Dear PSci 21 class, Here, at long last, is the _optional_ article on Greek mythology and constallations I'd been promising. I didn't want to send it out sooner, since I wanted everyone to concentrate on Mid-Term Exam 1. I will also send separate messages containing my science fiction reading and movie list, and an article on math for teachers. Don't worry, this will be the last time I use this list of e-mail addresses. Best, ====================================================================== Dr. F. A. Ringwald ... to further the progress of science, Department of Physics to guide to an understanding California State University, Fresno of the majesty of the heavens, 2345 E. San Ramon Ave., M/S MH37 to emphasize that Fresno, CA 93740-8031 under the great celestial firmament, Phone: 559-278-8426 there is order, interdependence, and unity. Fax: 559-278-7741 -- Adler Planetarium, Chicago ====================================================================== Greek Mythology and Constellations ---------------------------------- Copyright 2000, by F. A. Ringwald Version 1.00, 2000 September 18 WARNING: Greek and Roman myths are _not_ politically correct. If this offends you, do not read this file, and delete it at once. You may wish to read it anyway: if we are to learn from history, it must be honest. Mythology is not history, of course, but it shows us the values of the real, historical people who made up the stories. Athena, the war goddess, is much more powerful than her brother Ares (or Mars), the war god, because Athena was also the goddess of wisdom: the Greeks admired cleverness in battle more than brute strength. On the other hand, from their stories, you can tell something else about the ancient Greeks: they were not as kind to their women as we like to think we are. What will people 23 centuries from now think of us, you might wonder? For why the planets, satellites, and features on them are given the names they have, see the Gazeteer of Planetary Nomenclature, by the International Astronomical Union, at: http://wwwflag.wr.usgs.gov/USGSFlag/Space/nomen/nomen.html The Pantheon ------------ In Greek and Roman mythology, 12 gods and goddesses reigned supereme from Mount Olympus, with minor gods in every river, and sprites in every tree. Zeus, the thunder god, was the supreme god. When the Romans took over Greece, they fell in love with its culture, and so incorporated most Greek gods into their religion. Zeus therefore became the Roman god Jupiter. The other Olympians were: Hera (Roman Juno), wife of Zeus, goddess of marriage and the home. Poseidon (Roman Neptune), brother of Zeus, god of the sea. Athena (Roman Minerva), daughter of Zeus, goddess of war. She was also the goddess of wisdom, and was therefore much more powerful than her half-brother Ares. Ares (Roman Mars), son of Zeus, god of war. Apollo, son of Zeus, god of light and music, in some traditions also identified as the Sun god. Artemis (Roman Diana), daughter of Zeus, goddess of hunting. Hermes (Roman Mercury), son of Zeus, messenger of the gods. Aphrodite (Roman Venus), who rose mysteriously from the sea, goddess of love and beauty. Hephaistos (Roman Vulcan), son of Zeus and Hera, god of the forge. Demeter (Roman Ceres), sister of Zeus, goddess of the harvest. Dionysus (Roman Bacchus), son of Zeus, god of wine. Attending the fire was another major goddess: Hestia (Roman Vesta), sister of Zeus, goddess of the hearth, who gave her throne to Dionysus. Another major god who rarely spent time in Olympus, preferring his own realm, was: Hades (Roman Pluto), brother of Zeus, god of the dead. These live on as the days of the week, in Spanish and French: Sunday = domingo = dimanche (from dominus, Latin for "lord"); Monday = lunes = lundi (from luna, Latin for "moon"); Tuesday = martes = mardi (the day of Mars); Wednesday = mie'rcoles = mercredi (the day of Mercury); Thursday = jueves = jeudi (the day of Jupiter); Friday = viernes = vendredi (the day of Venus); Saturday = sa'bado = samedi (the day of Saturn). English uses the corresponding northern European deities: Sunday = the Sun's day; Monday = the Moon's day; Tuesday = day of Tyr, the war god, the Norse counterpart of Mars; Wednesday = day of Woden, another war god, (loose) counterpart to Mercury; Thursday = day of Thor, the thunder god, counterpart to Jupiter; Friday = day of Freya, the love goddess, counterpart to Venus; Saturday = Saturn's day. The week got 7 days in the first place because the ancient Babylonians, long before the Greeks, Romans, or Norse, realized