I chose to read this book thinking its focus was history. What I did not realize until about the second third of the book was that it would also get into a great deal of astronomy and physics. Perhaps I should have delved further before reading to learn the author was a college professor and physicist who based the book on a course he teaches.

The book is a history, starting with prehistoric efforts to track seasons for purposes of crop planting and harvesting, with astronomy and the locations of heavenly bodies used to ascertain the time of day (e.g. sun overhead), time of year (e.g. sun doesn't rise as high in the sky), time of month (e.g. the size of the moon in the sky), and how other heavenly bodies were used to keep time. Orzel takes us from sundials, to the present, explaining ancient Mayan structures, Stonehenge and other early efforts to time the seasons, how calendars were created and their evolution, as well as timekeeping at the level of our clocks, watches, cell phones and other electronic devices. Lots of enlightening discussion of early efforts to keep time.

From the earliest civilizations he describes efforts to measure the time of day, including sundials, water clocks (which work on cloudy days), hourglasses, and the development of mechanical clocks, then on to electronic clocks using quartz crystals, atomic clocks and future, more advanced atomic clocks. While much of this is enjoyable, the text is full of references to principles of astronomy and physics, explained in the text and further in detailed asides. The many illustrations were very helpful in conveying some of these scientific concepts, but once Orzel got into the theories of general and special relativity and how time bends near heavenly objects exerting strong gravitational forces, things got beyond my ready comprehension.

The last third of the book, in particular, includes a great deal of science that explains how timekeeping has advanced. Unless one has recently taken a course in astronomy or physics, much of this will be dense and slow going. I for one was not interested in the basics of cesium atomic clocks nor the future of laser clocks. But I did enjoy learning about how our GPS system relies on highly accurate timekeeping, which in turn is aided by the atomic clocks on the many GPS satellites orbiting our home planet.

If you are a science buff, you will likely love this book. If you are more of a history buff or simply have an interest in timekeeping, you will find this book slow going but one can skip the detailed science and focus on the history.

Thanks to Net Galley and the publishers for providing an electronic copy of this book in exchange for an objective review which I have hopefully provided.

Overall, an interesting and entertaining book detailing, well, the history of timekeeping. But, in addition to lots of fun facts about the evolution of timekeeping but also the influence of politics and culture (and vice versa — ie the influence of keeping time on culture). There are moments where the author gets a bit in the weeds with science, but, on the whole a quite intriguing read.

This book is full of information about timekeeping from around the world, from different cultures and how the systems created to manage time changed in time. It's slow-paced reading but I took my time with it. I loved the book because I understood better the difference between the Julian and Gregorian calendars and time zones and other things that we can hear about or still have to deal with them.

A Brief History of Timekeeping is both history and science, and so is the kind of book I gravitate to.

Author Chad Orzel starts with a strong statement in his introduction - "we [humanity] are and always have been a species that builds clocks". He then goes on to do a pretty good job justifying that statement with the rest of the book, which takes us from Neolithic megastructure timekeeping to today's atomic clocks that keep the time on our cellphones current, and the (historically extremely accurate) quartz watches many of us wear on our wrists.

Orzel is a scientist himself - holding a PhD in Chemical Physics - and also a Professor at Union College in Schenectady, NY. He's the author of several other pretty well received popular science books, such as the humorously titled How to Teach Relativity to Your Dog and How to Teach Quantum Physics to Your Dog.

In this book Orzel promises to keep the content "approachable and engaging for as broad an audience as possible". To do so, he separates out more technical discussions into sidebars set off from the main text. You can choose to delve into the sidebars, or skip them knowing you'll still get the gist of what he's talking about. This approach works pretty well in the early chapters of the book (and yes, of course I read the sidebars). But later in the book as he gets into quantum physics and atomic clocks the main text gets pretty darn technical and the sidebars grow to multiple pages. I'm not too proud to admit that most, if not all, of the chapter on Quantum Clocks was way over my head. Well, my college days are far behind me, and it's apparent that I've hit that age where I've forgotten more than most college kids know.

In general though I found the book enjoyable. There is plenty of history here I didn't know about, and some things, like the advanced water clocks of China, that I was aware of but learned much more about. He's spends a fair amount of time on the Aztecs and their cosmology and calendar system, which I thoroughly enjoyed.

My personal preference in a history of science book like this one is that the author go heavy on the history and keep the science to the "explain it to me like I'm a fifth grader" level. This book is apparently adapted from a course Orzel teaches in the Physics Department at Union, and so perhaps for that reason the science throughout was a bit "heavier" than I would have liked. So for that reason I give A Brief History of Timekeeping Three Stars ⭐⭐⭐.

Solstice caves. Gregorian compromise. "Give us our 11 days!" Mayan calendar ends (order your refills!). tictictic, the measure of time.

Orzel writes really clearly, even when the story is convoluted. The Julian calendar worked for 15 centuries before its rounding-error affected everyday life. I've read on this change in many books, but Orzel's is by far the best. But he also explains the Hebrew and Islamic moon-based calendars. One I never understood and the other was rare in my life until recently. Chronometers, for surveying and particularly for locating yourself east-to-west on the high seas, in search of treasure.

If you dig time, you must read this. Easily the best I have ever seen.

Author Chad Orzel draws upon his experience as a professor to teach readers about the methodology of timekeeping on the largest and very smallest scale that we can conceive for now. Calling it a "brief" history brings to mind that the experience of time is relative, and this was a very slow read for me. The book is probably more engaging and accessible on the printed page based on a description of side bars in the introduction, which did not display as intended in the e-arc sent to my kindle.

This is a solid entry in the history of timekeeping genre. It's not technical so intelligent non-specialists should be OK with most of it. If you do have a technical background, there's enough here to keep your interest going. My one criticism would be more about editing than the coverage of the topic. Instead of starting with the oldest known timekeeping efforts, we need a big beginning to get our attention. My interest waned as I worked my through the older history, though I had seen a lot of the material before. Recommended for interested teens through all ages.

This review is based on an ARC of A Brief History of Timekeeping: The Science of Marking Time, from Stonehenge to Atomic Clocks, which I received courtesy of NetGalley and the publisher (BenBella Books).

I'm not gonna lie, this one was a bit tedious. A Brief History of Timekeeping is undeniably well written, and many aspects of the history fascinated (as well as educated!) me. In the end though, I'm just not that interested in clocks.

If you have a curiosity for clocks or obscure histories in general, definitely check out A Brief History of Timekeeping!