As we start to examine the astronomy of Ancient Greece we hear of the myth cycles of Theseus and Perseus, episodes from both of which appear in the night sky. These myth cycles help us to understand the conception the ancient Greeks had to the civilizations that came before them, the Minoans and the Mycenaeans and prepare us for the early cosmology of ancient Greece.

Transcript

Good evening and welcome to the Song of Urania, a podcast about the history of astronomy from antiquity to the present with new episodes every full moon. My name is Joe Antognini. Well in the last five episodes our focus has been on the astronomy of the Babylonians and we’ve followed its development from the earliest inscriptions we have around 2000 BC up until its pinnacle in the last few centuries BC when it was under the rule of the Persians and the Macedonians. There is still quite a bit that I’ve had to leave out about the Babylonians in the interest of time, and here and there I’ll briefly make mention of other aspects of their astronomy that I left out because, by virtue of having the most sophisticated astronomy of the ancient world, they had a strong influence on the astronomy of nearby cultures, particularly the Greeks. But if this series ever has a hope of getting to the present day as the tagline promises, we need to move along.

So, now our attention turns to the civilization that built upon the astronomy of the Babylonians and ultimately developed a cosmological model which would hold sway in the West for some fifteen centuries — the Greeks.

Now, in order to understand the development and unique characteristics of Greek astronomy we are going to have to back up in time a little bit. When we finished with the Babylonians we had made it to the last few centuries BC. After the death of Alexander the Great, Babylon was squabbled over by Alexander’s generals in what have come to be called the Wars of the Diadochi, diadochi roughly meaning successor. These wars were hard on the citizens of Babylon and many of them left the city. Finally, in 275, one of the diadochi named Seleucus forced the residents of Babylon to move to his newly constructed capital city some 40 miles north, which he modestly named Seleucia. But a remnant of priests remained at the Babylonian temple because astronomical records continue for some time, with the last record we have dating to around 100 AD.

We will one day return to these events from the Greek perspective, but by 300 BC quite a lot has already happened over in Greece, so now we need to back up quite a few centuries.

Now you may recall from Episode 4 that one of the defining events in the history of the ancient world was the Late Bronze Age Collapse during the 12th century BC. All across the region, from the eastern Mediterranean to North Africa, to the Levant and Near East, civilizations suddenly collapsed over the course of just a few decades. The Kassite Empire in Babylonia collapsed, along with the Hittite Empire in Anatolia, or modern day Turkey, and the Amorite states in the Levant. The kingdom of Egypt survived the collapse, but was drastically weakened, both in terms of territory controlled and overall economic power. And the late bronze age collapse did not spare the region we are now going to turn our attention to, where modern day Greece resides. During the Bronze Age, this part of the world hosted two notable civilizations, the Minoans and the Mycenaeans.

The Minoans were the older of the two and built a vibrant kingdom that emerged very early on the island of Crete around 3000 BC and developed for some 15 centuries before beginning a gradual decline around the 16th century BC and then suddenly disappearing during the Late Bronze Age Collapse around 1100 BC. Later in the series we may talk about the astronomy of the Minoans, but for now the relevance of the Minoans to our story of the Greeks is that they built their civilization on land that the Greeks later occupied and this civilization persisted in the cultural memories of the Greeks through their mythical founder, King Minos.

According to the myth, King Minos had a son named Androgeus who regularly competed in the Olympic Games every four years. Androgeus was a skilled athlete and excelled in the games. At the time, Aegeus was the king of Athens and had a brother named Pallas, who was apparently an extraordinarily prodigious man and had fifty sons, collectively called the Pallantides.

Now, as we’ll see throughout our discussion of ancient Greece, there is no canonical form of the Greek myths in the same way that there is, for example, a canonical telling of the stories of the Hebrew Bible. In the Greek myths details or even major plot points can vary widely between different authors. In one telling of the story, the Pallantides became jealous of Androgeus’s athletic prowess and assassinated him. In another version of the story, they became good friends with Androgeus, which made King Aegeus nervous. King Aegeus feared that Pallas might use his sons’ friendship with Androgeus to conspire with King Minos to assassinate him and usurp the throne, and so King Aegeus preemptively killed Androgeus.

Whatever the details, Androgeus winds up murdered in Athens and King Minos is understandably upset. He sends the entire Cretan fleet to Athens to demand satisfaction from King Aegeus. King Aegeus either does not know who the assassin was or, perhaps, was himself responsible for the murder and so he puts the entire city of Athens at the mercy of King Minos. King Minos then exacts a terrible tribute from Athens. Every seven years the city would have to send the seven most courageous young men and the seven most beautiful maidens in the city to Knossos, the capital city of Crete, where they would be thrown into a terrifying structure called the labyrinth.

