Alfonsine TablesFROM: http://www.britannica.com/topic/Alfonsine-Tables

Alfonsine Tables, also spelled Alphonsine Tables, the first set of astronomical tables prepared in Christian Europe. They enabled calculation of eclipses and the positions of the planets for any given time based on the Ptolemaic theory, which assumed that the Earth was at the centre of the universe. The introduction states that the work was prepared in Toledo, Spain, for King Alfonso X of León and Castile under the direction of Jehuda ben Moses Cohen and Isaac ben Sid. Although no Castilian version survives, internal evidence—they were calculated for 1252, the initial year of the reign of Alfonso, and at the meridian of Toledo—supports the introduction. The tables were not widely known, however, until a Latin version was prepared in Paris in the 1320s. Copies rapidly spread throughout Europe, and for more than two centuries they were the best astronomical tables available. First printed in 1483, the Alfonsine Tables were an important source of information for the young Nicolaus Copernicus before his own work superseded them in the 1550s.

FROM: https://en.wikipedia.org/wiki/Alfonsine_tables

Production

Alfonso X assembled a team of scholars, known as the Toledo School of

Translators, who among other translating tasks, were commanded to produce new tables that

updated the Tables of Toledo. The new tables were based on earlier astronomical works and

observations by Islamic astronomers, adding observations by astronomers Alfonso had gathered in

Toledo, among them several Jewish scholars, like Yehuda ben Moshe and Isaac ibn Sid.[1] He also

brought Aben Raghel y Alquibicio and Aben Musio y Mohamat, from Seville, Joseph Aben Alí and

Jacobo Abenvena, from Córdoba, and fifty more from Gascony and Paris.[2]

The instructions for the Alfonsine tables were originally written in

Castilian Spanish. The first printed edition of the Alfonsine tables appeared in 1483, and a second

edition in 1491.[3]

Georg Purbach used the Alfonsine tables for his book, Theoricae novae

planetarum (New Theory of the Planets). Nicolaus Copernicus used the second edition in his work.

One use of these and similar astronomical tables was to calculate ephemerides, which were in turn

used by astrologers to cast horoscopes.

Methodology

The methods of Claudius Ptolemy were used to compute the table,

dividing the year into 365 days, 5 hours, 49 minutes, 16 seconds—very close to the currently

accepted figure. Copernicus's observation that his system could explain the planetary motions with

no more than 34 circles has been taken to imply that a large number of additional epicycles had

been subsequently introduced into the Ptolemaic system in an attempt to make it conform with

observation.[5] (There is a famous (but probably apocryphal)[6] quote attributed to Alfonso upon

hearing an explanation of the extremely complicated mathematics required to demonstrate

Ptolemy's geocentric model of the solar system: "If the Lord Almighty had consulted me before

embarking on creation thus, I should have recommended something simpler.") However, modern

computations[7] using Ptolemy's unmodified theory have replicated the published Alfonsine tables.

ARABIAN ASTRONOMY

Following Ptolemy, Greek astronomy rapidly declined and ended with the

Arabian conquest of Alexandria in AD 641. Although the magnificent library and museum were

destroyed, the Arabs encouraged learning and for the next 800 years developed an important

astronomical tradition of their own. Observatories were established at a number of cities including

Damascus, Cairo, Baghdad, and Meragha. One of the greatest stimuli to Arabian astronomy was the

need to calculate and maintain the Islamic calendar, which demanded new mathematical methods

and more precise timekeeping.

