Guglielmo Marconi

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Guglielmo Marconi (around 1907) Signature of Guglielmo Marconi

Guglielmo Marconi ([ ɡuʎˈʎɛlmo marˈkoːni ]), since 1924 1st Marchese of Marconi (born  April 25, 1874 in Bologna ; † July 20, 1937 in Rome ), was an Italian radio pioneer and founder of the Wireless Telegraph & Signal Company , which later became Marconi Company became. In 1909 he received the Nobel Prize in Physics for his practical work in the field of radio telegraphy together with Ferdinand Braun , who developed the theoretical basis for it .

Life

One of Marconi's first broadcasters. The upper metal plate serves as an antenna.

Guglielmo Marconi was born as Guglielmo Giovanni Maria Marconi, the second son of the Italian aristocratic landowner Giuseppe Marconi and his Irish wife Annie Jameson, granddaughter of John Jameson, the founder of the Jameson & Sons whiskey distilleries . Together with his older brother Alfonso, he and his mother spent their early childhood from 1879 to 1881 in the English city of Bedford at a private school, then returned to Italy with his family and went to Florence until the age of 14 , then for two Years in Livorno , at school, where he also received private lessons in natural sciences from Vincenzo Rosa . In the summer of 1892 he attended a few lectures with Augusto Righi and Bernardo Dessau at the University of Bologna , but never got the higher education entrance qualification and admission for a regular study at the university or the military academy. The essential period for his important work fell in the period from 1894 to just after the turn of the century. In 1909 he received the Nobel Prize in Physics.

On March 16, 1905, Marconi married Beatrice O'Brien, daughter of the 14th Baron of Inchiquin. The marriage has three children, the daughters Degna and Gioia and the son Giulio. The marriage was divorced in 1924 and declared null and void in 1927, allowing Marconi to remarry. In his second marriage, he married Maria Cristina Bezzi Scali on June 16, 1927, and in 1930 his daughter Maria Elettra Elena Anna was born. Marconi was 53 years old when he married the second time and was almost twice his wife's age.

In 1923 he joined the Italian National Fascist Party (PFN). 1924 Marconi was on the proposal of the fascist government by King Viktor Emanuel III. ennobled and received the title Marchese (German: Margrave ). In 1928 he became president of the Italian National Council for Science , in 1930, at the suggestion of Benito Mussolini, he became president of the Accademia Nazionale dei Lincei (Royal Italian Academy of Sciences), which also made him a member of the grand fascist council . In 1931 he became a member of the Vatican Pontifical Academy of Sciences . However, since Marconi advocated an alliance with England against the party line, tensions arose again and again. In 1932 Marconi became a member of the US National Academy of Sciences .

On July 19, 1937, Marconi suffered a stroke in Rome , which he died the following day. He was buried there with a state act and after the completion of a mausoleum at the family headquarters in the Villa Griffone in Pontecchio near Bologna , he was transferred there in October 1941. Marconi was adored in his homeland, but he achieved his greatest economic success in England, where most of the original documents and objects are located.

plant

Start time

Marconi in 1896 with his transmitter and receiver unit

In 1894, at the age of 20, he first dealt with the theoretical work of Heinrich Hertz , and in 1895 he began his first practical experiments on the so-called Hertzian waves , an early term for electromagnetic waves . He initially carried out the experiments at the family home in the Villa Griffone and was able to wirelessly bridge distances of around two kilometers with the first experimental setups. As a transmitter he used pop-spark transmitters , modified the structures in various details and tried out various improvements in experiments.

In the summer of 1895 he also made some of his experiments over 1.5 km away in Salvan in the Swiss Alps. In 1896 Marconi built a “device for detecting and registering electrical vibrations”. The detection of the high-frequency vibrations was based on the so-called coherer , which contains metal filings in a thin glass tube. The received high-frequency oscillation changes the electrical resistance of the arrangement, whereby various parameters such as the grain size and the alloy of the metal chips used have a significant influence on the function. Various types of coherers had already been used by Édouard Branly in 1890 and independently thereof by Alexander Stepanowitsch Popow in 1893 . Popow did not use the coherer to receive messages, but to detect lightning discharges .

