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History Of Electrical Engineering
This article details the history of electrical engineering. Ancient developments Long before any knowledge of electricity existed, people were aware of shocks from electric fish. Ancient Egypt Ancient Egypt () was a cradle of civilization concentrated along the lower reaches of the Nile River in Northeast Africa. It emerged from prehistoric Egypt around 3150BC (according to conventional Egyptian chronology), when Upper and Lower E ...ian texts dating from 2750 BCE referred to these fish as the "Thunderer of the Nile", and described them as the "protectors" of all other fish. Electric fish were again reported millennia later by ancient Greek, Roman Empire, Roman and Science in the medieval Islamic world, Arabic naturalists and Islamic medicine, physicians. Several ancient writers, such as Pliny the Elder and Scribonius Largus, attested to the numbing effect of electric shocks delivered by electric catfish and electric rays, and knew that such shocks could travel along c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrical Engineering
Electrical engineering is an engineering discipline concerned with the study, design, and application of equipment, devices, and systems that use electricity, electronics, and electromagnetism. It emerged as an identifiable occupation in the latter half of the 19th century after the commercialization of the electric telegraph, the telephone, and electrical power generation, distribution, and use. Electrical engineering is divided into a wide range of different fields, including computer engineering, systems engineering, power engineering, telecommunications, radio-frequency engineering, signal processing, instrumentation, photovoltaic cells, electronics, and optics and photonics. Many of these disciplines overlap with other engineering branches, spanning a huge number of specializations including hardware engineering, power electronics, Electromagnetism, electromagnetics and waves, microwave engineering, nanotechnology, electrochemistry, renewable energies, mechatronics/control ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mediterranean Sea
The Mediterranean Sea ( ) is a sea connected to the Atlantic Ocean, surrounded by the Mediterranean basin and almost completely enclosed by land: on the east by the Levant in West Asia, on the north by Anatolia in West Asia and Southern Europe, on the south by North Africa, and on the west almost by the Morocco–Spain border. The Mediterranean Sea covers an area of about , representing 0.7% of the global ocean surface, but its connection to the Atlantic via the Strait of Gibraltar—the narrow strait that connects the Atlantic Ocean to the Mediterranean Sea and separates the Iberian Peninsula in Europe from Morocco in Africa—is only wide. Geological evidence indicates that around 5.9 million years ago, the Mediterranean was cut off from the Atlantic and was partly or completely desiccation, desiccated over a period of some 600,000 years during the Messinian salinity crisis before being refilled by the Zanclean flood about 5.3 million years ago. The sea was an important ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
William Gilbert (astronomer)
William Gilbert (; 24 May 1544? – 30 November 1603), also known as Gilberd, was an English physician, physicist and natural philosophy, natural philosopher. He passionately rejected both the prevailing Aristotelian philosophy and the Scholasticism, Scholastic method of university teaching. He is remembered today largely for his book ''De Magnete'' (1600). A unit of magnetomotive force, also known as magnetic scalar potential, magnetic potential, was named the ''Gilbert (unit), Gilbert'' in his honour; it has now been superseded by the Ampere-turn. Life and work Gilbert was born in Colchester to Jerome Gilberd, a borough Recorder (judge), recorder. He was educated at St John's College, Cambridge. After gaining his Doctor of Medicine, MD from Cambridge in 1569, and a short spell as bursar of St John's College, he left to practice medicine in London, and he travelled on the continent. In 1573, he was elected a Fellow of the Royal College of Physicians. In 1600, he was elect ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mesopotamia
Mesopotamia is a historical region of West Asia situated within the Tigris–Euphrates river system, in the northern part of the Fertile Crescent. Today, Mesopotamia is known as present-day Iraq and forms the eastern geographic boundary of the modern Middle East. Just beyond it lies southwestern Iran, where the region transitions into the Iranian plateau, Persian plateau, marking the shift from the Arab world to Iran. In the broader sense, the historical region of Mesopotamia also includes parts of present-day Iran (southwest), Turkey (southeast), Syria (northeast), and Kuwait. Mesopotamia is the site of the earliest developments of the Neolithic Revolution from around 10,000 BC. It has been identified as having "inspired some of the most important developments in human history, including the invention of the wheel, the planting of the first cereal crops, the development of cursive script, mathematics, astronomy, and agriculture". It is recognised as the cradle of some of t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electroplating
Electroplating, also known as electrochemical deposition or electrodeposition, is a process for producing a metal coating on a solid substrate through the redox, reduction of cations of that metal by means of a direct current, direct electric current. The part to be coated acts as the cathode (negative electrode) of an electrolytic cell; the electrolyte is a solution (chemistry), solution of a salt (chemistry), salt whose cation is the metal to be coated, and the anode (positive electrode) is usually either a block of that metal, or of some inert electrical conductor, conductive material. The current is provided by an external power supply. Electroplating is widely used in industry and decorative arts to improve the surface qualities of objects—such as resistance to abrasion (mechanical), abrasion and corrosion, lubrication, lubricity, reflectivity, electrical conductivity, or appearance. It is used to build up thickness on undersized or worn-out parts and to manufacture metal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Galvanic Cell