Now, apologies if this story is about as winding as the labyrinth itself, but Greek myths are a fairly intricately constructed web which makes it hard to tell one story in isolation of all the others. At any rate, Minos and his two brothers, Sarpedon and Rhadamanthus, were all demi-gods, sons of the god Zeus and the mortal Phoenician princess Europa. And many years prior, before Minos had ascended the throne, he and his two brothers had been adopted as stepchildren of King Astorion, the second king of Crete, whose father had been the first king to sail to the island. After the death of King Astorion, the three brothers fought amongst themselves for the right to rule the island. Minos was victorious and banished his brothers. Sarpedon fled to Asia Minor in a region called Lycia where he founded a city called Miletus, which as we will see, later became an important city for astronomy. Incidentally, in some tellings, Miletus was a fair boy whom Minos and Sarpedon both fell in love with and was the origin of the quarrel between the two brothers after Miletus chose Sarpedon over Minos. The other brother, Rhadamanthus, ended up in Boeotia in central Greece, but also apparently was associated with the other islands of the Aegean.

All this is to say that King Minos had won the throne, but did not feel especially secure in his right to rule. So he prayed to Poseidon, the god of the sea, to send him a sign. And Poseidon answered his prayers and sent him a snow white bull, known today as the Cretan Bull. Now, something to know about relations between gods and mortals was that they were heavily dependent on sacrifice. When Poseidon sent King Minos the snow white bull, he expected King Minos to sacrifice the bull to him as a gesture of gratitude for the divine favor. But the bull was so beautiful that King Minos was loathe to give it up so he sacrificed an ordinary bull instead. This ingratitude enraged Poseidon, who then enlisted Aphrodite, the goddess of love, to cause King Minos’s wife, Queen Pasiphaë, to fall madly in love with the bull. In order to consummate her love, she ordered Daedalus, the finest craftsman in the land, to construct a hollow wooden cow that she could occupy. Daedalus then covered the wooden cow in a real cow hide so as to attract the Cretan bull. Queen Pasiphaë then, shall we say, came to know the bull in the Biblical sense, and gave birth to a half-man, half-bull creature which she named Astorion II, after its grandfather, but it became more commonly known as the Minotaur.

King Minos was, naturally, horrified by this development and so he ordered Daedalus to construct an intricate prison called the Labyrinth in which the passageways twisted and turned, opening one upon the other, so that even the wiliest of prisoners could not find an exit. The maze was so subtle that after constructing it, Daedalus himself was hardly able to escape his own creation. King Minos then imprisoned the Minotaur in the center of the Labyrinth where it would find and devour any unfortunate prisoners who were thrown in the Labyrinth with it.

Now, if I can briefly pause in the mythical narrative and turn back to the actual Minoans, the most impressive cultural artifacts that they produced were five extraordinary palaces across the island of Crete. By far the largest of these palaces is in the capital city of Knossos and was discovered by the archaeologist Arthur Evans in the year 1900. This palace is an enormous complex containing more than 1000 rooms, all connecting to one other in a complicated layout. Minoan artists also covered many of the walls in beautiful frescoes, a substantial fraction of which depict bulls, which apparently had special religious significance for the Minoans. On this basis Arthur Evans speculated that the palace of Knossos may have been the source of the ancient Greek myth of the labyrinth. Of course, in archaeology, as in astronomy, it is often difficult to find conclusive evidence and so there are other candidates for the historical source of the Labyrinth. In particular, there is a complex of caves near the city of Gortyn in the southern part of Crete which were expanded by humans. Or it is entirely possible that the mythical Labyrinth had no historical counterpart at all and was invented out of whole cloth by the ancient Greeks. One other note here, while we’re talking about the actual Minoans, is that the Kingdom of Minoa was not the name they had for themselves. The name Minoa was actually bestowed on them by Arthur Evans himself who speculated on the connection between the ancient civilization and the Greek myth of King Minos.

Well, to return to the mythic narrative, recall that many years later, after the death of his son Androgeus, King Minos had extracted a tribute of seven young men and seven young women from Athens. Every seven years Athens sent their most courageous young men and their fairest maidens to Crete where King Minos threw them into the Labyrinth to be devoured by the Minotaur.

And so things had proceeded for many years and during all this time, King Aegeus, the king of Athens, had had no children. Naturally he wanted an heir, so he did what all great Greek heroes did when they came at a crossroads in life — he went to visit the Oracle of Delphi. Then the Oracle of Delphi did what she did best — she provided a cryptic reply that invariably the hearer would not understand until it was too late and had come to pass. In this case, the Oracle told King Aegeus, “Loosen not the bulging neck of the wineskin great chief of the people, until you have reached the height of Athens, lest you die of grief.”

King Aegeus could not understand the meaning of the prophecy and on his journey home stopped at the palace of King Pittheus in Troezen who was renowned for his erudition and wisdom. During dinner, King Aegeus recounted the prophecy to King Pittheus who immediately understood its meaning. But King Pittheus did not tell King Aegeus. Instead, over the course of the dinner, Pittheus plied Aegeus with unmixed wine.

As a slight digression here, in ancient Greece wine was consumed copiously, but the Greeks almost exclusively diluted their wine with water, or sometimes snow for cold drinks. Drinking wine at full strength as we do today was seen has barbaric and potentially deadly. The Greek chronicler Pausanius tells in the second century AD in his book Description of Greece, that the Gallic chieftain Brennus had committed suicide by drinking undiluted wine. And Herodotus writes that the Spartan king Cleomenes I had adopted the practice of drinking wine undiluted from the barbaric Scythians and was subsequently driven insane. So when we see that Pittheus plied Aegeus with unmixed wine we are meant to understand that Aegeus was made well, truly, and hopelessly sloshed.