Sending attempts in England

Transmission attempt with a Marconis transmitter in May 1897 via the Bristol Channel

At the beginning of 1896, his experiments on the transmitter and receiver unit had progressed so far that he was considering a first patent for it. Marconi came back to London in February 1896 through a family friend, General Ferrero, who was then the Ambassador of Italy to England, demonstrated his order and submitted a detailed patent application in mid-1896. Through another family contact, his maternal cousin Henry Jameson-Davis, Contact was made with William Henry Preece in London in mid-1896 , then chief engineer of the British General Post Office . Impressed by Marconi's system, Preece subsequently became a supporter of Marconi. In December of the same year, Preece gave a demonstration of Marconi's broadcast system, claiming that Marconi was the inventor of wireless communications . This led to contradictions, especially in academic circles and at Oliver Lodge , since Lodge also made significant contributions to Marconi's radio system. However, Lodge had failed to recognize the relevant practical significance in earlier work and discoveries and to secure the inventions under patent law.

In May 1897, on the intention of Preece, the British Post Office made the first attempts at sending in the Bristol Channel from Flat Holm Island to the mainland, initially over a distance of about six kilometers. After several unsuccessful attempts, the message let it be so was transmitted using the Marconi pop-spark transmitter. Immediately afterwards, the transmission succeeded over a greater distance of approx. 15 km. The witness present during the trial of Adolf Slaby from Germany suggested it for the procedure, the appropriate term spark telegraphy , German Funkentelegrafie before, which resulted in the German terminology such as radio transmission established for wireless communication.

Company formation

Marconi 1901, with a transmitter system (right) and the matching receiver on the left

The Wireless Telegraph and Signal Co. was founded in London on July 20, 1897 . Marconi received substantial financial support from his family, especially from his cousin Henry Jameson-Davis: First Chairman of the Wireless Telegraph and Signal Co. , later renamed Marconi's Wireless Telegraph Co. Ltd , the whiskey distiller Jameson-Davis, seven the first eight partners in the company were people from the whiskey industry from Jameson-Davis. The patent rights were transferred to the newly founded company, making Marconi financially more independent. The American American Marconi Wireless Corporation was founded a few years later after the first successful wireless connections on November 22, 1899 and was incorporated into the Radio Corporation of America (RCA) in 1919 . One year later, the Marconi International Marine Co. was founded, which dealt with the installation and operation of radio transmitters on ships, an essential line of business for Marconi.

The founding of the Wireless Telegraph and Signal Co. resulted in a series of test transmission systems in the following two years, 1898 and 1899, with the range being continuously improved. The first paid radio telegram was sent to Bournemouth by Lord Kelvin from the Isle of Wight in early 1898 . Kelvin insisted on paying for the trial transfer. On March 27, 1899, there was the first wireless connection across the English Channel from the South Foreland Lighthouse near Dover to Wimereux . There were also several installations on ships. In 1899, during British military maneuvers, HMS Europa bridged a distance of around 150 km as a relay station via HMS Juno .

In 1900, Marconi achieved a further increase in range and, above all, selectivity through a technical improvement . In previous transmitter systems, there was only one oscillating circuit, which was the transmitter circuit and the oscillator circuit at the same time . Energy was withdrawn from this oscillating circuit by radiation, so that the damped oscillation quickly came to an end. A longer period of oscillation at a frequency that is as constant as possible, triggered by the popping spark, is desirable , but this is opposed by the need for the most efficient possible energy emission. By separating these two oscillating circuits and the only loose and adjustable coupling between them, Marconi was able to achieve an increase, especially in selectivity and range, with otherwise roughly the same power input. The process was granted as a British patent number 7777.