Among the greatest of Arabic astronomers were:

Al-Farghani (?–c.861) Albategnius (Al-Battani, Muhammad ibn Jabir) (c.850–929) Al-Sufi Abd al-Rahman (903–986) Abu'l-Wafa, Mohammed Al-Buzjani (940–998) Al-Quhi, Abu Sahl Wayjan ibn Rustam (c.940–c.1000) Alhazen Abu Ali al Hassan ibn al Haitham) (c.965–c.1040) Arzachel (Al-Zarqali, Abu Ishaq Ibrahim ibn Yahya) (1028–1087) Khayyáam, Omar (1048–1122) Abraham bar Hiyya Ha-nasi (c.1065–c.1136) Alpetragius (?–c.1204)

BAYER CONSTELLATIONS

Twelve constellations in the southern hemisphere that were first described by

Johann Bayer in his 1603 star atlas Uranometria. They are Apus (the Bird of Paradise), Chamaeleon,

Dorado (the Goldfish), Grus (the Crane), Hydrus (the Lesser Water Snake), Indus (the Indian), Musca

(the Fly), Pavo (the Peacock), Phoenix (the Firebird), Triangulum Australe the Southern Triangle,

Tucana (the Toucan), and Volans (the Flying Fish).

SELECTIONS FROM THIS WORK

Andromedadetails Aquila

details

Aradetails

Aurigadetails

Bootesdetails

Cancerdetails Canis Major

detailsCanis Minor

details

Carina Navisdetails Cassiopeia

details

Centaurusdetails

Cepheusdetails

Corona Meridionalisdetails

Corvusdetails

Craterdetails

Cygnusdetails

Delphinusdetails

Equuleusdetails

Eridanusdetails

Herculesdetails

Hydradetails

Leodetails Lepus

detailsLyra

details

List of Constellations by Accuracy of Bayer DesignationsPosted on 01.22by d684n

The brighter stars of constellations are designated by Greek letters according to Bayer Designations,

for which the original intent was for the brightest star of a constellation to be designated Alpha (α),

the second brightest Beta (β), the third brightest Gamma (γ), and so on through the Greek alphabet.

Astronomers, including Bayer, however, hardly made an effort to make Bayer Designations actually

indicate the brightest rank of stars in constellations, sometimes because it is hard to differentiate

brightnesses (Bayer designated the stars with Greek letters before sufficient modern quantitative

technology), sometimes because they wanted to have Greek letters outline patterns, and sometimes

when it seems that they could only have been fooling around. In any case, here is a list of

constellations ordered from most accurately Bayer-designated to most badly Bayer-designated. The

quantity first stated is the sum of the positive differences between the apparent magnitude of the

star actually Bayer-designated a Greek letter and the apparent magnitude of the star that should

have been respectively Bayer-designated that letter. Divided by the number of Bayer-designated

stars in the constellation, the final quantity shows the average amount by which a Bayer designation

in that constellation is off by magnitude.

Here’s a picture of Orion with eight labeled stars, with magnitudes attached, for reference.

Note that with less stars Bayer-designated, it is naturally

harder to make gigantic errors, and thus those most

impressively Bayer-designated are those with many stars

accurately Bayer-designated.

