Time and Time Zones

Front

What was the first method of telling time?

Back

Sundials

Front

What is the main limitation of a sundial?

Back

It requires sunlight to function

Front

Which device was commonly used on ships due to its stability?

Back

Hourglasses

Front

What significant advancement did the mechanical clock introduce?

Back

Swing of a pendulum

Front

What is the basis for scientific time today?

Back

Atomic clocks

Front

Why is keeping track of time important?

Back

For regulating daily lives and global communication

Front

What problem did different local times on the American railroad system present?

Back

Challenges in making train connections

Front

How many time zones are there on land?

Back

40

Front

What was the purpose of introducing time zones?

Back

To smooth out communication and travel schedules

Front

For how many hours does any given calendar date exist on the globe?

Back

50 hours