they could see 5 planets (Mercury, Venus, Mars, Jupiter, and Saturn), and two other objects (the Sun and the Moon) moving through the sky, and therefore took the number 7 to be special. During the French Revolution, along with adopting the metric system, a new calendar with a 10-day week was proposed; it never caught on, because weekends came less often! The Constellations ------------------ In 1930, the International Astronomical Union divided the entire sky into 88 constellations. Many in the Southern Hemisphere were named by Europeans in the 1600s, and reflect scientific interests of the time. These include Telescopium the telescope, Microscopium the microscope, Fornax the furnace, Sextans the sextant, Octans the octant (a navigational instrument made obsolete by the sextant), Pyxis the compass, and Antlia the air pump. That's right, Antlia the air pump: at the time, the air pump was a major scientific instrument, since one could make a vacuum with one---and this directly contradicted the ancient Greek philosopher Aristotle, who taught that "Nature abhors a vacuum." Many constellations in the Northern Hemisphere were named in ancient times, and have names from Greek and Roman mythology. That the IAU adopted Greek and Roman constellations in no way means that the Greeks and the Romans were the only people to make up constellations. Nearly all cultures do, since the patterns make the stars easier to identify, and therefore useful for navigation, and for timekeeping, essential for agriculture. For example, Ursa Major is the Greek constellation the Great Bear. In America, part of it is known a the Big Dipper. In England, this part is known at the Plough, or Charles's Wain, the wagon of King Charles. In China, it is the carriage. It is therefore pointless to argue about constellations: for all of them, someone has "another story." Even the "official" Greek ones, adopted by the IAU, are based mostly on Greek myths, which were told around campfires for centuries before they were written down. There are therefore always alternative ways that many stories come out: in the same way the children's game "telephone" can change stories, when repeated person to person, myths and legends will change, being based on oral tradition. In addition to constellation patterns on the sky, there are asterisms. Asterisms aren't official constellations: they're simple geometric patterns, usually only of the brightest stars, that serve as useful guides to finding the constellations. A famous asterism visible in summer in the Northern Hemisphere is the Summer Triangle. In fall one can see the Great Square of Pegasus. In winter one can see "the heavenly G", a large G-shaped group of constellations around Orion. The two stars at the end of the bowl of the Big Dipper can be used to find Polaris, the North Star. Polaris is special only because by coincidence, it is close to the North Celestial Pole. It therefore always appears due north of any observer who can see it above the horizon, in the Northern Hemisphere. It is by no means the brightest star in the sky: this really is a myth. Unfortunately, there is no "South Star," or bright star correspondingly close to the South Celestial Pole. Orion, the hunter, is a striking constellation, with many bright stars. Particularly striking are three bright stars in a row, the belt of Orion. Opposite the sky is Scorpius the Scorpion, who stung Orion to death. Next to Scorpius is Ophiuchus, the snake bearer---or the doctor, since Asclepius, the greatest of physicians in Greek mythology, learned all his art and all the secrets of the Earth from snakes, because he gave their mother a proper funeral, which the Greeks considered important. Gemini, the twins, is another winter constellation, next to Orion. In it are two first-magnitude stars, Castor and Pollux. In Greek mythology, Castor and Pollux were twin brothers, of Zeus and Leda, a mortal. Pollux was immortal, but Castor was not. The brothers loved each other so, that Pollux gave Castor half of his immortality---meaning that, when they died, they became the constellation. To the south and west of Orion are his two hunting dogs, the constellations Canis Major and Canis Minor. Canis Major has Sirius, the brightest star in the night sky. Canus Minor has first-magnitude Procyon. To the north of Orion is the constellation Auriga, the charioteer, with the first magnitude star, Capella. To the northeast of Orion, south of Auriga, is the constellation Taurus, the bull. Orion is shown fighting him, with his great club raised. His