Mathematical Astronomy & Physics

Spherical design with METAPOST

  • version 1.2, rev. 205, 2011-11-10 : deutsch
  • version 1.3, rev. 346, 2013-10-13 : english
    first published: 2011-07-19
    MSC Primary 70F15

In diesem von Denis Roegel(external link) inspirierten Artikel erkläre ich mit ein wenig euklidischer Geometrie die Grundlagen zum Zeichnen von korrekten 2-dimensionalen Bildern von 3-dimensionalen Kugeln, insbesondere von Kreisen auf Kugeloberflächen (wie Längen- und Breitenkreisen) mit METAPOST.

Diese Arbeit ist meinem Bruder Thomas gewidmet.

In this article inspired by Denis Roegel(external link) I explain with some Euclidean geometry the basics of drawing correct 2-dimensional figures of 3-dimensional spheres, in particular circles on spheres (like circles of longitude or parallels of latitude) with METAPOST.

This work is dedicated to my brother Thomas.

Inner Planets of Solar System

  • version 1.0, rev. 229, 2011-12-21 : 2012 weekly positions of inner planets
  • version 1.0, rev. 195, 2011-10-19 : solar.c source code
    first published: 2010-04-30
  • version 1.0, rev. 387, 2014-03-22 : english documentation
    first published: 2010-04-30
  • version 1.0, rev. 388, 2014-03-22 : deutsche Dokumentation
    first published: 2010-05-05
    MSC Primary 70F15

Dedicated to my wife Carmen on our wedding anniversary.

In this paper I visualise the orbits of the inner planets: Mercury, Venus, Earth and Mars. Since Kepler (1571-1630) we know the shape of these curves: they are ellipses, which are here put into their relative position and orientation.

The visualisation is provided by a drawing with METAPOST. In the new revisions only minor changes occur: the solar program now uses the excentricity for that date (instead of J2000.0), the drawing itself uses the customary planetary symbols (instead of text). The presentation is kept at high school level, introducing ideas in a conceptual manner, though not losing sight of computation.

Previous page: Mathematical Recreation
Next page: Algebra