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William Henry Preece
Sir William Henry Preece (15 February 1834 – 6 November 1913) was a Welsh electrical engineer and inventor. Preece relied on experiments and physical reasoning in his life's work. Upon his retirement from the Post Office in 1899, Preece was made a Knight Commander of the Order of the Bath (KCB) in the 1899 Birthday Honours. Biography Preece was born in Caernarfon (Gwynedd), Wales. He was educated at King's College School and King's College London. Preece studied at the Royal Institution in London (Great Britain) under Michael Faraday. He later was the consulting engineer for the Post Office (1870s). He became Engineer-in-Chief of the British General Post Office in 1892. He developed several improvements in railroad signalling system that increased railway safety. Preece and Oliver Lodge maintained a correspondence during this period. Upon Lodge's proposal of "loading coils" applied to submerged cables, Preece did not realise that " Earthing" would extend the distance and effi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Caernarfon
Caernarfon (; ) is a royal town, community and port in Gwynedd, Wales, with a population of 9,852 (with Caeathro). It lies along the A487 road, on the eastern shore of the Menai Strait, opposite the Isle of Anglesey. The city of Bangor is to the north-east, while Snowdonia fringes Caernarfon to the east and south-east. Carnarvon and Caernarvon are Anglicised spellings that were superseded in 1926 and 1974 respectively. Abundant natural resources in and around the Menai Strait enabled human habitation in prehistoric Britain. The Ordovices, a Celtic tribe, lived in the region during the period known as Roman Britain. The Roman fort Segontium was established around AD 80 to subjugate the Ordovices during the Roman conquest of Britain. The Romans occupied the region until the end of Roman rule in Britain in 382, after which Caernarfon became part of the Kingdom of Gwynedd. In the late 11th century, William the Conqueror ordered the construction of a motte-and-bailey cas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ground (electricity)
In electrical engineering, ground or earth is a reference point in an electrical circuit from which voltages are measured, a common return path for electric current, or a direct physical connection to the Earth. Electrical circuits may be connected to ground for several reasons. Exposed conductive parts of electrical equipment are connected to ground, to protect users from electrical shock hazard. If internal insulation fails, dangerous voltages may appear on the exposed conductive parts. Connecting exposed parts to ground will allow circuit breakers (or RCDs) to interrupt power supply in the event of a fault. In electric power distribution systems, a protective earth (PE) conductor is an essential part of the safety provided by the earthing system. Connection to ground also limits the build-up of static electricity when handling flammable products or electrostatic-sensitive devices. In some telegraph and power transmission circuits, the ground itself can be used as one condu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thought Experiment
A thought experiment is a hypothetical situation in which a hypothesis, theory, or principle is laid out for the purpose of thinking through its consequences. History The ancient Greek ''deiknymi'' (), or thought experiment, "was the most ancient pattern of mathematical proof", and existed before Euclidean mathematics, where the emphasis was on the conceptual, rather than on the experimental part of a thought-experiment. Johann Witt-Hansen established that Hans Christian Ørsted was the first to use the German term ' (lit. thought experiment) circa 1812. Ørsted was also the first to use the equivalent term ' in 1820. By 1883 Ernst Mach used the term ' in a different way, to denote exclusively the conduct of a experiment that would be subsequently performed as a by his students. Physical and mental experimentation could then be contrasted: Mach asked his students to provide him with explanations whenever the results from their subsequent, real, physical experiment differed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Drain-pipe Theory
The electronic–hydraulic analogy (derisively referred to as the drain-pipe theory by Oliver Lodge) is the most widely used analogy for "electron fluid" in a metal conductor. Since electric current is invisible and the processes in play in electronics are often difficult to demonstrate, the various electronic components are represented by hydraulic equivalents. Electricity (as well as heat) was originally understood to be a kind of fluid, and the names of certain electric quantities (such as current) are derived from hydraulic equivalents. As with all analogies, it demands an intuitive and competent understanding of the baseline paradigms (electronics and hydraulics), and in the case of the hydraulic analogy for electronics, students often have an inadequate knowledge of hydraulics. Paradigms There is no unique paradigm for establishing this analogy. Different paradigms have different strengths and weaknesses, depending on how and in what ways the intuitive understanding of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Earth's Magnetic Field
Earth's magnetic field, also known as the geomagnetic field, is the magnetic field that extends from Earth's interior out into space, where it interacts with the solar wind, a stream of charged particles emanating from the Sun. The magnetic field is generated by electric currents due to the motion of convection currents of a mixture of molten iron and nickel in Earth's outer core: these convection currents are caused by heat escaping from the core, a natural process called a geodynamo. The magnitude of Earth's magnetic field at its surface ranges from . As an approximation, it is represented by a field of a magnetic dipole currently tilted at an angle of about 11° with respect to Earth's rotational axis, as if there were an enormous bar magnet placed at that angle through the center of Earth. The North geomagnetic pole actually represents the South pole of Earth's magnetic field, and conversely the South geomagnetic pole corresponds to the north pole of Earth's magnetic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Guglielmo Marconi
