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selfAdjoint said:
It was an improved lunar theory the Royal Navy was looking for, in aid of "lunar distances" longitude methods, when it set that 18th century competition that Harrison won on a technicality with his totally irrelevant clock.
That "totally irrelevant" clock may mean little to you, but it and its competitors made global navigation and trade (and projection of military force) a lot safer and more viable. Historically, pragmatic, results-oriented innovations have made investment and risk-taking more attractive, and have served us well. Theoreticians can postulate and publish all they want, but the "modeler" that delivers reliable goods will collect all the ducats. Fact of life. Until reliable clocks, navigators could accurately determine their latitudes, but had no idea of their longitude save dead-reckoning and an occasional sighting of a previously-established benchmark. That clock made shipping a lot less risky.
 

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selfAdjoint said:
was an improved lunar theory the Royal Navy was looking for, in aid of "lunar distances" longitude methods, when it set that 18th century competition that Harrison won on a technicality with his totally irrelevant clock.
:surprise: I believe that the accuracy of longitude methods based in "lunar distances" was scant. On the contrary, the Harrison's chronographs were a great advance to navigation. Its H-4 model showed an error of 39.2 seconds over a voyage of 47 days, three times better than required to win the £20,000 longitude prize
 
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ryokan said:
:surprise: I believe that the accuracy of longitude methods based in "lunar distances" was scant. On the contrary, the Harrison's chronographs were a great advance to navigation. Its H-4 model showed an error of 39.2 seconds over a voyage of 47 days, three times better than required to win the £20,000 longitude prize
This is OT, but I can't help it. The accuracy of lunar distances improved greatly in the late 18th century, precisely due to the improvements in the theory of the Moons motions. The reason a modern sextant is a sixty degree arc instead of a 45 degree one, which would suffice for altitudes (angles are doubled in a sextant because of the properties of a rotating mirror), is that 120 degrees was required for lunars. Nathaniel Bowditch made his name teaching the crew of a ship, including the cook, to take lunars and reduce the data to longitude; this was in the early 19th century.

Bowditch's book The American Practical Navigator is still in print, although the chapter on lunars was dropped years ago. For that matter the US Naval Academy at Annapolis has stopped teaching celestial navigation to midshipmen. "Now that we have GPS satellites, we don't need it." They'll find out about that when the EMP comes!

Harrison was utterly unable to manufacture his clocks in quantities sufficient to fit the needs of the Royal Navy. In fact until about 1820, nobody used chronometers at sea because nobody could afford them, they had to be handmade. Longitudes were universally, and quite adequately, figured by lunars. Finally improvements both in design and manufacturing made chronometers generally available, and not long after that Sumner discovered the line of position, and modern celestial navigation was off and running.

But the Cinderella legend of Harrison's chronometer, which gets retold every generation, and in which the astronomers play the role of the ugly stepsisters, is bad bad history.
 
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selfAdjoint said:
This is OT
Harrison was utterly unable to manufacture his clocks in quantities sufficient to fit the needs of the Royal Navy. In fact until about 1820, nobody used chronometers at sea because nobody could afford them, they had to be handmade. Longitudes were universally, and quite adequately, figured by lunars. Finally improvements both in design and manufacturing made chronometers generally available, and not long after that Sumner discovered the line of position, and modern celestial navigation was off and running.

But the Cinderella legend of Harrison's chronometer, which gets retold every generation, and in which the astronomers play the role of the ugly stepsisters, is bad bad history.
Yes. This is OT.
Although improvements in design and manufacturing were needed, Harrison's chronometer was a great advance as conception (a mechanical versus an only astronomical instrument).
What do you mean by the expression "Cinderella legend" about Harrison?
 
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Sure it was a great advance, but IT DID NOT MEET THE NEEDS OF THE ROYAL NAVY, which has set the competition in order to improve the longitude measurements on its hundreds of major ships. Harrison just couldn't meet this. But the RN had neglected to specify that detail in the competition bylaws, so they had to pay him the money.

