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Schwabe, Samuel Heinrich

observed cycle pharmacy astronomy

[sch vah buh] (1789–1875) German astronomer: discovered the sunspot cycle.

Schwabe studied pharmacy in Berlin but, although he took over his mother’s pharmacy business, his real enthusiasm was in astronomy. When he was 40 he sold the business and expanded to full time his interest in astronomy. From 1826 he had observed the Sun, projecting its image from a small (2 inch/5 cm) telescope, in an effort to find a hypothetical planet within the orbit of Mercury, hoping to see it in transit across the Sun’s disc. In this way he became interested in sunspots, and observed them daily for the rest of his long life.

By 1843 he could announce that they appeared to increase and decrease in number over a 10-year period. Later study of records by the Swiss astronomer J R Wolf (1816–93) confirmed this, and refined the periodicity to 11.1 years. At about the same time J Lamont (1805–79) showed that the Earth’s magnetic field also varied over about a 10-year cycle, which alternated between weak and strong, and that the trend of the cycle could also be observed in Earth’s weather conditions and in plant growth.

All attempts to observe a new ‘innermost planet’ have failed prediction of it in 1845 (he even named it Vulcan) was based on perturbations in Mercury’s orbit, which by 1916 were deduced to result from relativity effects.

Schwabe was the first to record Jupiter’s Great Red Spot, in a sketch of 1831.

Schwann, Theodor [next] [back] Schwab, Charles - Overview, Personal Life, Career Details, Chronology: Charles Schwab, Social and Economic Impact

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