Dār al-Ḥikma
دار الحكمة
Small self-contained pieces. Each one is a single page — open it, use it, save it if you like. Nothing you need to install, nothing phoning home.
Three reference frames, one turning sky.
An interactive celestial sphere that holds the horizonal, equatorial and ecliptical frames together at once, so a single point can be named three ways as the sky turns. Includes an eleven-step walkthrough, a latitude and sidereal-time drive, and the quadrant problem laid out in full.
Ptolemy's models, seen from the pole of the ecliptic.
The eccentric Sun, deferents, epicycles and the equant, the mean conjunctions of Jupiter and Saturn, and the Moon's two months — animated on real dates, with Sayyid at the centre and the royal stars on the rim. Set your birthday and see whether you were born conjunctional or preventional.
Arithmetic in sixties.
Degrees, minutes and seconds added, subtracted and converted with every carry and borrow shown; signs to absolute longitude, time to arc and back. An eleven-step walkthrough on the lesson's own examples, endless practice with diagnostic hints, and a slate that works your homework without telling you the answer first.
The calculator beside the three books.
Built for casting charts by hand. Enter angles and times as they're written, switch between absolute longitude and zodiacal signs, and form and apply interpolation ratios. Registers hold your LST, RAMC and obliquity, and the history keeps every step of the work. Bring a table of houses, an ephemeris and an atlas. Add the Takht to your phone and work offline.
The tables of a zīj, beside the Takht.
Built for casting charts by hand: a daily ephemeris of the seven planets from 1800 to 2200, at 00:00 or 12:00 UT; an atlas of 144,876 places with their latitude, longitude and longitude correction; a pocket table of houses for your latitude and LST; and Lesson 5’s worksheet, rows 8 to 47, with the reference values filled in and every calculation left blank. Print them on Letter or A4, or save the Jadāwil as one file and work offline. Bring the Takht for the arithmetic.
Interpolation in a table of houses.
The Midheaven by sidereal time, the Ascendant by sidereal time and latitude, a planet by the hour of birth — the two ratios drawn as crossing lines, the lesson's worksheet filled one row at a time, and the direct calculation beside it so you can see why your program differs.