Canes Venatici: 0/2=0

Leo Minor: 0/1=0

Lynx: 0/1=0

Vulpecula: 0/1=0

Sextans: 0.02/5<0.01

Coma Berenices: 0.18/3=0.06

Scutum: 0.44/7=0.06

Dorado: 1.47/12=0.12

Vela: 0.92/7=0.13

Sculptor: 2.22/16=0.14

Lacerta: 0.28/2=0.14

Triangulum Australe: 1.44/10=0.14

Corona Australis: 1.77/11=0.16

Apus: 1.66/10=0.17

Volans: 1.66/10=0.17

Centaurus: 4.07/23=0.18

Monoceros: 1.09/6=0.18

Circinus: 1.49/8=0.19

Columba: 2.91/15=0.19

Mensa: 2.91/15=0.19

Cassiopeia: 4.79/24=0.20

Lyra: 2.73/13=0.21

Perseus: 4.65/22=0.21

Canis Minor: 1.52/7=0.22

Corona Borealis: 4.51/20=0.23

Delphinus: 2.26/10=0.23

Chamaeleon: 2.94/13=0.23

Caelum: 1.72/7=0.25

Camelopardalis: 0.74/3=0.25

Crux: 2.98/12=0.25

Grus: 5.25/21=0.25

Pictor: 3.05/12=0.25

Hydrus: 4.20/16=0.26

Reticulum: 2.69/10=0.27

Virgo: 6.69/24=0.28

Lupus: 6.83/24=0.28

Equuleus: 2.03/7=0.29

Triangulum: 1.75/6=0.29

Pyxis: 2.92/10=0.29

Horologium: 3.00/10=0.30

Gemini: 7.01/23=0.30

Andromena: 7.57/24=0.32

Cepheus: 5.70/18=0.32

Phoenix: 7.30/23=0.32

Indus: 5.07/15=0.34

Telescopium: 4.09/12=0.34

Cancer: 7.90/23=0.34

Lepus: 4.47/13=0.34

Pegasus: 7.65/22=0.35

Hercules: 8.01/23=0.35

Leo: 8.43/24=0.35

Ursa Minor: 3.53/10=0.35

Aries: 6.79/19=0.36

Serpens: 8.64/24=0.36

Crater: 4.34/12=0.36

Ara: 5.48/15=0.37

Musca: 4.04/11=0.37

Fornax: 7.5/20=0.38

Norma: 3.87/10=0.39

Boötes: 9.41/24=0.39

Aquarius: 9.42/24=0.39

Pavo: 8.75/22=0.40

Draco: 9.56/24=0.40

Ophiuchus: 9.22/23=0.40

Auriga: 9.24/23=0.40

Cygnus: 9.79/24=0.41

Pisces: 10.07/24=0.42

Tucana: 6.34/15=0.42

Hydra: 10.37/24=0.43

Microscopium: 4.47/10=0.45

Carina: 3.60/8=0.45

Octans: 10.80/24=0.45

Aquila: 10.37/23=0.45

Eridanus: 10.38/23=0.45

Capricornus: 10.92/24=0.46

Taurus: 10.98/24=0.46

Cetus: 10.22/22=0.46

Orion: 11.56/24=0.48

Ursa Major: 12.25/24=0.51

Piscis Austrinus: 7.34/14=0.52

Antlia: 3.73/7=0.53

Canis Major: 11.64/21=0.55

Puppis: 5.13/9=0.57

Sagitta: 5.13/8=0.64

Corvus: 4.62/7=0.66

Libra: 14.57/18=0.81

Sagittarius: 19.76/24=0.82

Scorpius: 20.12/22=0.91

Brightest stars in Libra: β (2.61), α (2.75), σ (3.25), υ (3.60), τ (3.66), γ (3.91), θ (4.13)

Brightest stars in Sagittarius: ε (1.79), σ (2.05), ζ (2.60), δ (2.72), λ (2.82), π (2.88), γ (2.98), η (3.10), φ

(3.17), τ (3.32)

Brightest stars in Scorpius: α (1.06), λ (1.62), θ (1.86), δ (2.29), ε (2.29), κ (2.36), β (2.56), υ (2.70), τ

(2.82), π (2.89), σ (2.90), ι (2.99)

In Scorpius, it can be seen that in α through λ, what is being designated is the backbone of the

scorpion, traced from the heart upwards and then downwards. In Sagittarius, whatever pattern is

being used is thoroughly mysterious, and α (3.96) literally comes 16th in the Greek letters. In these

exceptional cases, Bayer Designations may show important patterns, but whatever they are,

brightness is completely out of the question.

Copernican Revolution

The dramatic and far-reaching change from a geocentric to a

heliocentric worldview prompted by the work of Nicolaus Copernicus (see Copernican System). It

enabled the true status of the Earth, as an ordinary planet, to be realized and marked the beginning

of the end for the belief that there was a fundamental division between the nature of things

terrestrial and extraterrestrial. As Bishop John Wilkins noted,1 classical philosophers had asked:

of what kind of matter that should be, of which the heavens are

framed, whether or no of any fifth substance distinct from the four elements, as Aristotle holds, and

with him some of the late Schoolmen, whose subtill brains could not be content to attribute to those

vast glorius bodies, but common materials, and therefore they themselves had rather take pains to

prefer them some extraordinary nature ...

