w3m dump (worldhistory.substack.com)
| johnlk wrote:
| 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 wrote:
| Why not just install one on the outside window sill?
| yencabulator wrote:
| Maybe you can use a window?
|
| https://www.flickr.com/photos/jlcarmichael/albums/7215768048...
| keiferski wrote:
| 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 (He Shi Ji , 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
|
| 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
| loppink wrote:
| 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.
| bombcar wrote:
| 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 wrote:
| 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 wrote:
| Reminds me of how the Pueblo leader Pope 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 wrote:
| > 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/C...
| jes5199 wrote:
| traditionally, every culture used seasonal/unequal hours! just,
| in Europe, the advantage of mechanical clocks was so great that
| the culture changed to fit the technology
| kang wrote:
| 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 wrote:
| 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-longit...
| vbezhenar wrote:
| > 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 wrote:
| 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 wrote:
| I used a wall "atomic" clock for a couple decades. It would
| synchronize itself with a government radio signal.
| dgacmu wrote:
| WWVB is great if you can get the signal -- I have two of
| those clocks in different rooms, and only one of them
| synchronizes.
| jrockway wrote:
| Newer clocks use the phase modulated signal: https://www.
| nist.gov/system/files/documents/2017/05/09/NIST-...
|
| If you have AM-based clocks, you might find that these
| work better. However, nobody advertises which module
| they're using, so it's kind of a crapshoot. I
| specifically bought a phase modulation WWVB receiver and
| it reliably receives the signal every night. I also have
| a random $7 clock from Amazon that pretty much
| synchronizes every night. Living in NYC, this is truly
| amazing to me; I never ever got the AM signal here.
| creeble wrote:
| Thanks for that! Didn't know there were two kinds of
| radios.
|
| I have one clock that always works perfectly, syncs after
| DST 100% of the time. Another that always requires manual
| reset twice a year, defeating it's purpose.
| cvoss wrote:
| It's an incredible feat to me that a single station can
| broadcast to the almost the entire US, Mexico, and even
| parts of South America at the right time of day [0]. (I
| believe this is why many clocks check for the signal
| overnight.) It's achieved by using an extremely low
| frequency, at 60 kHz. The antenna is enormous and
| suspended between 4 towers.
|
| [0] https://tf.nist.gov/stations/wwvbcoverage.htm
|
| [1] https://www.nist.gov/pml/time-and-frequency-
| division/time-di...
| ghaff wrote:
| Communication with subs uses ELF/SLF (3-300 Hz) when
| they're underwater--in the US case from some big
| communications stations. The coastal VLF stations, like
| in Cutler Maine are more in the 24 kHz range. As I
| recall, at one point, there were ecological concerns with
| the ELF stations but apparently the projects ended up
| going ahead.
| russdill wrote:
| The mems temperature controlled oscillators are also very
| good, 0.05ppm range (about a second every 8 months). They
| are tiny and low power, but still >$79.
| dekhn wrote:
| https://en.wikipedia.org/wiki/Shortt%E2%80%93Synchronome_clo.
| ..
|
| technically it's "electromechanical" but does not use GPS,
| WiFi, quartz, or atomic methods. To make thigns this accurate
| you need extremely good temperature compensation, close-to-
| frictionless bearings, run in a vacuum, use a pair of
| pendulums, etc.
|
| When you reach that level of accuracy, you end up basically
| building a sensitive measurement device that is influenced by
| second and third order terms like subtle changes in the shape
| of the earth.
| throw0101d wrote:
| > _Are there any available clocks with that precision?_
|
| Citizens says +-1s/year with their Caliber 0100:
|
| * https://www.citizenwatch-global.com/the-
| citizen/lineup/cal01...
|
| * https://www.hodinkee.com/articles/citizen-eco-drive-
| caliber-...
|
| Solar powered as well.
|
| It should be noted that Harrison's watches were low-volume
| productions, so could be tuned very accurately--and their
| accuracy was a matter of life and death for ships and their
| crew. Most mechanical watches 'normal' people can get
| nowadays are produced at much higher volumes, and so aren't
| adjusted as much--especially since few people demand it and
| are willing to pay for it:
|
| * https://www.hodinkee.com/articles/how-accurate-should-
| your-m...
|
| The Harrison watches/clocks were built for the British
| government/Navy, so were fairly price insensitive (military
| procurement and such).
|
| Being 1 minute off in time throws off distance by 15 nautical
| miles (~28 km), so being off by a second can cause about 500m
| worth of position inaccuracy.
|
| Also: it may not be a big deal if your clock/watch drifts as
| long as it does so at a _known, consistent rate_ which you
| can adjust for.
| SoftTalker wrote:
| > Being 1 minute off in time throws off distance by 15
| nautical miles
|
| I'm surprised that the accuracy of a hand-held sextant used
| while standing on a rolling/pitching deck is good enough
| for that to matter very much.
