Hole Lotta Electron Going On!

I know it’s been a good long while since I posted anything to the blog, and my instinct suggests that I should ease into things, maybe start out with an astronomical image and a snarky comment… Keep things simple!

But I ran across this image, and I couldn’t resist. It accompanies a press release about high-powered lasers at UC Santa Barbara. And um, wow! Take a look at the caption:

“Artist’s rendition of electron-hole recollision. Near infrared (amber rods) and terahertz (yellow cones) radiation interact with a semiconductor quantum well (tiles). The near-ir radiation creates excitons (green tiles) consisting of a negative electron and a positive hole (dark blue tile at center of green tiles) bound in an atom-like state. Intense terahertz fields pull the electrons (white tiles) first away from the hole and then back towards it (electron paths represented by blue ellipses). Electrons periodically recollide with holes, creating periodic flashes of light (white disks between amber rods) that are emitted and detected as sidebands. (Credit: Peter Allen, UCSB)”

If brevity is the soul of wit, well…

I think the first thing that confuses is the poorly-conveyed temporal element. If I’m supposed to read something as a sequence in time, either follow a convention (e.g., left to right for English readers, rather than bottom to top, as in this case) or execute it as a sequence of images… Or an animation. But the static image above doesn’t convey the sense of time passing or a series of events.

The more fundamental issue, however, seems to be the presentation of diagrammatic information in what I think of as a “reified” manner. By taking a basic representational diagram and adding elements that suggest a photoreal environment, the image ends up confusing the issues: it takes an abstract representation and describes it with a visual language that suggests real, physical objects. Instead of color-coded dashed lines, for example, we get sparkly little cylinders that look like beads you’d pick up on West 37th Street in Manhattan.

I can only imagine that some grad student got their hands on Blender and went a little wild… “Ooh, I can make these transparent and shiny!” Which is all well and good, but it gets in the way of communicating he fundamental concepts: the gloss may attract attention, but it obscures the underlying content.

(Just as an aside, when I went in search of the Wikipedia article on excitons, in order to provide a helpful link, I ran across an even more psychedelic image! But my little brain just couldn’t deal with writing about both that one and the one above…)

Honestly, I don’t know how to illustrate the remarkably complicated subject of the press release. But the above illustration does not seem to help.

And unfortunately, this kind of thing happens quite a bit in the world of press release images… Because the main interest lies in choosing the flashiest possible image(s), the clarity of the message often becomes obfuscated.