“If you decide to follow me, I will take you to where I believe our knowledge of time has reached: up to the brink of that vast nocturnal and star-studded ocean of all that we still don’t know.”
So, you can get a book exploring the nature of time, written by a theoretical physicist? Sign me up! Seriously, sign me up. I love reading material that stretches my understanding of the world and “The Order of Time,” by Carlo Rovelli delivers.
As Rovelli explains, “The nature of time has been at the center of my life’s work in theoretical physics,” so it’s no wonder he took the time—yes, I went there, and you can expect more—to write about it. “The Order of Time” is not only scientific but delightfully philosophical and beautifully written. It isn’t easy reading. What I mean is that I understood Rovelli’s explanations and descriptions, but when I attempted to share my newfound knowledge with a friend the words just wouldn’t come out. So, I went back and read sections aloud, but his blank stare informed me that a paragraph or two out of context does not explain the totality of what Rovelli is discussing and what I am trying to explain. My journey into understanding physics was exciting but entirely personal. I couldn’t convey what I learned, which just proved to me that physicists are cut from a different cloth.
So, let me tell you a couple things that I do remember well enough to explain. Did you know that time moves more slowly the closer you are to the ground? That a precision watch set in the mountains and at sea level will show different times? And it’s not just time but processes, meaning that people at sea level age more slowly than those living in the mountains. So, is this why the Fountain of Youth is in Florida?
My question is who figured this out? Who would even think this to figure it out? Of course, that person is Einstein. Another lesson learned in this book is that physics does not describe how things evolve ‘in time’ but how things evolve in their own times, and how ‘times’ evolve relative to each other. Using the word relativity is also an Einstein thing.
However, Einstein isn’t the only physicist we meet. Ludwig Boltzmann believed heat was the microscopic agitation of molecules—atoms and molecules were not widely believed in during Boltzmann’s time. Sir Isaac Newton had a lot to say about time, as did Aristotle. Bruce DeWitt and John Wheeler, two American physicists, wrote an equation relating to quantum gravity. Anytime I was introduced to physicists or mathematicians, I couldn’t help but be amazed at the questions they asked in order to make the discoveries they did. I may not be able to explain what I read but that did not stop me from appreciating the sheer genius of these scientists. One line in particular stood out for me: “The ability to understand something before it’s observed is at the heart of scientific thinking.” It’s a special kind of person that understands before it’s seen and then asks why?
Rovelli uses the last chapter in “The Order of Time” to reflect on death. This chapter is more journal writing than scientific writing. Time isn’t a concept as much as it’s a feeling. It’s as if he is trying to get all of us to think more about our life and yes, the time we have left on Earth. “Do we exist in time, or does time exist in us?” Physicists like Rovelli may try to answer, but in the end, only we can decide how to treat time in our life.