| throw0101d wrote:
| > [...] _for that to matter very much._
|
| Life and death at times:
|
| > _The Scilly naval disaster of 1707 was the loss of four
| warships of a Royal Navy fleet off the Isles of Scilly in
| severe weather on 22 October 1707.[a] Between 1,400 and
| 2,000 sailors lost their lives aboard the wrecked
| vessels, making the incident one of the worst maritime
| disasters in British naval history.[2] The disaster has
| been attributed to a combination of factors, including
| the navigators ' inability to accurately calculate their
| positions, errors in the available charts and pilot
| books, and inadequate compasses.[3]_
|
| * https://en.wikipedia.org/wiki/Scilly_naval_disaster_of_
| 1707
|
| When you're trying to find a tiny speck of an island
| (Pitcairn, Saint Helena, _etc_ ) in the middle of an
| ocean it's also important.
| SoftTalker wrote:
| Yeah I get that it's important, I just didn't realize
| that angles could be meaured so accurately by eye at that
| time (especially on a ship that's moving around on even a
| moderate sea).
| throw0101c wrote:
| > _I just didn 't realize that angles could be meaured so
| accurately by eye at that time_
|
| Sextants have a bit of magnification (usually 4x, but
| sometimes 7x or higher). Higher mag allows for better
| accuracy at the cost of more shaking of the view.
|
| Basic explanation:
|
| * https://www.youtube.com/watch?v=30_wEda3ltM
| storyinmemo wrote:
| > Modern sextants can read the angle to a 0.1 minute
| level of accuracy, i.e. one-600th of a degree or one-
| tenth of a mile. In practice, actual accuracy to one-half
| mile is acceptable and quite good. The usual standard is
| accuracy to within five miles. The sextant (or octant) is
| meant to get the ship across the ocean. Once near the
| coast (20-100 miles) the more accurate techniques of
| piloting are relied upon for a safe landfall. The sextant
| is still the standard instrument for taking the
| observations required for celestial navigation.
|
| https://www.ion.org/Museum/item_view.cfm?cid=2&scid=14&ii
| d=2...
|
| One thing that helps with a pitching deck is that the
| horizon and object remain the same angle. Like a camera
| following race car, the objects move together.
| ghaff wrote:
| Fairly price insensitive.
|
| As I understood the exhibits in Greenwich, the Harrison
| clocks were largely eclipsed by cheaper versions by the
| time payment issues were resolved and they made it into
| widespread production.
| LeoPanthera wrote:
| > Are there any available clocks with that precision?
|
| Yes! The term you need to type into Google is "High Accuracy
| Quartz". The most easily available wristwatches with this
| level of accuracy are the Bulova Precisionist line.
|
| Watchuseek has a subforum about HAQ:
| https://www.watchuseek.com/forums/high-accuracy-quartz-
| watch...
| complaintdept wrote:
| 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 wrote:
| 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.
| russfink wrote:
| 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 wrote:
| >> 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 wrote:
| 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 wrote:
| > 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/72142513818073.
| ..
| shagie wrote:
| 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
|
| > 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.
| darby_eight wrote:
| Eh this seems a lot less interesting than language and laughter
| bee_rider wrote:
| Ants, of course, famously optimize. I think most creatures
| optimize somehow, I mean doing things wastefully is way to end
| up with an energy deficit, aka starve.
|
| Humans have an interesting tendency to bump themselves out of
| local optima, via instincts called "boredom" and "curiosity."
| These are not strictly human traits I think, but humans tend to
| get bored more often than other creatures, tend to accumulate
| large amount of resources which allow them to follow their
| curiosity a bit further, and are very good at communicating the
| results of this boredom.
| yencabulator wrote:
| I give you slime molds:
| https://news.ycombinator.com/item?id=29114686
| WalterBright wrote:
| 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 wrote:
| 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
| n1b0m wrote:
| Thanks for sharing. Just started listening
| HelloMcFly wrote:
| 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.
| antognini wrote:
| One of the most impressive aspects of Babylonian and Chinese
| eclipse predictions was simply the social organization that
| was required to collect the necessary data. These records
| were collected almost continuously over centuries. The
| Babylonian astronomical records which span around seven
| centuries and are arguably the longest continuous scientific
| program any civilization has produced.
| shagie wrote:
| It then helped establish the study of the precession.
| Hipparchus used the Babylonian astronomical information to
| look into changes over hundreds of years.
|
| https://en.wikipedia.org/wiki/Babylonian_astronomy#Influenc
| e...
|
| > In 1900, Franz Xaver Kugler demonstrated that Ptolemy had
| stated in his Almagest IV.2 that Hipparchus improved the
| values for the Moon's periods known to him from "even more
| ancient astronomers" by comparing eclipse observations made
| earlier by "the Chaldeans", and by himself. However Kugler
| found that the periods that Ptolemy attributes to
| Hipparchus had already been used in Babylonian ephemerides,
| specifically the collection of texts nowadays called
| "System B" ....