By Cinderella legend I mean the story as usually told with Harrison as the poor little outsider, and the Astronomer Royal as the rival with a less accurate method(yet more practical then and therafter, which is never stated). Eventually the Prince rewards the outsider. The parallels with Cinderella should be obvious.
 
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selfAdjoint said:
Sure it was a great advance, but IT DID NOT MEET THE NEEDS OF THE ROYAL NAVY, which has set the competition in order to improve the longitude measurements on its hundreds of major ships. Harrison just couldn't meet this. But the RN had neglected to specify that detail in the competition bylaws, so they had to pay him the money.

By Cinderella legend I mean the story as usually told with Harrison as the poor little outsider, and the Astronomer Royal as the rival with a less accurate method(yet more practical then and therafter, which is never stated). Eventually the Prince rewards the outsider. The parallels with Cinderella should be obvious.
Thank you for your answer. Now, I agree completely.
 
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RingoKid said:
Polynesians have traditions of defining tribal boundaries that required placing marker stones or burial sites that signified the land of the people of that area. These markers stones were laid out to resemble constellations with the knowledge of them being recorded in song/chant of legendary deeds by ancestors and gods.
That is very interesting and new for me. But could it be directly extrapolated to Stonehenge? Are there evidences of other non-Polynesian archaeoastronomical places constructed to define tribal boundaries?
 
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I believe many old world cultures would have done the same with their observatories, being the point's from which their tribal terrtories and sacred sites were defined. Feng shui is basically the same principle only in archaeo-astronomy it is extrapolated to greater distances in laying out the borders of lands tied to peoples as opposed to just building and architecture tied to individuals and castes within society.

I really don't know much about stonehenge but I don't see why it couldn't serve the same purpose.

I wonder if anyone is actually pursuing the search for land/constellations in old world sites...Pleiades type constellations would a good one to look for first.

The knowledge of this and the associated sites would only have been known to high priests/druids/shamen and be most closely guarded, probably why you may not have heard of this before

Polynesian traditions in the form of chants/ songs/stories were told to entertain and teach in much the same way as christian parables. The same story could be told using the upper jawbone or the lower. The upper being the story interpreted by an initiate knowing the coded messages the lower a mere bedtime story to entertain children.

unfortunately there aren't many wisened elders around or young ones willing to listen with the upper jawbone. The last persons they would have told of this knowledge in colonial times as relates to polynesians would have been christian missionaries and the like so with our culture being one whose traditions were passed on orally...makes it hard to pick up the trail again but the trails are still out there

In this picture we have a representation of the jawbones linked to a Tuatara (prehistoric NZ native lizard) known to be keeper of knowledge for Maori
http://www.waitaha.com/tuatara.jpg

Try reinterpreting this site with the upper jawbone

http://www.waitaha.com/

or this from our native american family

http://www.unm.edu/~abqteach/ArcheoCUs/99-01-02.htm [Broken]
 
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RingoKid said:
I believe many old world cultures would have done the same with their observatories, being the point's from which their tribal terrtories and sacred sites were defined. Feng shui is basically the same principle only in archaeo-astronomy it is extrapolated to greater distances in laying out the borders of lands tied to peoples as opposed to just building and architecture tied to individuals and castes within society.In this picture we have a representation of the jawbones linked to a Tuatara (prehistoric NZ native lizard) known to be keeper of knowledge for Maori
http://www.waitaha.com/tuatara.jpg

Try reinterpreting this site with the upper jawbone

http://www.waitaha.com/

or this from our native american family

http://www.unm.edu/~abqteach/ArcheoCUs/99-01-02.htm [Broken]
Thank you for these interesting webpages.
Thus, at least in these cultures, the social, polithic, interest (tribal boundaries) would prevail over the economic worries (sowing time). Is it correct? (although, of course, the social and economic are entangled)
 
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  • #10
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Is in Goseck the oldest observatory?

Here is an interesting link (Sorry,it is in german): http://www.spiegel.de/spiegel/inhalt/0,1518,328900,00.html [Broken]
 
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