It’s about Time

The concept of "time" is a fascinating one that I like to revisit again and again. It is truly a rabbit hole that gets weirder and weirder the more one thinks about it. Here, I present my thoughts about physicist Carlo Rovelli's "The Order of Time" - as well as two other thought-provoking literary works about the nature of time.


The concept of “time” is a fascinating one that I like to revisit again and again in my reading, watching, thinking and discussing. Time is truly a rabbit hole that gets weirder and weirder the more one thinks about it. One might start with fun time travel conundrums like those in Back to the Future and end up with fundamental doubts about our perception of the universe. Worse – the chill of existential dread rapidly materializes once a deeper understanding of time and causality starts putting big fat question marks all around that treasured notion of free will.

On this occasion, I just finished The Order of Time by Italian quantum physicist Carlo Rovelli. It’s a short, elegant and almost poetic treatment of this fundamental topic. I will elaborate on the book below. But I am writing this piece because The Order of Time made me think of other works that also deal with the concept of time in intriguing and well-executed ways. One, The Story of Your Life by Ted Chiang, is a short story. The other, Watchmen, is a graphic novel. They all have something unique to offer for readers who want to ponder how, why and if the ticking of the clock is the fundamental beat of life.

The Order of Time – the universe needs no clock

Rovelli’s book is quite an achievement. In just 200-odd pages he takes the reader on an accessible and fascinating journey with a clear and effective structure:

First, he deconstructs all of our intuitive notions of “time”. There is no absolute measure of time. There is no common “present”. There is no universal flow of time.

Then, Rovelli draws on his own research of quantum physics to present a description of the universe where “time” does not need to exist as a fundamental feature of reality (!)

Finally, having demolished the concept of time, he constructs it again! Not as a fundamental building block of the world, but as a feature of human perspective, human reasoning and human memory.

Contrary to what one might think at first glance, this journey from human intuition, via the “true” nature of reality, and ending with human reasoning, is immensely accessible. Compared to other staples of the physics pop science genre, such as Stephen Hawking’s A Brief History of Time, the prose flows masterfully and it’s simply a joy to read.

Rovelli presents his mind-bending pieces of insight with easy-to-grasp metaphors. He anchors the tale in the findings and arguments of influential physicists like Newton, Boltzmann and Einstein, but he wisely steers clear of an all-encompassing history of science. He also underlines what is experimentally verified, what is close to consensus, and what is still hotly debated (including his own take on a “theory of everything”, loop quantum gravity).

The author’s metaphors help deliver crucial points to the reader. The universe does not consist of things, but of events. Or, as the author puts it, it consists not of things like a stone, but of events like a kiss. Another well-put point is that our inability to grasp many of the mind-boggling features of general relativity and quantum mechanics is down to the inadequacy of our grammar. It is just as ingrained in us to think of past, present and future as it was for ancient people thinking of the Earth as flat. Ancient Greek thinkers also struggled to explain to their contemporaries that, on a spherical Earth, above is below and below is above (think New Zealand in relation to Spain). Just as we now take it for granted that the Earth is a sphere, Rovelli opens the door for humans in the future seeing time in a way that is more “true to life”.

Many of Rovelli’s points were not new to me. The effects of velocity and mass on time are well-known to any amateur student of Einstein’s theories of relativity. Yet, I admit that that some points, which should have been obvious to me, genuinely gave me an “a-ha!” experience. The most central one of these concerns the second law of thermodynamics and entropy. Rovelli emphatically explains that the only fundamental equation in physics that distinguishes between the past and the future addresses the question of entropy. This is the only equation that indicates the proverbial “arrow of time”. In all other aspects, nothing in physics sees the past as different from the future.

Yet it is exactly Rovelli’s treatment of entropy that leaves me asking for more. He posits that we experience the passing of time because of our particular perspective on entropy. And here, he uses a metaphor that to me seems lacking. Rovelli tells us that our experience of the flow of time (and of ever-increasing entropy) stems from our particular perspective – and from the resulting blurring of our vision/perception. As I read the book, in another part of the vast universe, the relationship could well be different, and potential sentient creatures there would experience a universe where time has no arrow. Where there is no past and no future.

