Johann Christian Poggendorff

Johann Christian Poggendorff (December 29, 1796 - January 24, 1877), German physicist, was born in Hamburg.

Introduction

Poggendorff was a physicist of high (although not of the very highest) rank. He was wanting in mathematical ability but was an "able and conscientious experimenter". Poggendorff never displayed in any remarkable degree the power of scientific generalization, which, whether accompanied by mathematical skill or not, never fails to mark the highest genius in physical science. He was, however, very fertile and ingenious in devising physical apparatus. By far the greater and more important part of his work related to electricity and magnetism. Poggendorff is known for his electrostatic motor which is analogous to Wilhelm Holtz's electrostatic machine.

Biography

His father, a wealthy manufacturer, having been all but ruined by the French siege, he had, when only sixteen, to apprentice himself to an apothecary in Hamburg, and when twenty-two began to earn his living as an apothecary's assistant at Itzehoe. Ambition and a strong inclination towards a scientific career led him to throw up his business and remove to Berlin, where he entered the university in 1820. Here his abilities were speedily recognized, and in 1823 he was appointed meteorological observer to the Academy of Sciences.

Even at this early period he had conceived the idea of founding a physical and chemical scientific journal, and the realization of this plan was hastened by the sudden death of Ludwig Wilhelm Gilbert, the editor of "Gilbert's Annalen der Physik", in 1824 Poggendorff immediately put himself in communication with the publisher, Barth of Leipzig, with the result that he was installed as editor of a scientific journal, "Annalen der Physik und Chemie", which was to be a continuation of "Gilbert's Annalen" on a somewhat extended plan. Poggendorff was admirably qualified for the post, and edited the journal for 52 years, until 1876. In 1826, Poggendorff developed the mirror galvanometer, a device for detecting electric currents.

He had an extraordinary memory, well stored with scientific knowledge, both modern and historical, a cool and impartial judgment, and a strong preference for facts as against theory of the speculative kind. He was thus able to throw himself into the spirit of modern experimental science. He possessed in abundant measure the German virtue of orderliness in the arrangement of knowledge and in the conduct of business. Further he had an engaging geniality of manner and much tact in dealing with men. These qualities soon made Poggendorff's "Annalen" the foremost scientific journal in Europe.

In the course of his fifty-two years editorship of the "Annalen" Poggendorff could not fail to acquire an unusual acquaintance with the labors of modern men of science. This knowledge, joined to what he had gathered by historical reading of equally unusual extent, he carefully digested and gave to the world in his "Biographisch-literarisches Handworterbuch zur Geschichte der exacten Wissenschaften", containing notices of the lives and labors of mathematicians, astronomers, physicists, and chemists, of all peoples and all ages. This work contains an astounding collection of facts invaluable to the scientific biographer and historian. The first two volumes were published in 1863; after his death a third volume appeared in 1898, covering the period 1858-1883, and a fourth in 1904, coming down to the beginning of the 20th century.

His literary and scientific reputation speedily brought him honorable recognition. In 1830 he was made royal professor, in 1834 Hon. Ph.D. and extraordinary professor in the University of Berlin, and in 1839 member of the Berlin Academy of Sciences. Many offers of ordinary professorships were made to him, but he declined them all, devoting himself to his duties as editor of the "Annalen", and to the pursuit of his scientific researches. He died at Berlin on the January 24, 1877.

Illusion

The "Poggendorff Illusion" is an optical illusion that involves the brain's perception of the interaction between diagonal lines and horizontal and vertical edges. It is named after Poggendorff, who discovered it in the drawing of Johann Karl Friedrich Zöllner, in which he showed the Zöllner illusion in 1860. [cite journal
title = Ueber eine neue Art von Pseudoskopie und ihre Beziehungen zu den von Plateau und Oppel beschrieben Bewegungsphaenomenen
author = Zöllner F
journal = Annalen der Physik
volume = 186
issue =
pages = 500–25
year = 1860
url = http://gallica.bnf.fr/ark:/12148/bpt6k151955/f512.table
doi = 10.1002/andp.18601860712 ] In the picture to the left, a straight black line is obscured by a dark gray rectangle. The black line appears disjointed, although it is in fact straight; the second picture illustrates this fact.

References

ee also

* Chromic acid cell

Publications

* J. C. Poggendorff, "Annalen Der Physik", Ser. 2, Vol. 139, pp 513-546 (1870)
* J. C. Poggendorff, "Biographisch-Literarisches Handwörterbuch der exakten Naturwissenschaften" "(Tr. "biographic-literary hand dictionary of the accurate natural sciences"). Johann Ambrosius Barth, Leipzig, 1863.
* Emil Frommel, "Johann Christian Poggendorff" (Berlin, 1877)

External artricles

;General
* " [http://f3wm.free.fr/sciences/es_disk.html Poggendorff's disk] ". (fr. "Disque de Poggendorff") f3wm.free.fr, 2004-11-08.

;Illusion
* [http://www.cut-the-knot.org/Curriculum/Geometry/Illusion.shtml Poggendorf Illusion]
* [http://www.cut-the-knot.org/Curriculum/Geometry/CircularPoggendorf.shtml Circular Poggendorf Illusion]
* [http://epsych.msstate.edu/descriptive/Vision/Poggendorf/pog02.html Poggendorf Illusion]
* [http://www.enane.de/ontoform.htm Explanation of the Poggendorff, Hering, and Zoellner illusions]

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