Neutrino - definition of a neutrino

Neutrino - definition of a neutrino Definition: The neutrino is an elementary particle which holds no electrical charge, travels at nearly the speed of light, and passes through ordinary matter with virtually no interaction. Neutrinos are created as part of radioactive decay. This decay was observed in 1896 by Henri Bacquerel, when he noted that certain atoms seem to emit electrons (a process known as beta decay). In 1930, Wolfgang Pauli proposed an explanation for where these electrons could have come from without violating conservation laws, but it involved the presence of a very light, uncharged particle emitted simultaneously during the decay. Neutrinos are produced through radioactive interactions, such as solar fusion, supernovae, radioactive decay, and when cosmic rays collide with the Earths atmosphere. It was Enrico Fermi who developed a more complete theory of neutrino interactions and who coined the term neutrino for these particles. A group of researchers discovered the neutrino in 1956, a finding which later earned them the 1995 Nobel Prize in Physics. There are actually three types of neutrino: electron neutrino, muon neutrino, and tau neutrino. These names come from the their partner particle under the Standard Model of particle physics. The muon neutrino was discovered in 1962 (and earned a Nobel Prize in 1988, 7 years before the earlier discovery of the electron neutrino earned one.) Early predictions indicated that the neutrino may have had no mass, but later examinations have indicated that it has a very small amount of mass, but not zero mass. The neutrino has a half-integer spin, so it is a fermion. It is an electronically neutral lepton, so it interacts through neither the strong nor electromagnetic forces, but only through the weak interaction. Pronunciation: new-tree-no Also Known As: Electron NeutrinoMuon NeutrinoTau Neutrino

The debasement of the coinage Research Paper Example | Topics and Well Written Essays - 1000 words

The debasement of the coinage - Research Paper Example Coins have been used as collectors’ items and mediums of expression, but largely used as currency since historical times. Historical minting techniques are still being used, though nowadays people leverage on technology for efficiency. Precious metals and mints require techniques used to ensure that the value of the constituent precious metal does not exceed the face value of the coin. Understanding these techniques plays a critical role in understanding inflation control. Introduction The use of precious metals as a medium of exchange is said to have began in Egypt, though this took the form of rings, wafers and bars.According to Vincent Lannoye, Lydia, nowadays referred to as Turkey, was the first smelter of small ingots having a royal seal to certify legality and weight (19). Rulers quickly integrated these micro-ingots into their economies. The Lydian people accepted payments in electrum metal, which is an alloy of gold and natural silver. These micro-ingots developed into coins that were minted by masculine men who could strike blank discs to leave engravings that certified the origin of the coins. Through the centuries, coin making, referred to as coinage, improved fast. More regular coins became available through the replacement of the bank discs with regular laminated metal plates. Later, quasi-uniform coins came into existence with the replacement of the hammer with the screw-press and furthered the adoption of the rolling-press, which was rotated by horse power. Minting Minting of coins has been a precise and well-guarded function of selected mints commissioned and governed by respective authorities in various countries. From the outset, the minting procedure involved producing precise blanks with defined weights and composition and producing coin-striking tools. Principally, these requirements still hold from historical times, as observed by the Marshall Cavendish Corporation, only that the methods have been improving with technical progress a nd industrialization (507). Historically, the Lydian people poured the molten electrum into suitable forms, starting from simple moulds to more complicated ones. In the 16th Century, the thickness of metal sheets was reduced through hammering with the blanks cut out using shears, then filed and hammered to the desired thickness and weight. The period about 1550 saw a German silversmith, known as Marx Schwab, invent screw pressing. This involved two heavy iron screws pressing the coin metal so as to achieve the desired thickness. Roller-mills facilitated the production of uniform metal strips from which metal punches cut the blanks (Christopher Howgego 76). The mechanized form of this technique still finds application in modern coin minting. The Industrial Age discovery since 1830 allowed hundreds of circulation coins to be produced in a minute, with modern mechanical mints adopting even faster speeds. Therefore, the United States Mint, the manufacturer and distributor of American co ins, has its modern process borrowed from this history. The mint punches blanks from coiled metal strips, referred to as blanking. This would then be softened through heating in an annealing furnace, and then taken through a washer and dryer. The blanks then pass through an upsetting mill onto a coining press that stamps the inscriptions and designs to guarantee genuineness. The resultant coins would then be inspected for quality, counted and bagged. Governments have throughout the history supplied more coins than would be possible if the coins were made of pure precious metals. Normally, some portion of the precious metal used to make the coin would be replaced by a base metal. Howgego states that copper and nickel are some of the commonly used base metals (43). This in turn reduces the intrinsic value of the coin, referred to as â€Å"debasing.† This way, authorities produce a lot more coins that it would have been otherwise possible. C. E. Challis observes that the coins i n circulation could have fiat values lower than the