Otto von Guericke - establishment of the physics of vacuums

Otto von Guericke (November 20, 1602 – May 11, 1686 (Julian calendar); November 30, 1602 – May 21, 1686 (Gregorian calendar) was a German scientist, inventor, and politician. His major scientific achievement was the establishment of the physics of vacuums.

Biography
Guericke was born to a patrician family of Magdeburg, Germany. He served as the mayor of Magdeburg from 1646 to 1676.

Air Pressure and the Vacuum

L'electrisée: an electrostatic device demonstrating "this virtue, almost magic,... called electric" (engraving, c. 1750)In 1650 he invented a vacuum pump consisting of a piston and an air gun cylinder with two-way flaps designed to pull air out of whatever vessel it was connected to, and used it to investigate the properties of the vacuum in many experiments. Guericke demonstrated the force of air pressure with dramatic experiments. He had joined two copper hemispheres of 51 cm diameter (Magdeburg hemispheres) and pumped the air out of the enclosure. Then he harnessed a team of eight horses to each hemisphere and showed that they were not able to separate the hemispheres. When air was again let into the enclosure, they were easily separated. He repeated this demonstration in 1663 at the court of Friedrich Wilhelm I of Brandenburg in Berlin, using 24 horses.

With his experiments Guericke disproved the hypothesis of "horror vacui", that nature abhors a vacuum, which for centuries was a problem for philosophers and scientists. Guericke proved that substances were not pulled by a vacuum, but were pushed by the pressure of the surrounding fluids.

Other research
Guericke applied the barometer to weather prediction and thus prepared the way for meteorology. His later works focused on electricity, but little is preserved of his results. He invented the first electrostatic generator, the "Elektrisiermaschine", of which a vesion is illustrated in the engraving by Hubert-François Gravelot, ca 1750 (illustration, right).

Guericke died in Hamburg, Germany. The Otto von Guericke University of Magdeburg is named after him.

Literature
(All these books are in German)

Die Welt im leeren Raum.
Otto von Guericke 1602-1686., Ausstellungskatalog, 2002.,
ISBN 3-422-06374-9
Otto von Guericke.
Schneider, Ditmar: Ein Leben für die Alte Stadt Magdeburg. 2004,
ISBN 3-519-25153-1
Neue 'Magdeburgische' Versuche über den leeren Raum
Otto von Guericke,
Reihe Ostwalds Klassiker, Bd. 59: Übersetzung von Guerickes "Experimenta nova Magdeburgica de vacuo spatio", 1672. (Magdeburger Halbkugeln) 1996,
ISBN 3-8171-3059-7
Guericke, Otto von: Gesamtausgabe, 24 Bde.
Bd.2/1/1 Guericke, Otto von: Otto von Guerickes Neue (so genannte) Magdeburger Versuche über den leeren Raum. Ottonis de Guericke Experimenta Nova (ut vocantur) Magdeburgica de Vacuo Spatio. Faksimile d. latein. Ausg., 1672. 2002.
ISBN 3-89923-015-9,

External links
Wikimedia Commons has media related to:
Otto von GuerickeUniversity at Magdeburg
The complete text of Experimenta nova (ut vocantur) magdeburgica de vacuo spatio primùm
http://www.desy.de/expo2000/deutsch/dhtmlbrowser/webthemen/04_vakuum/ottovonguericke_druck.htm
Short Biography
http://www.volksstimme.de/guericke/default.asp?column=introduktion
Extensive pages on the Guericke Year in Magdeburg
http://www.deutsches-museum.de/en/collections/ausgewaehlte-objekte/meisterwerke-i/halbkugel/
The famous half-spheres
http://video.uni-magdeburg.de/film.php?Kennz=8
Otto of Guericke and Magdeburg hemisphere video
http://www.mdcc-fun.de/rhythm.university/otto.gericke.video.translation.introduction.html
English video translation

For the complete inventors list please click here