Alexander Stepanovich Popov

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Alexander Stepanovich Popov
Alexander Stepanovich Popov.jpg
Born(1859-03-16)16 March 1859
Turyinskiye Rudniki settlement, Perm Governorate, Russian Empire (present-day Krasnoturyinsk, Sverdlovsk Oblast, Russia)
Died13 January 1906(1906-01-13) (aged 46)
St. Peterburg, Russian Empire
Known for Radio
Awards Order of St. Anna of 3rd and 2nd grades
Order of Saint Stanislaus (Imperial House of Romanov) of 2nd grade
Silver medal of Alexander III reign honour on the belt of Order of Alexander Nevsky
Prize of Imperial Russian Technical Society
Signature
Alexander Popov signature.svg

Alexander Stepanovich Popov (sometimes spelled Popoff; Russian : Алекса́ндр Степа́нович Попо́в; March 16 [ O.S. March 4] 1859 – January 13 [ O.S. December 31, 1905] 1906) was a Russian physicist who is acclaimed in his homeland and some eastern European countries as the inventor of radio. [1] [2] [3]

Russian language East Slavic language

Russian is an East Slavic language, which is official in the Russian Federation, Belarus, Kazakhstan and Kyrgyzstan, as well as being widely used throughout Eastern Europe, the Baltic states, the Caucasus and Central Asia. It was the de facto language of the Soviet Union until its dissolution on 25 December 1991. Although, nowadays, nearly three decades after the breakup of the Soviet Union, Russian is used in official capacity or in public life in all the post-Soviet nation-states, as well as in Israel and Mongolia, the rise of state-specific varieties of this language tends to be strongly denied in Russia, in line with the Russian World ideology.

Old Style and New Style dates 16th-century changes in calendar conventions

Old Style (O.S.) and New Style (N.S.) are terms sometimes used with dates to indicate that the calendar convention used at the time described is different from that in use at the time the document was being written. There were two calendar changes in Great Britain and its colonies, which may sometimes complicate matters: the first was to change the start of the year from Lady Day to 1 January; the second was to discard the Julian calendar in favour of the Gregorian calendar. Closely related is the custom of dual dating, where writers gave two consecutive years to reflect differences in the starting date of the year, or to include both the Julian and Gregorian dates.

Russian Empire Former country, 1721–1917

The Russian Empire, also known as Imperial Russia or simply Russia, was an empire that existed across Eurasia and North America from 1721, following the end of the Great Northern War, until the Republic was proclaimed by the Provisional Government that took power after the February Revolution of 1917.

Contents

Popov's work as a teacher at a Russian naval school led him to explore high frequency electrical phenomena. On May 7, 1895 he presented a paper on a wireless lightning detector he had built that worked via using a coherer to detect radio noise from lightning strikes. This day is celebrated in the Russian Federation as Radio Day. In a March 24, 1896 demonstration, he used radio waves to transmit a message between different campus buildings in St. Petersburg. His work was based on that of another physicist – Oliver Lodge, and contemporaneous with the work of Guglielmo Marconi. Marconi had just registered a patent with the description of the device two months after first transmission of radio signals made by Popov. [4]

Coherer

The coherer was a primitive form of radio signal detector used in the first radio receivers during the wireless telegraphy era at the beginning of the 20th century. Its use in radio was based on the 1890 findings of French physicist Edouard Branly and adapted by other physicists and inventors over the next ten years. The device consists of a tube or capsule containing two electrodes spaced a small distance apart with loose metal filings in the space between. When a radio frequency signal is applied to the device, the metal particles would cling together or "cohere", reducing the initial high resistance of the device, thereby allowing a much greater direct current to flow through it. In a receiver, the current would activate a bell, or a Morse paper tape recorder to make a record of the received signal. The metal filings in the coherer remained conductive after the signal (pulse) ended so that the coherer had to be "decohered" by tapping it with a clapper actuated by an electromagnet, each time a signal was received, thereby restoring the coherer to its original state. Coherers remained in widespread use until about 1907, when they were replaced by more sensitive electrolytic and crystal detectors.

Radio Day, Communications Workers' Day or Radio and Television Day is a commemoration of the development of radio in Russia. It takes place on 7 May, the day in 1895 on which Alexander Popov successfully demonstrated his invention.

