The History of Time ppt


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The History of Time By Josh P & Connor K

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The Egyptians were the first people who created a twenty-four hour day. these hours. The Egyptians thought they were the first to invent the shadow clock, but they were mistaken. At the same time, the Chinese, Babylonians, Greeks and the Romans were using devices to tell time. Sundials just because that's how they decided to tell time.   The Sundial

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The major fault with sundials and shadow clocks is obvious...They don't work at night! People wanted to know what time it was all through the night without having to check the position of the stars. So they Egyptians a water clock. He took a big bucket of water, filled it with water up to a specific line. He then cut a small hole in the bottom of the bucket and marked off lines on the bucket after each hour had passed.     Water clocks

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There were, of course, some problems with this water clock as well. This is where sand came into effect. The inventor of the sand clock is unknown but the sand clock or hourglass was commonly used in ancient times and is still used today. They are often found in board games or are used as kitchen timers. Is there an hourglass in your home? Hourglass

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The first mechanical clocks had a weight that would slowly lower, moving gears which moved a hand which showed the hour. They could only be built in tall towers because the weights needed to fall a great distance or else the clocks would only work for a short amount of time. In Salisbury, England you can see the oldest clock in the world, built in 1386. The first tick

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Galileo made an amazing contribution to the world of time, simply by not paying attention in church. Galileo was standing in church watching the huge chandelier swinging back and forth from the ceiling of the cathedral. Galileo noticed that no matter how short or swing was, it took exactly the same amount of time to complete a full swing. The chandelier gave Galileo the idea to create a pendulum clock. It would keep accurate time until the pendulum stopped.   The Pendulum

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In the 1920s, scientists discovered quartz crystals could keep even more accurate time than a pendulum and were only off about 1/500 of a second each year. Half way through the 20th century, atomic clocks were built that would only be off by one second every 300 million years. Who really needs a clock that accurate? Quartz crystals & Atomic clocks

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It is evident that times have certainly changed. Clocks have made major improvements since the days of the shadow clock. Now we have accurate, reliable clocks that we can use day and night. Some of our clocks will run for years without so much as a change of batteries or a twist of a little knob. We have certainly developed the concept of time and incorporated it into our lives. Where we are today

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Info Pics Bibliography

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The End

Tags: history maths time science education

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