Whether puzzling at a blackboard, scuba diving, or piloting a plane, physicist Claudia de Rham feels powerfully pulled to gravity.
Most days, you can find Claudia de Rham at Imperial College London, where she is a professor conducting research at the interface of particle physics, cosmology, and gravity.
Some days, you can find her by looking up. She might be in the cockpit of a small plane passing overhead.
Or she might be found diving under the sea testing her buoyancy in the Indian Ocean.
The Swiss-born scientist chronicles her relationship with gravity in her new book The Beauty of Falling: A Life in Pursuit of Gravity, published in April by Princeton University Press. “Flying high in the air and diving deep under water are two of the most thrilling ways to defy gravity, at least here on Earth,” writes de Rham. She traces her insatiable curiosity to the period when her Swiss family lived in Madagascar, where she lay on her back gazing up at a seeming infinity of stars, each exerting its own gravity.
In this interview with FirstPrinciples, de Rham explains how gravity is a “witty character” at the centre of her life and work.
FirstPrinciples: Why do you focus specifically on gravity?
Claudia de Rham: Gravity is really such a fascinating phenomenon for so many reasons. The first reason is because it’s challenging and yet a witty character. We all know that we are subject to its strain, and yet we all love to defy it. Gravity is one of the first phenomena we experience and learn to play with, both in embracing it and in challenging it.
Of course, gravity is so much more than just a game. You may think of it as what keeps our feet firmly on the ground, but it’s also what has allowed the Earth and the solar system to form. In fact, it’s what has allowed the whole galaxy and its billions of stars to form. It’s what has permitted the whole universe to allow life and evolve in the way it has done.
But that’s not even scratching the surface of how fundamental gravity is. Gravity is what makes space and time come to life.
Deep down what I find even more fascinating and fundamental about gravity is how universal it is. You feel and experience gravity independently of your mass, size, colour, or charge. You can be a feather, a hammer, a planet, a black hole, or even something as light as light itself, and you will still feel the gravitational pull of the Earth.
You can never shield yourself from gravity. It connects everything to everyone, everywhere, all the time. Gravity is universal in every sense of the term.
FP: You fly planes and scuba dive. What inspires these adventures? What do you want to try next?
CdR: All these experiences are very much driven by a desire to embrace gravity and let myself be part of its game, being part of something bigger than me.
Being a scientist is an exploration and adventure, one that aims at understanding the laws of nature at the most fundamental level; I see diving and flying as part of the same exploration, but perhaps more physical.
I’d love for the next adventure to be one that involves really experiencing complete free-fall for a while – perhaps in outer space orbiting the Earth! For now, that’s a far-away dream, but there are still so many ways to explore with what we have around us.
FP: Have your activities underwater and in the sky informed your research?
CdR: Theoretical physics can sometimes be a very competitive field which requires overcoming many ups and downs. It requires the right balance of logic, creativity, and intuition. In this way, the process is quite similar to the adventures I’ve experienced. In many of the activities I have pursued, you have to stick to them past the point of discomfort; you have to be incredibly determined, and you have to learn to remain cool-headed even when everything around you may seem counterintuitive. In these experiences, and in research, you have to learn to enjoy some struggle. That’s where the adventure really starts. In research, that’s where creativity really kicks in.
FP: What inspired you to write The Beauty of Falling?
CdR: The idea of writing a book had been playing in the back of my mind for quite some time. It was driven by the desire to share these unique experiences I’ve had and the passion for understanding nature at a fundamental level.
It’s not only about sharing knowledge – it’s about the scientific process itself, the journey we take together to knowledge.
Writing The Beauty of Falling was driven by my desire to go back to the roots of what it means to search for a more fundamental understanding of nature. I wanted to demonstrate how curiosity is anchored within all of us and that this curiosity can do amazing things.
People I meet sometimes seem to have an allergic reaction to physics – likely connected to an unpleasant high school experience. I hope my book is a way to connect with people who may feel disconnected from science, that it will connect with the curiosity within them.
FP: What did you learn about yourself and your research through writing the book?
CdR: It was during Covid lockdown that I started thinking more concretely about a book and how to bring it to life. It wasn’t that I had more time then – quite the opposite! I suddenly had to homeschool our three young daughters in a tiny London apartment, mark hundreds of exams remotely, turn all my lectures online, and so much more.
Thinking about the book became the best mental escape during lockdowns. It became clearer and clearer in my mind why I had always been so fascinated with gravity. I learned more about myself in writing the book than I anticipated. Throughout the process, flashbacks of fun times playing with gravity kept popping in my mind. These were moments that felt like complete freedom. They allowed me to reconnect with the fun that had fueled my research originally, and had attracted me to gravity in the first place.
FP: What do you find most amazing or surprising about the universe?
CdR: The fact that the universe exists in the first place, and the conditions are just right for us to be here and explore it, is one of the biggest, most fascinating mysteries.
What I’d love to better understand in my lifetime is what we call the cosmological constant problem. That problem exists at the interface between the two major pillars of modern physics: quantum mechanics and gravity as described by general relativity.
From the realm of quantum particle physics, we would expect empty space, or what we call the vacuum, to be filled with energy – the quantum vacuum energy of all the particles we know. Taking this at face value and embedding it within the framework of general relativity, we would expect this vacuum energy to lead to an accelerated expansion of the universe (which should be at the very least 56 orders of magnitude faster than what is currently observed).
In fact, this expected rate of acceleration is so fast that if we took it seriously, space between the Earth and the Moon should be stretching so fast that the Moon would seem to recede away from us faster than the speed of light, disappearing from view. Clearly that is not the case, so something went wrong in our expectations – right there at the interface of the two best theories of science is the biggest puzzle we’ve ever faced. This cosmological constant problem has been known for almost a century and is the biggest discrepancy in the whole history of science.
FP: What keeps you up at night?
CdR: Physics is always what keeps me sane and rooted. I dream about it and often talk about it in my sleep, or so I’m told. But it rarely keeps me up at night because it’s something I know I can actually work through. In fact, I often wake up with much clearer ideas on how to go about a particular research question that I have, with my thoughts much more structured.
At the moment, I’m particularly interested in understanding the connection there may be between the physics we experience in our everyday life and physics that only manifests itself at very high energy scales within the realm of quantum gravity, to which we have no direct access. What I find really fascinating is that although we have no direct access to quantum gravity, it may still have specific consequences or imprints on the physics of our world in ways we could potentially probe.
