Was there a decline and fall of the classical astronomer in the 4th/5th century?

Was there a decline and fall of the classical astronomer in the 4th/5th century?

  • YES

    Votes: 2 40.0%
  • NO

    Votes: 3 60.0%
  • OTHER

    Votes: 0 0.0%

  • Total voters
    5
Dec 2011
4,862
Iowa USA
#11
No I see those as two different jobs. Without the accurate measurement of the stars, deciding on distance north and south were difficult. The observer would produce the charts and the navigator would interpret them on his voyage.

The Polynesians did rely a lot on the stars, but had other techniques that seem to border on the supernatural lol. Things like the shape of a wave, the color of the water etc.

And as for Kepler he pretty much used all of Tyco Brahe's observation to come up with his laws of planetary motion.
The Polynesians' feats of navigation through an advanced (learned visual thinking skill, like hitting a curve ball in baseball) pattern recognition of the interference patterns in the waves might be considered a suggestion of validity to the "wild" speculation that the dolphins are the aquatic apes? We know that dolphins have evolved a sonar which uses same "sensing" of interference that the Polynesians were able to master....
 
Last edited:
May 2011
2,940
Rural Australia
#12
To answer the question on the OP, in my opinion there was a lack of analysys and scarcity of method. This meant more properly a stagnation. At the end, this "renounce" to the analytic methodology is a reason why the Ptolemaic system resisted for more than a millenium.

In other words it was like the knowledge of the ancient world remained "frozen".
It is interesting that you use the word "frozen".

Today the history of astrology reveals that there are two zodiacs - the sidereal and the tropical. (See extract below).

Did the knowledge of the precession of the equinoxes fall through the cracks of Western knowledge after the 4th or 5th century?

It would appear to me that the tropical zodiac reflects the sidereal zodiac as it was at the beginning of the 4th century. (See further below).


Sidereal and tropical astrology - Wikipedia

Sidereal and tropical are astrological terms used to describe two different definitions of a year. They are also used as terms for two systems of ecliptic coordinates used in astrology. Both divide the ecliptic into a number of "signs" named after constellations, but while the sidereal system defines the signs based on the fixed stars, the tropical system defines it based on the position of vernal equinox in the northern hemisphere (i.e., the intersection of the ecliptic with the celestial equator). Because of the precession of the equinoxes, the two systems do not remain fixed relative to each other but drift apart by about 1.4 arc degrees per century. The tropical system was adopted during the Hellenistic period and remains prevalent in Western astrology. A sidereal system is used in Hindu astrology, and in some 20th century systems of Western astrology.​

The WIKI article above states that the tropical system was adopted during the Hellenistic period, however to what extent was the adoption of the tropical zodiac simply a consequence of losing the knowledge of the movement of the stars as a consequence of the precession of the equinoxes?

How long have these two zodiacs been drifting apart?" These estimates are as follows ...

221 CE (Fagan-Bradley)
291 CE (Krishnamurti)
285 CE (Lahiri ayanamsa)

So to return to your last comment AlpinLuke, it appears to me that not only did the knowledge of the ancient world remain "frozen", but the very astrological slash astronomical zodiac used by the western world was a "frozen" instance of the sideral zodiac as it was about the time Diocletian planted his last cabbages.
 

AlpinLuke

Forum Staff
Oct 2011
26,833
Italy, Lago Maggiore
#13
The Polynesians' feats of navigation through an advanced (learned visual thinking skill, like hitting a curve ball in baseball) pattern recognition of the interference patterns in the waves might be considered a suggestion of validity to the "wild" speculation that the dolphins are the aquatic apes? We know that dolphins have evolved a sonar which uses same "sensing" of interference that the Polynesians were able to master....
I read now this reference to Polynesians and the way they navigated. Actually there would be also an easy astronomical system: it's not difficult to know your latitude, during the day thanks to the sun, during the night thanks to the stars around the celestial pole [North or South it's the same]. If you have to reach a isle at a latitude of ... 15.22N and you know it's West of the isle where you are, at a latitude of 12.11N, you just have to navigate North until you will be at a latitude of 15.22N then you will navigate West and, sooner or later, you will meet the isle you are looking for [without having to know your longitude]. This, obviously, requires markers to record the position of the stars with reference to the isles [so their latitude] or a kind of register with the data of the isles. There were real schools where they were used to teach the techs of navigation based on the observation of the stars.

Anyway, since accuracy [any system they used] wasn't certain, as indicators they carried with them pigs [animals with great sense of smell, able to feel a land at 40km ...] and they launched birds in the sky [if they didn't come back land was near ...]. Also clouds and waves were clues of the presence of an isle.
 
Likes: Kotromanic

Willempie

Ad Honorem
Jul 2015
5,304
Netherlands
#14
Navigation. The only way to get accurate latitude measurements was to have accurate measurement of the stars.
Not really, the sun and a calendar are enough if you traverse the North Sea or Mediterranean. For the praying times you could easily get by on Bede's writings.

Apparently the medieval chaps were more concerned with things like wheelbarrows, deep plowing and weaponry innovation than with staring at some stars at night. So yes the thesis is correct when looking at western Europe (Spain may be different).
As far as actual science goes, their main concerns were time and light. So their interest in astronomy was mainly to tell time (horlogium nocturnum), where apparently you had to tell the time by observing the stars and cross reference them with astronomical tables.
 
May 2011
2,940
Rural Australia
#15
Ptolemy - Wikipedia

Claudius Ptolemaeus; c. AD 100 – c. 170)[2] was a mathematician, astronomer, geographer and astrologer. ......... Ptolemy wrote several scientific treatises, three of which were of importance to later Byzantine, Islamic and Western European science. The first is the astronomical treatise now known as the Almagest, although it was originally entitled the Mathematical Treatise

Almagest - Wikipedia

The Almagest was preserved, like most of extant Classical Greek science, in Arabic manuscripts (hence its familiar name). Because of its reputation, it was widely sought and was translated twice into Latin in the 12th century, once in Sicily and again in Spain​

It looks like the popularity of Ptolemy's books waned after the Christian revolution of the 4th century.

Astrology is listed as a capital crime (death penalty) at least by the year 386 CE