Wired MAY 26, 2016 - by Stephon Alexander


Everyone has his or her favorite drink in hand. There were bubbles and deep reds, and the sound of ice clinking in cocktail glasses underlay the hum of contented chatter. Gracing the room were slender women with long hair and men dressed in black suits, with glints of gold necklaces and cuff links. But it was no Gatsby affair. It was the annual Imperial College quantum gravity cocktail hour.

The host was dressed down in black from head to toe - black turtleneck, jeans, and trench coat. On my first day as a postdoctoral student at Imperial College, I had spotted him at the end of a long hallway in the theoretical physics wing of Blackett Lab. With jet-black wild hair, beard, and glasses, he definitely stood out. I said, "Hi," as he walked by, curious who he was, and with his "How's it going?" response, I had him pegged. "You from New York?" I asked. He was.

My new friend was Lee Smolin, one of the fathers of a theory known as loop quantum gravity, and he was in town considering a permanent job at Imperial. Along with string theory, loop quantum gravity is one of the most compelling approaches to unifying Einstein's general relativity with quantum mechanics. As opposed to string theory, which says that the stuff in our universe is made up of fundamental vibrating strings, loop quantum gravity focuses on space itself as a woven network of loops of the same size as the strings in string theory. Lee had just finished his third book, Three Roads To Quantum Gravity, and was on a mad rush to mail out the manuscript to his editor. I accompanied him through the drizzle to the post office and for a celebratory espresso - the first coffee of hundreds we'd share in the future.

Lee had offered up his West Kensington flat for the quantum gravity drinks that evening to give the usual annual host, Faye Dowker, a break. Faye enjoyed being the guest lecturer that evening. Slim, bespectacled, and brilliant, she was also a quantum gravity pioneer. While Professor Dowker was a postdoc she studied under Steven Hawking, working on wormholes and quantum cosmology, but her specialty transformed into causal set theory. After a couple of hours, the contented chatter gave way to Faye as she presented her usual crystal-clear exposition of causal sets as an alternate to strings and loops. Like loop quantum gravity, causal sets are less about the stuff in the universe and more about the structure of space-time itself. But instead of being weaved out of loops, space-time is described by a discrete structure that is organized in a causal way. The causal-set approach envisions the structure of space analogous to sand on a beachhead. If we view the beachhead from afar, we see a uniform distribution of sand. But as we zoom in, we can discern the individual sand grains. In a causal set, spacetime, like a beach made up of sand, is composed of granular "atoms" of space-time.

Scattered into the quantum gravity mixer were those working primarily on string theory, like the American theorist, Kellogg Stelle, who was a pioneer of p-branes, as well as one of my postdoc advisors. In mathematics, a membrane is a two-dimensional extended object - that is, it takes up space. A p-brane is a similar object in higher dimensions. The strings of string theory can collectively end on p-branes. And coming at quantum gravity from a yet another route, there was Chris Isham, the philosophical topos theory man who played with mathematical entities that only "partially exist." Postdocs studying all avenues of quantum gravity filled in the gaps between the big brains in the room. It wasn't exactly a gathering of humble intellect. It was scenes like that, that made me feel like I didn't have the chops, the focus, to sit behind a desk in a damp office manipulating mathematical symbols for hours like the others. Fortunately, Chris had shown he believed in my abilities to make a contribution to cosmology by encouraging me to get out of the office and get more involved with my music. Working on physics ideas and calculations in between sets, at the jazz dives of Camden town, I found myself trying hard to believe that it would give me a creative edge in my research. That was a beginning. Ideas started flowing. But something more was about to change.

