Tracing the history of medieval astronomy
Having gotten our preliminary estimate for the eccentricity and position of apogee
let us investigate the differences which can be derived from them in the ecliptic arcs which we week to determine at each of the oppositions [in turn].
In this post, we’ll cover Ptolemy’s method for the first opposition. Continue reading “Almagest Book X: Correction for Equant – First Opposition”
In the last post, we began the process of determining Mars’ eccentricity and the position of apogee. The technique is fundamentally similar to the three eclipse method used for the moon, but the presence of the equant is throwing a wrench in things.
Specifically, right at the beginning of the last post we had to make an assumption about $\angle BDG$ that we know was incorrect. We’re not quite ready to address that, but for now we’ll work on finishing finding the line of apsides as well as the eccentricity as if that assumption were correct. Then, in future posts, we’ll go about trying to iteratively correct that assumption. Continue reading “Almagest Book X: Preliminary determination of Mars’ Apogee & Eccentricity – Part 2”
Now that we’ve laid out what we’re going to be attempting to do, let’s get started on finding the line of apsides and eccentricity. Continue reading “Almagest Book X: First Iteration of Mars’ Apogee & Eccentricity – Part 1”
In the last Almagest post, Ptolemy explained that for the models of the superior planets, we’ll be needing to use oppositions. So with that explained, we’ll begin by working to develop the model for Mars by looking at its eccentricity and apogee. However, this isn’t going to be nearly as straightforward as it has been previously. As we’ll see, we’re missing some of the angles and arcs that would be needed for this. Thus, Ptolemy is going to use an iterative method to close in on them. Continue reading “Almagest Book X: Observations and Introduction to Iterative Calculations for Apogee and Eccentricity”
I’ve gotten confirmation on all my classes for Gulf Wars. A list is below the fold. Continue reading “Gulf Wars 2024 Schedule”
I have finished my review of the Vatican Graecus $1594$ manuscript and it is available in my Google Doc. If you’d like to view the original manuscript, it can be found here, starting on $155r$1.
Discussion of this catalog below the fold. Continue reading “The Almagest Manuscripts – Vatican Graecus 1594”
Welcome to 2024 everyone!
$2023$ is now behind us, so I want to take a moment to review my progress for this year. Continue reading “2023 in Review”
Having completed the preliminary models for the inferior planets, Mercury and Venus, Ptolemy now turns his attention towards the superior ones: Mars, Jupiter, and Saturn. Continue reading “Almagest Book X: Preliminary Comments Regarding the Models for Superior Planets”
Now that we’ve worked out the mean speed of Venus about the epicycle, we can now determine where it was on the epoch date. Continue reading “Almagest Book X: Venus’ Epoch Position”
Continuing with our process of finding the position of Venus about the epicycle at two widely discrepant points in time, we’ll now look at one from Timocharis. Continue reading “Almagest Book X: Position of Venus About the Epicycle on Oct 10/11 271 BCE”