Transatlantic radio link

Radio station on Poldhu in Cornwall; first transmitting antenna that was destroyed by a storm before it was commissioned
Second transmitting antenna with which the first transatlantic radio link succeeded

On Poldhu on The Lizard peninsula in Cornwall , the construction of a first radio station began at the end of 1900, with which the first transatlantic connection should be carried out. The transmission systems were largely planned by John Ambrose Fleming , scientific advisor at Marconi at the time. The transmitter, designed for an output of approx. 25  kW , was financed by Marconi's company Wireless Telegraph and Signal Co. and set up on the coast with a clear view to the west. Work on the first station was completed in January 1901. Even before the first transmission attempts could take place, the antenna construction collapsed due to the weather during a storm. In the same year, a second antenna, consisting of 60 individual wires, stretched between two 46 m high masts, was installed as a makeshift.

On December 12, 1901 then succeeded Poldhu from the first, but unconfirmed transatlantic radio reception of a very short signal, three points for the Morse code letter S . The St. John's facility in North America could only receive messages. Marconi was at the receiving station and around noon noted the reception in his diary. However, there were no other witnesses, also because of the bad weather conditions at the station at the time, and later investigations based on the noon time of the day and the performance of the transmitting station in Poldhu assume that the three clicks that the Marconi made for the Morse code from the Letter S held, was atmospheric disturbance and was not sent by Poldhu.

In 1902, systematic range tests were carried out on the warship USS Philadelphia . It was found that the reception in the late evening and night hours is significantly better than in the late morning and at lunchtime. The underlying daytime-dependent physical changes in the ionospheric layers were still unknown at the time and were only discovered around 25 years later by Edward Victor Appleton . In 1902 Marconi was able to further improve the transmitter system and transmit longer and clear test messages in both directions across the Atlantic Ocean.

The first public transatlantic communication took place on January 18, 1903: Marconi exchanged greetings between US President Theodore Roosevelt and the King of England Edward VII from the Marconi Wireless Station in Cape Cod , Massachusetts . The system was adopted by the Kriegsmarine. From the end of 1903, radio telegrams were transmitted daily between Glace Bay in Nova Scotia and Poldhu in Cornwall over a distance of 3840 km. Marconi also communicated with the passing ship traffic on the Atlantic from the Mizen Peninsula in southwest Ireland . On June 26, 1905, Iceland received the first telegram in its history, even before a submarine cable was laid.

Since 1907 there was a wireless transatlantic telegraph service for the public from the western Irish town of Derrygimla near Clifden . The broadcasting station was destroyed during the Irish Civil War in 1922. Marconi later dealt with the use of short and microwaves .

Marconi succeeded in establishing almost a world monopoly in the early days of maritime radio traffic . Opponents were mainly German developments by Ferdinand Braun at Siemens & Halske and Adolf Slaby at AEG ; from 1903 also Telefunken and DEBEG founded in 1911 .

Others

Because of his contribution to wireless telegraphy Marconi was a free passage for the maiden voyage of the RMS Titanic offered in April 1912th However, he had to deal with correspondence and therefore took the RMS Lusitania three days earlier , as there was a stenographer on board this ship. Three years later, in April 1915, Marconi took part in the last completed ocean crossing of the Lusitania , which was sunk by the German submarine U 20 on its subsequent crossing .

Together with Pope Pius XI. and Giuseppe Gianfranceschi SJ he was one of the creators of Vatican Radio , which started operating on September 21, 1930.

Commemoration

Plaque in the Basilica of Santa Croce , Florence
Marconi on the last Italian 2000 lire banknote

When Marconi died, all radio communications worldwide were suspended for two minutes in his memory.

The municipality of Sasso Marconi bears his name. About three kilometers north of Sasso Marconi are the Villa Griffone - today's Marconi Museum - and the Marconi mausoleum .

In recognition of his achievements, the asteroid (1332) Marconia and a moon crater on the back of the moon are named after him. The international airport in the Italian city of Bologna is also called Guglielmo Marconi . In memory of him, an annual amateur radio contest is called the Marconi memorial contest . In the Italian language, a radio operator is called a marconista .

