Waves in an Impossible Sea by Matt Strassler is one of the best science books for lay readers that I’ve ever read—and I’ve read a lot of ‘em. The topic of quantum field theory is, and will forever remain, far beyond my abilities and understanding. The idea that fields (whatever they are) fill the cosmos at both the smallest and the largest possible dimensions exceeds my comprehension. Nevertheless, I loved reading Waves in an Impossible Sea which is both beautifully written and highly informative. I read the latter half of the book in small bites to give myself time to ruminate, and I’ll definitely want to go back and read sections again, as Strassler suggested.
Strassler is a theoretical physicist who currently teaches at Harvard, and he clearly uses what he’s learned as a teacher as he makes the quantum world more accessible to the rest of us. As a retired public-school educator, I particularly appreciated his orderly, step-by-step explanations, gradually building our understanding. He begins with accessible examples from the everyday world whenever possible, and keeps us informed of where he plans to proceed within the text.
Chapter 11, an exploration of wave phenomena in the sphere of sound and music especially resonated with me. Years ago, colleagues and I developed and taught a multidisciplinary instructional unit for my gifted middle schoolers on the science and art of sound and music. It was one of my favorite units to teach; I discovered new things about the world each time I taught it.
Among many other activities, my students and I learned about how sound waves (and waves in other media) work. We demonstrated compression waves with a slinky stretched out on the floor. We sent waves traveling down the slinky and watched them reflect and echo back when they arrived at one end. We generated waves from both ends of the slinky and watched them pass through one another and continue traveling, just as we can hear sounds from multiple sources simultaneously.
We used a long rope on the floor to produce standing waves, as described in Strassler’s text. The kids discovered that working to produce higher harmonics that higher frequencies required more energy to produce. They experienced this increase in energy directly, because they were the ones working up a sweat. I also had them connect the mass of a vibrating object with its pitch—and then understand that in terms of Newton’s laws of motion.
We also built a “sound cannon” –essentially a drum–with a cardboard cylinder we tightly sealed on one end with a piece of Tyvek. We lit a candle and pointed the open end of the drum at the base of the flame. When we sharply tapped the Tyvek, students could see the flame flicker, or even get blown out if the tube was aimed just right. Students could see direct evidence that sound made the air move, even if it was invisible.
We even calculated the speed of sound in air by synchronizing the sharp claps of a clave echoing off the back wall of our school building from a known distance. I was amazed at the level of accuracy (usually within 5-10%) my students managed to achieve with such a crude method. I believe this technique is analogous to measuring light or gravitational waves with an interferometer. Unfortunately, I didn’t think of that analogy until I read Strassler’s book this summer, years after I retired from the classroom. I would have loved to have had this book as a resource as I planned my lessons, to extend the scope of the unit’s content, and my own depth of understanding.
Waves in an Impossible Sea is enlightening, mystifying and entertaining. After all, we apparently live in, and are part of, a quantum universe. Strassler’s book will expand your understanding of the cosmos and even help you feel right at home.
Read Matt Strassler’s blog here: https://profmattstrassler.com/blog