* 1939 – 1945, the Second Battle of the Atlantic.

Subsequent formalizations were framed as attempts to define " effective calculability " or " effective method "; those formalizations included the Gödel – Herbrand – Kleene recursive functions of 1930, 1934 and 1935, Alonzo Church's lambda calculus of 1936, Emil Post's " Formulation 1 " of 1936, and Alan Turing's Turing machines of 1936 – 7 and 1939.

* 1890 – Anthony Fokker, Dutch aviation engineer ( d. 1939 )

* 1939 – André Ouellet, French-Canadian politician

* 1852 – Ferdinand von Lindemann, German mathematician ( d. 1939 )

* 1939 – Alan Ayckbourn, English writer

* 1939 – Johnny Raper, Australian rugby league footballer

* 1939 – The 1939-40 New York World's Fair opens.

* 1939 – NBC inaugurates its regularly scheduled television service in New York City, broadcasting President Franklin D. Roosevelt's N. Y. World's Fair opening day ceremonial address.

* 1939 – First flight of the turbojet-powered Heinkel He 178, the world's first jet aircraft.

* 1939 – William Least Heat-Moon, American author

* 1939 – Edward Patten, American singer-songwriter and producer ( Gladys Knight & the Pips ) ( d. 2005 )

* 1939 – Bulle Ogier, French actress

* 1939 – Romano Prodi, Italian politician and statesman

* 1939 – Hércules Brito Ruas, Brazilian footballer

* 1939 – Albert Einstein and Leó Szilárd write a letter to Franklin D. Roosevelt, urging him to begin the Manhattan Project to develop a nuclear weapon.

* 1939 – Benjamin Barber, American theorist

* 1939 – Wes Craven, American director

* 1939 – John W. Snow, American politician, 73rd United States Secretary of the Treasury

* 1984 – Marvin Gaye, American singer ( The Moonglows ) ( b. 1939 )

* 2001 – Trinh Cong Son, Vietnamese composer ( b. 1939 )

Eastern European theorists include Pyotr Stolypin ( 1862 – 1911 ) and Alexander Chayanov ( 1888 – 1939 ) in Russia ; Adolph Wagner ( 1835 – 1917 ), and Karl Oldenberg in Germany, and Bolesław Limanowski ( 1835 – 1935 ) in Poland.

* 1939 – First flight of the Lockheed P-38 Lightning.

Lockheed was delivering airplanes to Japan until May 1939.

On 4 September 1939, a Lockheed Hudson of No. 224 Squadron RAF attacked a Dornier Do 18 over the North Sea with inconclusive results but became the first British aircraft to engage the enemy in the Second World War.

However, in 1939, Rapport discovered that if larva of normal flies were fed with silver salts, they develop into yellow bodied flies irrespective of their genotype.

* 1939 Tea for Three ( dramatised by Margery Vosper from the short story Accident )

Merriam-Webster's Dictionary of English Usage says, " The list contains ( in approximate historical order from 1789 to 1939 ) such terms as Columbian, Columbard, Fredonian, Frede, Unisian, United Statesian, Colonican, Appalacian, Usian, Washingtonian, Usonian, Uessian, U-S-ian, Uesican, United Stater.

There has been a trade in diving to catch abalone off parts of the United States coast from before 1939.

The journal began in Strasbourg as Annales d ' histoire économique et sociale ; it moved to Paris and kept the same name from 1929 to 1939.

In 1939, coinciding with the start of World War II, Rene Dubos reported the discovery of the first naturally derived antibiotic, gramicidin from B. brevis.

In 1939, a heated debate took place over whether to prohibit communists from serving in ACLU leadership roles.

Aalto's early experiments with wood and his move away from a purist modernism would be tested in built form with the commission to design Villa Mairea ( 1939 ) in Noormarkku, the luxury home of the young industrialist couple Harry and Maire Gullichsen.

Informally known as " The Big Book " ( with its first 164 pages virtually unchanged since the 1939 edition ), it suggests a twelve-step program in which members admit that they are powerless over alcohol and need help from a " higher power "; seek guidance and strength through prayer and meditation from God or Higher Power of their own understanding ; take a moral inventory with care to include resentments ; list and become ready to remove character defects ; list and make amends to those harmed, and then try to help other alcoholics recover.

Nin left Paris in the late summer of 1939, when residents from overseas were urged to leave France due to the upcoming war and returned to New York City with Guiler ( who was, on his own wish, all but edited out of her diaries published in her lifetime and whose role in her life is therefore difficult to gauge ).

The Beowulf manuscript was transcribed from an original by two scribes, one of whom wrote the first 1939 lines and a second who wrote the remainder, so the poem up to line 1939 is in one handwriting, whilst the rest of the poem is in another.

But in 1939, Robert Oppenheimer and others predicted that neutron stars above approximately three solar masses ( the Tolman – Oppenheimer – Volkoff limit ) would collapse into black holes for the reasons presented by Chandrasekhar, and concluded that no law of physics was likely to intervene and stop at least some stars from collapsing to black holes.

In fact, far from it being a dedicated panzer spearhead arm, less than 15 percent of the Luftwaffe was designed for close support of the army in 1939.

Gold, silver and garnet grave goods from the Anglo-Saxon ship burial at Sutton Hoo ( 1939 ) and late Roman silver tableware from Mildenhall, Suffolk ( 1946 ).

Bundaberg rum was first produced in 1888, production ceased from 1907 to 1914 and from 1936 to 1939 after fires, the second of which caused rum from the factory to spill into the nearby Burnett River.

Ernest Hemingway lived in Cuba from 1939 and stayed until shortly after the Cuban revolution.

Relations further deteriorated when, in January 1948, the U. S. State Department also published a collection of documents titled Nazi-Soviet Relations, 1939 – 1941: Documents from the Archives of The German Foreign Office, which contained documents recovered from the Foreign Office of Nazi Germany revealing Soviet conversations with Germany regarding the Molotov-Ribbentrop Pact, including its secret protocol dividing eastern Europe, the 1939 German-Soviet Commercial Agreement, and discussions of the Soviet Union potentially becoming the fourth Axis Power.

Some rare comic books include copies of the unreleased Motion Picture Funnies Weekly No. 1 from 1939.