Sunday, September 5, 2010

Ode to the Ptolemaic Venus

This is an assignment from back in (undergraduate) college.  We were asked to write a 3 to 5 page essay about Ptolemy's treatment of the planet Venus, so of course I wrote an essay in verse.  It probably took me 10 times longer than the assignment should have, but I'm still happy with the result.  It occurred to me this morning that I hadn't posted this, so here it is.

Of planets fair and fairer still ‘tis Venus that’s most bright
Before sunrise or after set when Moon conceives the night.
Described by motion circular, the learned Ptolemy claims
Through Almagest, in which for wisdom he enshrined his name
In tomes of history, the planets move about the earth
In just such way divinity would give the sky its birth.
And yet a question plagues his work (that long was held as True):
What of the equant, we must ask, that gives appearance due
Measure against the doubt that our observance fuels with sight,
When Venus struts across the sun in variable flight,
That circles lone cannot describe except with forced constraint
Of center offset that a line to epicycle paints,
Describing thus by motion circular about a path
Itself circular? It is here we later find the wrath
Astronomers to come will hold, and doubt ourselves whether
Ptolemy can be justified in sending this tether
To bind the motion of our star (the brightest and most fair).
If circles can only describe the heavens with repair
By inconsistent equant, then it seems simplicity
(Which is a gauge of truth and, more, this task’s felicity)
Is lost, with both epicycle and eccentricity.

Our author asks if we can judge by earth’s shallow standard
What is ‘simple’ to heaven high, or if instead it’s slandered
By our unwitting questions, thus in Book Thirteen he writes:
“We should not judge the simple by what nature’s spirit frights
To changeability, for we forever move and change
And find ‘simplicity’ of constant motion out of range
Of human possibility.” Therefore we must rethink
Whether objections on these grounds must surely start to sink
Beneath other concerns, or if instead we will challenge
The bold proclaiming Ptolemy and for ourselves avenge
Our first complaint. Defense, it seems, is possible on grounds
That, while eternal, motion such as this is hardly bound
By laws divine, for though we cannot know the mind of God,
We can ask whether “constant motion” is but a facade
For Ptolemy through which his physics he can then imbue
Without having to worry whether ultimately True
His universe remains. For his concern, I think, is not
For Truth complete, but rather what he passionately sought
Was explication of mathematics pure, and what we see
In starry night that seems to us to move with constancy,
And more, still left in this is something true, we may decree.

To Venus, then, we must direct our literary gaze,
For in the star of love our enterprise may yet be razed.

If from appearance first our author asks us to derive
The motion of a planet that a theory can describe
By means of observation first, then reason soon applied,
Allowing first predictive sight, and then to physics tied,
Then we are blessed with math divine that morning star abides.

If from a misconception, though, of earth-bound universe,
Accepting as a truth assumptions now found as perverse,
And then applying oft sought visage to a path rehearsed
By circles impiously from their very source reversed,
And put in hands of man, then sadly we are cursed.

Returning to the open of astronomy’s great work
Confronts us with a disparate opinion which to shirk:
That Ptolemy, a charlatan, has hidden us from truth
(Despite his claims that to do so would be a bit uncouth),
Or else that he may be aware of centric point besides
The earth. It hinges on a phrase, a clause he leaves aside,
Which some translate as “simple” where we may have “simplistic,”
And this is where suggestions of heaven heliocentric
Are born. If Venus, to rephrase the thought, moves by mean sun,
Which Ptolemy himself admits, it seems with only one
Small step we can deduce that circles epicyclic move
About the sun itself, and we with bright planet of love.

Regardless of translation we approach a reason odd
For why this cannot be the case, that, if we still must prod
Into the nature of the heavens, it will soon be clear
That nothing could exist on earth (letting alone the air)
If quick about the sun we twirled. In this there is complaint
That gravity and Newton fix, but now ‘tis still a feint,
Avoiding possibilities this system strong implies,
But undermining eloquence, and thus we cast aside
The whole affair, rather to face a truth left incomplete
Than ‘knowledge’ false. Such quick restraint an admirable feat
It is for our learnèd astronomer, who did not shroud
In propositions ostentatious falsehood far more loud;
For in philosophy there is no room to hold the proud.

Questions of equant left and doubts of insincerity,
In Venus we find questions still of what the point may be.
Why Almagest was written, so much time and effort spent
On tracking nightly skies with inaccurate equipment
If only to arrive at a confusion unresolved
By equant line, a paltry thing, that neigh the problem solves?
Alas that problems physical which plague this work divine
Could come from planet Venus, causing questions unrefined!

Before an answer I propose to why we read this book
I first ask that we contemplate the task that undertook
Great Ptolemy when every night he gazed on spinning sky,
Imagining and measuring where in the heavens lie
The Beauty that first Euclid gazed upon so well.
And in this task he found there was a story still to tell
Of Euclid’s pure geometry in heaven ably mirrored,
That now he too, toward realms of gods, had fortunately peered.
He did not see a universe that spun around a pole
Impaled in sun, but rather saw the spinning human soul
And heard the music that only the goddess, Venus, sings
When morning comes, or evening falls, and love through cosmos rings,
For that is where humanity must find its hidden wings.

My answer, then, I fear I have precluded with too much
A hint. My reader likely has proposed to guess that such
A world as our astronomer unfolds we ought to see
Because in his great work he shows us true divinity.
Not Truth as we would have it in our ultimate repose,
But truth as best we can perceive, with senses so imposed
Upon our reason, that only in math do we see pure
An abstract world that, free from us, provides our wonder cure,
Proclaiming Truth as Ptolemy, who saw Venus as we,
And knew that in his human sight could only hope to see
Its motion through the heavens from his humble place on ground,
While it, so perfect in its light, about the stars was wound
Like justice, or a true account, or Plato’s fleeting forms
That hide themselves and so withstand the ever-blowing storms
Of false impression. In such way soft Venus moves the mind
To Beauty, and in Beauty’s hearth we may at long last find
A Truth that only Beauty’s breath could e’er hope to unwind.

1 comment:

  1. Thought of this while watching Venus by the crescent moon this evening. :-)