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81 invariable pendulum
English-Russian big polytechnic dictionary > invariable pendulum
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82 physical pendulum
English-Russian big polytechnic dictionary > physical pendulum
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83 reversible pendulum
English-Russian big polytechnic dictionary > reversible pendulum
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84 torsion pendulum
English-Russian big polytechnic dictionary > torsion pendulum
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85 phase swing
English-Russian dictionary of Information technology > phase swing
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86 friction pendulum
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87 frictional pendulum
English-Russian big medical dictionary > frictional pendulum
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88 compound pendulum
The English-Russian dictionary general scientific > compound pendulum
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89 mathematical pendulum
English-Russian big polytechnic dictionary > mathematical pendulum
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90 Huygens, Christiaan
SUBJECT AREA: Horology[br]b. 14 April 1629 The Hague, the Netherlandsd. 8 June 1695 The Hague, the Netherlands[br]Dutch scientist who was responsible for two of the greatest advances in horology: the successful application of both the pendulum to the clock and the balance spring to the watch.[br]Huygens was born into a cultured and privileged class. His father, Constantijn, was a poet and statesman who had wide interests. Constantijn exerted a strong influence on his son, who was educated at home until he reached the age of 16. Christiaan studied law and mathematics at Ley den University from 1645 to 1647, and continued his studies at the Collegium Arausiacum in Breda until 1649. He then lived at The Hague, where he had the means to devote his time entirely to study. In 1666 he became a Member of the Académie des Sciences in Paris and settled there until his return to The Hague in 1681. He also had a close relationship with the Royal Society and visited London on three occasions, meeting Newton on his last visit in 1689. Huygens had a wide range of interests and made significant contributions in mathematics, astronomy, optics and mechanics. He also made technical advances in optical instruments and horology.Despite the efforts of Burgi there had been no significant improvement in the performance of ordinary clocks and watches from their inception to Huygens's time, as they were controlled by foliots or balances which had no natural period of oscillation. The pendulum appeared to offer a means of improvement as it had a natural period of oscillation that was almost independent of amplitude. Galileo Galilei had already pioneered the use of a freely suspended pendulum for timing events, but it was by no means obvious how it could be kept swinging and used to control a clock. Towards the end of his life Galileo described such a. mechanism to his son Vincenzio, who constructed a model after his father's death, although it was not completed when he himself died in 1642. This model appears to have been copied in Italy, but it had little influence on horology, partly because of the circumstances in which it was produced and possibly also because it differed radically from clocks of that period. The crucial event occurred on Christmas Day 1656 when Huygens, quite independently, succeeded in adapting an existing spring-driven table clock so that it was not only controlled by a pendulum but also kept it swinging. In the following year he was granted a privilege or patent for this clock, and several were made by the clockmaker Salomon Coster of The Hague. The use of the pendulum produced a dramatic improvement in timekeeping, reducing the daily error from minutes to seconds, but Huygens was aware that the pendulum was not truly isochronous. This error was magnified by the use of the existing verge escapement, which made the pendulum swing through a large arc. He overcame this defect very elegantly by fitting cheeks at the pendulum suspension point, progressively reducing the effective length of the pendulum as the amplitude increased. Initially the cheeks were shaped empirically, but he was later able to show that they should have a cycloidal shape. The cheeks were not adopted universally because they introduced other defects, and the problem