5 ms·

The Antikythera mechanism – 254:19 ratio

zefhous 2y ago
I’m just here to fulfill the Hacker News rule that any post mentioning the Antikythera Mechanism must have a comment linking the excellent Clickspring build videos. https://youtube.com/playlist?list=PLZioPDnFPNsHnyxfygxA0to4RXv4_jDU2 https://youtube.com/playlist?list=PLZioPDnFPNsHnyxfygxA0to4R...
- beeforpork 2y ago
  Thank you! I was waiting for it so I could click on it again. :-)
- mattbillenstein 2y ago
  Excellent videos - and the one thing that sticks with me was the speculation that watchmaking and the processes that it requires eventually leads to the type of technology we have today. I think the line goes if the greeks of that era had been allowed to progress another 300-400 years, they may have been able to land on the moon...
- etrautmann 2y ago
  This is why I love HN, thanks for sharing
sgt101 2y ago
https://www.bbc.co.uk/programmes/m0024x0g https://www.bbc.co.uk/programmes/m0024x0g Up to date and with a very good discussion of the 254:19 gearing. Also much more detail on the history of the mechanism.
Alex3917 2y ago
If you're in Athens, the Herakleidon museum has not only an exhibit about this, but about all sorts of other advanced Greek technology: coin-operated vending machines, drink-serving robots, water-powered telegraphs, etc. While this specific device may (or may not) have been a one-off, it's undeniable that ancient Greece was basically the real-life version of a Steampunk-based society. (With the caveat that ancient Persia probably had similar technology at one point also, but most of that has since been destroyed by the British and others throughout history.)
- hyhconito 2y ago
  Oh damn it. Missed that one entirely. I will have to come back again.
  - jcims 2y ago
    Same!!! I just asked chatgpt “Based on what you know about me, what do you think I would be interested in seeing in Athens?” The Herakleidon Museum was third on the list. May have to try this again in the future.
    - hyhconito 2y ago
      Never thought of using it for that. Annoyingly I’m in Athens right now but flying back tomorrow way too early to sneak a visit in :(
      - jcims 2y ago
        That airport is a bit of a haul. :/
        hyhconito 2y ago
        Was even worse last week. Got off plane and metro was on strike.
    - dwighttk 2y ago
      what does chatgpt know about you?
      - fragmede 2y ago
        As you chat with it, it'll pick up random details from conversations (eg owns a cat) and stick it into a limited memories folder, which can be manually inspected and cleared out as desired.
- Terr_ 2y ago
hyhconito 2y ago
Ha literally just saw that this morning in the National Archaeological Museum in Athens! Lurking here paid off. A good read.
meew0 2y ago
> I’ve always liked blogging about calendrical things, but I don’t remember doing anything on the Metonic cycle before. If I had written faster, I could’ve published it on Friday the 13th. Too bad. On the other hand, you published it during a full moon. That's at least slightly appropriate given the subject matter :)
casenmgreen 2y ago
I was living in Athens, and visiting the museums, and I had no idea - I walked around a corner in the National and pow - the Mechanism, THE Mechanism, was there, right in front of me. WOW. Also, Elgin marbles need to be returned. Parthenon is defaced by their absence.
- sneak 2y ago
  They’re not putting them outside again; they’d be inside in the Acropolis museum. The Parthenon (blown up as it is) would still be missing them.
  - euroderf 2y ago
    Speaking of which, where's the apology from Türkiye for storing ammo there ?
- globnomulous 2y ago
  [flagged]
  - lioeters 2y ago
    > In 2021, UNESCO concluded that the UK government had an obligation to return the marbles and called upon the UK government to open negotiations with Greece. > Asked about the possible return of the Marbles, the British Culture Secretary, Michelle Donelan replied: "I can sympathise with some of the arguments but I do think that is a very dangerous and slippy road to embark down." > ..Fulfilling all restitution claims would empty most of the world's great museums – this has also caused concerns among other European and American museums.
    - manarth 2y ago
      > would empty most of the world's great museums whilst growing other museums around the world with art and culture in an authentic setting, with a closer connection to their cultural and historical context.
- 2y ago
analog31 2y ago