While Faye gave her living-room lecture, I honed in on someone else I had noticed throughout the evening. Dressed in black like Lee Smolin, he had a strong face and a gold tooth that shone every time someone engaged him in conversation. The way he listened to Faye, with such focus, I assumed he was a hardcore Russian theorist. It turned out he had come with Lee. When Lee noticed I was still hanging around after the talk, he invited me to join them as Lee walked his goldtoothed friend back to his studio in Notting Hill Gate. I was curious what research this friend was going to churn up and what school of quantum gravity he'd slot into. I had to work to keep pace with the animated duo as we walked along welllit high streets, dipping in and out of dark London mews. This guy was no regular physicist, I soon realized. Their conversation was unprecedented. It started with the structure of spacetime and the relativity of time and space according to Einstein. That wasn't the strange part. Soon, they were throwing commentary around on the mathematics of waves and somehow kept coming back to music. This gold-toothed wonder was getting more intriguing by the minute.

That was my first encounter with Brian Eno. Once we reached his studio, we exchanged phone numbers, and he generously lent me one of his bikes - indefinitely. At the time, I didn't know who Brian was, but that changed a week later when I told a friend and band member about him. Tayeb, a gifted British-Algerian bassist and ooud player (an Arabic string instrument), was at first dumbfounded by my shameful ignorance. "Bloody hell, Stephon... you met the master."

Brian Eno, former member of the English rock band Roxy Music, established himself early on as a great innovator of music. He was part of the art rock and glam rock movement, when rock and roll took on a new sound by incorporating classical and avant-garde influences. The rocker look was dressed up with flamboyant clothes, funky hair, and bright makeup: think Lou Reed, Iggy Pop, and David Bowie. Brian was the band's synthesizer guru, with the power to program exquisite sounds. The beauty of synthesizers in those days lay in their complexity. In the early days, one had to program them - unlike synthesizers today, with preset sounds at the touch of a button. Popularity hit Roxy Music hard and fast, and Eno promptly had enough of it, so he left Roxy Music, and his career continued to flourish. He produced the Talking Heads and U2 and went on to collaborate with and produce greats such as Paul Simon, David Bowie, and Coldplay, to name a few. In addition, he continued with synthesizers and emerged as the world's leading programmer of the legendary Yamaha DX7 synthesizer.

I wondered why an artist like Brian would be interested in matters of space-time and relativity. The more I got to know Brian, I knew it wasn't a time filler, or for his health. What I was about to discover during my two years in London was that Brian was something I've come to call a "sound cosmologist." He was investigating the structure of the universe, not inspired by music, but with music. Often times he would make a comment in passing that would even impact my research in cosmology. We began meeting up regularly at Brian's studio in Notting Hill. It became a pit stop on my way to Imperial. We'd have a coffee and exchange ideas on cosmology and instrument design, or simply veg out and play some of Brian's favorite Marvin Gaye and Fela Kuti songs. His studio became the birthplace of my most creative ideas. Afterward, I'd head to Imperial, head buzzing, spirits high, motivated to continue my work on calculations or discussions on research and publications with fellow theorists.

One of the most memorable and influential moments in my physics research occurred one morning when I walked into Brian's studio. Normally, Brian was working on the details of a new tune - getting his bass sorted out just right for a track, getting a line just slightly behind the beat. He was a pioneer of ambient music and a prolific installation artist. Eno described his work in the liner notes for his record, Ambient 1: Music For Airports: "Ambient music must be able to accommodate many levels of listening attention without enforcing one in particular; it must be as ignorable as it is interesting." What he sought was a music of tone and atmosphere, rather than music that demanded active listening. But creating an easy listening track is anything but easy, so he often had his head immersed in meticulous sound analysis.

That particular morning, Brian was manipulating waveforms on his computer with an intimacy that made it feel as if he were speaking Wavalian, some native tongue of sound waves. What struck me was that Brian was playing with, arguably, the most fundamental concept in the universe - the physics of vibration. To quantum physicists, particles are described by the physics of vibration. And to quantum cosmologists, vibrations of fundamental entities such as strings could possibly be the key to the physics of the entire universe. The quantum scales those strings play are, unfortunately, terribly intangible, both mentally and physically, but there it was in front of me - sound - a tangible manifestation of vibration. This was by no means a new link I was making, but it made me start to think about its effect on my research and the question Robert Brandenberger had put to me: How did structure in our universe form?