shield is an arc of faint stars, warding off the bull's attack. Centaurus is too far south to be easily visible from mid-northern latitudes. This is too bad, because it is a large and spectacular constellation, rivaling Orion in splendor and in number and diversity of astrophysically interesting objects. Its has two first-magnitude stars, Alpha Centauri and Beta Centauri; nowhere else in the sky are two stars this bright so close to each other. In Greek mythology, the Centaurs were wild, uncouth, destructive creatures---except for Chiron, who was kind and wise, and who educated young heroes before they would go out and do their famous deeds. A prominent spring constellation is Ursa Major, the great bear. In America, part of it is often referred to at the Big Dipper, with seven bright, second-magnitude stars tracing the shape of a dipper. In Greek mythology, the bear was Callisto, a lover of Zeus. Hera, his wife, became so angry, she turn Callisto into a bear, and then picked her up by the tail and hung her in the sky, which is why she has such a long tail (most bears don't). Hera put Callisto just in front of Canes Venatici, the hunting dogs, which chase her around the Pole Star, Polaris, forever. Ursa Minor, the little bear, is the constellation Polaris is in: it is Callisto's child. Polaris is at the tip of the tail of Ursa Minor; one degree south of the tip of the tail of Ursa Major is the famous Whirlpool Galaxy, also called M51. The Greeks weren't the only people to have associated this constellation with a bear, either: this is found clear across Asia and among the Native Americans. If these stories do have a common origin, the bear dates at least as far back as the last Ice Age, 10-12 thousand years ago, predating even the earliest agriculture or civilization. The two stars at the end of the bowl of the dipper point to Polaris. One can use the dipper to point to other constellations, too: the other two stars in the bowl point down to Regulus, the first magnitude star in Leo the lion. The handle of the Big Dipper points to Arcturus, a first-magnitude star in the constellation Bootes, the herdsman. If one continues following this arc, one comes to another first-magnitude star, Spica, in the constellation Virgo, the maiden. One can remember this by "follow the arc to Arcturus, and speed on to Spica." To the Greeks, Virgo was Persephone, goddess of fertility; when she arrived in the sky in Spring the Earth bloomed, and when she left the sky in Fall, it withered. In the Summer sky is the Summer Triangle. The triangle is an asterism composed of three first-magnitude stars, Vega, Deneb, and Altair. Vega is in the constellation Lyra, the Lyre. It is a distinctive little constellation, with five third- to fourth-magnitude stars within 10 degrees, mostly south of Vega. Lyra the Lyre is the instrument of Orpheus, the greatest of musicians, who could make rocks weep with his playing. Deneb is in the constellation Cyngus the Swan. Cygnus is Zeus, who appeared to Leda in the form of a swan. Altair is in the constellation Aquila, the Eagle, which depicts another manifestation of Zeus. Delphinus, the dolphin, is a distinctive little constellation, between Cygnus and Aquila. In the myth of Bacchus, the god of wine, Bacchus fell asleep on the beach, and was kidnapped by pirate sailors, who thought someone so well-dressed must be a prince. Bacchus woke up and told them who he was. The sailors didn't believe him. Bacchus then revealed himself in all his glory: he grew to such a large size, he filled the ship, with vines entwining the sails. The sailors panicked and jumped into the sea. Bacchus felt sorry for them, and turned them into dolphins. The ancient Greeks thought this explained why dolphins are so intelligent. (There is a similar story involving Julius Caesar, the Roman emperor---not a myth, but a real, historical person. The Romans were a less romantic but more practical people than the Greeks, much like Americans are to the English, and this story shows the difference. Again, pirates kidnapped Caesar, and took him to sea. Again, Caesar told them who he was, and they laughed at him. Caesar didn't turn them into dolphins, though: he had them crucified.) Hercules is in the spring sky, just west of the Summer Triangle. Hydra, a monster he slew, straddles the equator, and stretches over 100 degrees across the sky. Slaying the hydra was the second of his twelve labors. The first of these labors was when he slew the Nemean Lion, a lion with a hide so thick, weapons couldn't pierce