Alvy Ray Smith book review: We are awash in digital light

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In A Biography of the Pixel, Smith’s aim is to set down clearly the trajectory of two important, intertwined stories. The first story is the development of computer images, from origin to digital ubiquity. There are, in Smith’s telling, many names, places, and breakthroughs missing from the record, and he has taken on the job of adding them back in with an engineer’s eye for precision. The second story, unfolding in parallel, is about the impact of those images—a transformative force Smith calls “Digital Light.” It encompasses basically everything we experience through screens, and he argues convincingly that it is among the most important innovations in human communication since the first simple depictions of daily life were etched on the walls of caves.

The humble pixel

As Smith demonstrates repeatedly, far too much credit has been allowed to slide to the supposed wizardry of individual geniuses. The reality is a muddy, overlapping history of groups of inventors, working by turns in competition and in collaboration, often ad hoc and under considerable commercial or political pressure. 

Thomas Edison and France’s Lumière brothers, for example, were great promoters and exploiters of early film technology. Both exhibited full systems circa 1895 and were happy to claim full credit, but neither built the first complete system of camera, film, and projector all (or even mostly) on their own. The real answer to the question of who invented movies, Smith writes, is a “briar patch” of competing lineages, with parts of the system developed by erstwhile partners of Edison’s and similar parts by a handful of French inventors who worked with the Lumières. 

Among the crucial figures relegated to history’s dustbin were William Kennedy Laurie Dickson (an odd European aristocrat who designed and built the first movie camera for Edison) and Georges Demenÿ (whose design was copied without credit by the Lumières). Smith shows perhaps too much of his exhaustive work in rescuing these convoluted origin stories—there are similarly tangled muddles at every major stage in the development of computers and graphics—but his effort to set the historical record straight is admirable. 

The main drawback of all this wrangling with the egos and avarice of several generations of forceful men (they are, alas, virtually all men) is that it sometimes distracts Smith’s focus from his larger theme, which is that the dawn of Digital Light represents such a rare shift in how people live that it deserves to be described as epochal. 

Digital Light, in Smith’s simplest definition, is “any picture composed of pixels.” But that technical phrase understates the full import of the “vast new realm of imagination” that has been created by its rise. That realm encompasses Pixar movies, yes, but also video games, smartphone apps, laptop operating systems, goofy GIFs traded via social media, deadly serious MRI images reviewed by oncologists, the touch screens at the local grocery store, and the digital models used to plan Mars missions that then send back yet more Digital Light in the form of jaw-dropping images of the Red Planet’s surface. 

And that barely begins to cover it all. One striking aspect of Smith’s book is that it invites us to step just far enough back from the constant flow of pixels that many of us spend most of our waking hours gazing at to see what a towering technological achievement and powerful cultural force all this Digital Light represents.

Fourier contributed the insight that everything we see could be described as the sum of a series of waves. Or, as Smith more poetically phrases it, “The world is music. It’s all waves.”

The technological breakthrough that made all this possible is, as Smith’s title suggests, the humble pixel. The word itself is a portmanteau of “picture element.” Simple enough. But the pixel has been mischaracterized in popular usage to refer to the blurry, blocky supposed inferiority of poorly rendered digital images. Smith wants us to understand that it is, rather, the building block of all Digital Light—a miraculous, impossibly varied, endlessly replicable piece of information technology that has literally changed how we see the world. 

The misunderstanding begins, Smith explains, with the fact that a pixel is not a square, and it is not arranged alongside other pixels on a neat grid. Pixels can be rendered on displays as such, but the pixel itself is “a sample of a visual field … that has been digitized into bits.” The distinction might sound esoteric, but it’s crucial to Smith’s argument for the pixel’s revolutionary impact. The pixel is stored information that any device can display as Digital Light. And digital devices can do this because pixels are not approximations but carefully calibrated samples of a visual field, which has been translated for digital uses into a collection of overlapping waves. These pixels, Smith writes, are not reductions of the visual field so much as “an extremely clever repackaging of infinity.”

The new wave

The process by which a pixel generates Digital Light—whether in the form of words on a screen or an icon on a smartphone or a Pixar movie on the big screen—is built on three mathematical breakthroughs that predate the modern computer. The first of these was achieved by Jean Joseph Fourier, a French aristocrat and regional governor under Napoleon in the early 1800s. Fourier contributed the foundational insight that not just sound but heat and everything we see and much else could be described as the sum of a series of waves, representing various frequencies and amplitudes. Or, as Smith more poetically phrases it, “The world is music. It’s all waves.”