Sound is a vibration that pushes a medium, such as air or something solid, to create traveling waves of pressure. Different sounds create different vibrations, which in turn create different pressure waves. We can draw pictures of these waves, called waveforms. A key point in the physics of vibrations is that every wave has a measurable wavelength and height. With respect to sound, the wavelength dictates the pitch, high or low, and the height, or amplitude, describes the volume.

If something is measurable, such as the length and height of waves, then you can give it a number. If you can put a number to something, then you can add more than one of them together, just by adding numbers together. And that's what Brian was doing - adding up waveforms to get new ones. He was mixing simpler waveforms to make intricate sounds. To physicists, this notion of adding up waves is known as the Fourier transform. It's an intuitive idea, clearly demonstrated by dropping stones in a pond. If you drop a stone in a pond, a circular wave of a definite frequency radiates from the point of contact. If you drop another stone nearby, a second circular wave radiates outward, and the waves from the two stones start to interfere with each other, creating a more complicated wave pattern. What is incredible about the Fourier idea is that any waveform can be constructed by adding waves of the simplest form together. These simple "pure waves" are ones that regularly repeat themselves.

Linked by the physics of vibration, Brian Eno and I bonded. I began to view Fourier transforms in physics from the perspective of a musician mixing sound, seeing them as an avenue for creativity. The bicycle Brian lent me became the wheels necessary to get my brain from one place to another faster. For months, the power of interdisciplinary thought was my adrenaline. Music was no longer just an inspiration, not just a way to flex my neural pathways, it was absolutely and profoundly complementary to my research. I was enthralled by the idea of decoding what I saw as the Rosetta stone of vibration - there was the known language of how waves create sound and music, which Eno was clearly skilled with, and then there was the unclear vibrational message of the quantum behavior in the early universe and how it has created large-scale structures. Waves and vibration make up the common thread, but the challenge was to link them in order to draw a clearer picture of how structure is formed and, ultimately, us.

Among the many projects Brian was working on at the time was one he called "generative music." In 1994 Brian launched Generative music to a studio full of baffled journalists and released the first Generative software piece at the same time. The Generative music idea that came to fruition about a decade later was an audible version of a moiré pattern. Recall our pond ripples interfering to create complex patterns. These are moiré patterns, created by overlapping identical repeating patterns, and there are an infinite variety of them. Instead of two pebbles creating waves, generative music rested on the idea of two beats, played back at different speeds. Allowed to play forward in time, simple beat inputs led to beautiful and impressive complexity - an unpredictable and endless landscape of audible patterns. It is "the idea that it's possible to think of a system or a set of rules which once set in motion will create music for you... music you've never heard before." Brian's first experiment with moiré patterns was Discreet Music, which was released in 1975. It remains a big part of his longer ambient compositions such as Lux, a studio album released in 2012. Music becomes uncontrolled, unrepeatable, and unpredictable, very unlike classical music. The issue becomes which inputs you choose. What beats? What sounds?

What I began to see was a close link between the physics underlying the first moments of the cosmos - how an empty featureless universe matured to have the rich structures that we see today - and Brian's generative music. I began to wonder if structure could have originated from a single starting pattern of waves, like Brian's generative sound. I needed Fourier transforms and inspiration from Brian's musical brain. After all, he was playing with the Fourier idea with an intuition that transcended that of most physicists. I wanted to develop this intuition to be able to be creative with it. When I walked up to him as he was manipulating the waveforms that morning, he looked at me with a smile and said, "You see, Stephon, I'm trying to design a simple system that will generate an entire composition when activated." A lightbulb flickered in my brain. What if there were a vibrational pattern in the early universe capable of generating the current complex structure that we live in, the complex structures that we are? And what if these structures had an improvisational nature? There were some lessons in improvisation I first had to learn.

Excerpted from The Jazz Of Physics: The Secret Link Between Music And The Structure Of The Universe by Stephon Alexander.