King Pittheus then made his daughter Aethra sleep with the drunken King Aegeus. Later that night, as she was sleeping Athena, the goddess of wisdom, came to Aethra in a dream and instructed Aethra to waken, and quickly go to the neighboring island of Sphaeria. (Incidentally, this detail comes to us from the same Pausanius who warned us about the deadly effects of drinking unmixed wine in his Description of Greece.) In Sphaeria she was to pour out a libation to summon Poseidon and lay with him as well. The resulting child, named Theseus, was thus the son of both Poseidon and Aegeus and, like the hero Herecles, was demigod — half human and half divine.

After King Aegeus woke up the next day, undoubtedly with a terrific hangover, he learned what he had done and it was not long before he discovered that Aethra was pregnant. King Aegeus needed to return to his kingdom, so he removed his sandals and sword and placed an enormous boulder on top of them. He then told Aethra that his son would be ready to come to his kingdom when he could remove the boulder and retrieve the items.

Well sixteen years passed and Theseus grew in strength until one day he was able to move the rock and claim his father’s sandals and sword. Theseus then set out to meet his father in the kingdom of Athens. Theseus had the option of traveling to Athens by boat or over land, and being a young, scrappy hero in search of adventure and glory, he decides that the passage by land will be the more dangerous of the two journeys and opts for that. And indeed, in his travels along the bandit-infested roads he encounters six monsters, known as the Six Labors of Theseus. The first and last were the most well known. Theseus’s first labor was his encounter with the giant Periphetes, who wielded and enormous iron club. After Theseus defeats Periphetes he takes the club for himself and is often depicted holding it in art.

In his sixth and final labor he encounters Procrustes who had a home in which he would invite weary travelers to rest. When he put them in his bed he would ensure that they fit exactly. If they were too tall, he would amputate the excess length from their body, and if they were too short he would stretch them out until they were precisely long enough. When Theseus passed by, Procrustes made the fatal mistake of attempting to play the same trick on the hero. Theseus then turned the trick around on Procrustes and chopped off his legs and head so that he would fit his own bed. The myth of Procrustes gives us today the term Procrustean or a Procrustean bed, which is an arbitrary standard which must be adhered to no matter how absurd the consequences.

Well after his six labors Theseus arrived at long last in Athens. Now, the ancient world was in general what we might today call a low trust environment. If an armed stranger arrived in town it was oftentimes wise to be somewhat wary. And likewise for the stranger, when arriving in an unknown town it was best to be somewhat on guard. So Theseus kept his identity secret for a time when he arrived.

In the meantime King Aegeus had married a woman named Medea. Well, woman is perhaps not quite right because her grandfather was Helios, the Sun god. So she was partially divine. Medea plays an important role in the story of the Golden Fleece with Jason and the Argonauts. This is quite a detailed story which would take us too far astray, but during the quest for the Golden Fleece, Medea had done some very bad things, including murdering her brother, chopping him up into pieces, and scattering his body parts across an island so as to prevent her father from capturing Jason. But after the adventures of the Golden Fleece, Medea and Jason had settled down in Corinth and gotten married and she bore him anywhere between one and fourteen children depending on the version. But after 10 years of marriage Jason abandoned Medea and his children to marry the princess Creusa, daughter of King Creon. Shakespeare writes that hell hath no fury like a woman scorned, and Medea is certainly not the sort of woman you want to scorn. As the myth is told in Euripedes’s tragedy Medea, Medea then sends Creusa a dress covered in poison which kills her, and then her father, King Creon, when he tries to save her. Medea then murdered her children and fled Corinth on a flying chariot given to her by her grandfather Helios.

Medea went through some adventures on her flight from Corinth, but ultimately she ended up in Athens where she met and married King Aegeus. So this is our hero Theseus’s stepmother. Upon Theseus’s arrival into Athens Medea immediately recognizes him as Aegeus’s son. Well Medea had also borne King Aegeus a son named Medes and she wanted Medes to inherit the Athenian throne. Medea convinced King Aegeus that the stranger Theseus was a threat and should be disposed of. And as always, Medea had a plan for how to do this.

If you recall the snow-white bull that Poseidon had given King Minos as a sign that he was the rightful ruler of Crete, with which his wife Pasiphaë had fallen in love with and ended up with the birth of the Minotaur and the construction of the Labyrinth, well this same bull had gone on a rampage across Crete, destroying whatever it came across. One of the 12 labors of the hero Heracles, who has quite an involved story of his own, was to capture the Cretan Bull, which Heracles duly did and then transported out of Crete and onto mainland Greece. From there the bull wandered into the town of Marathon and became known locally as the Marathonian bull. The bull was wreaking havoc at this point and so Medea proposed to King Aegeus that Theseus be sent on what she believed to be a suicide mission to capture the bull. Well, Theseus happily accepts the challenge, has more adventures along the way, but ultimately kills the bull and drags it all the way back to Athens where King Aegeus cooks the bull and holds a ceremonial banquet.

