The Roman Notion of the Age of the Galaxy, By the Clever Use of Math

So, if the long title didn’t set you off, please read on if you like astronomy and archaeoastronomy (yes, it exists I didn’t make that up. Here’s the Wikipedia link: http://en.wikipedia.org/wiki/Archaeastronomy). Anyway, I was reading a source for a crummy paper I have to write that’s due on Monday. Yeah, the Monday everyone returns from Thanksgiving break. *quick sulk of silence* 

The paper I’m writing is going to be on an interesting writing by Cicero about Scipio Aemilianus Africanus (AKA Scipio Africanus the Younger) who supposedly had a dream while waging war in Africa on Carthage. Strange, but hey it’s Rome. 

If you’re not interested in who the people I’m talking are and just want to know how old the entire galaxy is supposed to be, scroll down. I’ll be with you in a moment. Cicero (full name: Marcus Tullius Cicero) was elected consul of the Roman Republic in 63 BCE. He wasn’t only a consul - he was a poet, an orator, a statesman, a philosopher, laywer, and theorist. He was also exiled from Rome by Julius Caesar for three years. In fact, Cicero is widely regarded as one of Rome’s greatest orators. That means he was great at talking. He also wrote a shit ton of literature. One of the more famous pieces is called On the Republic (De re publica) which is where Scipio’s Dream comes from. Scipio Aemilianus Africanus was consul about 100 years before Cicero. Actually, Scipio Aemilianus Africanus was consul twice - once in 147 BCE and again in 134 BCE. The guy destroyed Carthage after his predecessor as consul couldn’t. It earned him the nickname “Africanus” which means “conqueror of Africa” rather than “the African”. 

Ah, so I’ve made it to the part where we find out how old the galaxy/universe is and where the notion comes from. By the way, in this dream Scipio Aemilianus Africanus is talking with his uncle and adopted grandfather Scipio Africanus in heaven. There is a passage in Scipio’s Dream (a Book within On the Republic) that reads:

The bulk of mankind, indeed, measure their year by the return of the sun, which is only one star. But, when all the stars shall have returned to the place whence they set out, and after long periods shall again exhibit the same aspect of the whole heavens, that is what ought properly to be called the revolution of a year, though I scarcely dare attempt to enumerate the vast multitude of ages contained in it. For as the sun in old time was eclipsed, and seemed to be extinguished, at the time when the soul of Romulus penetrated into these eternal mansions, so, when all the constellations and stars shall revert to their primary position, and the sun shall at the same point and time be again eclipsed, then you may consider that the grand year is completed. Be assured, however, that the twentieth part of it is not yet elapsed. (De re publica 6.22)

Everyone knows Romulus and Remus. However, Remus died (or was killed) while Romulus made Rome. Rome’s founding date is given as 753 BCE and Romulus died (e.g. “when the soul of Romulus penetrated into these eternal mansions…”) in 717 BCE according to Livy (another famous Roman writer) and Roman legend. In the story, the Scipios are in heaven looking out over the Milky Way galaxy and Scipio the Elder is pointing out the eternity of the universe. He seems to know that the entire galaxy, and not just the solar system, also revolves. Remember, this was written in 51 BCE about Scipio in 149 BCE. 

Now to the maths. Earlier in the Book, it is written:

When I had arrived in Africa, where I was, as you are aware, military tribune of the fourth legion under the consul Manilius… (De re publica 6.9.)

and, in the actual dream:

Before two years, however, are elapsed, you [Scipio the Younger] shall be consul, and complete its [Carthage] overthrow; and you shall obtain, by your own merit, the surname of Africanus, which, as yet, belongs to you no otherwise than as derived from me. (De re publica 6.11)

Scipio, despite being too young, is elected consul of Rome in 147 BCE. Also, before he was consul, Scipio the Younger fought in the Battle of Carthage in 149 BCE. Oh look, two years before he became consul :D 

So we have two dates: the date Romulus dies (717 BCE) and the date of Scipio’s dream (149 BCE) and a quote about the stars eventually returning from “whence they came”. Go ahead and reread the last sentence of that quote. Just for you, I’ll requote it. 

Be assured, however, that the twentieth part of it is not yet elapsed. (De re publica 6.22)

Scipio Africanus the Elder says that a twentieth of the time the galaxy takes to revolve hasn’t quite yet passed. I bet a lot of you are saying “Ah ha! I get it!” In case you don’t, don’t worry not all of us are mathematically inclined (and don’t worry, I’m usually not either).  

The time from 717 BCE to 149 BCE is almost a 20th of the time it takes for the universe to make one revolution. 717-149=568. For the sake of ease, let’s say that 568 years is 1/20 of the time it takes the universe to make 1 revolution. In that case, 568*20=11,360. According to Cicero and, posthumerously, Scipio Africanus the Elder the stars (i.e. the Milky Way) take roughly 11,400 years to complete one full revolution around whatever.  

Phew… didn’t think I was ever gonna tell you, huh? Well guess what? That may seem like a long time but current estimates place 1 revolution of the Milky Way galaxy at 15-50 million years. Yeah. Do you know what inhabited the planet 15 million years ago? Sharks and rodents. (http://en.wikipedia.org/wiki/Langhian#Paleontology)

Samhain - Autumn Cross-Quarter 7 November 2012

Today is a cusp of the seasons, the turning of fall into winter. 

Face it:  if the Summer Solstice is Midsummer Night, and we sing about the Bleak Mid-Winter at Winter Solstice time, then the solstices and equinoxes can not be “The first day of ——” as the calendar publishers would have it. 

So today is the First Day of Winter, or Samhain, or the Turn of Winter, or — as we call it at my house, “Cain’s Birthday” !!!