William Sansome Tucker

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Major William Sansome Tucker OBE [1] (1877 Kidderminster, Worcestershire - 1955 Guelph, Ontario, Canada) [2] was an English pioneer in acoustical research and inventor of the acoustic mirror [3]

Contents

Early life

Tucker was born in Kidderminster, the son of William Tucker, an artist painter, and his wife Anna. Tucker married in Chorlton-on-Medlock, Lancashire, in 1906.

Career

Tucker lectured on physics in London. Following the outbreak of World War I, Tucker joined the British Army as a private soldier. He was posted to the Experimental Sound Ranging Station at Kemmel Hill in Belgium which was under the command of Lawrence Bragg. [4] As part of the London Electrical Engineers, Territorial Force, Tucker was granted a commission, being promoted from lance corporal to temporary second lieutenant, General List in April 1916. [5]

At Kemmel Hill, Tucker undertook research into 'sound ranging': the process of using microphones and mathematics to determine the position of enemy artillery. Bragg had been wracked by doubts and problems with the military command structure. Tucker formed an experimental sound ranging section, which spearheaded the development of an effective system of sound ranging enemy guns. Vital to the success was Tucker's invention of a 'hot wire' microphone, capable of identifying the shell sound wave and the following report of the gun that fired it. The breakthrough had come from Bragg, who found that the water closet at the farmhouse where he was billeted, allowed him, once seated inside, to detect sound and pressure differences of shell waves and gun waves as they passed overhead. [6]

Tucker researched how to cool platinum wire with the air currents caused by the sound-waves they were detecting. Mouse-holes and rum jars provided a clue here, as there were two mouse-holes by Tucker's bed and he noticed a draught of cool air whenever the gun-wave arrived. Tucker devised a microphone consisting of a thin, electrically heated wire, stretched over a small hole in a container (he used rum jars, but the low-frequency acoustic resonance of wooden ammunition boxes, forming a Helmholtz resonator, was soon found to give better results). [7] [8] The decrease in the electrical resistance of the wire as the gun-wave struck was recorded by a Wheatstone bridge and galvanometer. [6]

Tucker had to send for platinum wire to be delivered to him at Kemmel Hill, before he could run trials. The rapid oscillations of the shell waves had almost no effect on the wire, whilst the gun-reports resulted in well-defined 'breaks' on the 35mm cine film used to record the oscillations, due to the deflection of the wire by the pressure of the gun wave. By September 1916, Tucker's new microphones had been supplied to all sound-ranging sections. [6]

In 1917, sound-ranging was further developed so that allowances could be made for poor weather conditions, as sudden gusts of wind could cool the wire: the most effective method found was to wrap the devices in several layers of camouflage netting. [8] Tucker developed a system of moveable microphones to improve detection techniques, allowing for a high degree of accuracy in determining the position of the enemy guns. By the end of the war it was possible to determine where the gun was pointing, and how large it was. The technique could also be extended to listen out for enemy aircraft; as a result, Tucker became Director of Acoustical Research, Air Defence Experimental Establishment, Biggin Hill.

His work eventually led to vast parabolic 'sound mirrors' being constructed from concrete. Some of these sound mirrors still survive along England's south coast, such as those to be found at Denge, near Dungeness, to the west side of a lake slightly north of Lydd-on-Sea, and others uncovered in 2014 at Fan Bay near Dover. [9] Tucker's work was superseded by the development of radar, which made sound-ranging using the great concrete mirrors obsolete. Some known locations for the sound mirrors were documented in a series of photographs by Joe Pettet-Smith in 2018. [10]

Related Research Articles

Acoustics Branch of physics involving mechanical waves

Acoustics is a branch of physics that deals with the study of mechanical waves in gases, liquids, and solids including topics such as vibration, sound, ultrasound and infrasound. A scientist who works in the field of acoustics is an acoustician while someone working in the field of acoustics technology may be called an acoustical engineer. The application of acoustics is present in almost all aspects of modern society with the most obvious being the audio and noise control industries.