Reminds me of finding a pair of gears in a box of lathe accessories, with 50 and 127 teeth.
- mauvehaus 2y ago
  For anyone who isn't aware: that's the pair of gears with the smallest number of teeth (and by extension, largest teeth for a given size pair of gears) in the ratio of 2.54:1. As I'm not a machinist, I'm not going to try to explain just where in the geartrain you'd use this pair to convert your metric machine lathe into a US customary lathe, but that's what they're for.
  - analog31 2y ago
    There's typically a gear train that communicates the rotation of the spindle to the threading mechanism. This is so that you can turn a precise number of threads per unit length, and to take multiple passes to reach the desired thread depth. There's a multi-ratio gearbox that sets the thread pitch. The 2.54 ratio lets you turn metric threads on a US machine, with the help of tables in the manual for how to set all of the levers. Machinists hate it, and these days will prefer to buy a die for the occasional threading job.
    - mikewarot 2y ago
      I think if I had to do metric threads often, I'd switch to an electronic leadscrew, like the one from Clough42.[1] [1] https://github.com/clough42/electronic-leadscrew/wiki https://github.com/clough42/electronic-leadscrew/wiki
    - mauvehaus 2y ago
      The remaining problem is that metric threads are specified by the mm between peaks, whereas US customary threads are specified by threads/inch. It's not immediately obvious to me (not a machinist) that the 127/50 ratio gets you the ability to cut metric threads without a mess of other head-scratching because you're now dealing with period instead of frequency.
atmosx 2y ago
> My sketch of the Sun-Earth-Moon system assumes a heliocentric solar system, something that wasn’t known to the Greeks of the first century BCE. I am not sure this is entirely accurate. According to Wikipedia: > The notion that the Earth revolves around the Sun had been proposed as early as the 3rd century BC by Aristarchus of Samos,[1] who had been influenced by a concept presented by Philolaus of Croton (c. 470 – 385 BC). In the 5th century BC the Greek philosophers Philolaus and Hicetas had the thought on different occasions that the Earth was spherical and revolving around a "mystical" central fire, and that this fire regulated the universe.[2] In medieval Europe, however, Aristarchus' heliocentrism attracted little attention—possibly because of the loss of scientific works of the Hellenistic period.[b] Source: https://en.m.wikipedia.org/wiki/Heliocentrism https://en.m.wikipedia.org/wiki/Heliocentrism Contrary to the recent revisionist version of the “dark ages”, they were pretty dark if you were a Greek of the Hellenistic period, an Athenian 5th century BC or a Roman the next 500-800 years. Loss of philosophical (locked in monasteries) and technical knowledge is common and Heliocentrism or the blood circulation system (Egyptians during the Ptolemy era had knowledge comparable to the one we will acquire again 18th century) are two prime examples.
- arp242 2y ago
  You can argue semantics on this, but "wasn’t known to the Greeks of the first century BCE" is basically accurate, or certainly "accurate enough" for this context. All of the heliocentric writers were basically little more than "this idea some guy had", and geocentric views as described by e.g. Aristotle were dominant.
  - globnomulous 2y ago
    If that's true, then by the same reasoning you're also saying that heliocentrism wasn't known to the Europe of (insert any time before the mid 1600s), because it was little more than an idea some guy had, not dominant or accepted. But nobody would characterize the history of the science that way, because it simply isn't true. "Wasn't known to the Greeks" is inaccurate, particularly in its historical context, since science and philosophy were often "little more than 'this idea some guy had.'"
  - 2y ago
robertlagrant 2y ago
Hah - I watched that Veritasium video the other day.
hoseja 2y ago
I once heard that the mechanism was too fine/the gear train too large that it could not possibly actually work without stripping the gears or seizing due to friction.
- floxy 2y ago
  Does anyone know if Clickspring ever finished making a copy of the mechanism? Seems like the last update was from ~2 years ago. https://www.youtube.com/watch?v=ML4tw_UzqZE https://www.youtube.com/watch?v=ML4tw_UzqZE https://www.youtube.com/@Clickspring/videos https://www.youtube.com/@Clickspring/videos

