"The Order Of Time", a book by Carlo Rovelli
The concept of time, one of the greatest remaining scientific mysteries, fascinates me. In July, 2017, The Lighthouse Peddler ran my review of Why Time Flies by Alan Burdick*. I wanted to know more, so here we go again.
The Order of Time is divided into three sections: The Crumbling of Time, The World Without Time, and The Sources of Time. It’s impossible to read about the subject as Rovelli describes it, though, without introducing other components: space, energy, heat, stuff that happens, stuff that doesn’t, and most importantly, entropy.
Understanding the concept of entropy is central to Rovelli’s theory of time. So, let’s start with his definition. “The growth of entropy is nothing other than the ubiquitous and familiar natural increase of disorder.” Entropy refers to the idea that everything in the universe eventually moves from order to disorder, and entropy is the measurement of that change. It occurs when heat passes from hot to cold; heat only passes from hot bodies to cold bodies, never the other way around.
The Order of Time tackles many of the questions posed in Why Time Flies and adds a number more. Provocative questions: How long is the present? Time is a measurement of change, if nothing changes does time stop passing? Does time even flow at all? Is only the present “real” with the past and future not being real? Or are they all equally real?
The laws of physics make no differentiation between past and future, cause and effect. Yet we remember the past; why can’t we remember the future? Rovelli presents a strong case that it has to do with entropy. Only where there is heat is there a distinction between past and future. The past leaves traces of itself in the present because entropy was low in the past. That’s the difference between the past and the future. The only difference, Rovelli asserts.
The Order of Time explores the aspect of memory that refers to the past. Rovelli helps us understand, for example, how we can enjoy music, remembering what we just heard and anticipating what’s to come even though we are always only in the present moment.
The author suggests that we’re better off and more accurate describing the world not as collection of things, but of events. Things “persist in time,” events have a limited duration. “If by ‘time,’” he says, “we mean nothing more than happening, then everything is time.” In the study of time we are exploring the world as it happens, not as it is.
Rovelli suggests skipping chapters 9 &10 if the technology intimidates you. It did me, but I read them anyway.
He opens chapter 12 by asking, “what are we as human beings? what, then, am I?” In chapter 13 he summarizes what we’ve learned. And he closes the book with his personal spiritual philosophies. In its own way, this is a profound book. I encourage you to explore both books but suggest that you read Why Time Flies first.
Understanding and absorbing the concept, the machinations, the very existence of time is difficult… even for scientists such as Carlo Rovelli. Still he offers a thought provoking and interesting perspective. Burdick’s Why Time Flies offers more insight into how we came to measure and experience time on a day to day basis. It’s full of surprises without delving too deeply into the science.
How does time work? We don’t know. Things are certainly not what they seem to be. But The Order of Time shares compelling, albeit sometimes difficult, theories that get my mind to spinning; so much so, that I’m looking forward to reading the book again. I’m not a scientist. And I didn’t understand everything I read. But I found it fascinating and mind bending nonetheless.
For all that I don’t quite grasp, I have to admire, applaud and feel encouraged by Rovelli’s point of view. We humans are a curious bunch. In its own way, as the book concludes, The Order of Time offers an interesting and, for me, hopeful perspective. Not bad for a book on science.
From Joel: By the way, there’s a typo in my earlier book review that I didn’t catch until now. The universe was created 14 billion years ago, not 14 million years. My mistake!