Saint Petersburg Federal city in Northwestern, Russia

Saint Petersburg is Russia's second-largest city after Moscow, with 5 million inhabitants in 2012, part of the Saint Petersburg agglomeration with a population of 6.2 million (2015). An important Russian port on the Baltic Sea, it has a status of a federal subject.

Early life

Born in the town of Krasnoturinsk, Sverdlovsk Oblast in the Urals as the son of a priest, he became interested in natural sciences when he was a child. His father wanted Alexander to join the priesthood and sent him to the Seminary School at Yekaterinburg. [2] There he developed an interest in science and mathematics and instead of going on to Theology School in 1877 he enrolled at St. Petersburg university where he studied physics. [2] [5] After graduation with honors in 1882, he stayed on as a laboratory assistant at the university. However the salary at the university was inadequate to support his family, and in 1883 he took a post as teacher and head of laboratory at the Russian Navy's Torpedo School in Kronstadt on Kotlin Island. [2]

Sverdlovsk Oblast First-level administrative division of Russia

Sverdlovsk Oblast is a federal subject of Russia located in the Ural Federal District. Its administrative center is the city of Yekaterinburg, formerly known as Sverdlovsk. Its population is 4,297,747.

Yekaterinburg City in Sverdlovsk Oblast, Russia

Yekaterinburg, alternatively romanised Ekaterinburg, is the fourth-largest city in Russia and the administrative centre of Sverdlovsk Oblast, located on the Iset River east of the Ural Mountains, in the middle of the Eurasian continent, on the Asian side of the boundary between Asia and Europe. It is the main cultural and industrial centre of the oblast. In 2017, it had an estimated population of 1,488,791. Yekaterinburg has been dubbed the "third capital of Russia", as it is ranked third by the size of economy, culture, transportation and tourism. It is located about 1,420 kilometres (880 mi) to the east of Moscow.

Saint Petersburg State University is a Russian federal state-owned higher education institution based in Saint Petersburg. It is the oldest and one of the largest universities in Russia.

Radio wave receiver

Drawing of Popov's radio wave based lightning detector Popovs first receiver.png
Drawing of Popov's radio wave based lightning detector

Along with his teaching duties at the naval school Popov pursued related areas of research. Trying to solve a problem with the failure in the electrical wire insulation on steel ships (which turned out to be a problem with electrical resonance) led him to further explore oscillations of high frequency electrical currents. [6] His interest in this area of study (including the new field of "Hertzian" or radio waves) was intensified by his trip in 1893 to the Chicago World's Columbian Exposition in the United States where he was able to confer with other researchers in the field. [7]

Electrical resonance occurs in an electric circuit at a particular resonant frequency when the imaginary parts of impedances or admittances of circuit elements cancel each other

Electrical resonance occurs in an electric circuit at a particular resonant frequency when the impedances or admittances of circuit elements cancel each other. In some circuits, this happens when the impedance between the input and output of the circuit is almost zero and the transfer function is close to one.

Oscillation repetitive variation of some measure about a central value

Oscillation is the repetitive variation, typically in time, of some measure about a central value or between two or more different states. The term vibration is precisely used to describe mechanical oscillation. Familiar examples of oscillation include a swinging pendulum and alternating current.

Worlds Columbian Exposition Worlds Fair held in Chicago in 1893

The World's Columbian Exposition was a world's fair held in Chicago in 1893 to celebrate the 400th anniversary of Christopher Columbus's arrival to the New World in 1492. The centerpiece of the Fair, the large water pool, represented the long voyage Columbus took to the New World. Chicago bested New York City, Washington, D.C., and St. Louis for the honor of hosting the fair. The Exposition was an influential social and cultural event and had a profound effect on architecture, sanitation, the arts, Chicago's self-image, and American industrial optimism.