Electronic oscillator Type of electronic circuit

An electronic oscillator is an electronic circuit that produces a periodic, oscillating electronic signal, often a sine wave or a square wave or a triangle wave. Oscillators convert direct current (DC) from a power supply to an alternating current (AC) signal. They are widely used in many electronic devices ranging from simplest clock generators to digital instruments and complex computers and peripherals etc. Common examples of signals generated by oscillators include signals broadcast by radio and television transmitters, clock signals that regulate computers and quartz clocks, and the sounds produced by electronic beepers and video games.

A hydrophone is a microphone designed to be used underwater for recording or listening to underwater sound. Most hydrophones are based on a piezoelectric transducer that generates an electric potential when subjected to a pressure change, such as a sound wave. Some piezoelectric transducers can also serve as a sound projector, but not all have this capability, and some may be destroyed if used in such a manner.

Microphone Device that converts sound into an electrical signal

A microphone, colloquially called a mic or mike, is a device – a transducer – that converts sound into an electrical signal. Microphones are used in many applications such as telephones, hearing aids, public address systems for concert halls and public events, motion picture production, live and recorded audio engineering, sound recording, two-way radios, megaphones, radio and television broadcasting. They are also used in computers for recording voice, speech recognition, VoIP, and for non-acoustic purposes such as ultrasonic sensors or knock sensors.

Recording studio

A recording studio is a specialized facility for sound recording, mixing, and audio production of instrumental or vocal musical performances, spoken words, and other sounds. They range in size from a small in-home project studio large enough to record a single singer-guitarist, to a large building with space for a full orchestra of 100 or more musicians. Ideally, both the recording and monitoring spaces are specially designed by an acoustician or audio engineer to achieve optimum acoustic properties.

Lawrence Bragg Australian-born British physicist and X-ray crystallographer

Sir William Lawrence Bragg, was an Australian-born British physicist and X-ray crystallographer, discoverer (1912) of Bragg's law of X-ray diffraction, which is basic for the determination of crystal structure. He was joint recipient of the Nobel Prize in Physics in 1915, "For their services in the analysis of crystal structure by means of X-rays"; an important step in the development of X-ray crystallography.

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William Henry Bragg British scientist

Sir William Henry Bragg was an English physicist, chemist, mathematician, and active sportsman who uniquely shared a Nobel Prize with his son Lawrence Bragg – the 1915 Nobel Prize in Physics: "for their services in the analysis of crystal structure by means of X-rays". The mineral Braggite is named after him and his son. He was knighted in 1920.

Thermoacoustics is the interaction between temperature, density and pressure variations of acoustic waves. Thermoacoustic heat engines can readily be driven using solar energy or waste heat and they can be controlled using proportional control. They can use heat available at low temperatures which makes it ideal for heat recovery and low power applications. The components included in thermoacoustic engines are usually very simple compared to conventional engines. The device can easily be controlled and maintained.

Rijke tube

The Rijke tube is a cylindrical tube with both ends open, inside of which a heat source is placed that turns heat into sound, by creating a self-amplifying standing wave. It is an entertaining phenomenon in acoustics and is an excellent example of resonance.

Acoustic mirror

An acoustic mirror is a passive device used to reflect and focus (concentrate) sound waves. Parabolic acoustic mirrors are widely used in parabolic microphones to pick up sound from great distances, employed in surveillance and reporting of outdoor sporting events. Pairs of large parabolic acoustic mirrors which function as "whisper galleries" are displayed in science museums to demonstrate sound focusing.