Medea was probably frustrated by Theseus’s success, but she decided to do what she knew best — poison him. If you want something done right, sometimes you just have to do it yourself. At the banquet she handed Theseus a poisoned cup, but as Theseus reached out to grab it, King Aegeus spied the sword he had left under the rock in Troezen and realized that the stranger was his own son. He jumped up and knocked the cup out of Theseus’s hand and embraced him. Medea was then forced to flee yet again and has further adventures in which, as you might expect, she murders more of her own family members.

So we now have the young hero Theseus in Athens, where, if you recall to the beginning of this story, the city is forced to pay the tribute to King Minos of seven young men and seven young women every seven years. When King Minos demands his tribute next, Theseus volunteers to go and kill the Minotaur. Well King Aegeus isn’t very thrilled about this plan, but in the end, this is a mythical story after all and he can’t keep the hero from embarking on his adventures. Theseus and the other 13 victims sail off for Crete in a ship with black sails. Before leaving, Theseus agrees with his father that when he returns he will fly white sails on the ship if all has gone well, but if he should die, the crew will fly black sails instead.

Naturally, as sacrificial victims, Theseus and the thirteen others could not bring any weapons with them on the journey. But on their arrival they had the honor of being greeted by King Minos and Theseus told him that he was a son of Poseidon. To test Theseus’s boast, King Minos took off a golden ring, tossed it into the ocean, and asked Theseus to retrieve it. Theseus dove in and a short while later return with not only the ring but also a crown that Amphitrite, the wife of Poseidon and queen of the sea had given to him while he was underwater. Theseus then presented the crown to King Minos’s daughter Ariadne who was present and watching the spectacle. Ariadne immediately fell in love with Theseus.

Secretly, before Theseus and his compatriots were thrust into the Labyrinth, she slipped to him a small sword and a ball of thread that he could use to retrace his steps through the Labyrinth. That was all the help Theseus needed and with his sword and the thread of Ariadne, he slew the Minotaur and was able to escape triumphant. Then he and Ariadne escaped Crete to elope, along with Ariadne’s sister and the 13 other Athenian victims. On the way back to Athens they stopped on the island of Naxos to rest. But there, Theseus abandons his new lover while she is still sleeping and sails away from Naxos without her. Different versions of the story give Theseus different motivations for abandoning Ariadne. Some of them say that he could not trust her because she betrayed her father and others say that he learned that she was already married to Dionysus, the god of wine. Since Theseus was as mythic hero of Athens, Athenian versions of the story say that he was visited by Athena in his sleep, who told him that he had to leave her as she was destined to be the wife of Dionysus. Whatever the reason, after she is abandoned she is inconsolate until Dionysus arrives whereupon she falls in love with him and marries him. In celebration of their marriage Dionysus takes her crown and puts in the heavens where it became the constellation Corona Borealis, or the northern crown. In other versions of the story the crown was originally Dionysus’s and was either given to Ariadne drunkenly before she met Theseus, or given to her as a wedding gift after he marries her. At any rate, there you have the somewhat tenuous connection of this long tale to astronomy. But we have come so far that I would be remiss if I did not spend a little longer concluding the tale.

Upon his triumphant return, Theseus, either so happy to be back, or upset that he had to abandon Ariadne, depending on the version, forgets to change the sails of the ship from black to white. His father, King Aegeus, seeing the black sails approach believes that Theseus is dead and throws himself off a cliff into the sea, which is why the sea is called the Aegean Sea.

Theseus’s defeat of the Minotaur was a tremendous victory for Athens. To celebrate Theseus’s deeds and thank the gods, every year thereafter they sailed the same ship to the sacred island of Delos for a religious ritual. Over the centuries, various parts of the ship rotted away and when they did the Athenians replaced them with fresh parts. Eventually, every part of the ship had been replaced. This story gave rise to the philosophical problem known as the Ship of Theseus and the problem is this. If you replace a single part of a ship, say a single board on the deck, can you call it the same ship? Intuition would say yes. But now, over time, you replace one part every year until centuries later, every part has been replaced. Is it now the same ship? If we accept that changing a single part does not produce a different ship. It would seem that replacing any individual part of the ship would not fundamentally change the sameness of the ship. But in the end you are left with a ship with entirely different parts. Now you have a dilemma. If you believe that the ship is somehow different, you are forced to identify a certain moment when the ship had changed, despite the fact that each change was essentially infinitesimally small. On the other hand, suppose you believe that it is still the same ship, despite the different parts. Now what would happen, as Thomas Hobbes asked many centuries later, if you go and reconstruct the ship using the original parts that you have removed. Which of the two is the original ship?

This question may seem to be nothing more than a game of semantics, but the philosophical issues at play are actually deeper than you might think because the same problem is at hand in what is known in philosophy as the problem of the self. We all, of course, have some self-identity, and this self identity is not a matter of semantics. We have some very deep sense of what it is to be oneself and that that this self is different than other people’s self. We perceive that when we wake up in our bed in the morning we are the same person who went to sleep in that same bed the previous night. We don’t go to sleep one night as Sally and then wake up the next morning in a different bed as Jane, nor do we have the experience of being born anew in the morning as an entirely separate self from the person who went to sleep in the bed the previous night. So intuitively we believe that there is some continuity in our conception of the self from moment to moment and day to day, and even over the course of our lifetime even though we change dramatically from childhood to adulthood to old age. But the same problems at play in the problem of the self are at play in the Ship of Theseus, but without the metaphysical baggage of notions like consciousness and memory.

