Astronomicum Caesareum as code/website
The Astronomicum was originally commissioned in a very small printing run-less than two hundred were made, because each page and volvelle (pictured below) had to be hand colored. It was the product of Apius' twin genius for astronomy and printing, and was in many ways a work of passion. The question I want to consider here, however, is how the Astronomicum would change if it was transposed into the form of a website or computer program.
In some ways, we don't have to guess: websites that simulate the movement of the planets exist today, and are even widespread. The one I'll consider here as an archetype for an entire genre is NASA's own, found at http://space.jpl.nasa.gov/.
What are the differences between these two media?
Well, first and perhaps most obviously: our way of interacting with the work is different. In the came of the Astronomicum, one manipulated a series of volvelles and consulted tables to determmine the movement of the celestial bodies; on the NASA website, one simply needs to select the proper input and the required information pops out. In some ways, this may seem to be a strict improvement; but I would point out two things here. The first is that the Astronomicum probably facilitated greater understanding of the planetary movements. The physical process of moving the discs and the mental work required in consulting the tables probably made the Astronomicum in many ways a better learning tool. But secondly and conversely, the Astronomicum presumably demanded greater familiarity with the science of astronomy; to my untrained eye, the diagrams and charts seemed entirely arcane.
Which brings me to another significant change in the media: their audiences, and cultural impact. The Astronomicum was the sole property of elites, both because of its high price and because of the education required to use it. On the other hand, the NASA website is available and relatively comprehensible even to those who (like myself) are neophytes when it comes to astronomy. This would, I think, mean two things. The first is that the Astronomicum did not generally serve as a first introduction to the subject; it was too expensive and rare, and required too much knowledge right out of the gate. The second is that the Astronomicum represents in many ways a larger societal fact of its time: astronomy as such was the property of elites, those who had both the money and the time to afford tutoring or the materials to learn.
What's most interesting to me, however, is the change in aesthetics between these two asstronomical devices--and what it says more generally about the world views surrounding their production.
Consider the art work of the Astronomicum. It is lush, extravagent, beautifully colored; the study of the stars is taken as an opportunity to pour out artistic talent. Even more than that, however, that artistic talent is channelled into a very particular style, which often seems to make reference to an apparent agent behind the movements of the planets. Often a hand is shown holding a volvelle, which one must assume is a reference to the Deity holding and maintaining the movements of the planets. Even the text is often arranged in patterns that are architectural--as pillars, for example--which speaks to the view of the cosmos as the organized and meaningful product of a master architect. By meaningful, by the way, I don't particularly mean in contrast to nihilism; there was a common belief that “The entire sense-perceptible world is like a sort of book written by the finger of God” (originally spoken by Hugh of St. Victor, found in Charles Taylor's A Secular Age 94). The universe is meaningful in the same way a book is meaningful, at least in the mind of many pre-modern Europeans: there is an author trying to communicate a meaning through it.
Consider the NASA website. I don't at all want to argue that it argues for a meaningless universe, per se; rather that it simply isn't thinking along that axis at all. The reason at work here is essentially instrumental, as far as I can make out; the simulation is barebones, simply giving the information in the most efficient way possible. It's not that the NASA website thinks that the universe is or isn't the product of a Creator of some sort; it's more that it's just not concerned with that question, but is instead concerned with the mechanics of the universe for their own sake, or for the sake of human convenience or knowledge.
It might be pointed out that this isn't necessarily down to a shift in media, but in the surrounding culture; but I think the two are related. The book (particularly a book like the Astronomicus) as a medium bespeaks effort, an aesthetic drive; it's material in a way that a website simply is not, and, because of this, is owned by a single individual (rather than being publically available). It can be precious, rare, valuable; almost a relic. A website, on the other hand, is driven by usability. That's not to say there's no aesthetic value or effort put into that medium; in fact, just the opposite is the case. But, generally, the aesthetic is one that values clarity, utility, the experience of the user. (It should be noted that NASA's site is relatively barebones). This shift indicates, I think, a change in the approach to the subject matter that the Astronomicus is concerned with, and indeed the cosmos in general, from being fundamentally centered on something apart from humanity (generally a deity) to a worldview generally centered on humanity.