Johannes Fabricius

Johann Fabricius (also Johannes Fabricius; born January 8, 1587 Resterhafe ( Ostfriesland), † January 10, 1617 in Dresden ) was a German astronomer. He discovered independently by Galileo Galilei and other sunspots.

Life

Childhood and youth

Johann Fabricius was the eldest son of eight children of the pastor and astronomer David Fabricius, who ran extensive astronomical and meteorological research and was in correspondence with Tycho Brahe, Johannes Kepler and Simon Marius.

Little is known about Johann Fabricius ' childhood and youth. As a twelve year old Johann survived a disease of the plague that struck northern Germany in 1598 as an epidemic. He later attended, like his father, the Latin school in Brunswick. From there he sent his father often Weather reports this in his " calendarium " recorded.

Study

After leaving school he took in May 1605 to study at the University of Helmstedt, in the already his father had studied. In addition to the usual basic studies at the Faculty of Philosophy he studied medicine. However, he changed already in 1606 at the University of Wittenberg, where he stayed for three years and in addition to grammar, dialectic and rhetoric and geometry, astronomy, chronology and studied physics. From Wittenberg from 1608 he wrote a letter to Johannes Kepler. In addition to astronomy he worked, like his father, with astrology and was convinced that they deliver reliable findings. In addition, he believed he had found a method of weather forecasts. 1609 Fabricius went to Leiden to study at the local university medicine. In the summer of 1611 he returned to Wittenberg and acquired in September the title of Master of Philosophy. About his life almost nothing is known. Obviously, he studied further medicine. He died on a trip to Basel, where he wanted to earn his medical doctor.

Discovery of sunspots

During his time in Leiden Fabricius bought a telescope, which he brought to his father's house in Osteel. He observed, inter alia, the sun, which was not without danger, as he had no tools to mitigate the bright light. He only moved the observation time in the morning and evening hours when the sun was less garish. On February 27, 1611 he took first true dark spots on the sun. Since he was initially unsure if it was an optical illusion or atmospheric phenomena, he repeated his observations, which he hinzuzog his father. And their eyes were affected, they later turned to a less dangerous method of observation: Using a pinhole they turned the sunlight into a darkened room and watched the sun disk on a white piece of paper ( the principle of the camera obscura ). The existence of the spots could be proven beyond doubt. The daily movement of the sun wheel has been reduced to an appropriate self-rotation of the sun. In June of the same year Johann Fabricius published in Wittenberg a 22seitige treatise De Maculis in sole observatis et cum Sole conversione apparent earum narratio, in which he describes all the details of the discovery and his father ascribes a due share.

The discovery was in contrast to the traditional view of Aristotle, after the sun was perfect, and the doctrine of the Church, according to which the sun as it were " untainted " as the Virgin Mary should be. Although the Italian Galileo, the Englishman Thomas Harriot and the German Christoph Scheiner had noticed spots on the sun already in 1610, but Fabricius was the first who described the discovery in a scientific treatise. However, Galileo and Scheiner went over his work in the aftermath silence. As a discoverer of sunspots Fabricius is given by Simon Marius in Mundus Jovialis ( 1614) and by Kepler in the Ephemerides novae ( 1618). Fabricius ' writing was long forgotten.

Johannes Kepler regretted his words of " gifted and zealous young man who lives on through his writing on Sunspots " early death.

Works

• John Fabricius Phrysii De Maculis in brine observatis, et cum Sole conversione apparent earum, narratio etc. Witebergae Anno M.DC.XI.