Friday, April 6, 2012
The Historical Origins of the Constellations
The age of Classical astronomy began with the labours of Eudoxus and others, about four centuries before the Christian Era, but there was an Earlier astronomy whose chief feature was the arrangement of the stars into constellations.
The best known of all such arrangements is that sometimes called the "Greek Sphere," because those constellations have been preserved to us by Greek astronomers and poets. The earliest complete catalogue of the stars, as thus arranged, that has come down to us was compiled by Claudius Ptolemy, the astronomer of Alexandria, and completed 137 a.d.In this catalogue, each star is described by its place in the supposed figure of the constellation, whilst its celestial latitude and longitude are added, so that we can see with considerable exactness how the astronomers of that time imagined the star figures. The earliest complete description of the constellations, apart from the places of the individual stars, is given in the poem of Aratus of Soli—The Phenomena, published about 270 b.c.]
Were these constellations known to the Hebrews of old? We can answer this question without hesitation in the case of St. Paul. For in his sermon to the Athenians on Mars' Hill, he quotes from the opening verses of this constellation poem of Aratus:—
"God that made the world and all things therein, seeing that He is Lord of heaven and earth, dwelleth not in temples made with hands; neither is worshipped with men's hands, as though He needed anything, seeing He giveth to all life, and breath, and all things; and hath made of one blood all nations of men for to dwell on all the face of the earth, and hath determined the times before appointed, and the bounds of their habitation; that they should seek the Lord, if haply they might feel after Him, and find Him, though He be not far from every one of us: for in Him we live, and move, and have our being; as certain also of your own poets have said, For we are also His offspring."
The poem of Aratus begins thus:—
"To God above we dedicate our song;To leave Him unadored, we never dare;For He is present in each busy throng,In every solemn gathering He is there.The sea is His; and His each crowded port;In every place our need of Him we feel;For we His offspring are."
Aratus, like St. Paul himself, was a native of Cilicia, and had been educated at Athens. His poem on the constellations came, in the opinion of the Greeks, next in honour to the poems of Homer, so that St. Paul's quotation from it appealed to his hearers with special force.
The constellations of Ptolemy's catalogue are forty-eight in number. Those of Aratus correspond to them in 1]almost every particular, but one or two minor differences may be marked. According to Ptolemy, the constellations are divided into three sets:—twenty-one northern, twelve in the zodiac, and fifteen southern.
The northern constellations are—to use the names by which they are now familiar to us—1, Ursa Minor, the Little Bear; 2, Ursa Major, the Great Bear; 3, Draco, the Dragon; 4,Cepheus, the King; 5, Boötes, the Herdsman; 6, Corona Borealis, the Northern Crown; 7, Hercules, the Kneeler; 8, Lyra, the Lyre or Swooping Eagle; 9, Cygnus, the Bird; 10,Cassiopeia, the Throned Queen, or the Lady in the Chair; 11, Perseus; 12, Auriga, the Holder of the Reins; 13, Ophiuchus, the Serpent-holder; 14, Serpens, the Serpent; 15,Sagitta, the Arrow; 16, Aquila, the Soaring Eagle; 17, Delphinus, the Dolphin; 18, Equuleus, the Horse's Head; 19, Pegasus, the Winged Horse; 20, Andromeda, the Chained Woman; 21, Triangulum, the Triangle.
The zodiacal constellations are: 1, Aries, the Ram; 2, Taurus, the Bull; 3, Gemini, the Twins; 4, Cancer, the Crab; 5, Leo, the Lion; 6, Virgo, the Virgin; 7, Libra, the Scales,—also called the Claws, that is of the Scorpion; 8, Scorpio, the Scorpion; 9, Sagittarius, the Archer; 10, Capricornus, the Sea-goat, i. e. Goat-fish; 11, Aquarius, the Water-pourer; 12, Pisces, the Fishes.
The southern constellations are: 1, Cetus, the Sea-Monster; 2, Orion, the Giant; 3, Eridanus, the River; 4, Lepus, the Hare; 5, Canis Major, the Great Dog; 6, Canis Minor, the Little Dog; 7, Argo, the Ship and Rock; 8, Hydra, the Water-snake; 9, Crater, the Cup; 10, Corvus, ]the Raven; 11, Centaurus, the Centaur; 12, Lupus, the Beast; 13, Ara, the Altar; 14, Corona Australis, the Southern Crown; 15, Piscis Australis, the Southern Fish.
Aratus, living four hundred years earlier than Ptolemy, differs only from him in that he reckons the cluster of the Pleiades—counted by Ptolemy in Taurus—as a separate constellation, but he has no constellation of Equuleus. The total number of constellations was thus still forty-eight. Aratus further describes the Southern Crown, but gives it no name; and in the constellation of the Little Dog he only mentions one star, Procyon, the Dog's Forerunner. He also mentions that the two Bears were also known as two Wagons or Chariots.
