Book 5, Question 140
Why Does History Use Different Clocks Than Homework?
Homework is measured in minutes and hours, but history is measured in years, centuries, and much longer spans. Scientists choose a time scale that fits what they are studying. It is like picking the right ruler for the job.
From the book
Page from A Million Whys Book 5
More fun facts
- The Greeks and Romans used temporal hours, which stayed in use for more than 2,500 years.
- The water clock was the sundial's nighttime partner. It measured the hours after dark.
- By the 13th century, craftspeople in Europe had invented the mechanical clock.
- By the 15th century, more and more clocks were being made for people's homes.
- In the 16th century, astronomer Tycho Brahe found that even the best clocks were too unreliable for science.
- In the 1800s, the town clock, the railroad and the Sun could all tell people a different time.
Sources: Scientific American, Smithsonian Magazine
Questions kids ask
How did people tell time at night long ago?
Some used water clocks, which measured the hours when a sundial could not work.