The Order of Time

Railway time was synchronized as GMT by recommendation in the UK in 1847 (unlike Rovelli's seemingly mistaken account on p55).If E=mc2 then the speed of light is relevant and constant. Speed is distance over time. Rovelli doesn't even mention how this is reconciled with the points he is making.There seems no explanation of the use of time differences, synchronized to some sort of "now" in GPS. Presumably there has to be a "now" moment when information needs to be retrieved or sent to distant spacecraft.The age of the universe is often spoken about. What would that mean? Hmmm.A deeply unsatisfying book, at least for me and a very poor second to the clarity of eg. Stephen Hawking, Richard Feynman or now, quite a few others.

This book is very well written and difficult to put down after starting to read it. It is a wonderful account of historical and current thinking on the nature of time. You will still be confused about this at the end of the book but you will realise you are not alone: scientists are confused also! Since Einstein most scientists accept that mass and motion affect time : the author says that the time at your head is different to the time at your feet for example. I think there is confusion between time and clocks. Clocks do not record time, they count ticks and the counting is certainly affected by mass and motion so a watch on your head would record a different count to a watch on your feet. The time , however, would be the same for both. The pendulum on a grandfather clock would stand still in zero gravity but time would go marching on.

Carlo Rovelli seems to lead our understanding of Time. He writes clearly and succinctly. Thought provoking and deep. Suggest the reader takes on Seven Brief Lessons on Physics by Rovelli before delving into this beautiful little book.

I have to say I was disappointed with this book. Being a fan of the subject matter and having read a number of books on the topic I was excited to read this given the glowing press it tends to receive.Unfortunately, having read this and Rovelli's much shorter 7 Brief Lessons in Physics, I have come to the conclusion that his writing style is just not for me. I don't really know if it just the way in which he writes with such flowery language or if this is more to do with it being translated from Italian but I found it difficult to follow at times. Whilst I realise that the topic itself is challenging and not exactly the most straightforward to get your head around, I found his writing a lot more difficult to understand and digest than others, often having to re-read sentences and sometimes whole paragraphs just to get to grips with exactly what he was saying. Not only that but I felt the book kept promising more and never really getting round to delivering on it. Ultimately by the time I had finished, I felt unfulfilled by it.Others may enjoy his less direct and generally more elaborate way of writing, I mainly just found it verbose and more difficult to digest, which, given the complexity of the subject matter, I feel is a real problem.

A lovely little book, written in a friendly way. Carlo presents some very difficult concepts of quantum physics and relativity in the most accessibly way I've come across. I'm not saying it's easy to understand but he writes very lucidly and clearly. I was glad the book was small and very to-the-point!