Well this is at least supposedly a podcast about the history of astronomy so we cannot answer fundamental problems in philosophy. But this story does illustrate how the Greeks pulled from this cultural background to develop what we today would regard as more serious philosophical or scientific questions. And the fact that one of the great English philosophers, Thomas Hobbes, fifteen centuries later, was still seriously pondering these questions provides a hint of the impact that Greek ideas had on the development of Western intellectual culture.

At any rate I’ve now told you the story of Theseus and King Minos and now you understand the history of Minoan civilization. Not the real history of the Minoan Kingdom, of course, but the history of the Minoan civilization as perceived by the ancient Greeks. At the very beginning of this episode I mentioned that there were two civilizations in the region that predated the Greeks: The Minoans, whom we just discovered and the Mycenaeans.

But as with the Minoans, memories of the Mycenaean civilization also persisted in Greek culture. So now I’ll invite you to settle in as I tell you the tale of the remnant of Mycenaean culture in Greek memory in the myth of Perseus. Now the tale of Theseus and King Minos had fairly limited representation in the heavens. The crown that Theseus or Dionysus gives to Ariadne is all that makes it into the sky as the constellation Corona Borealis. By contrast the tale of Perseus sprawls out over a vast portion of the sky and spans a half dozen constellations.

As with all great Greek heroes, Perseus is a demigod and the story of his birth is a short tale in its own right. At one time, the king of Argos was a man named Acrisius. Just like King Aegeus in the tale of Theseus, King Acrisius was unable to produce a son and eventually, fed up, went to the Oracle of Delphi for advice. In a way, King Acrisius was lucky in that the oracle he received was apparently not cryptic. But the bad news was that he learned that he was not to produce a son, and to make matters worse, his daughter would bear a son who would kill him. So naturally, King Acrisius returned home and locked his daughter Danaë in a tower whose only opening was to the sky so that no one could enter or leave.

Sometime later Zeus discovered Danaë locked in this tower and fell in love with her. So he caused a rain of gold to fall upon the tower which then impregnated Danaë. When King Acrisius learned that his daughter had become pregnant with Perseus despite his best efforts to lock her away, he considered killing the child. But King Acrisius realized that doing so would only invite the wrath of the Furies, the goddesses of vengeance. So he did what any well adjusted king would do and locked both the child and its mother in a wooden chest and then threw the chest out to sea.

As the god of the sea, Poseidon, was Zeus’s brother, this made Perseus Poseidon’s nephew, and so when King Acrisius threw the baby into the ocean, Poseidon looked favorably on his nephew and calmed the seas and carried the chest to the island of Seriphos. There the chest with the baby Perseus and its mother was discovered by a fisherman named Dictys who also happened to be brother to the king of the island, Polydectes. Dictys took Perseus to Polydectes, who adopted him as his own son.

As Perseus grew up, Polydectes began to fall in love with Perseus’s mother Danaë. But Perseus didn’t entirely trust Polydectes and wouldn’t let him come close to her. So Polydectes came up with a plan to circumvent the meddling kid. At the time, the bachelorette on everyone’s minds was Hippodamia, the beautiful princess of Pisa. But her father, King Oenomaus, had heard a prophecy that he would be killed by his son-in-law. He therefore challenged every suitor to Hippodamia to a chariot race. If the suitor won, he gained the right to marry his daughter. But if King Oenomaus won, he would execute the man. King Oenomaus had mounted the heads of eighteen failed suitors around his palace as a warning to any other young men against getting any ideas.

Well, Polydectes, Perseus’s adopted father, knew that Hippodamia was sought after enough that it would be believable if he announced that he was going to try to marry Hippodamia. So announce it he did and he then demanded gifts from his courtiers. If he was to beat King Oenomaus in a chariot race he needed the fastest horses in the land. So everyone in his court was to provide him a suitable horse.

But what Polydectes knew was that Perseus had no horses and so wasn’t able to give his father any gift at all. So Perseus instead asked Polydectes to name anything on the Earth and he would go and capture it for him. The trap was then set and Polydectes asked Perseus to bring him the head of Medusa.

According to Ovid, Medusa had been a beautiful maiden, the daughter of the primordial sea god Porcys and his sister Ceto. Poseidon became attracted to Medusa after seeing her in the temple of Athena and had raped her right then and there in the temple. This was not pleasing to Athena, but Athena, in a terrible instance of victim blaming, blamed the victim Medusa and transformed her into a Gorgon — a hideous woman with snakes for hair whose gaze was so terrifying that any poor soul who looked upon her face was immediately turned into stone. The gods of the ancient Greeks were not especially known for their just dealings with mortals.

Thanks to Perseus, Medusa is the best known of the Gorgons, but there were actually two others, Stheno and Euryale. Although the three were sisters, Stheno and Euryale were immortal, and Medusa, being the youngest of the three, was mortal. Since all three were present in the temple when Medusa was raped Athena had transformed all three into Gorgons.

Being a demigod, Perseus had the gods on his side and Athena visited him to provide advice for his quest and gave him a mirrored shield by which he could look at Medusa without turning to stone. Zeus, in turn, gave him a sword of adamantine that he could use to slaw the Gorgon, and Hermes lent him the Talaria, his winged sandals. Athena then advised Perseus to find the Graeae, three old women who were sisters of the Gorgons and who could tell Perseus the whereabouts of Medusa.

The Graeae were so tremendously old that they had only a single eye and single tooth among them, which they then shared between each other to speak and to see. Perhaps Perseus asked the Graeae nicely for the location of Medusa and was rebuffed, or perhaps not, but at any rate as one of the old women passed the eye to her sister, Perseus stole it and held it ransom until they told him the location of Medusa’s cave. From them he also stole a knapsack in which to transport Medusa’s head and the helm of invisibility, a hat created by Hades that could be worn to render the wearer invisible that the Graeae had somehow ended up with. In some versions the Graeae had also acquired Hermes’s winged sandals and he steals those, too rather than receiving them from Hermes directly. And in other versions the Graeae didn’t have the helm of invisibility but instead Athena gave it to Perseus herself.

But in the end Perseus has all the tools he needs and now knows the location of Medusa somewhere near the end of the Earth. He flies there using the winged sandals of Hermes and then puts on the helm of invisibility, thereby becoming invisible, uses the mirrored shield to find Medusa and Zeus’s sword to cut off her head. He then puts her head in the Graeae’s knapsack, and being invisible, can flee from the wrath of Medusa’s other two sisters. Medusa, being pregnant with the child of Poseidon, then gives birth to this child, a young man with a golden sword named Chrysaor, and the winged horse Pegasus, both of whom spring from the blood of her neck after her decapitation. Incidentally, the detail about Pegasus and Chrysaor being birthed from the blood of Medusa’s neck, rather than a more usual birth, means that these were higher births — births of gods rather than mortals. In a similar way, the goddess Athena was borne from the head of Zeus fully formed.

On the long journey back, Perseus stopped in the land of King Atlas. Atlas was a Titan — one of the ancient race of gods that had originally ruled the cosmos. But after their children, the gods of Olympus like Zeus, Hera, Poseidon, and all the rest of the more familiar Greek gods, had rebelled against their parents and banished them to the underworld of Tartarus. Atlas, however, was banished to the end of the Earth. The popular modern depiction of Atlas supporting the weight of the world on his shoulders does not actually appear in the original Greek myths. Instead in the Greek myths he was made to support the dome of heaven upon his shoulder. Despite Atlas’s punishment it seems that his realm was quite lovely and although he was cursed to support the vault of heaven upon his shoulders, he seemed to be free enough to engage in other activities, at least for the purposes of this myth. Most prized in his lands was an orchard where the trees produced golden apples hanging from golden branches amid golden leaves.

Atlas had been warned a prophecy that a son of Zeus would come to his orchard and steal his golden apples, so when Perseus showed up and announced that he was a son of Zeus and asked Atlas for his hospitality, Atlas immediately told him that he was not welcome in his land and to flee, whereupon he attempted to make Perseus leave. Perseus, being a demigod, was strong, but no match for a Titan. So instead he pulled out the head of Medusa and held it before Atlas who immediately turned to stone, thus forming the Atlas mountain range in northern Africa.

Now the mythic narrative is a little contradictory where Atlas is concerned. Although the Greeks related that the petrification of Atlas was the origin of the Atlas mountains, they also insist that the prophecy that Atlas was worried about was later fulfilled when Herecles, another son of Zeus came and stole the golden apples as one of his 12 labors, and in that story Atlas is fine as fettle and moving about freely to defend his precious apples. So there’s perhaps a bit of a plot hole there, but let’s maybe not get too hung up on it.

After leaving the kingdom of Atlas, Perseus was passing through Aethiopia on his way home. Now a quick word about Aethiopia. To the Greeks, Aethiopia did not just represent the modern land we call Ethiopia. Instead Aethiopia, spelled with an extra A in front, was the entire region of the world to the south and west of Egypt, and particularly referred to the most distant southwestern parts, today around the countries of Algeria and Libya.

At that time a man named Cepheus was king of Aethiopia and his wife Cassiopeia was queen. Cassiopeia was vain and proud and boasted that she was more beautiful than even the sea-nymphs. Now as you might expect, boasting that you or anyone else for matter, is more beautiful than any goddess will not end well for you. Poseidon was enraged and sent a flood to destroy the land. King Cepheus consulted the oracle of Ammon who counseled him to sacrifice his daughter Andromeda to Poseidon. So King Cepheus chained his daughter to a rock by the sea to be devoured by the great sea monster Cetus, sent by Poseidon.

And it is upon this ghastly scene that Perseus happens as he is flying through Aethiopia. He sees a beautiful woman chained to a rock and Cetus fast approaching. So Perseus comes to the rescue. In some tellings of the story, before saving her from the terrible sea monster, he takes some time to bargain with her parents and gets them to agree that if he saves her she will marry him.

Well regardless of the details he slays Cetus with his sword and saves Andromeda and there is a grand feast and everyone celebrates. Or almost everyone anyway. An awkward detail that King Cepheus and Cassiopeia left out when they were frantically bargaining with Perseus is that she was actually already engaged to someone else. King Cepheus had already betrothed her to his own brother, Andromeda’s uncle, Phineus. My most accounts Phineus wasn’t especially interested in Andromeda except as a way to gain the Aethiopian throne. But with his political ambitions crumbling before his eyes Phineus was not at all happy during the banquet and at some point snapped and threw his spear at Perseus. Evidently Phineus was a poor shot because he missed, but then all hell broke loose in the banquet hall as all of Phineus’s friends proceeded to brawl with the guests of King Cepheus who came to like Perseus and were on his side.

In the middle of this general chaos, Perseus shouted, “Let all who are my friends avert their eyes” and raised up the head of Medusa, thereby turning Phineus’s allies into stone. Well, it seems to me something of a miracle that this gimmick didn’t turn everyone else at the banquet into stone, too, because I think I would have looked at anyone who had shouted that in the middle of a fight no matter whose side I was on. But I suppose that just goes to show that I would have made a poor Bronze age warrior anyhow.

Now somehow Phineus himself had not looked upon the head of Medusa, and seeing that all his friends had turned to stone, begged Perseus with his face turned to the side to spare his life. But Perseus was one stone-cold man and swung the face of Medusa in front of Phineus’s face and turned him to stone anyway.

This entire episode features prominently in the night sky. Near the north celestial pole we have the constellations Cepheus and Cassiopeia. Cepheus is a little faint, but Cassiopeia makes a recognizable ‘W’ or ‘M’ shape depending on the season and time of night and represents Cassiopeia sitting on her throne. The story is that the gods placed Cassiopeia so close to the north celestial pole so that 50% of the time she would be upside down, in a lesson of humility towards the gods. A little south of Cassiopeia and Cepheus is the constellation of Andromeda, their daughter, and the three constellations together thereby make up the royal family. To the west is the constellation of Pegasus, the winged horse that sprung from the neck of Medusa after her decapitation. Three of the stars of Pegasus along with one of the stars of Andromeda make an asterism known as the Great Square of Pegasus. Then to the east of Andromeda is the constellation of none other than Perseus himself, and a little ways south of Andromeda is the great constellation of Cetus, the sea monster, one of the largest constellations in the sky. The constellation of Cetus itself is a part of another vast region of the sky known as the Sea or the Water where a large number of watery constellations are all clustered next to each other. Adjacent to Cetus we have Eridanus, the river and Pisces, the fish, which in turn is next to Aquarius, the water bearer, and then is next to Pisces Austrinus, the southern fish. And these two are next to Capricornus, the sea goat, which then turns into Delphinus, the dolphin. Capricornus, Aquarius, and Pisces are all zodiacal constellations and may have gained their watery associations because the Sun passes through them during winter, which is the rainy season in the Mediterranean.

Well before I get too carried away with all this astronomy, we should wrap up the story of Perseus, but you will be relieved to hear that it is getting close to the happily ever after ending. Perseus and his new bride Andromeda return to Seriphos where his adopted father Polydectes had evidently attempted to take advantage of Perseus’s absence and had violently thrust himself upon Perseus’s mother Danaë, forcing her into hiding. Upon learning of this Perseus then petrifies Polydectes with Medusa’s head and coronates as king Polydectes’s brother, the fisherman Dictys, who had originally discovered Perseus and his mother in the wooden chest. Having fulfilled his quest, Perseus returned the sword to Zeus, the winged sandals to Hermes, and gave the head of Medusa to Athena as a gift, who mounted it upon her shield.

The final episode of the adventures of Perseus varies in the telling, but in one version Perseus’s grandfather, King Acrisius, heard of Perseus’s exploits and that he was coming home. As you’ll recall, King Acrisius had been worried about the prophecy that the son of his daughter was to kill him. Fearing that Perseus would try to come home to Argos, Acrisius left for Larissa where there happened to be an athletic competition. Unbeknownst to him Perseus had already arrived at Larissa and was competing in that very competition. During one of the games, Perseus’s discus throw veered off course and struck his father, killing him, thereby fulfilling the prophecy.

Although Perseus was the heir to the throne in Argos, he voluntarily exiled himself since he had come to the throne by killing its occupant, even if inadvertently. So Perseus gave the throne to his cousin Megapenthes and Perseus wandered off into the countryside. At some point during his wanderings he either dropped his hat or the top of his sword, or found a particularly interesting mushroom, all of which mean mycenae in Greece, and there founded the city of Mycenae and the Mycenaean civilization where, unusually for Greek mythology, he lived happily ever after with his wife Andromeda. Well, some versions do have him coming across the head of Medusa as an old man, trying to kill some people with it, finding that it doesn’t seem to work, and then taking a look at it himself, whereupon he himself turned into stone in an ancient version of looking down the barrel of a gun and pulling the trigger when it doesn’t fire at your enemies. But most accounts don’t deal with the death of Perseus which would probably imply that there was nothing interesting to tell there and that he died peacefully as an old man.

So there you have it, the Greek histories of Minoan and Mycenaean civilization. As I discussed in the first episode of this series, I think that it’s important that we try to understand the development of astronomy in the context of the cultures where the science was developed rather than trying to impose our own modern ideas about what ancient science should be. These myths were deeply ingrained in the Greek mindset and this inevitably influenced the development of astronomical thought, either through the implications these stories had for cosmology and cosmogony, or as a reaction against these ideas by freethinkers, who in turn, suffered sanctions from the broader society for rejecting accepted modes of thought.

We’ll notice a few things about these two histories. The first is that they are fundamentally heroic. By this I mean that the histories are not at all concerned with most of the things that we moderners are interested in, like who the common people were, how many of them there were, what their customs and political structures were, or anything of the sort. The histories are focused almost exclusively on the actions of a small number of heroic figures: kings, queens, princes, and their dealings with great monsters and the like.

Another feature of this history is that they are not so interested in the literal truth or consistency of the narrative. They tend much more to be interested in good storytelling and moral teaching. So these Greek tales bear some similarities but also some differences to the Israelite and Babylonian histories we encountered in our earlier episodes. The Israelite history, in particular, was similar in that the main concern of the authors of the books of the Hebrew Bible was the moral lessons their stories told. When Israel was ruled by kings who were faithful to God and obedient to His law, Israel prospered. When the kings were faithless and turned to strange gods, Israel suffered. But unlike the Greek myths, the ancient Israelites placed a much higher premium on developing a canonical version of their texts. We have some evidence of competing stories, most notably the two creation stories told in the first two chapters of Genesis, but this is the exception rather than the rule of the Hebrew Bible. By contrast in Greece, it seems that the broad outlines of the important mythic stories were well known, but Greek authors had a lot of freedom to elaborate on the details of these stories as they saw fit. And they felt no compunction to ensure that their version was consistent with versions that other authors had told before them.

This freewheeling intellectual culture was really one of the hallmarks that distinguished Greek civilization from other civilizations in Mesopotamia. Like the Greeks, the Babylonians had writing, and in fact had developed it far earlier than them. But writing among the Babylonians was limited to a special class of people and was reserved for very important documents. But in Greece it seems that everyone had some new idea in them and was writing that idea down. Now unfortunately, as we’ll discuss in probably the next episode, many of these works were lost, but we have other works that referred to them and classicists have worked out a complex web of citations, paraphrase, quotations, and plagiarism of many of these earlier works from later works which do survive. This kind of intellectual free-for-all just didn’t exist in Babylonia.

The Greek myths also put a stronger emphasis on the heroic than the stories told in the Hebrew Bible, which is itself already very focused on the actions of a small number of heroic figures. But a consistent theme throughout the Hebrew Bible is also the relationship that God establishes between Himself and the people of Israel through his various covenants. The Book of Exodus prominently features the deeds of Moses and Aaron, but then has a great deal to say about how the people as a whole behaved as well, either by assenting to the covenant that God presented to them through Moses or by rejecting it by worshiping the golden calf. But the Greek people as a whole really feature very little in the Greek myths at all. The closest we come to a representation of the Greek people is the device of the chorus in Greek theatre. During the play there would be a collection of people standing together on stage who would comment on the goings-on on stage to provide the dramatic reaction of the Greek people to the actions of the heroes. But nevertheless, unlike the Israelite people in the Hebrew Bible, the Greek chorus was a passive character and rarely had any causal impact on the drama on stage.

There is one other feature of these myths that is especially relevant for our narrative about the history of astronomy — namely that the stories — and thereby the gods — became intertwined with the heavens. The Greeks were not unique in this regard. Every civilization has picked out constellations on the sky and has developed stories to identify with the constellations, and more broadly has associated the sky with the divine. But the fact is that the standard 88 constellations we have today are largely the same as the ancient Greeks, not those of any other culture. Now, the Greeks borrowed some of their constellations from the Babylonians, but it is not the fact that those constellations were Babylonian that we still have them — rather they only survived to today because the Greeks happened to adopt them. Likewise we don’t identify any of the Egyptian constellations, or any of the constellations of the Celts, Norse, Vandals, or any of the other dozens of tribal peoples that populated Europe. Our constellations today are just one of the fossils of Greek science that persist to modernity as a consequence of the massive influence that the ancient Greeks had on the development of astronomy and the sciences more generally in the West.

Now from what I’ve said to this point, there is nothing tremendously unique about the thought of the Greeks. They had wonderful myths, yes, but so has every other culture. But it is important to understand the origins of Greek thought in order to understand how it evolved other ways of understanding the world aside from the mythic.

As we had discussed in the previous episodes, the Babylonians had developed a sophisticated set of procedures to predict the patterns of behavior in the sky, but were never really interested in understanding anything deeper than that. The Greeks were different — not immediately, as we have seen, but eventually, and we will next come to that. But it is late now and so we’ll have to trace the development of this thought in the next episode. I hope you’ll join me then. Until the next full moon, good night and clear skies.