25 May 2020


Joseph Mazur. The Clock Mirage: Our Myth of Measured Time. Yale University Press, 2020.

I have long been fascinated by the mystery of time and specifically anomalies associated with it. So it will be no surprise that I found this book particularity interesting. It is a genuinely fresh approach to the subject and I learnt many things that I never knew. Always a sign of a good book. This is particularly true when they are delivered in an easy to read form as here, so do not panic that the author is a US emeritus professor of mathematics, as his writing skills balance out any fear of being overwhelmed by theory.
The concept behind the book is simple. How and why do we measure time and in what sense is this real or subjective? Whilst it is framed through the concept of how clocks developed from sundials to atomic measurement then seeking to prove how relativity is true by flitting them on aircraft, the book always teases at the questions that lie beneath.

Sounds simple put like that. But the truth is, like many topics we just take for granted as an everyday experience, time turns out to be anything but simple. The psychology of its perception and its basis in wider reality may not at all be the same.

Mazur's questions are wide ranging. Take sundials. We have many old clocks but few very old sundials as they are made of stone and being of necessity outdoors, they weather and disappear. Stated like that it is obvious, but is a question I never asked, like many that pop up in this book. That is the skill of the author. Asking the obvious that is in plain sight yet we may ignore its importance.

An engaging aspect of this book is that it unfolds like a story with relatively short chapters on different themes punctuated by what he calls 'Interludes' between each one that are short anecdotes or interviews with people in all walks of life illustrating the themes that have just been discussed more broadly.

So we might read about how division of time used in the modern world came about via multiple systems across the ages and have to grasp the way in which the brain can or cannot properly perceive them and then see it fleshed out by what Olympic athletes or downhill skiers feel as they win titles by tiny fractions of a second.

Or how time is dealt with by people not living on Earth - passing an entire year in orbit aboard the international space station. How do you perceive time in such a timeless environment? Something many ordinary citizens have had to face unexpectedly in the Covid pandemic where lock-down changed our link with time. He even quizzes prisoners in isolation almost preempting this thought.

Broader questions, such as temporal anomalies or time travel are not a big part of the book. Understanding how scientists and philosophers think about the meaning of time though factors back into these things very much.

You will also find delightful new ideas such as how the division of time into 24 hours happened to prove so useful even though that could not have been realised when it was envisaged. Or how and why we perceive time differently at various stages in our lives.

The author has a nice way of being set off on trains of thoughts by innocent asides. A young girl sat behind him on a flight asks a parent why there are seven days in a week not eight? Adults take things for granted as 'that's how it is' in ways younger minds do not. But like many questions around time it leads into a fascinating discussion. Or his debate with a student when teaching relativity and time dilation and the student asks him how if he is on a spaceship moving at 50% light speed he can cause the Earth's rotation from so far away to change so that his twin back home ages differently to him in deep space?

This book is not so much about time but the human relationship with it, and if we modify its flow by interaction. It is a refreshingly oblique look at something we all experience every moment of our lives yet tend to see as a given. It is not that at all. So if what time really is interests you this book will be right up your street. The author even quotes Lewis Carroll on the subject – a writer that inspired me on the matter from childhood. Needless to say I enjoyed this book greatly -- Jenny Randles.

No comments: