Jewish CosmologyExplore Jewish time through astronomy.

Animation library

114 animations

One-time payment · ILS 50.00 · Full animation library

Mathematics and geography

Map and geography

Maps, locations, distances and projections.

Planar geometry and trigonometry

Lines and chords, squares and rectangles, triangles, circles and areas.

Trigonometric functions

Chord, versines, their half-angle forms, exsecant and excosecant on the unit circle.

Spherical geometry and trigonometry

Great circles, spherical triangles and distances on a sphere.

Functions, series and calculus

Functions, sequences, limits, derivatives and integrals.

Coordinate transformations

Moving between coordinate systems and reference frames.

Interpolation

Estimating intermediate values between calculated points.

Sky and motion

Precession

The changing orientation of the celestial poles and equinoxes.

Axial tilt / obliquity

The orientation of a rotating body and its orbital plane.

Ecliptic

The Earth–Sun plane and its projection onto the sky.

The path of the Sun

The Sun’s apparent daily and annual motion.

Equinoxes

The intersections of the celestial equator and the ecliptic.

Moon phases and motion

Sun–Earth–Moon geometry, illumination and the observer’s sky.

Nodes

Where an orbit crosses a reference plane.

The celestial sphere

The horizon, poles, zenith and celestial reference circles.

Models and the solar system

Rambam’s nine galgalim

Nine transparent Earth-centred layers with a cutaway and synchronized sky views.

Epicycle theory

Circular constructions used in historical planetary models.

Geocentrism

Earth-centred descriptions of celestial motion.

Heliocentrism

Sun-centred descriptions of planetary motion.

The solar system

The Sun, planets and their orbital relationships.

Jewish calendar