Astrolabe

“A marvel of mechanics, desired by scholars, seafarers, and fortune tellers alike.”
—Salim al’Dhalsim, far trader from Thalusa, 1037 FB

Astrolabes are complex instruments that astrologists use to determine the calendar date, the time of day, the future position of the constellations, and the arrival of dawn and dusk.

It is said Niobara of Anchopal, the most famous astronomer in Aventurian history, invented the astrolabe centuries ago. Those who particularly use it are scholars dedicated to astronomy, spellcasters who want to determine the ideal time to cast rituals, and real and self-proclaimed fortune tellers. Seafarers also can use it to find their position while at sea.

An astrolabe consists of a stackable number of discs and hands. To employ it, the user first sets the current date or the date to be calculated, and then sets a prominent celestial body such as the sun, moon, or the North Star. Next, the user sets the corresponding positions of the wandering stars, the Circle of Twelve, and other constellations, if possible. The astrolabe then reveals how far the stars stand over the horizon, shows if they are rising or falling, and describes how they will move in the next few weeks. Additionally, the user can tell the current time of day.

Besides flat astrolabes, spherical versions (known as armillary spheres) mainly reveal the orbits of individual stars and constellations around Dere and in relation to each other. Laymen find them much easier to use, as they require less complex calculations, and art collectors think they are visually more attractive, but astrologists know that they are not as precise as flat astrolabes. In fact, the mere presence of an armillary sphere can help boost profits for those who cast horoscopes for customers. Ever since the Starfall, astrolabes have been rendered unreliable. It is still possible to calculate future celestial events from the current starry sky, but often these predictions do not correspond with those obtained on existing astrolabes, which are now good for seeing only a few days into the future, at best.

Researchers are hard at work revising calculations and designing more reliable devices, but it will be quite some time before the changes in the night sky find their way into astrolabes and scientists can get back to their research. Existing devices still correctly show the positions of stars in ancient days, so they still have some use, but some experts wonder whether new versions of these tools will prove successful.

Astrolabes are available across Aventuria, wherever astronomers conduct their research. This is particularly true in the Lands of the Tulamydes, in the Horasian Empire, in temples of Hesinde and Phex, and wherever prophets make their homes.

“An astrolabe is an indispensable tool for mages who devote themselves to invocations and thus need to determine the paths of the constellations and the wandering stars.”
—Mirhiban al’Orhima, Tulamydian fire mage