I want to learn more about this. It is so crucial. I do not sit with a firm understanding if other parts of the universe are not subject to the second law of thermodynamics and why that would be the case. The book does not deliver a satisfactory answer. So I’ve now resorted to other sources, most notably the amazing YouTube channel PBS SpaceTime to learn more about this, to me, surprisingly crucial concept of entropy. From the video below I’ve already learned that my school teachings of entropy as “disorder” is an unfortunately wide-spread misunderstanding. Also in praise of the SpaceTime video, the entropy metaphor with a Go board seems to me more instructive than Rovelli’s deck of cards.

Did Rovelli’s description of entropy leave you wanting more? Check out PBS SpaceTime

So yes, one is left with unanswered questions, but that is the price of a concise and focused book. I do not blame Rovelli too much for this editorial choice. He still covers many exciting and mind-boggling features of quantum mechanics and relativity. And ultimately, the book is more succesful than Hawking’s seminal pop science publication because it stays more on topic and does not veer into territory that is too difficult to cover in even a double-length pop science book.

Rovelli is clearly a very skilled writer and an extremely well-read intellectual. That much is clear from a physics book that opens each chapter with a quote from Horace, and where references to philosophers and thinkers like Saint Augustine, Descartes, Proust and Kant are plentiful and well-connected to the subject at hand. It veers dangerously close to pretentiousness at times, as if the author wants to show off his multi-disciplinary knowledge, but for the most part it works well. I believe that it also helps ground a tale that deals not only with physics but also with the human experience of time. As such, drawing upon a range of thoughtful humanists is not without merit. The final part of the book successfully brings back the question of time to something we – as mere mortals – can more easily relate to.

All in all, I can thoroughly recommend The Order of Time to anyone with even a vague interest in the concept of time. It is a book that is easy to recommend, because the text flows so well, the language is delicious and equation-free, and the time commitment needed is relatively small. The book raises some questions that are left unanswered but also plants insights from the weird world of quantum physics that are sure to stay with the reader long after reading and fuel his/her curiosity further.

Beyond Rovelli’s treatment of time

So by now you’ve either decided to read The Order of Time yourself or you’re thinking that you would rather discover the concept of time through a different medium. Or maybe you’ve already read Rovelli’s book and seek other perspectives on the question?

Just as I felt that Amado’s Captains of the Sands provoked within me more thoughts about poverty in Brazil than statistics and newspapers do, so I think that physical phenomena are often more effectively treated in works of fiction than in works of pop science.

Below I present two good examples for fellow students of time and its mysteries that want more than a physicist’s theoretical thoughts and theses.

Story of your Life – perceptions of time with an emotional impact

While reading The Order of Time, I instinctively thought back on one of the best science fiction short stories I’ve read: Ted Chiang’s Story of your Life is only 70 pages. Yet it delivers some of Rovelli’s most poignant points within the framework of a thrilling and genuinely touching tale.

I do not wish to spoil anything. There is a twist that is thought-provoking and heartbreaking at the same time. The short story follows two scientists, a linguist and a physicist, who attempt to decipher and understand an obscure alien language. Insights from both linguistics and physics abound. And it is the latter that are elegantly presented to both the main character and the reader. One memorable – and illustrated – example involves Fermat’s principle of least time:

This Fermat’s principle – and other findings by the two scientists – prompt a very interesting discussion about the nature of time and reality and how we perceive it. Is it wise to link events in causal chains of cause and effect? Or is it just how we are used to seeing and thinking about the world? What if there is no such sequence of cause and effect? What if there is no flow of time? Is it not only thus that a beam of light can refract in the most time-efficient manner; by knowing “in advance” where its destination has to be? Causality versus teleology? Is one more “correct” than the other?

The short story is terrific. It is well-written with no unnecessary baggage and descriptions. Its characters come to life and the mystery is compelling. And on top of all this, we get extremely interesting thoughts and questions about the nature of time and free will.

