What is the history of clocks?

Sundials

The first time-measuring devices known to a man are sundials. Sundials are an analogue clock device that remained in continual use for many thousand of years, and even manage to survive until today. Analogue means that it keeps changing by moving smoothly from one point to another without any jumps or breaks.

Sundials were an extremely useful invention that helped people measure time. Sundials don't have hands like a clock. Instead of hands they have a shadow cast by the sun and you look at the shadow to tell the time of day.

Grandfather Clocks

A clock that has a long pendulum that swings back and forth in a steady rhythm is a grandfather clock. With every swing, wheels inside the clock turn slowly, and the wheels move the hands around the face of the clock.

Cuckoo Clocks

Cuckoo clocks are basically a pendulum that strikes hours of the day. When the hands of a cuckoo clock reach the start of a new hour, the clock makes sounds like a cuckoo bird and it moves to each note. It is unknown who invented the cuckoo clock, but they started in the Black Forest in Germany back in the 1600's and are still popular today.

How Clocks Have Changed

When we look over the last 500 years we can see clocks have changed because of people's fashion and technology. From 1600’s-1700’s, some common clocks were lantern clocks and grandfather clocks. From the 1800’s-1900’s it was the banjo clock and carriage clock. Today we have digital clocks that don't have hands and we tell time by looking at computers and phones. In the future clocks will be even more than technology that changes the way we tell time.

TiMe DEPENDS ON Where You Are

All around the Earth there are different time zones because the sun might be shining over one place on Earth but on the opposite side it is night time. Time is different depending on were you live. Like when it's 6:00am and the sun rises for us in New York, in Alaska it would only be 2:00am and totally dark. That means they are four hours behind New York because it will take four more hours for the sun to finally rise in Alaska.

China is about twelve hours different than New York, because it is on the opposite side of the Earth. So if it is 12:00 noon in New York, it is 12:00 midnight in China!

Traveling Can Confuse Your Body

Traveling across time can confuse your body clock because you are used to a different time zone. For example, when people fly a big distance they can get something called jetlag. Their body might be hungry to eat breakfast even though it's actually time to go to bed.

Keeping Track of Time

When you're in space you really can't tell time because we notice time by the way the Earth spins (rotates) toward and away from the sun. The spinning of the Earth makes days and night and lets you see the way time changes.

To be able to keep track of time changes, Earth was cut into 24 imaginary pieces called time zones. There is one time zone for each hour in the day. That is why it is a different time right now in different places all around the world.