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G. Giacomelli and L. Patrizii University of Bologna and INFN. The legacy of Galvani and Volta in contemporary science. Introduction Electricity in ‘700 Galvani Galvani’s Techniques Volta Galvani-Volta dispute The legacy of Galvani and Volta Technical names from Galvani, Volta.
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G. Giacomelli and L. Patrizii University of Bologna and INFN The legacy of Galvani and Volta in contemporary science • Introduction • Electricity in ‘700 • Galvani • Galvani’s Techniques • Volta • Galvani-Volta dispute • The legacy of Galvani and Volta • Technical names from Galvani, Volta Colloquium Stanford University December 2004
1. Introduction • 1998 Bicentennial of Galvani’s death : Celebrations in Bologna • 1999 Bicentennial of the invention of the battery by Volta: Celebrations in Pavia, Como Workshops, Seminars, Exhibits, Itinerant Exhibitis and multimedial activities in Italy and abroad www.bo.infn.it/galvani http.//ppp.unipv.it/Volta/ Itinerant Exhibitions of The legacy of Galvani and Volta in contemporary science for Italian Institutes of Culture Famous Galvani – Volta dispute with important consequences in Physics, Physiology, Medicine,… L. Patrizii, G. Giacomelli,INFN-Bologna
2. Electricity in ‘700 First studies of electricity “ Electricism” “Irritability” of muscles, … Sources of electricity Leyden Jar Electrostatic machine Medicine, Philosophy, Physics, ….: No clearcut divisions L. Patrizii, G. Giacomelli,INFN-Bologna
3. Luigi Galvani • 9/9/1737 Born (via Marconi 25, Bologna) • 1759 Graduates in Medicine at Bologna Univ. “ “ Philosophy • 1762Marries • 1763 Lecturer in Medicine at the Bologna Univ. • 26/1/1781 First frog “Jump” (contraction) • 1782 Prof. of Obstetrics at Inst. of Sciences • 1791 Publishes “ De Viribus Electricitatis in Motu Musculari. Commentarii” 1792 Starts the dispute with Volta • 1794 Publishes “L’Arco Conduttore” • 1795 Travels to Rimini and Senigallia to study electric fishes (“Il Taccuino”) • 1798 Refuses to pledge allegiance to the “Cisalpine Republic” • 4/12/1798Dies • Professor Emeritus
4. Galvani’s Techniques Frog prepared “ as usual ” : • lower body with exposed nerves metal inserted in the vertebral canal - various connections Electricity from Leyden Jar Electrostatic machine Lightning and thunder Animal electricity artificial natural L. Patrizii, G. Giacomelli,INFN-Bologna
Anatomical theatre Bologna L. Patrizii, G. Giacomelli,INFN-Bologna
Galvani’s Discoveries in 1780-1790 • First frog “jumps” : Galvani touches crural nerve in presence of external sources of electricity • Frog jumps when Galvani touches a nerve and a spark is made by a distant machine (first detection of e. m. waves ? ) • Frog with antenna in balcony and lightning (e. m. waves) • First electrical circuit: frog jumps when he simply connects nerve-muscle with a metalwire Galvani concludes that intrinsic electricity is present in animals and that external conductors induce contractions by allowing for the flow of this internal electricity L. Patrizii, G. Giacomelli,INFN-Bologna
Frog prepared in the usual way for the experiment with the “Electrostatic machine” and the “Leyden jar” Galvani’s experiment with the frog prepared in the “usual way”, with the electrostatic machine and the Leyden jar L. Patrizii, G. Giacomelli,INFN-Bologna
Galvani’s “atmospheric discharge detector” Galvani’s atmospheric discharge detector Frog in balcony: wind and no lightning: legs touche metal L. Patrizii, G. Giacomelli,INFN-Bologna
- The Galvani’s lab was at his home with private help from relatives, friends, .... - Second half of ‘700: Institutes were formed, with labs for researchers - Academies: attached to the Institutes, were places for discussions L. Patrizii, G. Giacomelli,INFN-Bologna
5. Alessandro Volta • 18/2/1745 Born in Como • 1763 Completes his studies in a catholic seminar • 1769 First publication in physics. • 1775Invents the Electrophorus: first example of electrostatic machine based on the induction principle • 1776“Flammable air” from marshes (methane). Volta constructs an interesting gadget later called Volta’s Pistol. • 1778 Professor of Physics at the University of Pavia • 1780Condenser electroscope • 1781 - 1784 Travels to several european countries • 1792Startes the dispute with Galvani • End 1799Invents the battery • 1801Gold medal from Napoleon. Public life • 5/3/1827Dies L. Patrizii, G. Giacomelli,INFN-Bologna
Alessandro Volta L. Patrizii, G. Giacomelli,INFN-Bologna
6. Galvani–Volta dispute • 1791 Volta repeats Galvani’s experiments He gives importance to bi-metallic arc as source of electricity ( “ E’ la diversita’ dei metalli che fa”) • 1794 Galvani: it works even with single metal (less violent contractions) Volta : effects from metal-solution contact ( E’ la differenza che fa”) • 1797 Galvani : only contact of two nerves (no metal) This experiment is now considered the foundation of electrophysiology L. Patrizii, G. Giacomelli,INFN-Bologna
Galvani–Volta dispute • 1798 Galvani is fired . Dies • 1799 Volta : Electric Battery - Stacks of ( Ag – solution – Zn) • 1800 Volta receives gold medal by Napoleon • …Volta wins! …but Animal electricity exists! And it is much more complex than what one could possibly imagine Galvani: “In animals there is a particular machine capable of generating a disequilibrium” Now we know that this machine corresponds to the cell membrane with ionic pumps and Na+, K+ ionic channels Animals: systems of complex computer networks L. Patrizii, G. Giacomelli,INFN-Bologna
1799 Volta invents the pile, the first reliable source of electricity L. Patrizii, G. Giacomelli,INFN-Bologna
Neural circuit PET L. Patrizii, G. Giacomelli,INFN-Bologna
PET, Positron Electron Tomography L. Patrizii, G. Giacomelli,INFN-Bologna
7. The legacy of Galvani and Volta Galvani: Volta • From an academic dispute to great progress Animal electricity Biology of living organisms Father of electrophysiology Physics of non-living bodies Reliable sources of electricity Sensitive detectors A nerve is a conductor of large resistance. An electric signal moves at low velocity (~ 500 km/h) and is regenerated many times Electromagnetism E.M. waves Biophysics, Health Physics, Medical Physics TV – Communications Computers – Informatics Bio-electronics Transformation of economics and of society, progress in sciences and technologies, medicine, improvements in the quality of life, ...... L. Patrizii, G. Giacomelli,INFN-Bologna
22 terms with Galvani 8. Technical terms from Galvani, Volta Webster dictionary • 10 terms with Volta • Volt • Voltage • Voltmeter • Voltaic • … Physics : Galvanometer Medicine: Galvanotherapy Technology: Galvanotechnique ... Galvanizing !!! L. Patrizii, G. Giacomelli,INFN-Bologna
Lucia Galeazzi, Galvani’s wife L. Patrizii, G. Giacomelli,INFN-Bologna