Saaransh : Hey! Its story time.
Mom : Yes, but how do you know what time is it?
Saaransh : When it gets dark & my clock shows 10 pm. I know its bed time.
Mom : Well said. Today will tell you how clock was invented.
In ancient times people did not have tool to keep account of seconds, minutes & even hours. Morning, noon & evening was considered depending on position of the sun. This led to idea of a Sun dial.
There were Hourglass, candle clock, water clock…etc. but the need of more precise clock aroused during sea navigation.
Saaransh : Why for sea navigation?
Mom : Whenever any ship was navigating in the sea, it was difficult to measure how far the ship had sailed in particular direction. Sea doesn’t have landmarks to locate. With the help of clock, they could measure the distance ship might have covered in particular direction with given speed.
Saaransh : How would they know the direction?
Mom : Direction could be guessed by the position of Sun & Stars.
Saaransh : oh!
Mom : This story dates back to around 350 years ago. when Europe’s seafaring powers Spain, Netherlands, France each offered vast prizes to stimulate innovation in era’s crucial problem of sea navigation. Italian scientist Galileo accepted the challenge and started working on it. One day in the church he was watching the chandelier as it swung. He observed that the time required for each swing is same.
Saaransh : But how could he measure time as there were no clocks those days?
Mom : Correct he didn't have clock to measure but he measured it with his pulse rate.
This led to idea of pendulum clocks. But due to some ailment he became blind. So he described the device to his son Vincenzo who drew a sketch of it. Vincenzo began construction of a prototype but both died before it was completed.
Saaransh : How does the Pendulum clock work?
Mom : Pendulum clock measures time depending on the swings of pendulum.
After few years Dutch horologist Christian Huygens modified Galileo's pendulum clock.
Saaransh : Dutch means the people from Netherlands I know. But what is the meaning of Horologist?
Mom : Horology is the scientific study of time & clock making. A person practicing horology is called Horologist. Like the one who runs business is called businessman.
Saaransh : okay
Mom : So I was talking about Huygens. Huygens proposed the pendulums with small swings. An improvisation in the model of Galileo where he designed the wide swings of pendulum. Clock makers realized that only pendulums with small swings are isochronous.
Saaransh : What is isochronous?
Mom : Isochronous means occupying equal time. This helped in depicting precise time with all kinds of pendulum models. Thus this invention was credited to Christian Huygens in 1656.
Saaransh : Last time when I showed you Pendulum clocks you said they are antiques.
Mom : Yes, now they have become antique. With time, clock kept on evolving to present battery-operated clock.
Saaransh : okay!
Mom : Now our clock is ticking to remind us about the time to say good night dear!
Saaransh : Good night, Sweet dreams