Popov also read an 1894 article about British physicist Oliver Lodge's experiments related to the discovery of radio waves by German physicist Heinrich Hertz 6 years earlier. [7] On 1 June 1894, after the death of Hertz, British physicist Oliver Lodge gave a memorial lecture on Hertz experiments. He set up a demonstration on the quasi optical nature of Hertzian waves (radio waves) and demonstrated their transmission at distances up to 50 meters. [8] Lodge used a detector called a coherer , a glass tube containing metal filings between two electrodes. [5] When received waves from an antenna were applied to the electrodes, the coherer became conductive allowing the current from a battery to pass through it, with the impulse being picked up by a mirror galvanometer. After receiving a signal, the metal filings in the coherer had to be reset by a manually operated vibrator or by the vibrations of a bell placed on the table nearby that rang every time a transmission was received. [8] Popov set to work to design a more sensitive radio wave receiver that could be used as a lightning detector, to warn of thunderstorms by detecting the electromagnetic pulses of lightning strikes [1] using a coherer receiver. [1] [2]

Oliver Lodge British physicist

Sir Oliver Joseph Lodge, was a British physicist and writer involved in the development of, and holder of key patents for, radio. He identified electromagnetic radiation independent of Hertz' proof and at his 1894 Royal Institution lectures, Lodge demonstrated an early radio wave detector he named the "coherer". In 1898 he was awarded the "syntonic" patent by the United States Patent Office. Lodge was Principal of the University of Birmingham from 1900 to 1920.

Heinrich Hertz German physicist

Heinrich Rudolf Hertz was a German physicist who first conclusively proved the existence of the electromagnetic waves theorized by James Clerk Maxwell's electromagnetic theory of light. The unit of frequency, cycle per second, was named the "Hertz" in his honor.

Mirror galvanometer

A mirror galvanometer is an electromechanical instrument that indicates that it has sensed an electric current by deflecting a light beam with a mirror. The beam of light projected on a scale acts as a long massless pointer. In 1826, Johann Christian Poggendorff developed the mirror galvanometer for detecting electric currents. The apparatus is also known as a spot galvanometer after the spot of light produced in some models.

Operating principle

Circuit of Popov's lightning detector Popov receiver.png
Circuit of Popov's lightning detector

In Popov's lightning detector the coherer (C) was connected to an antenna (A), and to a separate circuit with a relay (R) and battery (V) which operated an electric bell (B). The radio noise generated by a lightning strike turned on the coherer, the current from the battery was applied to the relay, closing its contacts, which applied current to the electromagnet (E) of the bell, pulling the arm over to ring the bell. Popov added an innovative automatic reset feature of a "self tapping" coherer where the bell arm would spring back and tap the coherer, restoring it to its receptive state. [3] The two chokes (L) in the coherer's leads prevented the radio signal across the coherer from short circuiting by passing through the DC circuit. He connected his receiver to a wire antenna (A) suspended high in the air and to a ground (earth) (G). The antenna idea may have been based on a lightning rod and was an early use of a monopole wire aerial. [9]

Antenna (radio) electrical device which converts electric power into radio waves, and vice versa

In radio engineering, an antenna is the interface between radio waves propagating through space and electric currents moving in metal conductors, used with a transmitter or receiver. In transmission, a radio transmitter supplies an electric current to the antenna's terminals, and the antenna radiates the energy from the current as electromagnetic waves. In reception, an antenna intercepts some of the power of a radio wave in order to produce an electric current at its terminals, that is applied to a receiver to be amplified. Antennas are essential components of all radio equipment.

Relay electrical switch

A relay is an electrically operated switch. Many relays use an electromagnet to mechanically operate a switch, but other operating principles are also used, such as solid-state relays. Relays are used where it is necessary to control a circuit by a separate low-power signal, or where several circuits must be controlled by one signal. The first relays were used in long distance telegraph circuits as amplifiers: they repeated the signal coming in from one circuit and re-transmitted it on another circuit. Relays were used extensively in telephone exchanges and early computers to perform logical operations.

Electric bell mechanical bell that functions by means of an electromagnet

An electric bell is a mechanical bell that functions by means of an electromagnet. When an electric current is applied, it produces a repetitive buzzing or clanging sound. Electric bells have been widely used at railroad crossings, in telephones, fire and burglar alarms, as school bells, doorbells, and alarms in industrial plants, since the late 1800s, but they are now being widely replaced with electronic sounders. An electric bell consists of one or more electromagnets, made of a coil of insulated wire around an iron core, which attract a springy iron armature with a clapper. When an electric current flows through the coils, the electromagnet creates a magnetic field which pulls the armature towards it, causing the clapper to strike the bell.