Marconi was depicted on the last Italian 2000 lire banknote issued by the Banca d'Italia between 1990 and 2001.

literature

  • WJ Baker: A History of The Marconi Company . Routledge, 1970, ISBN 0-415-14624-0 .
  • Walter Kellogg Towers: Masters of space : Morse and the telegraph; Thompson and the cable; Bell and the telephone; Marconi and the wireless telegraph ; Carty and the wireless telephone; Publisher: Harper & brothers, New York & London, 1917
  • GB Marini Bettòlo: Guglielmo Marconi - Personal Memories and Documents . In: Rivista di Storia della Scienza . Vol. 3, 1986, p. 453 f.
  • F. Gardiol and Y. Fournier: Salvan, the cradle of telecommunications . In: Bulletin SEV / VSE 21-2007, pp. 24-28
  • Y. Fournier and F. Gardiol: Marconi et Salvan: à l'aube de la télécommunication sans fil. Ed. Porte-Plumes, Ayer 2009
  • M. Giorgi, B. Valotti: Guglielmo Marconi Wireless Laureate , Bononia University Press, 2010
  • Kurt Jäger, Friedrich Heilbronner: Lexicon of electrical engineers . 2nd Edition. VDE-Verlag, Berlin 2010, ISBN 978-3-8007-2903-6 , p. 273-274 .
  • Robert A. Chipman: Marconi, Guglielmo . In: Charles Coulston Gillispie (Ed.): Dictionary of Scientific Biography . tape 9 : AT Macrobius - KF Naumann . Charles Scribner's Sons, New York 1974, p. 98-99 .

Web links

Commons : Guglielmo Marconi  - collection of images, videos and audio files

Movies

  • Pioneer of wireless communication , film by Axel Engstfeld, 2011 at Terra X
  • Thomas Ammann: Milestones in early communication. DVD. Script: Susanne Päch. Camera: Johannes Kirchlechner. Series: PM Knowledge Edition. Milestones, 3rd no year (2007), 60 min.

Individual evidence

  1. ^ Accademia di scienze (ed.): Atti della Accademia di scienze, lettere e arti di Palermo: Scienze . Presso l'accademia, 1974, p. 11 .
  2. a b c d e f g h i R. W. Simons: Guglielmo Marconi and Early Systems of Wireless Communication. 1996, accessed March 31, 2016 .
  3. Roman Rota , Westmonasteriensis , coram Grazioli 11 April 1927, AAS 19 (1927) 217 -227 = RR Dec 19 (1927) 104-115
  4. a b Barbara Valotti: Biography Guglielmo Marconi. Retrieved April 1, 2016 .
  5. Fred Gardiol, Yves Fournier: Salvan, the cradle of telecommunications. Marconi and his first attempts at wireless communication in the Swiss Alps. (PDF; 486 kB) , Bulletin SEV / VSE 21/2007, pp. 24–28
  6. British Patent No. 12039 (1897) " Improvements in Transmitting Electrical impulses and Signals, and in Apparatus therefor ". Filing date June 2, 1896; Issued July 2, 1897
  7. Joachim Beckh: Lightning and anchor . tape 1 , ISBN 3-8334-2996-8 , pp. 261 .
  8. ^ British Patent No. 7777 (1900) " Improvements in Apparatus for Wireless Telegraphy ". Filing date April 26, 1900; Issued April 13, 1901
  9. Holy See: The Founding of Vatican Radio , accessed January 3, 2012
  10. Marconi @ the-moon.wikispaces.com (accessed October 14, 2010)
  11. ^ ZDF, February 13, 2011 about his work
  12. Introduces four pioneers in communication and storage technologies. In addition to Marconi and radio technology, these are Louis Daguerre and photography, Alexander Graham Bell and the telephone, and Thomas A. Edison and sound recording