But in the wake of Copernicus, wrote Wilkins, it was apparent:

... that the heavens do not consist of any such pure matter which can privilege them from the like

change and corruption as these inferior bodies are liable unto.

This breakdown of the Aristotelian dichotomy between terrestrial space

and the region beyond also saw the demise of the medieval belief in the physicality of demons and

other such semi-material extraterrestrials. The way was now open to the idea that there might be

other worlds like the Earth, and other creatures on those worlds that might resemble ourselves. As

demons and their ilk retreated to the realm of the purely spiritual, so post-Copernican intellectuals

began to ponder the possibility of alien life-forms made of flesh and blood.

At first, the new heliocentric scheme was resisted but not, as Lovejoy has pointed out,2 because it

demoted the Earth:

It has often been pointed out that the older picture of the world in

space was peculiarly fitted to give man a high sense of his own importance and dignity ... Man

occupied, we are told, the central place in the universe, and round the planet of his habitation all the

vast, unpeopled spheres obsequiously revolved. But the actual tendency of the geocentric system

was, for the medieval mind, precisely the opposite. For the center of the world was not a position of

honor; it was rather the place furthest removed from the Empyrean, the bottom of creation ... the

geocentric cosmography served rather for man's humiliation than for his exaltation ... Copernicanism

was opposed partly on the ground that it assigned too dignified and lofty a position to his dwelling

place.

Those who were among the first to voice support and provide

further evidence for the Copernican system, including Galileo, were not generally inclined to say

much about its implications for extraterrestrial life, though Bruno was an early exception. Instead, it

was left for others of a more speculative nature, such as Wilkins and Godwin, to begin to people the

newfound worlds. Yet when post-Copernican pluralism did take root it was not in response to hard

astronomical data (for there was still virtually none of this relevant to astrobiology) but rather to an

appeal to telelology and reasoning by analogy. In Lovejoy's words:

The more important features of this new conception of the world,

then, owed little to any new hypotheses based upon the sort of observational grounds which we

should nowadays call "scientific." They were chiefly derivative from philosophical and theological

premises. They were, in short, manifest corollaries of the principle of plenitude ...

The most fundamental tenet of those who advocated the plurality of

worlds in the wake of Copernicus was that God (or nature) makes nothing in vain. If there were other

planets, they must be inhabited. Otherwise why would they exist? (see plenitude of principle).

20 – 16 TH BC BABILONIAN CONCEPTS OF PHYSICSFROM: http://www.daviddarling.info/encyclopedia/B/Babylonian_astronomy.html

Babylonian astronomy goes back at least as far as 1,800 BC and centers mainly on the problem of establishing an accurate calendar, so that the emphasis was on recording and calculating the motions of the Sun and Moon. Early on, observation played an important role, but this gave way later to analyzing records of ancient observations, which in turn led to the mathematical prediction of current and future astronomical events. The continuity of civilization in this part of the world enabled records to be kept over a long enough period for features such as the precession of the equinoxes and the regularity of eclipses to be recognized.

The Babylonians also divided the sky into zones, the most important being that which lay along the ecliptic, the apparent path followed by the Sun, Moon, and planets across the backdrop of the sky. The Latin names of the signs of the zodiac as we know them today are translations of the old Babylonian constellations.

In connection with the planets, the Babylonians appear to have been motivated by religious-philosophical reasons to take note only of isolated events, such as a planet's first and last appearances in the sky. Such occurrences were taken to have astrological significance: they might foretell human fate. There is no evidence that the Babylonians, unlike the Greeks, came up with any geometrical model of the cosmos. Even so, at the height of its creativity, in the so-called Seleucid era, around 600 BC, Babylonian astronomy could predict planetary motions with surprising accuracy, thanks to careful observations and the fact that from ancient times the Babylonians had a powerful mathematical tool in the sexagesimal system of numbers – a place-value system based on 60 that we still use. Babylon became part of the Persian empire, and its glory dimmed for a while. However, after Alexander conquered the Persian empire, Babylon's culture and science had a significant influence on the Greeks.