History of Clocks and the Impact of Electricity on them.
In this poster we are going to show you the history and the development of the clock through time and how it has impacted society. We will also show how electricity has affected the development and effectiveness of clocks.
One of the first clocks on record is the sun clock. Sun clocks basically work on the principle that the position of a stationary object’s shadow will be in the same place at a certain time of day. The ancient people could put a scale on the shadow of an object like the obelisk in such a way that at dawn it is at one end and at dusk it is at the other. So that the people can have an estimate of how much daylight there is left. Also they could set a point to show when it is the middle of the day because at the middle of the day the sun will be highest in the sky so the shadow will be at its shortest. When the shadow is at its shortest they can put a mark at where it was on the scale. In some places they even made sun clocks that account for the different seasons because in different seasons the sun comes up and goes down at different times of day.
The sun clock was very useful to the ancient people because it helped the people of the ancient world to plan better for the rest of the day, which made the economy more effective.
There are some problems with sun clocks. For example they only work if it is daytime and the sun is not obstructed by anything, like a cloud. If one did not account for the change of season then the clock would only be accurate in the season that it was made. The main problem was that it was not very accurate. It was just about enough accurate to estimate time to within plus or minus 1 hour during daytime.
Another one of the early types of clocks is the water clock. It is defined by any time keeping device that has a regulated flow of water in or out of a container. The change in depth of the water in the container can be measured to calculate the amount of time passed. In 250 BC there was a mathematician called Ctesibius who invented a clock, which was named clepsydra (water thief), it was much more accurate than the normal water clocks of the time and it was the most accurate clock up until the 17th centaury, when a physicist called Christiaan Huygens showed how to use the swing of a pendulum to regulate the clock. Also in the 11th century Su Song, a Chinese mathematician, made an even more accurate water clock, which he used for astronomy.
The water clock was first used in the ancient times for applying water to crops for a more uniform spread of water. The water clock was also used in Rome to limit the length of speeches and by astronomers to record the time of a certain astronomical events.
The water clock was quite accurate, but because it is very hard to regulate the flow of water extremely accurately, it will display the wrong time after a few months. Also, in changing climate water would have different densities, which could affect the accuracy, and if you live in a climate that gets very cold in winter then the water would be too cold to exist in a liquid state.
The sand clock (hourglass) is used to measure a certain amount of time. It works by having sand or any type of powder in a glass cylinder, which is closed at both ends, and is very thin in the middle and wide at each end. When the sand clock is put vertically all the powder flows from one end to the other and it is designed for this to take a certain amount of time.
A clock like this is limited to only a certain amount of time and one has to flip it every time all the sand is at one of the ends. It is useful for working shifts for example on a ship there always has to be some one on the look out but people need to sleep as well so every one just does one hour of look out at night and they can use an hour glass to do this.
Fire clocks include...
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By Nico Stirling
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