Time's Pendulum: From Sundials to Atomic Clocks, the Fascinating History of Timekeeping and How Our Discoveries Changed the World

by Jo Ellen Barnett

A perfect balance of science, history, and sociology, Time's Pendulum traces the important developments in humankind's epic quest to measure the hours, days, and years with accuracy, and how our concept of time has changed with each new technological breakthrough. Written in an easy-to-follow chronological format and illustrated with entertaining anecdotes, author Jo Ellen Barnett's history of timekeeping covers everything from the earliest sundials and water clocks, to the pendulum and the more recent advances of battery-powered, quartz-regulated wrist watches and the powerful radioactive "clock," which loses only a few billionths of a second per day, making it nearly ten billion times more accurate than the pendulum clock. A tour of the discoveries and the inventors who endeavored to chart and understand time, Time's Pendulum also explains how each new advance gradually transformed our perception of the world.

Genres: Science, Nonfiction, History, Microhistory

334 pages, Paperback

First published March 21, 1998

Reviews

[Anthony Chase · Rating 5 out of 5]

Overall I felt the book Time's Pendulum by Jo Ellen Barnett that this was a fascinating book and really gave me an in depth look into how difficult it was to create the whole concept of time. I felt as though the time of the story was set up in an appropriate manner with time ranging from around 1300 BC early on all the way up to the twentieth century towards the end. I thought it was interesting to hear how some of the first clocks ever produced weighed thousands of pounds and had to be carried by many people in order for them to set it up. The sun dials noted in the book I felt were also informative because they gave an in depth look into how people would tell time before the age of the clocks. I never really got that bored reading the book for the most part and the chapters were a good length at around 15 pages each which made it relatively simple to be able to follow. The book also talks about everyday methods that one can use in order to tell the time if they don't have a watch on them such as locating which direction the sun is facing and picking up approximately what time of day it is based on where the sun is. All in all, I would have to say this was one of the more fascinating books I have read this year and I would recommend it to anyone even if they're aren't all that interested in time.

[Robert Swanson · Rating 3 out of 5]

Interesting.
Sometimes tried to hard to make it interesting, skip those parts.
Explained some things other books hinted at but didn't explain.

[Andrew · Rating 2 out of 5]

The first half details the history of keeping daily time: Our 24 hour period is a function of the earth & moon, and in the distant past the earth day may have been just six "hours" long. The first sundials divided the day into unequal periods (relating to the sun's angle) and the first water clocks kept duplicated these unequal periods. Plato had an alarm water clock) - metal balls were in the vessel which were lifted by the water level; when it reached a certain time, the balls fell out onto a metal plate.

We base our time on the Mesopotamian sexagesimal system - 60 is evenly divisible by 2,3,4,5,6, 10, 12, 15, 20, and 30. (Although after the French revolution, France used a decimal system that didn't last long.)

The first clock was invented about 1280. The pendulum increased accuracy (the period of the swing is dependent on its length). Local time dominated the world until the railroads - schedules needed a consistent frame of reference. Later time zones were incorporated. Crystals increased accuracy - the vibrate at a certain frequency.

The second half of the book details the history of determining the age of the earth. The first attempts used the Biblical account (which estimated the age at a few thousand years - and one was 4004 to be exact). Faced with geological and fossil evidence, scientists began to estimate thousands to millions of years. Radioactive clocks measure the half-live of various elements and date the earth at 4.5 billion years.

Carbon-dating is only used for newer (>50,000) which is the time of modern man. It's found that: Stone temples were built in Malta before the pyramids, crops were cultivate along the Rhine before they were on the Nile, a buried city in Turkey predates those is Mesopotamia.

[Wendy · Rating 3 out of 5]

Part One - The Time of Day was captivating and there seemed to be a tidbit on every page that was worth remembering. The facts and figures were relevant to the common man.

Part Two - The Time of the Earth ... after not remembering anything I read over 25 pages or feeling compelled to continue, I sighed, removed the bookmark and packed it to return to the library. Geologists, physicists and theologians would probably enjoy the second half.

[I]

The first part is good explaining history of time keeping and time measuring. Second part is about measuring earth's age, fossils etc which was not that interest. Overall, high recommended.