This week we are pleased to welcome Aric Mayer as a guest correspondent.  Aric’s work has previously been featured in our Photographer’s Showcase here and here.

The entire media experience this week seemed dominated by questions of color and politics. Numerous polls were taken asking variations of the question, “Is America ready for a black president?”  The results came back mixed.  Maybe yes, maybe no.  The question here has to be, what exactly does this mean?

The color palette below was generated from four popular images of Barack Obama and John McCain. These are the combined colors needed to recreate images of both of their faces in their entirety.

As a photographer with extensive experience in photo retouching for national publications, one of the first things that I learned was how to measure the color of a skin tone in an image. Colorimetrics is an interesting and exact science, and suffice it to say that it is possible using ink densities and light measuring tools to describe skin tones in very specific ways. What is surprising is how subtle the differences are between the skin tones of all races. Hues across the spectrum of ethnic groups vary only by a few percentage points. It turns out that all the possible hues and tones of human skin color do not make up an actual rainbow of diversity, but in fact are only a tiny sliver of the possible colors in the visible spectrum. Indeed, skin tones exist in a fairly mundane part of the spectrum, consisting mostly of light tans into dark browns, with subtle variations in color. These colors are dwarfed by the incredible diversity of other colors in the world, greens for instance, the color of chlorophyll. While we are hyper-attenuated to the cultural meanings of skin colors, we tend to categorize them into large groups; what we lack is a cultural language with which to accurately describe their appearance.

Biases and barriers in the political polls are written right into the questions. Barack Obama is not visibly black, nor is John McCain actually tinted white. But the cultural divide between them is frequently shown to be as extreme as the end points on the possible spectrum. The real polling question should not be, “Is America ready for a black president?” But instead, “Is America ready for what might lie between the two extremes?” 

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We are pleased to welcome Ivan Amato as a guest correspondent. Ivan is the author of the wonderful book, Super Vision: A New View of Nature.

A century ago, some of the best scientific minds were still debating whether atoms actually existed. Although atoms had long been a fabulously useful concept for making sense of chemical and material phenomena, no one had actually seen them. Their existence always was inferred, not confirmed by way of direct observations. Even so, well before World War I, almost all scientists believed that atoms were real.

Since then, microscopists and instrument designers have been inventing ever more clever ways to visualize the material world on ever finer scales. For years now, scientists have been using tools with names like scanning tunneling microscopes (STM) and high resolution transmission electron microscopy (HRTEM) to image the regimented geometry of crystalline samples’ constituent atoms. It has been way easier to image individual atoms of the heavier elements of the periodic table, such as tungsten and gold, compared to the atoms of lighter elements. Hardest of all has been imaging the lightest and smallest atoms of all, among them hydrogen and carbon atoms. These are the atoms most associated with life and with the biological chemistry that underlies life, which is why atomic-scale imaging has largely been the province of physicists and materials scientists who make products such as industrial catalysts and semiconductors.

A team of researchers at the University of California at Berkeley, led by physicist Alex A. Zettl, has found a way to use a standard-issue transmission electron microscope (TEM) to visually discern individual atoms of hydrogen and carbon. A small number of these atoms that were lingering in the TEM’s sealed and evacuated sample chamber had drifted onto an atomically thin sheet of graphene–a molecular grid of carbon atoms in the geometry of chicken wire-that the researchers had placed inside the chamber. In the image shown, to which the researchers have liberally applied image processing tools to produce the colors, the hydrogen atoms appear as green dots amidst a speckling of blue, which essentially is background noise due to the graphene. A lone red dot, with an arrow for extra emphasis, marks the location of a single carbon atom.

In a more raw form, the data from the TEM appears as squiggly traces that indicate how much a beam of electrons impinging on the sample scatters as the beam hits different locations of the sample’s microscape. A computer then transforms this scatter intensity data into a two-dimensional, black-and-white pictorial image that corresponds to the sample’s atomic landscape. Then, with additional image processing requiring the applications of aesthetic judgments, that is, choosing colors, the original data finally becomes the abstract “painting” seen here, a painting that harbors what appears to be scientists’ first glimpses of individual hydrogen atoms by way of TEM.

Unlike directly seeing a flower in your garden or the web page you are viewing by way of your own eyes and brain, “seeing” atoms requires mediation–a TEM, a computer, and image processing tools-to render what is otherwise invisible visible. Yet, eyes and brains also mediate our seeing. They constitute evolution-honed instrumentation that senses photons from objects and processes these signals in a way that we experience as seeing. Directly seeing with eyes, then, might be thought of a singly-mediated seeing, whereas using tools like TEMs might be thought of as doubly-mediated seeing.

Credit for image: Courtesy Zettl Research Group, Lawrence Berkeley National Laboratory and University of California at Berkeley. The Zettl group just published, in Nature (vol. 454, pp. 319-322), their first paper on the technique. The image above is not in the paper but is available at their web site.

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