Ion laser Type of gas laser

An ion laser is a gas laser that uses an ionized gas as its lasing medium. Like other gas lasers, ion lasers feature a sealed cavity containing the laser medium and mirrors forming a Fabry–Pérot resonator. Unlike helium–neon lasers, the energy level transitions that contribute to laser action come from ions. Because of the large amount of energy required to excite the ionic transitions used in ion lasers, the required current is much greater, and as a result all but the smallest ion lasers are water-cooled. A small air-cooled ion laser might produce, for example, 130 milliwatts of output light with a tube current of about 10 amperes and a voltage of 105 volts. Since one ampere times one volt is one watt, this is an electrical power input of about one kilowatt. Subtracting the (desirable) light output of 130 mW from power input, this leaves the large amount of waste heat of nearly one kW. This has to be dissipated by the cooling system. In other words, the power efficiency is very low.

RAF Denge

Denge is a former Royal Air Force site near Dungeness, in Kent, England. It is best known for the early experimental acoustic mirrors which remain there.

Crystal detector

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Acoustic location Use of reflected sound waves to locate objects

Acoustic location is the use of sound to determine the distance and direction of its source or reflector. Location can be done actively or passively, and can take place in gases, liquids, and in solids.

Carbon microphone

The carbon microphone, also known as carbon button microphone, button microphone, or carbon transmitter, is a type of microphone, a transducer that converts sound to an electrical audio signal. It consists of two metal plates separated by granules of carbon. One plate is very thin and faces toward the speaking person, acting as a diaphragm. Sound waves striking the diaphragm cause it to vibrate, exerting a varying pressure on the granules, which in turn changes the electrical resistance between the plates. Higher pressure lowers the resistance as the granules are pushed closer together. A steady direct current is passed between the plates through the granules. The varying resistance results in a modulation of the current, creating a varying electric current that reproduces the varying pressure of the sound wave. In telephony, this undulating current is directly passed through the telephone wires to the central office. In public address systems it is amplified by an audio amplifier. The frequency response of most carbon microphones, however, are limited to a narrow range, and the device produces significant electrical noise.

In land warfare, artillery sound ranging is a method of determining the coordinates of a hostile battery using data derived from the sound of its guns firing. The same methods can also be used to direct artillery fire at a position with known coordinates.

Sound amplification by stimulated emission of radiation

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Wind instrument Class of musical instruments with air resonator

A wind instrument is a musical instrument that contains some type of resonator in which a column of air is set into vibration by the player blowing into a mouthpiece set at or near the end of the resonator. The pitch of the vibration is determined by the length of the tube and by manual modifications of the effective length of the vibrating column of air. In the case of some wind instruments, sound is produced by blowing through a reed; others require buzzing into a metal mouthpiece, while yet others require the player to blow into a hole at an edge, which splits the air column and creates the sound.

References

  1. "Birthday honours". Flight . 7 June 1928. p. 414.
  2. Hannah Gay (2007). The history of Imperial College London, 1907-2007. Imperial College Press. p. 144. ISBN   9781860948183.
  3. "The concrete blocks that once protected Britain". BBC. 7 January 2019. Retrieved 23 August 2020.
  4. J.N. McKie (1996). "John Tindale (1878-1969) and the Genesis of the Radio-Telescope". Quarterly Journal of the Royal Astronomical Society. 37: 679. Bibcode:1996QJRAS..37..663M.
  5. "Second Supplement to London Gazette". The London Gazette . 7 April 1916. p. 3769.
  6. 1 2 3 Bragg, Lawrence (2015). Crystal clear : the autobiographies of Sir Lawrence and Lady Bragg (2015 ed.). Oxford University Press. pp. 89–91. ISBN   978-0198744306.
  7. Tucker, William; Paris, E.T. (3 March 1921). "A Selective Hot-Wire Microphone". Philosophical Transactions of the Royal Society of London. 221 (582–593): 390. Bibcode:1921RSPTA.221..389T. doi: 10.1098/rsta.1921.0011 .
  8. 1 2 van der Kloot, William (2004). "Sound Ranging". Great Scientists Wage the Great War : The First War of Science 1914-1918. Oxford, England: Fonthill. ISBN   9781781554029.
  9. "Fan Bay sound mirrors". Andrewgrantham.co.uk.
  10. "The concrete blocks that once protected Britain". BBC.