Thursday, October 25, 2012

Quanta


   
 

Quantum Drift

Apparatus to coax two beryllium ions (electrically charged atoms) into swapping the smallest measurable units of energy back and forth, National Institute of Standards and Technology
I am standing looking at the quantum computer, trying and failing to muster an appropriate sense of reverence. It is a lovely contraption: a stack of copper tiers lined with delicate electrodes and elaborate networks of plastic tubing. It is an impressive contraption: an example, I have been told, of some of the most advanced technology in the field. My lab guide proudly points out each of the computer’s components in turn – the refrigeration system humming with liquid nitrogen, a fastidiously positioned series of lasers, one tiny sapphire processing chip – and watches carefully for my reaction. I am trying and failing to be enthusiastic. I can only smile politely, swallow the nagging swells of a yawn, and do my best not to look bored.
Someday quantum computers will, their cheerleaders swear, sift through unprecedented volumes of information and solve processing problems once thought intractable. The military hopes to use them for extra-secure encryption, biologists hope to use them to unpack the mysteries of proteins, investment banks hope to use them to analyze minute market fluctuations, and everyone hopes to use them to store giant caches of data. But quantum computing is still a young field, and quantum computers can’t do any of it yet. At present, the one in front of me can factor the number fifteen.
That’s not why I’m struggling to stay interested, though. I don’t really mind that this machine is still performing unsophisticated tasks. I care more about the way it performs those tasks – because, in this sense, even the most rudimentary quantum computer is fascinating. It’s an oblique machine that thinks in tangents, uses ambivalence as fuel, and stubbornly stops working if asked too directly for an answer. It’s a machine whose very existence begs big questions about technological systems and the way we make sense of information – in short, about the nature of knowledge itself.
But no one here, in this cutting-edge lab, wants to unpack any of that. My lab guide is talking about the quantum computer as if it were an especially fancy toaster. A new, shiny machine with some nice bells and whistles. A new, shiny machine with no insight, no vision, and no politics. And it’s hard to get excited about that.
One way to talk about a quantum computer is to talk about the physics behind it. Its processing bits rely on superposition and entanglement, two characteristically quantum states. Superposition refers to the ability of a particle to exist as two distinct things at once; the classic physics analogy describes it as a cat that’s both dead and alive. Entanglement is essentially a version of superposition that occurs between multiple particles. Entangled particles coordinate their properties instantly, even when separated by distance. A change to a particle in an entangled set registers instantaneously in the rest.
In theory, the use of superposition and entanglement should give a quantum computer a processing edge over a traditional computer. Because they are superpositioned, a quantum computer’s bits (called qubits, short for quantum bits) each consider two pieces of information at once – 1 and 0 rather than 1 or 0, as in traditional binary code. And because they are entangled, they share their results instantaneously, as a matter of course. In theory, this means that qubits consider more information in a single step than bits, and that the advantage grows exponentially with each step of a calculation. A quantum computer should be able to do work that would tie up a traditional computer for hours, months, or years.
In practice, quantum computers are operating nowhere near this capacity. Qubits work messily, and don’t yet lend themselves reliably to systems. Researchers get excited if their qubits produce any answer a stable percentage of the time. The difficulty is magnified by another idiosyncrasy of quantum mechanics: quantum properties are ultra-sensitive to disturbance. Both superpositioned and entangled states break down if observed or measured. Physicists argue about what exactly it means to ‘observe’ or ‘measure’ something in a quantum state – a strange semantic debate that has dogged quantum mechanics since its inception – but the result remains the same. A qubit is easily derailed. The best can manage a few microseconds’ worth of work. Just enough time to factor a two-digit number, and hint at the possibilities of other, more interesting ways to think.
When I think about quantum computing, I don’t think about qubits. I’m reminded instead of a reclusive physicist I met on a artist residency at an old junk shop. He came to the space sometimes to browse books and sift through knick-knacks, and because he was odd, unassimilable, and probably brilliant, everyone wanted his attention. He largely ignored us, though, with the noted exception of the touchy-feely sculptor who shared my room. She knew nothing about physics, but she, he decided, understood physics. And so they embarked on a collaboration. He taught her to map algorithms in pretty geometric patterns, she helped organize the notes for his latest thought experiment, and they talked, ramblingly, for hours at a time.
The sculptor knew I was jealous, so she invited me along on one of their visits. Mostly I sat smiling politely while the two of them carried on a conversation I didn’t know how to join. They weren’t talking about the same thing, usually – he focused on the behavior of particles, she the quirks of creative process – but each spent a lot of time nodding, gesticulating, and gazing significantly into middle distance. I must have looked glazed, because an hour or so in, the physicist turned to me pointedly. You can’t always tell what you’re learning, he said. Or: you have to circle around a thing to really figure it out. Something to that effect. I kind of forget. Before I had shaken myself to full attention, he abruptly stopped talking, and the pointed look left his eyes. Noting the tattoo on my leg – a big blue ribcage – he pointed and giggled. “What is that?” he asked, shaking his head, bemused. “What is that?”
***
I gleaned some good information from the conversation with the physicist and the sculptor, but it seemed a little like using a multi-million dollar machine to factor the number fifteen. Not a particularly efficient use of resources. The people building quantum computers share this concern. Most experimental research in the field is aimed at fabricating more reliable qubits. The solutions are often poetic: qubits insulated by sapphires and diamonds, cooled to temperatures just above absolute zero by superconducting liquids. The solutions are always meticulous: qubits laid out in careful circuits with lasers and mirrors, modeled on algorithms born of years of painstaking thought.
I’m not immune to the bells and whistles, then. But I am wary of marveling too much, in part because it makes me forget the big-picture questions that necessitated them. One of the first theorists of quantum computing has insisted publicly that he doesn’t want to keep up with the technology’s practical developments. He thought up quantum computers while writing papers that were ultimately about something else, after all. One attempted to prove the existence of parallel universes; another sought to articulate the absolute limits of a computation. For the theorist, quantum computers are most importantly ideas about the nature of knowledge and reality. And with explanations that big at stake, he has trouble caring much what qubits look like.
***
My frustration at the lab felt similar, only more personal. A machine does far more than the task it performs. It is forged of historical moments, acts as a flash-point for contemporary questions, and always, inevitably, produces new cultures of its own. I wanted my lab guide to acknowledge all this so we could stop talking about calculations and ask what might be at stake for me and everyone I know.
Because when I look at the quantum computer, I see a logic that, directed carefully, could do more for us than crunch bigger numbers. It is an information processor with an associative imagination, an operating system whose modus operandi is delicate quirks and unpredictability, a machine that performs its best secrets away from the prying eyes of experts. Most structures in our lives don’t like to admit the efficacy of ambivalence or ambiguity. And yet there they both are, fueling what could be our most promising new machine: ambivalence and ambiguity, animated by a sense of purpose, an acute epistemological power, and the willingness to abide by practical rules. Ambivalence and ambiguity that are, furthermore, smart collaborators – that not only share their uncertainty, but sharpen it into a precise mode of communication.
I want to know what our lives would look like, reorganized by that logic. If we built work cultures that dispensed with bullet points, celebrated missed deadlines, and distrusted tidy bottom lines. Or wrote school curricula that combined frog dissection, gym class, and musical theater into one huge embodied biology. Or formulated linguistic theories which accounted for the communicative powers of raised eyebrows, weeks-long absences, and the things we ate for dinner last night. And enacted those theories through deliberate programs of winks and pregnant pauses. With a sigh of relief at the death of tight-knuckled directness and all that exhausting linearity.
I also want us to talk about the way we are already organizing our lives to look like the logic of a quantum computer. The way we move in bodies full of uncountable cultures’ tics; the way we figure out our sexualities through fluid notions of gender; the way we talk like the hybrid spawn of encyclopedias, multimedia pop art, and computer programmers; the way we piece together activist movements from fuzzy messages and insist on their ability to leverage meaningful changes. I wonder what it would take for us to confidently assert these quantum proclivities – the ones we’re quietly developing and those still nascent – as our most beloved paradigms. In service of a world of quantum sensibilities, quantum values, and productively nuanced quantum living.

