Editing John Ambrose Fleming (section)

==Activities and achievements==
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After leaving the [[University of Nottingham]] in 1882, Fleming took up the post of "electrician" to the Edison Electrical Light Company, advising on lighting systems and the new [[Ferranti]] alternating current systems. In 1884 Fleming joined University College London taking up the Chair of Electrical Technology, the first of its kind in England. Although this offered great opportunities, he recalls in his autobiography that the only equipment provided to him was a blackboard and piece of chalk. In 1897 the Pender Laboratory was founding at University College London and Fleming took up the [[Pender Chair]] after the £5000 was endowed as a memorial to [[John Pender]], the founder of [[Cable & Wireless plc|Cable and Wireless]].<ref>{{cite web|url=https://www.ucl.ac.uk/electronic-electrical-engineering/about/history-0|title=History: The early years, 1885–1950|website=UCL Electronic and Electrical Engineering|date=24 September 2018 |access-date=13 January 2023}}</ref>

In 1899 [[Guglielmo Marconi]], the inventor of radiotelegraphy, decided to attempt transatlantic radio communication. This would require a scale-up in power from the small 200–400 watt transmitters Marconi had used up to then. He contracted Fleming, an expert in power engineering, to design the radio transmitter. Fleming designed the world's first large [[radio transmitter]], a complicated [[spark gap transmitter|spark transmitter]] powered by a 25&nbsp;kW alternator driven by a combustion engine, built at [[Poldhu]] in [[Cornwall]], UK, which transmitted the first radio transmission across the Atlantic on 12 December 1901.

Although Fleming was responsible for the design, the director of the Marconi Co. had made Fleming agree that: "If we get across the Atlantic, the main credit will be and must forever be Mr. Marconi's". Accordingly, the worldwide acclaim that greeted this landmark accomplishment went to Marconi, who only credited Fleming along with several other Marconi employees, saying he did some work on the "power plant".<ref>{{cite journal |author=Cornwall Archaeological Society |title=Cornish archaeology |publisher=Cornwall Archaeological Society |oclc=8562888 }}</ref> Marconi also forgot a promise to give Fleming 500 shares of Marconi stock if the project was successful. Fleming was bitter about his treatment. He honoured his agreement and did not speak about it throughout Marconi's life, but after his death in 1937 said Marconi had been "very ungenerous".

In 1904, working for the Marconi company to improve transatlantic radio reception, Fleming invented the first [[thermionic]] [[vacuum tube]], the two-electrode [[diode]], which he called the oscillation valve, for which he received a patent on 16 November.<ref>Fleming Valve patent {{US patent|803684}}</ref> It became known as the [[Fleming valve]]. The [[Supreme Court of the United States]] later invalidated the patent because of an improper disclaimer and, additionally, maintained the technology in the patent was known art when filed.<ref>[http://www.mercurians.org/nov98/misreading.html "Misreading the Supreme Court: A Puzzling Chapter in the History of Radio"] {{webarchive |url=https://web.archive.org/web/20091219110734/http://www.mercurians.org/nov98/misreading.html 
|date=19 December 2009 }}. November 1998, Mercurians.org.</ref>

This invention of the [[vacuum tube]] is often considered to have been the beginning of [[electronics]].<ref>J.Summerscale (ed.) (1965). "The Penguin Encyclopedia", Penguin Books, Harmondsworth, UK.</ref><ref>{{cite book |last1=Macksey |first1=Kenneth |last2=Woodhouse |first2=William |year=1991 |chapter=Electronics |title=The Penguin encyclopedia of modern warfare: 1850 to the present day |publisher=Viking |page=110 |isbn=978-0-670-82698-8 |quote=The electronics age may be said to have been ushered in with the invention of the vacuum diode valve in 1902 by the Briton John Fleming (himself coining the word "electronics"), the immediate application being in the field of radio.}}</ref> Fleming's diode was used in radio receivers and [[radars]] for many decades afterwards, until it was superseded by [[solid state (electronics)|solid state]] electronic technology more than 50 years later.
[[File:John Ambrose Fleming 1906.png|thumb|John Ambrose Fleming (1906)]]
In 1906, [[Lee De Forest]] of the US added a control "grid" to the valve to create an amplifying [[vacuum tube]] RF detector called the ''[[Audion]]'', leading Fleming to accuse him of infringing his patents. De Forest's tube developed into the [[triode]] the first electronic [[amplifier]]. The triode was vital in the creation of long-distance telephone and radio communications, radars, and early electronic digital computers (mechanical and electro-mechanical digital computers already existed using different technology). The court battle over these patents lasted for many years with victories at different stages for both sides. Fleming also contributed in the fields of [[photometry (optics)|photometry]], [[electronics]], [[wireless telegraphy]] (radio), and electrical measurements. He coined the term ''[[power factor]]'' to describe the true power flowing in an [[AC power]] system.

Fleming retired from University College London in 1927 at the age of 77. He remained active, becoming a committed advocate of the new technology of Television which included serving as the second president of the [[Television Society]]. He was [[Knight Bachelor|knighted]] in 1929, and died at his home in [[Sidmouth]], Devon in 1945. His contributions to electronic communications and [[radar]] were of vital importance in winning [[World War II]]. Fleming was awarded the [[IEEE Medal of Honor|IRE Medal of Honor]] in 1933 for "the conspicuous part he played in introducing physical and engineering principles into the radio art".

In 1941 the [[London Power Company]] commemorated Fleming by naming a new 1,555 [[Gross register tonnage|GRT]] [[Coastal trading vessel|coastal]] [[Collier (ship type)|collier]] SS ''Ambrose Fleming''.<ref name=Burntisland>{{cite web |url=http://www.burntisland.net/ships-list-anderson.htm |title=Ships built by the Burntisland Shipbuilding Company Ltd: arranged by date of launch |last=Anderson |first=James B |editor-last=Sommerville |editor-first=Iain |year=2008 |work=Welcome to Burntisland |publisher=Iain Sommerville |access-date=16 June 2011}}</ref>

On 27 November 2004 a [[Blue Plaque]] presented by the [[Institute of Physics]] was unveiled at the [[Norman Lockyer Observatory]], [[Sidmouth]], to mark 100 years since the invention of the thermionic radio valve.