More Related Content
Similar to How is time measured? (20)
![[Medicalstudyzone.com] 1. AIIMS NOV EMBER 2015 SOLVED PAPER.pdf](https://cdn.slidesharecdn.com/ss_thumbnails/medicalstudyzone-250904212000-ef4cbf83-thumbnail.jpg?width=560&fit=bounds)
How is time measured?
- 1. d? re su eaα Mtime e sure immea s uTed to i s owments H nstru I Activity: Copy the notes under the heading above and complete the activity on slide 4
- 2. The Sundial Sundials record the time of day by using the position of the sun in the sky. First used by the Ancient Egyptians and the Sumerians (Middle East) First used around 5,500 years ago Two major types: 1. The Obelisk 2. The Gnomon
- 3. The Obelisk A tall monument with a pyramid shaped top (see picture to the right). Normally two are built at the same time. Normally located at the front of religious buildings such as the Temple of Karnak in Upper Egypt. The shadow of the obelisk created by the movement of the sun across the sky enables the citizens to divide the day into two parts.
- 4. The Gnomon SunDial ACTIVITY: Copy and complete the following sentences after watching the youtube video on the wiki page below A. Sundials were used in Egypt more than … B. They consisted of a simple stick pushed into the ground which cast a … C. To mark the passing of time Sundials were divided into … D. The central stake on the top of an obelisk or pillar was called a … E. There was no standard number of marking so the length of an hour was … F. When the length of a day was standardised into 12 hours the Sundial was … G. The gnomon had to face in a Northerly direction or bearing because …
- 5. Oil Lamps Used in Ancient China around 6000 years ago The level of burnt oil (oil reservoir) indicated the amount of time the lamp had been burning CANDLE CLOCKS Used for telling time in China approximately 1,400 years ago. The time it took for a candle to burn from one mark to another was measured. The problem was that some candles would burn quicker than others because of the variation in the quality of the candle wax. Did you know that the first mechanical clock was invented around 1275 AD by an Italian monk? The clock was driven by the slow pull of a falling weight, basically like a very big hour hand.
- 6. Language for Time Activity: Refresh your memory on all the time words you can think of by writing as many down in the space of a minute. See if you can beat your friend (Examples, yesterday, a minute ago, a while ago, etc) DAYS AND HOURS One of the most common ways that we like to measure time today is by dividing it up into days and hours. But this method of measuring time also has a history and has not always been used across the planet. It wasn’t until the Hellenistic Age of the Ancient Greeks (over 2,000 years ago) that it was decided that the unit of time called the hour should be a fixed measurement. Hipparchus, a Greek mathematician and astronomer, proposed dividing the day equally into 24 hours which came to be known as equinoctial hours. These are based on 12 hours of daylight and 12 hours of darkness on the days of the Equinoxes (2 days each year). However, ordinary people continued to use seasonally varying hours for a long time. Only with the advent of mechanical clocks in Europe in the 14 th Century, did the system we used today become commonly accepted? Comprehension Questions: Q1. What are equinoctial hours? Q2. When did western civilisation begin using equinoctial hours to measure the passing of time? Q3. Add the following historical ‘time words’ to your glossary: A year, Period, Era, Millennium, Century, Decade, Dynasty, Age
- 7. Language for Time Activity: Refresh your memory on all the time words you can think of by writing as many down in the space of a minute. See if you can beat your friend (Examples, yesterday, a minute ago, a while ago, etc) DAYS AND HOURS One of the most common ways that we like to measure time today is by dividing it up into days and hours. But this method of measuring time also has a history and has not always been used across the planet. It wasn’t until the Hellenistic Age of the Ancient Greeks (over 2,000 years ago) that it was decided that the unit of time called the hour should be a fixed measurement. Hipparchus, a Greek mathematician and astronomer, proposed dividing the day equally into 24 hours which came to be known as equinoctial hours. These are based on 12 hours of daylight and 12 hours of darkness on the days of the Equinoxes (2 days each year). However, ordinary people continued to use seasonally varying hours for a long time. Only with the advent of mechanical clocks in Europe in the 14 th Century, did the system we used today become commonly accepted? Comprehension Questions: Q1. What are equinoctial hours? Q2. When did western civilisation begin using equinoctial hours to measure the passing of time? Q3. Add the following historical ‘time words’ to your glossary: A year, Period, Era, Millennium, Century, Decade, Dynasty, Age