I’m just here to fulfill the Hacker News rule that any post mentioning the Antikythera Mechanism must have a comment linking the excellent Clickspring build videos. https://youtube.com/playlist?list=PLZioPDnFPNsHnyxfygxA0to4RXv4_jDU2 https://youtube.com/playlist?list=PLZioPDnFPNsHnyxfygxA0to4R...

beeforpork 2y ago
Thank you! I was waiting for it so I could click on it again. :-)
mattbillenstein 2y ago
Excellent videos - and the one thing that sticks with me was the speculation that watchmaking and the processes that it requires eventually leads to the type of technology we have today. I think the line goes if the greeks of that era had been allowed to progress another 300-400 years, they may have been able to land on the moon...
etrautmann 2y ago
This is why I love HN, thanks for sharing

sgt101 2y ago

https://www.bbc.co.uk/programmes/m0024x0g https://www.bbc.co.uk/programmes/m0024x0g Up to date and with a very good discussion of the 254:19 gearing. Also much more detail on the history of the mechanism.

Alex3917 2y ago

If you're in Athens, the Herakleidon museum has not only an exhibit about this, but about all sorts of other advanced Greek technology: coin-operated vending machines, drink-serving robots, water-powered telegraphs, etc. While this specific device may (or may not) have been a one-off, it's undeniable that ancient Greece was basically the real-life version of a Steampunk-based society. (With the caveat that ancient Persia probably had similar technology at one point also, but most of that has since been destroyed by the British and others throughout history.)

hyhconito 2y ago
Oh damn it. Missed that one entirely. I will have to come back again.
- jcims 2y ago
  Same!!! I just asked chatgpt “Based on what you know about me, what do you think I would be interested in seeing in Athens?” The Herakleidon Museum was third on the list. May have to try this again in the future.
  - hyhconito 2y ago
    Never thought of using it for that. Annoyingly I’m in Athens right now but flying back tomorrow way too early to sneak a visit in :(
    - jcims 2y ago
      That airport is a bit of a haul. :/
      - hyhconito 2y ago
        Was even worse last week. Got off plane and metro was on strike.
  - dwighttk 2y ago
    what does chatgpt know about you?
    - fragmede 2y ago
      As you chat with it, it'll pick up random details from conversations (eg owns a cat) and stick it into a limited memories folder, which can be manually inspected and cleared out as desired.
Terr_ 2y ago

hyhconito 2y ago

Ha literally just saw that this morning in the National Archaeological Museum in Athens! Lurking here paid off. A good read.

meew0 2y ago

> I’ve always liked blogging about calendrical things, but I don’t remember doing anything on the Metonic cycle before. If I had written faster, I could’ve published it on Friday the 13th. Too bad. On the other hand, you published it during a full moon. That's at least slightly appropriate given the subject matter :)

casenmgreen 2y ago

I was living in Athens, and visiting the museums, and I had no idea - I walked around a corner in the National and pow - the Mechanism, THE Mechanism, was there, right in front of me. WOW. Also, Elgin marbles need to be returned. Parthenon is defaced by their absence.

sneak 2y ago
They’re not putting them outside again; they’d be inside in the Acropolis museum. The Parthenon (blown up as it is) would still be missing them.
- euroderf 2y ago
  Speaking of which, where's the apology from Türkiye for storing ammo there ?
globnomulous 2y ago
[flagged]
- lioeters 2y ago
  > In 2021, UNESCO concluded that the UK government had an obligation to return the marbles and called upon the UK government to open negotiations with Greece. > Asked about the possible return of the Marbles, the British Culture Secretary, Michelle Donelan replied: "I can sympathise with some of the arguments but I do think that is a very dangerous and slippy road to embark down." > ..Fulfilling all restitution claims would empty most of the world's great museums – this has also caused concerns among other European and American museums.
  - manarth 2y ago
    > would empty most of the world's great museums whilst growing other museums around the world with art and culture in an authentic setting, with a closer connection to their cultural and historical context.
2y ago

analog31 2y ago

Reminds me of finding a pair of gears in a box of lathe accessories, with 50 and 127 teeth.

