Editing 1939 in science (section)

==Computer science==
* September 4 – [[Alan Turing]] and [[Gordon Welchman]] report to the United Kingdom [[Government Code and Cypher School]], [[Bletchley Park]].<ref>{{cite book|last=Smith|first=Michael|authorlink=Michael Smith (newspaper reporter)|title=Station X: the Codebreakers of Bletchley Park|edition=rev.|series=Pan Grand Strategy Series|year=2007|publisher=Pan Macmillan|location=London|isbn=978-0-330-41929-1|page=60}}</ref>
* October – [[John Vincent Atanasoff|John V. Atanasoff]] with [[Clifford Berry]] demonstrate the first prototype [[Atanasoff–Berry Computer]] at [[Iowa State University]].<ref>{{cite book|last=Mollenhoff|first=Clark R.|year=1988|title=Atanasoff: Forgotten Father of the Computer|isbn=978-0-8138-0032-5|publisher=Iowa State University Press|location=Ames|url-access=registration|url=https://archive.org/details/atanasoffforgott0000moll}}</ref>
* Publication of [[Vannevar Bush]]'s article "Mechanization and the Record" proposing a [[proto-hypertext]] [[collective memory]] machine which he soon afterwards calls '[[memex]]'.