Christoph Scheiner

The systematic observation of the Sun

from Hemleben: 'Galilei'

Father Christoph Scheiner observates the sunspots, from "Rosa Ursina", 1630

Christoph Scheiner was born July 1575 the 25th in Wald at Mindelheim in Bavaria and 1595 he entered the Jesuit order at Landsberg. Until 1609 he studied philosophy, theology, mathematics, and Hebrew, from 1610 until 1616 he was professor for the last two sciences.

In this time he also began with his astronomical activities, when in January 1612 his first writings about sunspots were published. Because the fact of sunspots at all was contradictious to the ecclesiastical scholarship of the virginity of the unchangeable sky and the celestial objects, Scheiner's letters to the Augsburg publisher Markus Welser were published under the pseudonym: "Apelles latens post tabulam" (Apelles hidden behind the table). For viewing the Sun Scheiner had used colored visor glass. His intentions were a test of the seen glance of spots on the solar disk, seen at deep foggy weather in 1611. These spots were discovered parallel by the East Frisian astronomer Johannes Fabricius (1587-1615) (son of David Fabricius (1564-1617), discoverer of the variability of Mira, see also John Goodricke) and the Italian physicist Galileo Galilei (1564-1642). The published work "Joh. Fabricii Phrysii de maculis in Sole observatis et apparente earm cum Sole conversione Narratio" came out already in 1611, while the "Istoria e dimonstrazioni intorno alle macchie solari e loro accidenti" of Galilei wasn't printed before April 1613.

To the three letters by Scheiner Galilei replied with three (not that nice) own letters, and while Scheiner was still convinced by the Ptolemaian view to the world order and discussing the spots as small planets within the Mercury orbit or even below the Moon orbit in favour to spots on the Sun, Galilei was sure about the shadows on the surface of the Sun and he interpreted it as another argument for the Copernican heliocentric world. With the concept of sub mercurian or sub lunar bodies Scheiner wanted to save the invariance of the higher celestial spheres.

The sun, 11.2.1999The sun, 16.11.1999

The Sun over Berlin, 11.2.1999 16:30h and 16.11.1999 15:00h CET

Scheiner was one of the first using astronomical telescopes for the following solar observations. This kind of telescope was described by Johannes Kepler (1571-1630) in 1611 and consists of two collecting lenses. It provides upside-down and left-to-right images but with better magnification and light collecting capabilities.

Since 1616 Scheiner was working as father confessor and also as a consultant for some of the leaders in Europe. Besides of this he published his work "Oculus, hoc est: fundamentum opticum" in 1619, in which he describes some of the facts about the human eye, so the refraction indices within the main eye parts like lense and glass body, he states the retina as the crucial part for the sense of viewing, and describes the functions for other parts like pupil and iris. 1624 he came to Rome and continued his efforts for the systematical observation of the Sun at the observatory of the Gregoriana. Following the movement of the sunspots he calculated the rotation times of the Sun, that is about 25 days near the equator and 31 days near the poles. With this Scheiner determined the equator and rotation axis of the Sun, he discovered the solar flares and the granulation of the photosphere.

His discoveries he wrote down in his work "Rosa Ursina", which preprint works lasted from 1626 to 1630 because of the numerous illustrations. Most of Scheiner's discoveries could be resolved by science late after his death. And although he rejected his first theories about sub mercurian bodies and accepted the fact of spots on the Sun as a contradiction to the philosophy of Aristoteles of the invariable celestial bodies, until his death at July the 18th, 1650 in Neisse he didn't move from his confession about the geocentric universe.

Sources:
Johannes Hemleben: Galilei, rororo 1969
Fritz Krafft, Adolf Meyer-Abich (Eds.): Große Naturwissenschaftler, Fischer 1970


Page history:
created 1999-03-22
modified 1999-03-24 Sun pictures
modified 1999-11-30 corrections
modified 2000-02-08 picture link corrected

To the Sky over Berlin...To the astronomy links...-- jd --