A galvanic cell or voltaic cell, named after the scientists Luigi Galvani and Alessandro Volta, respectively, is an electrochemical cell in which an electric current is generated from spontaneous oxidation–reduction reactions. An example of a galvanic cell consists of two different metals, each immersed in separate beakers containing their respective metal ions in solution that are connected by a salt bridge or separated by a porous membrane. Volta was the inventor of the voltaic pile, the first electrical battery. Common usage of the word ''battery'' has evolved to include a single Galvanic cell, but the first batteries had many Galvanic cells. History In 1780, Luigi Galvani discovered that when two different metals (e.g., copper and zinc) are in contact and then both are touched at the same time to two different parts of a muscle of a frog leg, to close the circuit, the frog's leg contracts. He called this " animal electricity". The frog's leg, as well as being a detector ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Baghdad Battery
The Baghdad Battery is the name given to a set of three artifacts which were found together: a ceramic pot, a tube of copper, and a rod of iron. It was discovered in present-day Khujut Rabu, Iraq in 1936, close to the ancient city of Ctesiphon, the capital of the Parthian (150 BC – 223 AD) and Sasanian (224–650 AD) empires, and it is believed to date from either of these periods. Its origin and purpose remain unclear. Wilhelm König, at the time director of the laboratory of the National Museum of Iraq, suggested that the object functioned as a galvanic cell, possibly used for electroplating, or some kind of electrotherapy. There is no electroplated object known from this period, and the claims are universally rejected by archaeologists. An alternative explanation is that it functioned as a storage vessel for sacred scrolls. Ten similar clay vessels had been found earlier. Four were found in 1930 in Seleucia dating to the Sassanid period. Three were sealed with bitumen and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iraq
Iraq, officially the Republic of Iraq, is a country in West Asia. It is bordered by Saudi Arabia to Iraq–Saudi Arabia border, the south, Turkey to Iraq–Turkey border, the north, Iran to Iran–Iraq border, the east, the Persian Gulf and Kuwait to the Iraq–Kuwait border, southeast, Jordan to Iraq–Jordan border, the southwest, and Syria to Iraq–Syria border, the west. The country covers an area of and has Demographics of Iraq, a population of over 46 million, making it the List of countries by area, 58th largest country by area and the List of countries by population, 31st most populous in the world. Baghdad, home to over 8 million people, is the capital city and the List of largest cities of Iraq, largest in the country. Starting in the 6th millennium BC, the fertile plains between Iraq's Tigris and Euphrates rivers, referred to as Mesopotamia, fostered the rise of early cities, civilisations, and empires including Sumer, Akkadian Empire, Akkad, and Assyria. Known ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atoms
Atoms are the basic particles of the chemical elements. An atom consists of a nucleus of protons and generally neutrons, surrounded by an electromagnetically bound swarm of electrons. The chemical elements are distinguished from each other by the number of protons that are in their atoms. For example, any atom that contains 11 protons is sodium, and any atom that contains 29 protons is copper. Atoms with the same number of protons but a different number of neutrons are called isotopes of the same element. Atoms are extremely small, typically around 100 picometers across. A human hair is about a million carbon atoms wide. Atoms are smaller than the shortest wavelength of visible light, which means humans cannot see atoms with conventional microscopes. They are so small that accurately predicting their behavior using classical physics is not possible due to quantum effects. More than 99.94% of an atom's mass is in the nucleus. Protons have a positive electric charge a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atomic Theory
Atomic theory is the scientific theory that matter is composed of particles called atoms. The definition of the word "atom" has changed over the years in response to scientific discoveries. Initially, it referred to a hypothetical concept of there being some fundamental particle of matter, too small to be seen by the naked eye, that could not be divided. Then the definition was refined to being the basic particles of the chemical elements, when chemists observed that elements seemed to combine with each other in ratios of small whole numbers. Then physicists discovered that these particles had an internal structure of their own and therefore perhaps did not deserve to be called "atoms", but renaming atoms would have been impractical by that point. Atomic theory is one of the most important scientific developments in history, crucial to all the physical sciences. At the start of ''The Feynman Lectures on Physics'', physicist and Nobel laureate Richard Feynman offers the atomic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Democritus
Democritus (, ; , ''Dēmókritos'', meaning "chosen of the people"; – ) was an Ancient Greece, Ancient Greek Pre-Socratic philosophy, pre-Socratic philosopher from Abdera, Thrace, Abdera, primarily remembered today for his formulation of an atomism, atomic theory of the universe. Democritus wrote extensively on a wide variety of topics. None of Democritus' original work has survived, except through second-hand references. Many of these references come from Aristotle, who viewed him as an important rival in the field of natural philosophy. He was known in antiquity as the ‘laughing philosopher’ because of his emphasis on the value of cheerfulness. Life Although many anecdotes about Democritus' life survive, their authenticity cannot be verified and modern scholars doubt their accuracy. According to Aristotle, Democritus was born in Abdera, on the coast of Thrace. He was a polymath and prolific writer, producing nearly eighty treatises on subjects such as poetry, harmon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrostatic Discharge
Electrostatic discharge (ESD) is a sudden and momentary flow of electric current between two differently-charged objects when brought close together or when the dielectric between them breaks down, often creating a visible electric spark, spark associated with the static electricity between the objects. ESD can create spectacular electric sparks (lightning, with the accompanying sound of thunder, is an example of a large-scale ESD event), but also less dramatic forms, which may be neither seen nor heard, yet still be large enough to cause damage to sensitive electronic devices. Electric sparks require a field strength above approximately 4 million V/m in air, as notably occurs in lightning strikes. Other forms of ESD include corona discharge from sharp electrodes, brush discharge from blunt electrodes, etc. ESD can cause harmful effects of importance in industry, including explosions in gas, fuel vapor and coal dust, as well as failure of solid state electronics components such as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
