* 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 – Apoorva Sengupta, Indian cricketer

* 2009 – Feroz Khan, Indian actor ( b. 1939 )

The last horsed regiment of the Indian Army ( other than the Viceregal Bodyguard and some Indian States Forces regiments ) was the 19th King George's Own Lancers which had its last mounted parade at Rawalpindi on 28 October 1939.

* 1939 – Joy Mukherjee, Indian actor and director ( d. 2012 )

* 1939 – Mulayam Singh Yadav, Indian politician

* 1939 – Shakuntala Devi, Indian calculating prodigy

Old television Indian Head test card | test pattern, created by RCA in 1939 and widely used until color television gained in popularity

* 1939 – Agnivesh, Indian activist and politician

< imagemap > File: 1930s decade montage. png | From left, clockwise: Dorothea Lange's photo of the homeless Florence Thompson show the effects of the Great Depression ; Due to the extreme drought conditions, the farms become dry and the Dust Bowl spreads through America ; The Battle of Wuhan during the Second Sino-Japanese War ; Aviator Amelia Earhart becomes an American national icon ; German dictator Adolf Hitler and the Nazi Party attempted to establish a New Order of absolute Nazi German hegemony in Europe, which culminated in 1939 when Germany invaded Poland, leading to the outbreak of World War II ; The Hindenburg explodes over a small New Jerseian airfield, effectively ending commercial airship travel ; Mohandas Gandhi walks to the Indian Ocean in the Salt March of 1930 .| 420px | thumb

These range from the large ceremonial Indian mound and cave at Nanih Waiya, built about 1700 years ago and sacred to the Choctaw ; to the still thriving Williams Brothers Store, a true old-fashioned general store founded in 1907 and featured in National Geographic in 1939 as a source of anything from “ needles to horse collars ”, and still offering everything from bridles, butter and boots to flour, feed and fashion.

* " Indian Summer " w. Al Dubin m. Victor Herbert Words 1939.

1939 Indian Dispatch Tow, 3-wheeler

1939 Indian 4, in the " World's Fair " color scheme, in commemoration of the 1939 New York World's Fair.

Captain Alan Villiers ( 1903 – 1982 ) documented the days of sailing trade in the Indian Ocean by sailing on dhows between 1938 and 1939 taking numerous photographs and publishing books on the subject of dhow navigation.

* Hindustani Lal Sena, ( Indian Red Army ), formed 1939

In the wake of western and Indian proliferation in music, composer and singer Ananda Samarakoon emerged from training at Rabindranath Tagore's school at Shanthiketalan to develop a uniquely Sinhalese music tradition in 1939.

In 1939, British officials had no plan for expansion and training of Indian forces, which comprised about 130, 000 men ( in addition there were 44, 000 men in British units in India in 1939.

* Indian locomotive class WL ( 1939 ), a four 4-6-2 locomotives built in 1939 that went to West Pakistan at partition

Mulayam Singh Yadav ( born 22 November 1939 ) is an Indian politician belonging to the Samajwadi Party from Uttar Pradesh. His supporters call him Netajee and Dhartiputra.