BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Talks.cam//talks.cam.ac.uk//
X-WR-CALNAME:Talks.cam
BEGIN:VEVENT
SUMMARY:Is Water H20? - Professor Hasok Chang\, History &amp\; Philosophy 
 of Science\, Cambridge
DTSTART:20111201T190000Z
DTEND:20111201T200000Z
UID:TALK34494@talks.cam.ac.uk
CONTACT:John O'Toole
DESCRIPTION:Every schoolchild knows that water is H2O\, but it was a terri
 bly difficult thing for scientists to learn originally. The story begins w
 ith the Chemical Revolution of the late 18th century\, in which Lavoisier'
 s notion that water was a compound of oxygen and hydrogen flew in the face
  of the traditional wisdom that it was an element. Opposition to Lavoisier
  persisted in various corners for much longer than usually recognised. Cav
 endish\, whose experiments had taught Lavoisier how to make water from hyd
 rogen and oxygen\, thought that hydrogen and oxygen were merely water with
  an excess or a deficit of 'phlogiston'. Priestley\, who had made oxygen b
 efore Lavoisier\, adopted Cavendish's view of water and defended it to his
  death in 1804. Even the electrolysis of water in 1800 failed to produce a
  complete consensus\, and in fact a significant condundrum was raised by t
 he macroscopic distance between the locations of oxygen-production and hyd
 rogen-production in electrolysis.\n \nDisputes about the mechanism of elec
 trolysis continued throughout the 19th century\, and deciding that water w
 as a compound was by no means the end of the story. When Dalton published 
 his atomic theory in 1808\, he gave the formula of water as HO\, with atom
 ic weights of H and O as (roughly) 1:8. Avogadro's H2O formula was publish
 ed shortly after this\, but it was initially rejected by the majority of c
 hemists. It took half a century of debates\, and in the end\, insights fro
 m organic chemistry before consensus\, was reached on the modern set of at
 omic weights and molecular formulae including H2O. This story of the chang
 ing ontology of water is not only fascinating in itself\, but illustrates 
 many important points about the nature of scientific knowledge and its dev
 elopment.\n \nProf Chang's research interests include history and philosop
 hy of chemistry and physics from the 18th century onward\; philosophy of s
 cientific practice\; other topics in the philosophy of science\, including
  measurement\, realism\, evidence\, pluralism and pragmatism. His book\, I
 s Water H2O? Evidence\, Pluralism and Realism\, will be available shortly 
 from Boston Studies in the Philosophy of Science (Springer).\n
LOCATION:Pfizer Lecture Theatre\,  Department of Chemistry
END:VEVENT
END:VCALENDAR