Humans have been putting in the constant effort since the very beginning to measure time accurately so that notable events could be recorded. To determine how situations and surroundings have progressed through the past, present, and how they are going to be in the future, they developed timepieces to determine the time.
In order to do so they developed multiple methods – efficient, inefficient, some methods overtook others, some were worked on further, some became the base of further inventions and some were thought up fresh…
In this article, we shed some light on what popular devices (clock) and methods were used then to determine the time.
Sundials And Obelisks
Sundials and Obelisks are the timepieces, which were the very first human efforts of telling time. Sundials are believed to have been the very first household clocks as per archeological finds. India’s Jantar Mantar, a UNESCO world heritage site, is the world’s largest stone sundial.
Sundial is described as a device that indicates the time using the shadow cast by the position of the sun on the reference scale. It consists of a flat scale (the dial/reference scale) and a gnomon which casts a shadow on the dial.
Much earlier obelisks were used as sundials which are now thought to have been built solely for religious purposes since they were originally erected in pairs at the entrances of ancient Egyptian temples. First made by Egyptians – it played a vital role in their religion and were prominent in their architecture.
Structure wise – Obelisk is a tall, four-sided pillar that ends with a pyramid at the top and was carved by the Egyptians from a single piece of stone, usually red granite from the quarries at Aswān.
You might identify obelisks from the movie – Spiderman: homecoming. The movie shows the Washington D.C. monument built to commemorate George Washington – is an obelisk.
In the past one of the popular methods of telling time was using a candle clock. Though it is not definite when the clock was first used, the earliest mention is in a Chinese poem by You Jiang.
A candle clock consists of a long candle that was marked at even intervals. The candle burnt at an even rate and indicated time. However, the time indicated by these clocks was observed to vary from person to person, even if lighted at the same time since the material of the wax varied.
The most famous clock was used by King Alfred the fourth of England, but the most complex candle clocks were fashioned by Al- Jazari which used candles, weights, and counterweights which moved a series of automata which displayed a readout of the time.
Oil Lamp Clock
Though it is unknown when oil lamp clocks were first used, it is believed that they were used mainly during the 18th century.
Oil lamps consist of a graduated flask which was used to hold the oil – usually whale oil which was obtained from the blubber of the whale. Blubber is a layer of fat under the skin of a sea mammal.
The whale oil burns completely and evenly. This fuel burns at a constant rate – the hours being counted as the fuel level lowers – indicating time.
The very first method which didn’t involve observation of the celestial bodies was a water clock. It’s very obvious that a sundial becomes pretty useless after sundown. One of the oldest sundials was found in the tomb of the Egyptian pharaoh Amenhotep I buried around 1500 BCE.
As far as its structure is concerned – a water clock is stone vessels with sloping sides. The vessel is then filled with water. The slope of the vessel allows water to drip at a nearly constant rate from a small hole near the bottom. The walls of the stone vessels were graduated on the inner surface which marked hours.
More efficient than any timekeeping device invented before modern times – an hourglass also called egg timer was first invented around the 12th century. Popular in art culture, an hourglass with wings depicts the well-known Latin epitaph – Tempus fugit (“time flies”).
A sand timer uses sand that falls from the upper container or bulb to the lower container which is symmetrical in design and is joined by a narrow neck which measures a predetermined span of time.
It was Galileo Galilei’s idea to use a suspended bob to regulate the motion of a time-telling machine for more accuracy in the 17th century. However, it was Christian Huygens a Dutch astronomer, physicist, and mathematician who first did the calculations and had a pendulum clock made.
The pendulum is a harmonic oscillator – meaning it swings back and forth in a definite time interval. This time interval depends on the length of the means of suspension and it resists swinging at other rates.
Bell telephone laboratories made the world’s first quartz clock in 1927. However, Seiko, a Japanese holding company and manufacturer of watches introduced the world’s first quartz watch by the name of Astron in 1969. Ever since then this simple way of timekeeping took over the world by rage.
A modern quartz clock uses an electronic oscillator that is regulated by a quartz crystal to keep time. This oscillator creates a signal of precise frequency making them more accurate than mechanical clocks. With time they have become more compact. They use some form of digital logic to count these signals and provide a numeric time display.
It was in 1879, lord Kelvin, an Irish Scottish mathematical physicist, and engineer proposed the idea to use an atomic transition to measure time. It wasn’t until 1949- the first atomic clock was built, but the first accurate atomic clock was developed in 1955 based on a certain transition of cesium 133 atoms.
Atomic clocks are the most accurate time-keeping instrument humanity has developed and makes continuous efforts to make them even more accurate.
In 2018, physicists at the National Institute of Standards And Technology developed a crazy accurate atomic clock which is off by less than half a second in 14 billion years- that is since the beginning of the universe. Such accuracy and precision make it a powerful scientific instrument.