The History of Timekeeping
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Apresentação que eu fiz em 2004 para meu speech, eu cursava inglês no CCAA. Hoje em dia eu olho para trás e vejo que só escolhia temas esquisitos... haha. O texto do meu trabalho está aqui: http://www.karensoarele.com.br/wp-content/uploads/2014/04/The-History-of-Timekepeeing.doc
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The History of Timekeeping
- 1. The History of Timekeeping Karen Isabelle Soares Karla Natalia Queiroz
- 2. The History of Timekeeping - 2/13 Using the Sun noon sunsetsunrise
- 3. The History of Timekeeping - 3/13 Sundial Clocks Oldest type of clock Also called sun clocks The shadow points to a number Depend on the sun
- 4. The History of Timekeeping - 4/13 Water Clocks Around 4,000 B.C. Babylon, Egypt, India or China Water traveled through a tube Tell time during the night
- 5. The History of Timekeeping - 5/13 Dividing the Year into Months 12 Moon cycles in a year Greeks divided the year in 12 months
- 6. The History of Timekeeping - 6/13 Dividing the Year into Days They divided the month in 30 days 360 Days in a year 360 Degrees in a circle 90° 180° 270° 360°
- 7. The History of Timekeeping - 7/13 Dividing the Day into Hours Egyptians and Babylonians Sunrise to sunset in 12 hours, sunset to sunrise also in 12 hours Whole day in 24 hours +
- 8. The History of Timekeeping - 8/13 Minutes and Seconds Sumerian Sexagenary Sistem
- 9. The History of Timekeeping - 9/13 Mechanical Clocks Invented in medieval Europe Common in churches and monasteries “Clock” is from the Latin word “clocca” One time-keeping hand
- 10. The History of Timekeeping - 10/13 Spring-powered Clocks Around 1500 Became very popular among the rich Was the precursor to accurate timekeeping
- 11. The History of Timekeeping - 11/13 Pendulum Clocks Developed by Christian Huygens around 1656 Pendulum clock had a minute hand Used to swing a lot (about 50 degrees) They stopped running after a while and had to be restarted
- 12. The History of Timekeeping - 12/13 Quartz Crystal Clocks Based on an electric property of the quartz crystal When you apply voltage, or electricity, and pressure, the quartz crystal vibrates or oscillates at a very constant frequency. Very precise
- 13. The History of Timekeeping - 13/13 Time Zones In 1884, delegates from 25 countries divided the world into time zones. The delegates divided the 360 degrees of the Earth into 24 zones of 15 degrees each. In the United States, there are four time zones: Eastern, Central, Mountain, and Pacific.