Making the Astrolabe. Construction, Materials & Plan

Numerous medieval sources detail the construction of an astrolabe.  Sebokht, ca 650 AD describes the astrolabe as follows: The material of it is brass, the form round and flat, it is composed of three or four tablets.  If they are raised, they are all found to be round, flat, and equal to each other. They…

Making the Astrolabe. Drawings

Part IV. The Rete The rete shows a stereographic projection of the sky. Unlike a modern planisphere, the rete is projected from the pole and the different plates provide the latitude dependency. The rete shows the ecliptic (also called the circle of signs) and the so-called fixed stars. These stars are the brightest stars in…

Making The Astrolabe – Drawings

III. The Plates The plate of an astrolabe is a stereographic projection of the celestial sphere for a given latitude. It shows lines of equal azimuth and altitude, as well at the projections of the Equator, and the tropics of Capricorn and Cancer. The Stereographic Projection The stereographic projection is also known as a plansipheric…

Making the Astrolabe – Drawings

II. A Primer on Astronomical Coordinate Systems In my last post in this series, I walked through the drawings of the mater. The next step is to create the drawings of the plates. This is the most mathematically complex part, as it is a 2D projection of the 3-D celestial sphere, which depends on the…

A Short Analysis of Male Arabic Names and Placenames

This is a list of names based entirely on a coin hoard found in Buseyra, documented in 'Le commerce régional et international au Xe siècle en Syrie'. Buseyra was the southern most outpost of Damascus, and an important stop for the pilgrim caravans that went from Damascus to Mecca. As such, it was a center…

Making the Astrolabe — Drawings

I. The Mater The astrolabe is part art, all science.  These elaborate works of art are first and foremost designed to be used as scientific instruments.  Many of them are engraved and inlaid with precious metals or gemstones.  However, despite being artistic objects, they are all designed as scientific instruments; they use scientific principles to…

Female Arabic Names A Survey From An Academic Article

Introduction This is a list of names and naming patterns based on an article that examines Shia genealogy via women’s names (https://www.jstor.org/stable/44946771). The article mainly focuses on names from the very early period of Islam in Arabia, from about 632 CE (the death of Muhammad) through till approximately 800 CE. All the texts examined in…

Classical Arabic Grammar — diatrical marks, the definite article, sun letters, and moon letters.

There are several things to consider when romanizing Arabic-- vowel sounds and diacritical marks being particularly important, together with understanding how different consonants behave with the definite article أل -- 'al'. There are several different transliteration systems, which represent the letters and diacritical marks in slightly different ways. Further, there are also various dialects of…

Astronomical Seasons

OK, time for this old chestnut again, as we approach the autumn equinox, and astronomically speaking, the start of autumn/fall and the end of summer. Astronomical seasons appear to deny all common sense as regards weather patterns and "common sense" -- for instance, astronomical winter starts at the Winter Solstice -- you know, around the…

‘India’ In The Middle Ages

Did you know -- you can have an "Indian" persona in the SCA? While European personas are popular, recent changes allow us to take a broader look at the pre-16th century world. However, while the history of these areas is in many cases very well recorded, they are not recorded in European languages, which makes…