זמן ומדידה

Giovanni de’ Dondi’s Astrarium as a Continuous Cosmic Clock

תוכן האובייקטים עצמם כתוב באנגלית ועדיין לא תורגם.

תקופה ומקור

Padua, completed 1364; known from de’ Dondi’s own treatise rather than from a surviving machine

מה הוא נבנה לעשות

To drive the manually set geometry of the equatorium continuously, so that a clock, a calendar, a planetarium and a mechanical evaluator of medieval astronomy were one instrument.

כיצד המנגנון פועל

A weight-driven clock and escapement supply a regulated temporal input. Branching gear trains convert it into the separate mean and anomalistic motions of the Sun, Moon and five planets, with non-circular gears in the Mercury and lunar mechanisms turning uniform motion into prescribed non-uniform motion.

קלט

One regulated time base from a weight-driven escapement.

טרנספורמציה

Branching gear trains, each carrying its own period and epoch, with non-circular gears synthesising the required non-uniform motions.

פלט

Several astronomical phases and calendar indices advancing concurrently, each on its own display.

מה מבוסס בראיות

הֶיסֵק: מתחייב מתמטית, או כמעט מתחייב, מן הראיות.

מה הוא מדגים

What it costs to make a model autonomous: once the instrument runs itself, every relation it holds must be embodied rather than set by hand each time.

כל המנגנונים