it. After strangling it with his enormous strength, he skinned it with his own claws, and wore the skin as armor. This is why paintings of Hercules often show him wearing a lion skin. The constellation Hercules is also next to the constellation Leo, the lion. Hercules is just south of the northern constellation Draco, the dragon. There were many dragons in Greek mythology, but this one is probably Ladon, the dragon Hercules slew while carrying out the eleventh of his twelve labors. Ladon guarded the tree bearing golden apples, at the end of the world. Hercules had to ask Atlas, the Titan who held up the sky, to pick them for him, or else he would die. Hercules, with his great strength, was able to hold up the sky, and Atlas, freed of his burden, almost left him there: only because Hercules tricked him into holding up the sky again, "so I can make a pad of the lion skin on my shoulders," did Hercules manage to get away. Constellations in the fall sky include Pegasus, Perseus, Andromeda, Cetus, Casseiopeia, and Cepheus. The Great Square of Pegasus is an easily identifiable asterism, again helpful for finding the other constellations. North of the square, along the Milky Way, is Perseus the Swordsman. He has just cut off the head of Medusa, a monster with snakes growing out of her head instead of hair, so ugly that looking at her would turn someone into stone. Perseus carries the head in his hand, at the location of the eclipsing binary star Algol, the Demon's Eye. This star, easily visible to the unaided eye, noticeably changes brightness, because it is an eclipsing binary. Perseus, a mortal son of Zeus, had help from his immortal siblings. He is flying with the winged sandals borrowed from Hermes (or Mercury), the messenger of the gods. He cut off Medusa's head with a sharp knife borrowed from Artemis, goddess of the hunt. He also had the polished shield of Athena, the goddess of wisdom, and was able to look at Medusa without being turned into stone, because he looked at the reflection in the shield. In the constellation, he is shown saving Andromeda, the princess, from being eaten by Cetus, the sea monster (or whale). She was chained to a rock to appease Poseidon, god of the sea, who was angry because her mother, depicted in the constellation Casseiopeia the Queen, had boasted she was more beautiful than his daughters. Her husband, depicted in the constellation Cepheus the King, looks on. Next to Andromeda is the constellation Pegasus, the flying horse, which sprang from the severed head of Medusa, much to the surprise of Perseus. It was later tamed by Bellerophon, who slew the Chimera, a monster with three heads, one of a lion, one of a goat, and one of a snake. The constellation Aries, the ram, is also visible in fall. Aries was a magical, flying ram, with a golden fleece. A band of heroes, including Orpheus and Hercules, and led by Jason, recovered this fleece, after a long voyage across the Black Sea on Argo, the ship. Argo is also a constellation, but it is no longer used; it has been broken up into four constellations: Vela the sail, Carina the keel, Puppis the stern, and Pyxis, the compass. Another southern constellation is Sculptor. This sculptor was Pygmalion, who created a statute of a woman so beautiful, he fell in love with it. A prayer to Aphrodite, the love goddess, was answered: the statue turned into a woman. There are many other myths and legends, about many other constellations. Telling them all could fill a book, and indeed, there are several wonderful books in which you can read more about these stories. D'Aulaires' Book of Greek Myths, by Ingri and Edgar Parin D'Aulaire, is a children's book, but it's still my favorite on mythology, partly because it's so beautifully illustrated. Nearly all the above was reproduced from memory from this book. The rest came from The Metamorphoses, by Ovid, the Roman poet of the 1st century A.D. By writing these myths down, Ovid became the authoritative source on them; his book is still in print, in both Latin and English. Finally, The Stars, by H. A. Rey, is another children's book that adults can read and enjoy. It's my favorite for learning constellations, since the author was brave enough to redraw many constellations, to make them look more like what they're supposed to look like. An extensive source of names of major and minor Greek gods and goddesses, and what major and minor planets they are named after, is The Nine Planets: A Multimedia Tour of the Solar System, by Bill Arnett, at: http://seds.lpl.arizona.edu/billa/tnp/