was eventually solved more prosaically by way of new escapements which reduced the swing of the pendulum. Huygens's clocks had another innovatory feature: maintaining power, which kept the clock going while it was being wound.Pendulums could not be used for portable timepieces, which continued to use balances despite their deficiencies. Robert Hooke was probably the first to apply a spring to the balance, but his efforts were not successful. From his work on the pendulum Huygens was well aware of the conditions necessary for isochronism in a vibrating system, and in January 1675, with a flash of inspiration, he realized that this could be achieved by controlling the oscillations of the balance with a spiral spring, an arrangement that is still used in mechanical watches. The first model was made for Huygens in Paris by the clockmaker Isaac Thuret, who attempted to appropriate the invention and patent it himself. Huygens had for many years been trying unsuccessfully to adapt the pendulum clock for use at sea (in order to determine longitude), and he hoped that a balance-spring timekeeper might be better suited for this purpose. However, he was disillusioned as its timekeeping proved to be much more susceptible to changes in temperature than that of the pendulum clock.[br]Principal Honours and DistinctionsFRS 1663. Member of the Académie Royale des Sciences 1666.BibliographyFor his complete works, see Oeuvres complètes de Christian Huygens, 1888–1950, 22 vols, The Hague.1658, Horologium, The Hague; repub., 1970, trans. E.L.Edwardes, AntiquarianHorology 7:35–55 (describes the pendulum clock).1673, Horologium Oscillatorium, Paris; repub., 1986, The Pendulum Clock or Demonstrations Concerning the Motion ofPendula as Applied to Clocks, trans.R.J.Blackwell, Ames.The balance spring watch was first described in Journal des Sçavans 25 February 1675, and translated in Philosophical Transactions of the Royal Society (1675) 4:272–3.Further ReadingH.J.M.Bos, 1972, Dictionary of Scientific Biography, ed. C.C.Gillispie, Vol. 6, New York, pp. 597–613 (for a fuller account of his life and scientific work, but note the incorrect date of his death).R.Plomp, 1979, Spring-Driven Dutch Pendulum Clocks, 1657–1710, Schiedam (describes Huygens's application of the pendulum to the clock).S.A.Bedini, 1991, The Pulse of Time, Florence (describes Galileo's contribution of the pendulum to the clock).J.H.Leopold, 1982, "L"Invention par Christiaan Huygens du ressort spiral réglant pour les montres', Huygens et la France, Paris, pp. 154–7 (describes the application of the balance spring to the watch).A.R.Hall, 1978, "Horology and criticism", Studia Copernica 16:261–81 (discusses Hooke's contribution).DV -
91 Shortt, William Hamilton
SUBJECT AREA: Horology[br]b. 28 September 1881d. 4 February 1971[br]British railway engineer and amateur horologist who designed the first successful free-pendulum clock.[br]Shortt entered the Engineering Department of the London and South Western Railway as an engineering cadet in 1902, remaining with the company and its successors until he retired in 1946. He became interested in precision horology in 1908, when he designed an instrument for recording the speed of trains; this led to a long and fruitful collaboration with Frank HopeJones, the proprietor of the Synchronome Company. This association culminated in the installation of a free-pendulum clock, with an accuracy of the order of one second per year, at Edinburgh Observatory in 1921. The clock's performance was far better than that of existing clocks, such as the Riefler, and a slightly modified version was produced commercially by the Synchronome Company. These clocks provided the time standard at Greenwich and many other observatories and scientific institutions across the world until they were supplanted by the quartz clock.The period of a pendulum is constant if it swings freely with a constant amplitude in a vacuum. However, this ideal state cannot be achieved in a clock because the pendulum must be impulsed to maintain its amplitude and the swings have to be counted to indicate time. The free-pendulum clock is an attempt to approach this ideal as closely as possible. In 1898 R.J. Rudd used a slave clock, synchronized with a free pendulum, to time the impulses delivered to the free pendulum. This clock was not successful, but it provided the inspiration for Shortt's clock, which operates on the same principle. The Shortt clock used a standard Synchronome electric clock as the slave, and its pendulum was kept in step with the free pendulum by means of the "hit and miss" synchronizer that Shortt had patented in 1921. This allowed the pendulum to swing freely (in a vacuum), apart from the fraction of a second in which it received an impulse each half-minute.