Were these constellations, so familiar to us to-day, known before the time of Aratus, and if so, by whom were they devised, and when and where?
They were certainly known before the time of Aratus, for his poem was confessedly a versification of an account of them written by Eudoxus more than a hundred years previous. At a yet earlier date, Panyasis, uncle to the great historian Herodotus, incidentally discusses the name of one of the constellations, which must therefore have been known to him. Earlier still, Hesiod, in the second book of his Works and Days, refers to several:—
"Orion and the Dog, each other nigh,Together mounted to the midnight sky,When in the rosy morn Arcturus shines,Then pluck the clusters from the parent vines.
Next in the round do not to plough forgetWhen the Seven Virgins and Orion set."
"And now, rejoicing in the prosperous gales,With beating heart Ulysses spreads his sails:Placed at the helm he sate, and marked the skies,Nor closed in sleep his ever-watchful eyes.There view'd the Pleiads and the Northern Team,And great Orion's more refulgent beam,To which around the axle of the skyThe Bear, revolving, points his golden eye."
Thus it is clear that several of the constellations were perfectly familiar to the Greeks a thousand years before the Christian era; that is to say, about the time of Solomon.
We have other evidence that the constellations were known in early times. We often find on Greek coins, a bull, a ram, or a lion represented; these may well be references to some of the signs of the zodiac, but offer no conclusive evidence. But several of the constellation figures are very unusual in form; thus the Sea-goat has the head and fore-legs of a goat, but the hinder part of a fish; and the Archer has the head and shoulders of a man, but the body and legs of a horse. Pegasus, the horse with wings, not only shows this unnatural combination, but the constellation figure only gives part of the animal—the head, neck, wings, breast, and fore-legs. Now some of these characteristic figures are found on quite early Greek coins, and yet earlier on what are known as "boundary stones" from Babylonia. These are little square pillars, covered with inscriptions and sculptures, and record for the most part the gift, transfer, or sale of ]land. They are dated according to the year of the reigning king, so that a clear idea can be formed as to their age. A great many symbols, which appear to be astronomical, occur upon them; amongst these such very distinguishing shapes as the Archer, Sea-goat, and Scorpion (). So that, just as we know from Homer and Hesiod that the principal constellations were known of old by the same names as those by which we know them to-day, we learn from Babylonian boundary stones that they were then known as having the same forms as we now ascribe to them. The date of the earliest boundary stones of the kind in our possession would show that the Babylonians knew of our constellations as far back as the twelfth century b.c., that is to say, whilst Israel was under the Judges.
We have direct evidence thus far back as to the existence of the constellations. But they are older than this, so much older that tradition as well as direct historical evidence fails us. The only earlier evidence open to us is that of the constellations themselves.
A modern celestial globe is covered over with figures from pole to pole, but the majority of these are of quite recent origin and belong to the Modern period of astronomy. They have been framed since the invention of the telescope, and since the progress of geographical discovery brought men to know the southern skies. If these modern constellations are cleared off, and only those of Aratus and Ptolemy suffered to remain, it becomes at once evident that the ancient astronomers were not acquainted with the entire heavens. For there is a large space in the south, ]left free from all the old constellations, and no explanation, why it should have been so left free, is so simple and satisfactory as the obvious one, that the ancient astronomers did not map out the stars in that region because they never saw them; those stars never rose above their horizon.
Thus at the present time the heavens for an observer in England are naturally divided into three parts, as shown in the accompanying diagram. In the north, round the ]pole-star are a number of constellations that never set; they wheel unceasingly around the pole. On every fine night we can see the Great Bear, the Little Bear, the Dragon, Cepheus and Cassiopeia. But the stars in the larger portion of the sky have their risings and settings, and the seasons in which they are visible or are withdrawn from sight. Thus we see Orion and the Pleiades and Sirius in the winter, not in the summer, but the Scorpion and Sagittarius in the summer. Similarly there is a third portion of the heavens which never comes within our range. We never see the Southern Cross, and hardly any ]star in the great constellation of the Ship, though these are very familiar to New Zealanders.
The outline of this unmapped region must therefore correspond roughly to the horizon of the place where the constellations were originally designed, or at least be roughly parallel to it, since we may well suppose that stars which only rose two or three degrees above that horizon might have been neglected.
From this we learn that the constellations were designed by people living not very far from the 40th parallel of north latitude, not further south than the 37th or 36th. This is important, as it shows that they did not originate in ancient Egypt or India, nor even in the city of Babylon, which is in latitude 32-1/2°.
But this vacant space reveals another fact of even more importance. It gives us a hint as to the date when the constellations were designed.
An observer in north latitude 40° at the present time would be very far from seeing all the stars included in the forty-eight constellations. He would see nothing at all of the constellation of the Altar, and a good deal of that of the Centaur would be hidden from him.
