De revolutionibus orbium coelestium De revolutionibus orbium coelestium De revolutionibus orbium coelestium ("On the Revolutions of the Heavenly Spheres") is the seminal work on the heliocentric theory of the Renaissance astronomer Nicolaus Copernicus (1473–1543). The book, first printed in 1543 in Nuremberg, Holy Roman Empire, offered an alternative model of the universe to Ptolemy's geocentric system, which had been widely accepted since ancient times. Copernicus initially outlined his system in a short, untitled, anonymous manuscript that he distributed to several friends, referred to as the "Commentariolus". A physician's library list dating to 1514 includes a manuscript whose description matches the "Commentariolus", so Copernicus must
Allegory of the Planets and Continents orbiting the Sun. The cornice of the painting symbolize the continents Europe, America, Africa, and Asia. Allegory of the Planets and Continents Allegory of the Planets and Continents is an 18th-century painting by Italian artist Giovanni Battista Tiepolo. Done in oil on canvas, the allegorical work uses human figures to represent members of the Greco-Roman pantheon, the planets, and four continents. The painting is an elaborate oil sketch made by Tiepolo in preparation for rendering a similar, larger version of his scene. Tiepolo's work was painted to be hung above a staircase of the Wurzburg Residence in Wurzburg, Germany. The