If it sounds vaguely familiar, it is because you may have seen the magnificent Hollywood movie, Arrival, which adapts Story of your Life for the big screen. While I loved the movie, I was still very positively surprised by the book, which spends less time on the (slightly overdone) political dimension of the movie and more time on the science and on the human and emotional aspects (which I won’t spoil).

The short story is a great companion to Rovelli’s book. Indeed, the latter also makes this exact point: Our experience of time is dependent on our particular perspective. And just as Rovelli touches upon the limits of our grammar, Story of your Life also highlights the importance of language for the human perception of reality. It’s simply a brilliant story!

Watchmen – a graphic novel that breaks up the past, present and future

Alan Moore and Dave Gibbons’ Watchmen is a piece of art. Set in an alternative version of the 1980s, its story is an extremely interesting one in its own right, commenting on a huge variety of themes. And in its utilization of the graphic novel format it weaves its stories across space and time in a brilliant fashion with stories within the stories, symmetrical juxtapositions and easter eggs galore.

Whoops. I just saw that both my nerd boner and pretentiousness meter went into the red there. So let me just stop and focus on Watchmen’s treatment of time.

One of the central characters in the graphic novel is Dr. Manhattan. He is one of the least relatable characters in a book full of difficult-to-relate-to assholes and losers. One of the things that makes him insufferable and outright inhuman is that he perceives time very differently from the way humans do.

A scanned picture from Watchmen

The image above shows an example thereof. “Time is simultaneous, an intricately structured jewel that humans insist on viewing one edge at a time, when the whole design is visible in every facet,” Dr. Manhattan says. It easily reminds me of points in both The Order of Time and Story of your Life: Our intuitive perception of time is quite possibly very, very limited. In questions of time, we are all still “flat Earthers”.

There is an even more impactful showcase of Dr. Manhattan’s perception of time in the middle of the book, where his thoughts jump across time and space, panel by panel, prompted by a single photograph he is looking at. It would not really work in a real book. But in the comic format, it works extremely well. It has to be experienced. It was the only part of the story that made me feel some sort of emotional connection with this otherwise cold and inhuman demi-god.

There is also something platonic about Dr. Manhattan. He has stepped out of the cave of ignorance: He sees and experiences time as it truly is. The effect of this is that normal human interaction becomes impossible, as Laurie (the girl in the picture above) showcases with her reaction: What is the point of discussing if Manhattan already knows the outcome. More generally, what is the motivation of “going through the motions” if the result is pre-ordained in a deterministic universe? These points are dealt with far more elegantly in Story of your Life because the perspective of the protagonist is more accessible for the reader. But the graphic, comic book images of Dr. Manhattan transcending time in the mere process of his thinking have stayed with me as a potent representation of what a non-linear perception of time might in fact truly feel like.

Those were my immediate reflections upon finishing Carlo Rovelli’s The Order of Time, including two other pieces of literature that deal with the concept of time in their own way. It is not the last time I will be pondering the questions of what time actually is and whether the answer to that question even matters. But it is hard not to feel a pang of unease at the thought of free will potentially being a well-woven illusion. Does it absolve one of responsibility? Does it make our so-called choices meaningless? I feel that Story of your Life actually raises these questions in a more powerful way than Rovelli’s book (which of course has a different purpose). So read that one first!

If this long blog post is to reach a conclusion of any kind it is a rather banal one: Attaining knowledge – even about something so scientific as the nature of time – should not only be done by studying physics and reading pop science books. Just as time seems to be more multifaceted than a simple, universal, one-directional river of seconds, so our attainment of knowledge is enriched both by hard facts and by brilliant fiction – and conversation. I have always held great admiration for great scientists. As time passes, my appreciation of great writers seems to increase substantially as well.

The Order of Time. By Carlo Rovelli (2018 [2017]), Penguin, 224 pages
Stories of your Life and Others. By Ted Chiang (2015 [2002]), Picador, 338 pages
Watchmen. By Alan Moore and Dave Gibbons (2005 [1987]), DC Comics, 416 pages

Cover image: Modern Art Clocks by Linnaea Mallette found on Public Domain Pictures.