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Astronomy Picture of the Day - The Antikythera Mechanism
APOD.NASA.gov ^ | 21 Mar, 2021 | Image Credit & License: Marsyas, Wikipedia

Posted on 03/21/2021 3:48:27 PM PDT by MtnClimber

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For more detail go to the link and click on the image for a high definition image. You can then move the magnifying glass cursor then click to zoom in and click again to zoom out. When zoomed in you can scan by moving the side bars on the bottom and right side of the image.

1 posted on 03/21/2021 3:48:27 PM PDT by MtnClimber
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To: MtnClimber

2 posted on 03/21/2021 3:48:39 PM PDT by MtnClimber (For photos of Colorado scenery and wildlife, click on my screen name for my FR home page.)
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To: 21stCenturion; 21twelve; 4everontheRight; abb; AFB-XYZ; America_Right; Art in Idaho; AZ .44 MAG; ...
Pinging the APOD list.

🪐 🌟 🌌


3 posted on 03/21/2021 3:49:15 PM PDT by MtnClimber (For photos of Colorado scenery and wildlife, click on my screen name for my FR home page.)
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To: MtnClimber
Well, no need in explaining anything regarding how this worked. It's all pretty self-explanatory from these pics...

Lol!







4 posted on 03/21/2021 3:58:05 PM PDT by ETL (REAL Russia collusion! DEMOCRAT-Russia collusion!! China-Russia collusion! Click ETL...)
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To: All; MtnClimber

Operation

On the front face of the mechanism there is a fixed ring dial representing the ecliptic, the twelve zodiacal signs marked off with equal 30-degree sectors. This matched with the Babylonian custom of assigning one twelfth of the ecliptic to each zodiac sign equally, even though the constellation boundaries were variable.

Outside that dial is another ring which is rotatable, marked off with the months and days of the Sothic Egyptian calendar, twelve months of 30 days plus five intercalary days. The months are marked with the Egyptian names for the months transcribed into the Greek alphabet. The first task, then, is to rotate the Egyptian calendar ring to match the current zodiac points. The Egyptian calendar ignored leap days, so it advanced through a full zodiac sign in about 120 years.[3]

The mechanism was operated by turning a small hand crank (now lost) which was linked via a crown gear to the largest gear, the four-spoked gear visible on the front of fragment A, the gear named b1. This moved the date pointer on the front dial, which would be set to the correct Egyptian calendar day.

The year is not selectable, so it is necessary to know the year currently set, or by looking up the cycles indicated by the various calendar cycle indicators on the back in the Babylonian ephemeris tables for the day of the year currently set, since most of the calendar cycles are not synchronous with the year.

The crank moves the date pointer about 78 days per full rotation, so hitting a particular day on the dial would be easily possible if the mechanism were in good working condition. The action of turning the hand crank would also cause all interlocked gears within the mechanism to rotate, resulting in the simultaneous calculation of the position of the Sun and Moon, the moon phase, eclipse, and calendar cycles, and perhaps the locations of planets.[43]

The operator also had to be aware of the position of the spiral dial pointers on the two large dials on the back. The pointer had a “follower” that tracked the spiral incisions in the metal as the dials incorporated four and five full rotations of the pointers. When a pointer reached the terminal month location at either end of the spiral, the pointer’s follower had to be manually moved to the other end of the spiral before proceeding further.[2]:10 ...”

https://en.wikipedia.org/wiki/Antikythera_mechanism#Operation


5 posted on 03/21/2021 4:03:48 PM PDT by ETL (REAL Russia collusion! DEMOCRAT-Russia collusion!! China-Russia collusion! Click ETL...)
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To: MtnClimber

My ‘Field Computer’ when I was in the Army in the 1980’s was the size of a Volkswagon Beetle - and it had it’s own trailer so I could haul it around!

How far we have come in such a short time. :)


6 posted on 03/21/2021 4:11:48 PM PDT by Diana in Wisconsin (I don't have 'Hobbies.' I'm developing a robust post-Apocalyptic skill set. )
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To: ETL

No wonder it doesn’t work. They forgot to clean it for a few thousand years.


7 posted on 03/21/2021 4:12:34 PM PDT by MtnClimber (For photos of Colorado scenery and wildlife, click on my screen name for my FR home page.)
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To: MtnClimber

It’s probably out of warranty, too, unless they got the extended plan.


8 posted on 03/21/2021 4:15:29 PM PDT by HartleyMBaldwin
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To: MtnClimber
predicting future star and planet locations as well as lunar and solar eclipses

Errr... it was probably used to help navigate the seas at night more than to predict the next eclipse. But you never know.

9 posted on 03/21/2021 4:53:12 PM PDT by monkeyshine (live and let live is dead)
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To: HartleyMBaldwin

They probably get 3-4 calls a day offering to renew...


10 posted on 03/21/2021 4:56:17 PM PDT by Clioman
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To: MtnClimber
There is reason to believe Archimedes himself made this instrument, it is mentioned by Cicero if I remembering correctly.
11 posted on 03/21/2021 5:07:38 PM PDT by Nateman (Keep Liberty Alive! Article V)
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To: MtnClimber
There is reason to believe Archimedes himself made this instrument, it is mentioned by Cicero if I am remembering correctly.
12 posted on 03/21/2021 5:10:14 PM PDT by Nateman (Keep Liberty Alive! Article V)
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To: HartleyMBaldwin

Sold as Blue-Point...


13 posted on 03/21/2021 5:57:31 PM PDT by Does so (The Media is the enemy of the people...Trial lawyers close behind...)
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To: MtnClimber

I had the good fortune to view this in the National Museum in Athens. My first impression was it looked like it was made with the technology one would find in a 19th century machine shop.


14 posted on 03/21/2021 6:01:47 PM PDT by KamperKen
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To: MtnClimber

Youtube “clickspring” watch him build a model. Amazing workmanship.


15 posted on 03/21/2021 6:30:04 PM PDT by stickandrudder (Another Bitter-Clinger! God-Family-Tribe)
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To: KamperKen

It is amazing when one considers it was all hand cut
with files which themselves were hand made.


16 posted on 03/21/2021 6:35:04 PM PDT by tet68 ( " We would not die in that man's company, that fears his fellowship to die with us...." Henry V.)
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To: KamperKen
I had the good fortune to view this in the National Museum in Athens. My first impression was it looked like it was made with the technology one would find in a 19th century machine shop.

There must have been so much that was lost during the dark ages.

17 posted on 03/21/2021 6:35:28 PM PDT by MtnClimber (For photos of Colorado scenery and wildlife, click on my screen name for my FR home page.)
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To: ETL

Pretty much proof right there that humanity was pretty advanced at some point and some idiot set us all back about 2000 years by taking out key people (& library of Alexandria?). To construct something that intricate, even “by hand”, would require some precision metalworking & removal equipment not to mention a great deal of mathematics.

Reminded me somewhat of the “Torpedo Data Computers” of WWII that US submarines used. But look how much went into something that just had to compute a firing angle.

https://maritime.org/tech/tdc.htm


18 posted on 03/21/2021 6:40:09 PM PDT by Uber-Eng (Northern Texan at heart...Help me save Michigan!!!)
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To: MtnClimber
"There must have been so much that was lost during the dark ages. "

That is probably true. It seems the ancient world was on the cusp of some technological breakthroughs but they did not take hold.
19 posted on 03/21/2021 6:41:39 PM PDT by KamperKen
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To: MtnClimber

Type of gov’t back then stopped progress. We have democrats in this country doing the same.


20 posted on 03/21/2021 7:25:07 PM PDT by minnesota_bound (I need more money. )
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