[br]Principal Honours and DistinctionsMaster of the Clockmakers' Company 1950. British Horological Society Gold Medal 1931. Clockmakers' Company Tompion Medal 1954. Franklin Institute John Price Wetherill Silver Medal.Bibliography1929, "Some experimental mechanisms, mechanical and otherwise, for the maintenance of vibration of a pendulum", Horological Journal 71:224–5.Further ReadingObituary, 1971, Proceedings of the Institution of Civil Engineers 56:396–7.F.Hope-Jones, 1949, Electrical Timekeeping, 2nd edn, London (a detailed but not entirely impartial account of the development of the free-pendulum clock).See also: Marrison, Warren AlvinDVBiographical history of technology > Shortt, William Hamilton
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92 swung
/swiɳ/ * danh từ - sự đua đưa, sự lúc lắc; độ đu đưa, độ lắc - cái đu - chầu đu - sự (đi) nhún nhảy =to walk with a swing+ đi nhún nhảy - quá trình hoạt động; sự tự do hành động =to give somebody full swing in some matter+ cho ai được tự do hoạt động trong việc gì - (âm nhạc) (như) swing music - nhịp điệu (thơ...) - (thể dục,thể thao) cú đấm bạt, cú xuynh (quyền Anh) - (thương nghiệp) sự lên xuống đều đều (giá cả) !in full swing - (xem) full !the swing of the pendulum - (nghĩa bóng) khuynh hướng xen kẽ, khuynh hướng muốn để các đảng lần lượt lên nắm chính quyền * nội động từ swung - đu đưa, lúc lắc =door swings to+ cửa đu đưa rồi đóng lại - đánh đu =to swing into the saddle+ đánh đu nhảy lên yên - treo lủng lẳng =lamp swings from the ceiling+ đèn treo lủng lẳng trên trần nhà - đi nhún nhảy =to swing out of the room+ đi nhún nhảy ra khỏi phòng - ngoặt (xe, tàu...) =to swing to starboard+ (hàng hải) quay ngoặt sang bên phải * ngoại động từ - đu đưa, lúc lắc =to swing one's feet+ đu đưa hai chân =to swing a child+ đưa đẩy cái đu cho một đứa trẻ - treo lủng lẳng, mắc =to swing a lamp on the ceiling+ treo lủng lẳng cái đèn lên trần nhà =to swing a hammock+ mắc cái võng - vung vẩy; lắc =to swing one's arms+ vung tay =to swing a club+ vung gậy =to swing a bell+ lắc chuông - quay ngoắt =to swing a car round+ lái ngoắt xe ô tô, quay ngoắt xe ô tô trở lại - (âm nhạc) phổ thành nhạc xuynh - (từ Mỹ,nghĩa Mỹ) lái theo chiều lợi =to swing the election+ lái cuộc bầu cử theo chiều có lợi cho mình !no room to swing a cat - (xem) room !to swing the lead - (xem) lead !he will swing for it - hắn sẽ bị treo cổ về tội đó -
93 маятник
муж.
1) pendulum качание маятника ≈ swing of pendulum колебание маятника ≈ swing of the pendulum
2) balance wheel -
94 oscillate
intransitive verb1) (swing like a pendulum) schwingen; oszillieren (fachspr.)2) (fig.) schwanken* * *os·cil·late[ˈɒsɪleɪt, AM ˈɑ:səl-]I. viII. vt▪ to \oscillate sth etw pendeln [o hin und her schwingen] lassen* * *['ɒsIleɪt]vi (PHYS)oszillieren, schwingen; (compass needle etc) schwanken; (rapidly) zittern; (fig) schwankenthe needle oscillated violently — die Nadel schlug stark aus
* * *A v/i3. ELEKa) hochfrequente Schwingungen ausführen oder erzeugenb) unbeabsichtigt oder wild schwingenB v/t in Schwingungen versetzen* * *intransitive verb1) (swing like a pendulum) schwingen; oszillieren (fachspr.)2) (fig.) schwanken* * *v.oszillieren v.pendeln v.schwingen v.(§ p.,pp.: schwang, geschwungen)vibrieren v. -
95 bob
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96 Bob
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97 bobs
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98 balance
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99 ticker
тикер имя существительное: -
100 balance wheel
маятник имя существительное:
См. также в других словарях:
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Swing wheel — Swing Swing, n. 1. The act of swinging; a waving, oscillating, or vibratory motion of a hanging or pivoted object; oscillation; as, the swing of a pendulum. [1913 Webster] 2. Swaying motion from one side or direction to the other; as, some men… … The Collaborative International Dictionary of English
Pendulum (mathematics) — The mathematics of pendulums are in general quite complicated. Simplifying assumptions can be made, which in the case of a simple pendulum allows the equations of motion to be solved analytically for small angle oscillations. Simple gravity… … Wikipedia
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