Having done much of the talking I wanted to do in the lab, it occurs to me that there is something else I wanted: for my lab guide to listen. There’s room in scientific narrative for the riff – the flight of fancy that enables whole new modes of thought – but, generally speaking, they’re supposed to be voiced by scientists. The best an engaged observer can hope to do is report on scientists’ progress, or consign their own thoughts to a modestly adjacent field: to science fiction, to artistic metaphor, to a politically utopian or dystopian imagination. A separate field that is allowed to play with science so long as it doesn’t take itself too seriously, so long as it isn’t too ambitious in imagining what purpose its contributions ought to serve.
The scientific climate from which quantum computers emerge, though, is one of blurred disciplinary boundaries: an intellectual space enlivened by attempts to merge quantum physics and computational theory and biology and epistemology, and by arguments about the deftest ways to do so. In this climate, it gets hard to draw strict distinctions between living systems and mechanical ones, and to cleanly map the interplay between metaphoric and material systems while speaking of either. It’s an intellectual space begging for creative pattern recognition and inventive cobbling-together – skills often left flabby in scientific discourses dominated by rationalism and reductionism. But there are plenty of deft thinkers roving the outskirts of these official scientific discourses. We are good with metaphor, know the art of conceptual bricolage well, and might contribute handily, if the lab cares to make room for us. If not, we have our own interests and our quantum ways of processing them, and will at least be spared its shiny, dutiful patter.

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