To help us determine where the sun is on a given date, Ptolemy sets out a table to allow us to more quickly look this up instead of needing to calculate how far around the ecliptic the sun has moved. This table is very similar to another set of tables Ptolemy would produce later: The Handy Tables. However, there are some notable differences between this table and the Handy Tables. Continue reading “Almagest Book III: Table of the Mean Motion of the Sun”
Data: Summer Solstice Solar Altitude
Happy Summer Solstice everyone!
Since one of the things Ptolemy was concerned with was the angle between the ecliptic and celestial equator, I built a solar angle dial to help determine this. Given that the measurements needed to be taken on the solstices (or a solstice and equinox), I set up the instrument today to take the measurement.