On the other hand, there are some bright constellations, such as the Phoenix and the Crane, unknown to the ]ancients, which would come within his range of vision. This is due to what is known as "precession;" a slow movement of the axis upon which the earth rotates. In consequence of this, the pole of the heavens seems to trace out a circle amongst the stars which it takes 25,800 years to complete. It is therefore a matter of very simple calculation to find the position of the south pole of the heavens at any given date, past or future, and we find that the centre of the unmapped space was the south pole of the heavens something like 4,600 years ago, that is to say about 2,700 b.c.
It is, of course, not possible to fix either time or latitude very closely, since the limits of the unmapped space are a a little vague. But it is significant that if we take a celestial globe, arranged so as to represent the heavens for the time 2,700 b.c., and for north latitude 40°, we find several striking relations. First of all, the Great Dragon then linked together the north pole of the celestial equator, and the north pole of the ecliptic; it was as nearly as possible symmetrical with regard to the two; it occupied the very crown of the heavens. With the single exception of the Little Bear, which it nearly surrounds, the Dragon was the only constellation that never set. Next, the Water-snake (see diagram, p. lay at this time right along the equator, extending over 105° of Right Ascension; or, to put it less technically, it took seven hours out of the twenty-four to cross the meridian. It covered nearly one-third of the equatorial belt. Thirdly, the intersection of the equator with one of the principal meridians of the sky was marked by the Serpent, which is carried by the ]Serpent-holder in a very peculiar manner. The meridian at midnight at the time of the spring equinox is called a "colure,"—the "autumnal colure," because the sun crosses it in autumn. Now the Serpent was so arranged as to be shown writhing itself for some distance along the equator, and then struggling upwards, along the autumnal colure, marking the zenith with its head. The lower part of the autumnal colure was marked by the Scorpion, and the foot of the Serpent-holder pressed down the creature's head, just where the colure, the equator, and the ecliptic intersected (see diagram, p..
It is scarcely conceivable that this fourfold arrangement, not suggested by any natural grouping of the stars, should have come about by accident; it must have been intentional. For some reason, the equator, the colure, the zenith and the poles were all marked out by these serpentine or draconic forms. The unmapped space gives us a clue only to the date and latitude of the designing of the most southerly constellations. We now see that a number of the northern hold positions which were specially significant under the same conditions, indicating that they were designed at about the same date. There is therefore little room for doubt that some time in the earlier half of the third millennium before our era, and somewhere between the 36th and 40th parallels of north latitude, the constellations were designed, substantially as we have them now, the serpent forms being intentionally placed in these positions of great astronomical importance.
It will have been noticed that Ptolemy makes the Ram the first constellation of the zodiac. It was so in his days, but it was the Bull that was the original leader, as we know from a variety of traditions; the sun at the spring equinox being in the centre of that constellation about 3000 b.c. At the time when the constellations were designed, the sun at the spring equinox was near Aldebaran, the brightest star of the Bull; at the summer solstice it was near Regulus, the brightest star of the Lion; at the autumnal equinox it was near Antares, the brightest star of the Scorpion; at the winter solstice it was near Fomalhaut, the brightest star in the neighbourhood of the Waterpourer. These four stars have come down to us with the name of the "Royal Stars," probably because they were so near to the four most important points in the apparent path of the sun amongst the stars. There is also a celebrated passage in the first of Virgil's Georgics which speaks of the white bull with golden horns that opens the year. So when the Mithraic religion adopted several of the constellation figures amongst its symbols, the Bull as standing for the spring equinox, the Lion for the summer solstice, were the two to which most prominence was given, and they are found thus used in Mithraic monuments as late as the second or third century a.d., long after the Ram had been recognized as the leading sign.
It is not possible to push back the origin of the constellations to an indefinite antiquity. They cannot at the very outside be more than 5000 years old; they must be considerably more than 4000. But during the whole of this millennium the sun at the spring equinox was in the constellation of the Bull. There is therefore no possible ]doubt that the Bull—and not the Twins nor the Ram—was the original leader of the zodiac.
The constellations, therefore, were designed long before the nation of Israel had its origin, indeed before Abraham left Ur of the Chaldees. The most probable date—2700 b.c.—would take us to a point a little before the Flood, if we accept the Hebrew chronology, a few centuries after the Flood, if we accept the Septuagint chronology. Just as the next great age of astronomical activity, which I have termed the Classical, began after the close of the canon of the Old Testament scriptures, so the constellation age began before the first books of those scriptures were compiled. Broadly speaking, it may be said that the knowledge of the constellation figures was the chief asset of astronomy in the centuries when the Old Testament was being written.
Seeing that the knowledge of these figures was preserved in Mesopotamia, the country from which Abraham came out, and that they were in existence long before his day, it is not unreasonable to suppose that both he and his descendants were acquainted with them, and that when he and they looked upward to the glories of the silent stars, and recalled the promise, "So shall thy seed be," they pictured round those glittering points of light much the same forms that we connect with them to-day.