Time has always been important to humans. For thousands of years we have been trying to figure out how best to measure time. Early astronomers studied the heavens to know the different seasons and when a year had passed. Knowing the seasons was very important to humans, once they discovered how to plant crops. They learned what seasons to plant and what seasons to reap. The very early humans learned how long it took for the sun to go down and then reappear. This wasn’t good enough for us and we wanted more accurate measurements of time. Many different kinds of devices were used in the early days of timekeeping. The ancient Egyptians divided a day into twelve hour periods and used obelisks to track the movement of the sun. Along with obelisks they developed a type of water clock. The water clock caught on and some ancient societies such as the ancient Greeks and even the ancient Chinese adopted them.

But clocks were not the only devices which were used by ancient people. Another type of clock was the candle clock. A candle would be divided into even sections and as it burned one could tell what section it got to. It seems candles would have had to be made in standard widths and materials if everybody wanted to know the same time. Another instrument which was used to tell time was known as shepherd dials and also known as a timestick. It is a cylinder used the same as a sundial and has a gnomon which juts out perpendicularly when the device hangs from a rope and the gnomon can be adjusted. It works similar to a sundial and a sundial is another instrument which was used to measure time. The clocks which relied on the sun only work when the sun was not obliterated by clouds. In those days these devices would give you nothing if the sun was blocked.

Perhaps the most famous ancient piece of timekeeping which everyone has seen is the hourglass. A device which was filled with sand at one end and empty at the other. Sand would slowly filter through a very narrow opening from the top to the bottom. Even in modern times this device is still sometimes used in cooking to time boiling an egg. People who had hour glasses which were the same size would get a rough approximation of the same time it took for the sand to leak out of the top and fill the bottom.

Here is where things get a little foggy. People believe the first mechanical clocks were invented in the fourteenth century in Europe. They think it took this long to invent a mechanical clock, because there were no gears invented before that. The truth is there were gears invented in China in the 27 century BC. These were not metal gears however. It was believed metal gears were invented in the Middle Ages, but this belief fell apart with the discovery of the Antikythera mechanism, a machine which acted like a mechanical computer and was found and knocked the scientific world on its ear, since it has been dated as far back as the 2nd century B.C. This device contained cut metal gears. Could cut metal gears have found their way into even earlier clocks than we suspect? If this device had cut metal gears who is to say a few early clocks were not created using the same types of gears and we just haven’t found them yet?

The earliest clocks used what was known as aVerge escapement system. It merely meant the mechanism is controlled by a gear train allowing the clock to advance at regular intervals. While this type of system was used from the 14th to the 19th centuries in clocks and pocket watches. In 1656 the first pendulum clock was invented. In the early 15th century the mainspring was invented which allowed for much smaller clocks and pocket watches. They became a lot more accurate when a balance spring was added in the mid-17th century. In 1735 a chronometer was invented. These are extremely accurate timepieces used on ships to determine their longitude. The time was measured on the clock and only came to being off five seconds in ten weeks. This was quite an accomplishment when you consider when it was built. Wristwatches are believed to have been invented in the 16th century but were prone to problems from exposure. Usually only women wore them. It wasn’t until the military ordered soldiers to wear them at the end of the 19 century, when they became popular for men. They were very important in coordinating military attacks.

It is kind of hard for us to believe today, but the first electric clock appeared in 1815 and was powered by a high-voltage battery. It was known as the electrostatic clock. Others give credit to a Scottish clock maker who filed the first patent for an electric clock in 1840. It seems the fascination with telling time never waned and there has always been an urge to improve timekeeping so a quartz crystal was added to many of our clocks and watches, because its oscillation made for a lot more accuracy.

This brings us to our latest clock invention. Scientists figured out if they measured the decay rate of cesium which was based upon the Cesium-133 atom, this rate could be used to power a clock which would have unparalleled accuracy. This became known as the atomic clock. One second on the atomic clock is equal to 9,192,631,770 cycles of the radiation. It is interesting to note some claim the most precise atomic clock loses only one second of time over the age of the universe. Will scientists pursue even more accurate clocks in the future and if so why? I have no way to know the answer this question, but knowing human nature there probably will be some scientists who will try and outdo the atomic clock. Maybe they’ll find an element whose decay rate is even more accurate. As to the question of why they would do this, we have no way of knowing if such things as time travel will be invented and if it is, it may require a clock so accurate it would never lose any time.