Einstein’s Clocks, Poincaré’s Maps by Peter Galison
Finished reading on 10th October 2017
What is simultaneity? How can clocks be synchronized? Why do we have 60 minutes in an hour instead of 100? These are some of the questions you’d find answers to in this book.
I wanted to read this book just because of the title – first of all it mentions Einstein, and secondly I remembered Poincaré’s name from one or another physics lecture.
This book starts out with the practical need for synchronizing clocks that was first felt at the observatories and on the railroad. In case of railroads it might sound more practical as it makes sense that even small differences in time can cause accidents in case of fast-moving trains. In the case of observatories however it was connected to the need to find your exact location on a map for cartographers etc.
As railroads covered more and more land surface with their grid it also became important and necessary to think of standardizing time. Which brings the book to the topic of what kind of ideas were proposed and how the Greenwich meridian came to be the one acknowledged as the prime meridian.
In addition to practical need and solutions, Galison goes into the idea of simultaneity as a basic idea in physics and philosophy and how it was approached differently.
It all leads us to the special theory of relativity.
Having read several books on relativity and Einstein before, I felt like this book gave me a different insight into special relativity. Maybe it was just because of the comparison with Poincaré’s ideas, or Galison showing it in the context of contemporary ideas of synchronizing clocks.
This book was interesting from the beginning to the end and approached time from a different perspective than what I’ve encountered before. It’s not a difficult book to get through, but it makes you appreciate having standardized time and accurate clocks, and might also make you think about why couldn’t we have decimal time instead?