Demonstrations

On 7 May 1895, Popov presented the paper "On the Relation of Metallic Powders to Electric Oscillations", which described his lightning detector, to the Russian Physical and Chemical Society in St. Petersburg. [7] Most Eastern sources regard Popov's lightning detector as the first radio receiver, [10] and the 7th of May has been celebrated since 1945 in the Russian Federation as "Radio Day". [2] However, there is no evidence Popov sent any type of message on that occasion. The first account of communication by Popov was a demonstration on 24 March 1896 at the Physical and Chemical Society, when some accounts say the Morse code message "ГЕНРИХ ГЕРЦ" ("HEINRICH HERTZ" in Russian) was received from a transmitter 250 meters away and transcribed on the blackboard by the Society president. [2] Historian Charles Susskind in 1962 concluded that Popov did not use radio waves for actual wireless communication before mid-1896. [5]

In 1895 Italian inventor Guglielmo Marconi began work on a purpose built wireless telegraphy system based on "Hertzian" (radio) waves, developing a spark-gap transmitter and a much improved automatically-reset coherer receiver. By mid-1895 Marconi had transmitted messages 1/2 mile (1600 meters). He then came up with the idea grounding his transmitter as well as his receiver and by mid-1896 he was transmitting radio messages a mile and a half (2400 meters). [11] Popov and Marconi's early work seems to have been done without knowledge of each other's system although reading Marconi's June 1896 patent disclosures led Popov to develop a long range wireless telegraphy system. [5]

One of Popov's receivers, with chart recorder (white cylinder) to record lightning strikes Popov1.jpg
One of Popov's receivers, with chart recorder (white cylinder) to record lightning strikes

His paper on his experiments: "On the relation of metallic powders to electrical oscillations", was published 15 December 1895. He did not apply for a patent for his invention. [3] In July 1895 he installed his receiver and a siphon recorder on the roof of the Institute of Forestry building in St. Petersburg. [1] and was able to detect thunderstorms at a range of 50 km, [5] however he was also aware of its communication potential. His paper, read at the 7 May 1895 meeting, concluded [2] [5]

I can express my hope that my apparatus will be applied for signaling at great distances by electric vibrations of high frequency, as soon as there will be invented a more powerful generator of such vibrations.

In 1896, the article depicting Popov's invention was reprinted in the 'Journal of the Russian Physical and Chemical Society'. In March 1896, he effected transmission of radio waves between different campus buildings in St. Petersburg. In November 1897, the French entrepreneur Eugene Ducretet made a transmitter and receiver based on wireless telegraphy in his own laboratory. According to Ducretet, he built his devices using Popov's lightning detector as a model. By 1898, Ducretet was manufacturing equipment of wireless telegraphy based on Popov's instructions. At the same time Popov effected ship-to-shore communication over a distance of 6 miles in 1898 and 30 miles in 1899.

Later work

Radio pioneer Alexander Popov on the 1989 USSR stamp. The text says "Inventor of radio, A. S. Popov, 1859-1906. Demonstration of the first radio, 1895" 1989 CPA 6117.jpg
Radio pioneer Alexander Popov on the 1989 USSR stamp. The text says "Inventor of radio, A. S. Popov, 1859–1906. Demonstration of the first radio, 1895"

In 1900 a radio station was established under Popov's instructions on Hogland island (Suursaari) to provide two-way communication by wireless telegraphy between the Russian naval base and the crew of the battleship General-Admiral Apraksin. The battleship had run aground on Hogland island in the Gulf of Finland in November, 1899. The crew of the Apraksin were not in immediate danger, but the water in the Gulf began to freeze. Due to bad weather and bureaucratic red tape, the crew of Apraksin did not arrive until January 1900 to establish a wireless station on Hogland Island. By February 5, however, messages were being received reliably. The wireless messages were relayed to Hogland Island by a station some 25 miles away at Kymi (nowadays Kotka) on the Finnish coast. Kotka was selected as the location for the wireless relay station because it was the point closest to Hogland Island served by telegraph wires connected to Russian naval headquarters. [12]