Guglielmo Giovanni Maria Marconi, 1st Marquis of Marconi (; 25 April 187420 July 1937) was an Italians, Italian inventor and electrical engineering, electrical engineer, known for his creation of a practical radio wave-based Wireless telegraphy, wireless telegraph system. This led to Marconi being credited as the inventor of radio, and he shared the 1909 Nobel Prize in Physics with Karl Ferdinand Braun "in recognition of their contributions to the development of wireless telegraphy".Guglielmo Marconi: The Nobel Prize in Physics 1909 . nobelprize.org Marconi was also an entrepreneur, businessman, and founder of Marconi Company, The Wireless Telegraph & Signal Company in the United Kingdom of Great Britain and Ireland, United Kingdom in 1897 (which became the Marconi Com ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flat Holm
Flat Holm ( cy, Ynys Echni) is a Welsh island lying in the Bristol Channel approximately from Lavernock Point in the Vale of Glamorgan. It includes the most southerly point of Wales. The island has a long history of occupation, dating at least from the Bronze Age. Religious uses include visits by disciples of Saint Cadoc in the 5th-6th century AD, and in 1835 it was the site of the foundation of the Bristol Channel Mission, which later became the Mission to Seafarers. A sanatorium for cholera patients was built in 1896 as the isolation hospital for the port of Cardiff. Guglielmo Marconi transmitted the first wireless signals over open sea from Flat Holm to Lavernock. Because of frequent shipwrecks, a lighthouse was built on the island, which was replaced by a Trinity House lighthouse in 1737. Because of its strategic position on the approaches to Bristol and Cardiff a series of gun emplacements, known as Flat Holm Battery, were built in the 1860s as part of a line of defe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lavernock
Lavernock ( cy, Larnog) is a hamlet in the Vale of Glamorgan in Wales, lying on the coast south of Cardiff between Penarth and Sully, and overlooking the Bristol Channel. Marconi and the first radio messages across open sea Following overland tests at Salisbury Plain during March 1897, on 13 May 1897, the Italian born and recently British based inventor, best known for his development of a radiotelegraph system, Guglielmo Marconi, assisted by George Kemp (who was a Cardiff based Post Office engineer) transmitted and received the first wireless signals over open sea between Lavernock Point and Flat Holm island. The very first message transmitted in morse code was "ARE YOU READY". This was immediately followed by "CAN YOU HEAR ME" to which the reply was "YES LOUD AND CLEAR". The morse recording slip for the first message is on display in the National Museum of Wales. Following the initial opening exchange there followed detailed technical messages in both directions indicat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paul J
Paul may refer to: *Paul (given name), a given name (includes a list of people with that name) *Paul (surname), a list of people People Christianity *Paul the Apostle (AD c.5–c.64/65), also known as Saul of Tarsus or Saint Paul, early Christian missionary and writer *Pope Paul (other), multiple Popes of the Roman Catholic Church *Saint Paul (other), multiple other people and locations named "Saint Paul" Roman and Byzantine empire *Lucius Aemilius Paullus Macedonicus (c. 229 BC – 160 BC), Roman general *Julius Paulus Prudentissimus (), Roman jurist *Paulus Catena (died 362), Roman notary *Paulus Alexandrinus (4th century), Hellenistic astrologer *Paul of Aegina or Paulus Aegineta (625–690), Greek surgeon Royals *Paul I of Russia (1754–1801), Tsar of Russia *Paul of Greece (1901–1964), King of Greece Other people *Paul the Deacon or Paulus Diaconus (c. 720 – c. 799), Italian Benedictine monk *Paul (father of Maurice), the father of Maurice, Byzan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oliver Heaviside
Oliver Heaviside FRS (; 18 May 1850 – 3 February 1925) was an English self-taught mathematician and physicist who invented a new technique for solving differential equations (equivalent to the Laplace transform), independently developed vector calculus, and rewrote Maxwell's equations in the form commonly used today. He significantly shaped the way Maxwell's equations are understood and applied in the decades following Maxwell's death. His formulation of the telegrapher's equations became commercially important during his own lifetime, after their significance went unremarked for a long while, as few others were versed at the time in his novel methodology. Although at odds with the scientific establishment for most of his life, Heaviside changed the face of telecommunications, mathematics, and science. Biography Early life Heaviside was born in Camden Town, London, at 55 Kings Street (now Plender Street), the youngest of three children of Thomas, a draughtsman and wood engr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arthur West Heaviside
Arthur is a common male given name of Brythonic origin. Its popularity derives from it being the name of the legendary hero King Arthur. The etymology is disputed. It may derive from the Celtic ''Artos'' meaning “Bear”. Another theory, more widely believed, is that the name is derived from the Roman clan '' Artorius'' who lived in Roman Britain for centuries. A common spelling variant used in many Slavic, Romance, and Germanic languages is Artur. In Spanish and Italian it is Arturo. Etymology The earliest datable attestation of the name Arthur is in the early 9th century Welsh-Latin text ''Historia Brittonum'', where it refers to a circa 5th to 6th-century Briton general who fought against the invading Saxons, and who later gave rise to the famous King Arthur of medieval legend and literature. A possible earlier mention of the same man is to be found in the epic Welsh poem ''Y Gododdin'' by Aneirin, which some scholars assign to the late 6th century, though this is still a mat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
