Clocks

Many schools are dropping analogue clocks in favour of digital clocks, as more young people do not know how to read them. Here is a look at how, through history, people have told the time.

• Surely, everyone can tell the time?

Not anymore, it seems. Many schools in the UK are scrapping traditional wall clocks because so many young people cannot tell the time. In 2018, a teacher told a conference that it was happening because pupils taking exams complained they could not read clock faces in exam halls.

A 2014 poll by a leading watchmaker found that one in seven British adults also struggle to decipher the intricacies of the two different arms on a clock.

• Why do we tell the time in this way?

Some things are dictated by the universe. A year takes slightly more than 365 days and, similarly, a day is a fixed length of time.

But how we divide up those days is completely up to us. The concept of dividing an hour into 60 minutes, and a minute into 60 seconds comes from the Babylonians. They used a sexagesimal system (counting in 60s) for astronomy and mathematics. They took the idea of 12 months from the Sumerians.

Dividing things into 12 (or 24 or 60, which are multiples of 12) makes a lot of sense. Whereas 10 is only divisible by 5 and 2, 12 is divisible by 3 and 4 as well.

• Has anyone tried to adapt this system?

Yes. In their zealous efforts to cut off France’s links with its past and to create a new utopia, the French revolutionaries of the late 18th century experimented with decimal time.

The new day had 10 hours. Each hour had 100 minutes, and each hour had 100 seconds. Noon was at 5 o’clock. To do this, they simply changed the length of a second, which is also an entirely man-made concept. The French also tried to change the calendar, creating 10-day weeks.

• Did it work?

No. Old habits die hard, and there were few practical reasons for non-mathematicians to change how they told time. Furthermore, replacing every clock and watch in the country would have been expensive.

• Let’s go back to the beginning. Who was the first person to measure time?

We cannot say for certain. But one of the earliest devices to measure time was the humble hourglass, which features two glass bulbs connected vertically by a narrow neck that allows a steady trickle of material (usually sand) to pass from the upper bulb to the lower one. It was invented in Babylonia, and quickly moved to Egypt.

The principle is similar to candle clocks. These were probably first used in China or Japan, but were also famously used by Alfred the Great. These are thin candles with regularly spaced markings. The burning of the wax down to the next marking indicates the passage of time.

• So when did modern clocks come about?

The earliest clockmakers were medieval Catholic monks, who lived by a strict schedule of work and prayers. The first clock recorded was built by the future Pope Sylvester II around the year 996.

The French mathematician and philosopher, Blaise Pascal (1623-1662), was the first person to wear a watch around the wrist. But it was the invention of the pendulum clock in 1656 that really brought timekeeping into the modern era.

The advantage of a pendulum clock is that it is a “harmonic oscillator”: it swings back and forth in precise intervals that are dependent on its length, and it does not swing at other rates.

• And digital clocks?

These were invented by Austrian engineer Josef Pallweber. In 1883, he created the “jump-hour” mechanism, which featured two windows in an enamel dial, through which hours and minutes were visible on discs.

To quote Stephen Hawking, “only time will tell”. As our lives continue to be ruled by time, scientists will urgently continue their attempts to improve how accurately we tell the time.

You Decide

1. Do you wear a watch? Why or why not?

Activities

1. Devise a whole new way of measuring time, and write a paragraph on why it should replace the current way.

Word Watch

Conference
The Partners in Excellence conference in London, a gathering of British teachers and education experts.
Intricacies
Details.
Slightly more than 365 days
The exact length of a year is 365.25 days which is why, every four years, there is an extra day: 29 February.
Sumerians
The oldest known civilisation in the world, Sumer was located in Mesopotamia (modern-day southern Iraq). Living along the Tigris and Euphrates rivers, Sumerian farmers were able to grow an abundance of grain and other crops, enabling them to settle in one place.
Alfred the Great
The King of Wessex (a kingdom in southern England) from 871 until 899, Alfred is by far the most famous figure in pre-Norman England.
Blaise Pascal
He is best known for Pascal’s triangle and his work on probability theory.
Enamel
Smooth, long-lasting, glossy type of paint.