Without the sun, life on earth could simply not be possible. The importance of the sun to our very existence has been acknowledged by the very earliest civilisations through worship and myths.
Sundials
Sundials have been used for millennia and excavations show that even the ancient Egyptians and Babylonians had their own versions. Their shadow clocks date back to 1500 BC and examples were found at excavations. Another mention is made in the book of Isaiah (Old Testament). That reference to the “dial of Ahaz” dates back to 700 BC and is the earliest known in of in written form.
It is thought that the ancient Greeks were introduced to sundials by Babylonians. The knowledge that the Greeks had acquired in the field of geometry did an enormous amount in the development of the time measuring device. It is said that the Greek mathematician and astronomer Theodosys of Bithynia (ca 160 BC – 100 BC) had developed a sundial that could work anywhere in the world. The Romans learnt of sundials from the Greeks.
Chankillo
Chankillo is located in the Peruvian desert and is considered to be an ancient monumental complex. It was built to take advantage of the movements of the sun in the same way that sundials were, but the passage of time it measures is different. Thirteen towers were built in a row on a low hill and run from North to South. When perused from a specific vantage point, the position of the sun (at sunrise) either directly above a tower or in one of the narrow gaps between them, will allow the observer to tell the date with an accuracy of 2 or 3 days. It is, in essence, a sun calendar! Only small portions of the tower remain and until 2008, scientists still had not determined which culture may have been responsible for the site.
Moondial
Still harnessing the light that is reflected from the moon’s surface onto the earth, moondials were invented to tell the time at night. They are only truly accurate when the moon is full. During other moon phases at can be as much as 5 hours and 36 minutes slow are fast! Advanced moondials come with charts that show the exact calculations needed to make an accurate reading.
Digital Sundial
A digital sundial diffuses the angle of the light that reaches it in different was so that the observer will (on the opposite side) see digits telling the time. The digit indicating the minutes only change in increments of five, effectively only showing a five or a zero depending on what the time is.
Noon Dial
Noon dials have been around for centuries and are used only to tell when 12:00 is reached locally. Noon dials were also used to correct mechanical clocks which were so inaccurate that they could lose a significant of time every day. Some noon dials were designed with a mounted lens so that the sun’s rays would heat a firing pan in a miniature cannon loaded with gunpowder. There was, of course, no ball in the cannon. It was purely used as an aural time guide. These devices were often called noon cannons and were popular in parks in Europe during the 19th century. In order to maintain accuracy, the position of the lens has to be moved seasonally.
Natural sunlight hold many health benefits and these days people even install skylights into their homes to increase exposure. In addition to the natural role the sun plays in our lives, humans have managed to extract from it even more value.
About the Author :
Louisa Theart is a freelance writer and musician. She loves sharing her curiosity for everything with the world.
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