|
| https://en.wikipedia.org/wiki/Axial_precession and
| https://en.wikipedia.org/wiki/Hipparchus
|
| > Earlier Greek astronomers and mathematicians were
| influenced by Babylonian astronomy to some extent, for
| instance the period relations of the Metonic cycle and
| Saros cycle may have come from Babylonian sources (see
| "Babylonian astronomical diaries"). Hipparchus seems to
| have been the first to exploit Babylonian astronomical
| knowledge and techniques systematically.
|
| > ...
|
| > Hipparchus probably compiled a list of Babylonian
| astronomical observations; Gerald J. Toomer, a historian of
| astronomy, has suggested that Ptolemy's knowledge of
| eclipse records and other Babylonian observations in the
| Almagest came from a list made by Hipparchus. Hipparchus's
| use of Babylonian sources has always been known in a
| general way, because of Ptolemy's statements, but the only
| text by Hipparchus that survives does not provide
| sufficient information to decide whether Hipparchus's
| knowledge (such as his usage of the units cubit and finger,
| degrees and minutes, or the concept of hour stars) was
| based on Babylonian practice
| WalterBright wrote:
| > you're underselling the accomplishment of determining some
| of these things, particularly predicting eclipses
|
| If you keep records over the decades, you can predict it.
| It's just a pattern, not an understanding. It wasn't until
| the last century, however, that the application of math to
| the precise orbits was able to predict the track of an
| eclipse very accurately.
| HelloMcFly wrote:
| > If you keep records over the decades, you can predict it.
|
| Of course we know that _now_ , but that level of
| understanding is hardly trivial to societies at those
| levels of development. To use our current understanding to
| be so underwhelmed - and to not be at all impressed by the
| scale at which they applied it for transforming and
| modernizing aspects of their growing societies - I don't
| know man, it honestly kind of shocks me and bums me out in
| equal measure.
| swatcoder wrote:
| > They still had no idea what the sun, moon, and planets were,
|
| The composition of celestial bodies is useless trivia until you
| have some very modern material and energy sciences that might
| start turning to them for inspiration. There will almost
| certainly be a collapse of the modern world, and losing that
| information will be the very very least of our problems.
|
| > nor even the layout of the solar system.
|
| Depending on which civilizations you're talking about and how
| ancient you mean, the paths of visible roving bodies (planets)
| were actually pretty well known in many places for thousands of
| years. The models used to anticipate positions were often more
| _convoluted_ than ours, but projected space and heliocentrism
| are ultimately just an optimization that wasn 't obvious,
| necessary, or meaningful given what little practical use there
| was to the paths of those planets until very recently.
|
| What those pop history shows mostly achieve is just reminding
| people that astronomical and scientific knowledge didn't start
| in the European Enlightenment, which is the takeaway that many
| people (in the US, especially) carry after high school. They're
| not really meant for someone like yourself. There's much more
| you might actually be impressed by in academic
| history/archaeology/anthropology and even in certain written
| pop history sources.
| antognini wrote:
| Also worth noting that pretty much every ancient civilization
| ended up figuring out the order of the planets, at least
| relative to earth. (It turns out not to be so difficult since
| this is directly related to their sidereal periods.)
| jrussino wrote:
| > There will almost certainly be a collapse of the modern
| world
|
| I hope your certainty is misplaced; this is just about the
| most horrifying prediction I can imagine.
|
| As far as I can tell, we're at a particularly precarious
| transition point with regard to how much energy we consume.
| If society "collapses" before hitting some technological
| checkpoint we don't get to try again - at least, not for a
| looong time - because we've nearly used up all of the low-
| hanging fruit in the planet's energy resources (fossil
| fuels).
| WalterBright wrote:
| Sure they watched the paths. That doesn't tell them what they
| were, how far away they were, helicentric vs geocentric, etc.
| Anybody can watch paths and notice they repeat.
|
| > heliocentrism are ultimately just an optimization that
| wasn't obvious, necessary, or meaningful given what little
| practical use there was to the paths of those planets until
| very recently
|
| True, but that wasn't my observation. My observation is it
| was not advanced, sophisticated, etc.
| antognini wrote:
| 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_z...
| dekhn wrote:
| Just build a digital sundial:
| https://www.thingiverse.com/thing:1068443
| renlo wrote:
| 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 wrote:
| 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 wrote:
| 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 wrote:
| 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
| hammock wrote:
| Also worth noting that some early timekeepers used the burning of
| incense to count down the time.
| foreigner wrote:
| I want a wrist-mounted sundial "watch" that automatically
| calibrates itself using my phone's GPS.
| nvader wrote:
| > 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 wrote:
| 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 wrote:
| 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 wrote:
| 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.
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