By the time the Apraksin was freed from the rocks by the icebreaker Yermak at the end of April, 440 official telegraph messages had been handled by the Hogland Island wireless station. Besides the rescue of the Apraksin's crew, more than 50 Finnish fishermen, who were stranded on a piece of drift ice in the Gulf of Finland, were saved by the icebreaker Yermak following distress telegrams sent by wireless telegraphy.[ citation needed ] In 1901 Alexander Popov was appointed as professor at the Electrotechnical Institute, which now bears his name. In 1905 he was elected director of the institute.[ citation needed ]

Death and legacy

Monument to Popov in Yekaterinburg city A. S. Popov.jpg
Monument to Popov in Yekaterinburg city

In 1905 he became seriously ill and died of a brain hemorrhage on January 13, 1906. [13] A minor planet, 3074 Popov, discovered by Soviet astronomer Lyudmila Zhuravlyova in 1979, is named after him. [14] At ITU Telecom World 2011, Igor Shchyogolev, Minister of Telecom and Mass Communications of the Russian Federation alongside Hamadoun Touré, Secretary General of the ITU, inaugurated the "Alexander Stepanovich Popov" conference room at ITU's headquarters in Geneva.[ citation needed ]

Family

Some of his descendents escaped to Manchuria during the Bolshevik Revolution and eventually made their way to the United States. Among others were his cousin, Dr. Paul Popov, who became a prominent physician in San Francisco and Paul's son, Egor Popov (1913–2001), who became a UC Berkeley Professor Emeritus of Civil and Environmental Engineering. [15] [16]

See also

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References

Citations

  1. 1 2 3 4 Smith-Rose, Reginald Leslie (2013). "Alexandr Popov". Encyclopædia Britannica Online. Encyclopædia Britannica, Inc. Retrieved 6 November 2013.
  2. 1 2 3 4 5 6 7 8 McKenna, Joe (2007). "Aleksandr Popov's Contributions to Wireless Communication". IEEE Engineering Hall of Fame. Institute of Electrical and Electronic Engineers. Archived from the original on 10 November 2013. Retrieved 6 November 2013.
  3. 1 2 3 (author name redacted) (January 1960). "Did Alexandr Popov invent radio?" (PDF). NSA Technical Journal. US: National Security Agency. 5 (1): 35–41. Archived from the original (PDF) on 10 November 2013. Retrieved 6 November 2013. declassified 8 January 2008
  4. ↑ Би-би-си, Артем Кречетников; Москва. "Кто на самом деле изобрел радио?". BBC News Русская служба.
  5. 1 2 3 4 5 6 Huurdeman, Anton A. (2003). The Worldwide History of Telecommunications. John Wiley and Sons. pp. 205–207. ISBN   0471205052. A picture of Popov's receiver appears on p. 207, fig. 12.2
  6. ↑ M. Radovsky, Alexander Popov Inventor of Radio, The Minerva Group, Inc.- 2001, pages 37–38
  7. 1 2 3 Christopher H. Sterling, Encyclopedia of Radio, Routledge – 2003, page 1820
  8. 1 2 Sungook Hong, Wireless: From Marconi's Black-box to the Audion, MIT Press, 2001, pages 30–32
  9. ↑ Sungook Hong, Wireless: From Marconi's Black-box to the Audion, MIT Press, 2001, page 202
  10. ↑ Electronics World, Volume 64, Ziff-Davis Publishing Company – 1960, page 78
  11. ↑ Sungook Hong, Wireless: From Marconi's Black-box to the Audion, MIT Press – 2001, page 202 (notes)
  12. ↑ "Aleksandr Popov". IEEE Global History Network. IEEE. Retrieved 21 July 2011.
  13. ↑ Oakes, Elizabeth H. (14 May 2014). A to Z of STS Scientists. Infobase Publishing. p. 253. ISBN   9781438109251 . Retrieved 6 May 2018.
  14. ↑ Dictionary of Minor Planet Names, 2003, vol.1, p.253
  15. ↑ Engineering Pioneer Egor Popov
  16. ↑ Connections: The EERI Oral History Series. Egor Popov

Sources

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