mauvehaus 2y ago
For anyone who isn't aware: that's the pair of gears with the smallest number of teeth (and by extension, largest teeth for a given size pair of gears) in the ratio of 2.54:1. As I'm not a machinist, I'm not going to try to explain just where in the geartrain you'd use this pair to convert your metric machine lathe into a US customary lathe, but that's what they're for.
- analog31 2y ago
  There's typically a gear train that communicates the rotation of the spindle to the threading mechanism. This is so that you can turn a precise number of threads per unit length, and to take multiple passes to reach the desired thread depth. There's a multi-ratio gearbox that sets the thread pitch. The 2.54 ratio lets you turn metric threads on a US machine, with the help of tables in the manual for how to set all of the levers. Machinists hate it, and these days will prefer to buy a die for the occasional threading job.
  - mikewarot 2y ago
    I think if I had to do metric threads often, I'd switch to an electronic leadscrew, like the one from Clough42.[1] [1] https://github.com/clough42/electronic-leadscrew/wiki https://github.com/clough42/electronic-leadscrew/wiki
  - mauvehaus 2y ago
    The remaining problem is that metric threads are specified by the mm between peaks, whereas US customary threads are specified by threads/inch. It's not immediately obvious to me (not a machinist) that the 127/50 ratio gets you the ability to cut metric threads without a mess of other head-scratching because you're now dealing with period instead of frequency.

atmosx 2y ago

> My sketch of the Sun-Earth-Moon system assumes a heliocentric solar system, something that wasn’t known to the Greeks of the first century BCE. I am not sure this is entirely accurate. According to Wikipedia: > The notion that the Earth revolves around the Sun had been proposed as early as the 3rd century BC by Aristarchus of Samos,[1] who had been influenced by a concept presented by Philolaus of Croton (c. 470 – 385 BC). In the 5th century BC the Greek philosophers Philolaus and Hicetas had the thought on different occasions that the Earth was spherical and revolving around a "mystical" central fire, and that this fire regulated the universe.[2] In medieval Europe, however, Aristarchus' heliocentrism attracted little attention—possibly because of the loss of scientific works of the Hellenistic period.[b] Source: https://en.m.wikipedia.org/wiki/Heliocentrism https://en.m.wikipedia.org/wiki/Heliocentrism Contrary to the recent revisionist version of the “dark ages”, they were pretty dark if you were a Greek of the Hellenistic period, an Athenian 5th century BC or a Roman the next 500-800 years. Loss of philosophical (locked in monasteries) and technical knowledge is common and Heliocentrism or the blood circulation system (Egyptians during the Ptolemy era had knowledge comparable to the one we will acquire again 18th century) are two prime examples.

arp242 2y ago
You can argue semantics on this, but "wasn’t known to the Greeks of the first century BCE" is basically accurate, or certainly "accurate enough" for this context. All of the heliocentric writers were basically little more than "this idea some guy had", and geocentric views as described by e.g. Aristotle were dominant.
- globnomulous 2y ago
  If that's true, then by the same reasoning you're also saying that heliocentrism wasn't known to the Europe of (insert any time before the mid 1600s), because it was little more than an idea some guy had, not dominant or accepted. But nobody would characterize the history of the science that way, because it simply isn't true. "Wasn't known to the Greeks" is inaccurate, particularly in its historical context, since science and philosophy were often "little more than 'this idea some guy had.'"
- 2y ago

robertlagrant 2y ago

Hah - I watched that Veritasium video the other day.

hoseja 2y ago

I once heard that the mechanism was too fine/the gear train too large that it could not possibly actually work without stripping the gears or seizing due to friction.

floxy 2y ago
Does anyone know if Clickspring ever finished making a copy of the mechanism? Seems like the last update was from ~2 years ago. https://www.youtube.com/watch?v=ML4tw_UzqZE https://www.youtube.com/watch?v=ML4tw_UzqZE https://www.youtube.com/@Clickspring/videos https://www.youtube.com/@Clickspring/videos