Clocks: Seven Things You Should Know (Paperback) (ISBN-13: 9798198875296)

We've done it so long, so automatically, that we've stopped noticing how strange it is - that a device on the wall has become the first authority we consult every day.

Where did the hours come from? Why does a second last exactly as long as it does? Who invented time zones, and why do thirty-eight of them exist when the math only requires twenty-four? Why does the most accurate clock ever built require occasional correction to keep up with the Earth? And is there any chance that the clock didn't just help us keep track of time, but changed the way we think?

Seven surprising answers follow.

WHAT THE CLOCK TOOK FROM US - Before the factory, most workers were paid by task, not by the hour. The clock didn't just schedule the industrial revolution. It redefined what it meant to sell your labor.

THE DAY WE INVENTED TIME - Time zones are not a natural fact of geography. They are a railroad industry fix, about 140 years old, still being argued over by nations that refuse to agree on what time it actually is.

THE CLOCK THAT SAVED SHIPS - For centuries, navigators could find their latitude but not their longitude. Thousands died on rocks they knew were there. The solution, when it finally came, was a carpenter's son from Yorkshire with a borrowed book on clockmaking.

THE MOST ACCURATE CLOCK IN THE WORLD IS WRONG - The atomic clock is so precise that it has revealed the Earth to be an unreliable timekeeper. Once a year or so, an extra second has to be inserted into official time by international agreement to keep atomic clocks in sync with a planet that won't hold still.

THE CLOCK YOU WERE BORN WITH - Every cell in your body runs a roughly 24-hour clock, independently and simultaneously. The 2017 Nobel Prize in Physiology went to the researchers who figured out how. Disrupting this clock - as shift workers do every night - has measurable costs.

THE WORST IDEA THAT WILL NOT DIE - Daylight saving time was not invented to help farmers. Farmers have always hated it. It was a World War I industrial measure, its energy-saving rationale has not held up, it produces a measurable spike in heart attacks and traffic accidents every spring, and it survives because the golf industry lobbies effectively.

HOW THE CLOCK MADE THE MODERN MIND - Lewis Mumford argued in 1934 that the mechanical clock - not the steam engine - was the defining machine of the modern age. His reason: it didn't just organize the workday. It reorganized how people think about time, sequence, cause and effect, and progress itself.

Part of the I'm No Expert, But series: short, accurate, accessible books about things most people have heard of and almost nobody actually knows.

Curious, a little lost, and taking notes.