Dark Matter Observed…
In Visualizations

A new press release from the European Southern Observatory (ESO) announces a lack of observational evidence for dark matter nearby: “New measurements show that the amount of dark matter in a large region around the Sun is far smaller than predicted and have indicated that there is no significant dark matter at all in our neighbourhood.”

Pretty significant stuff, but let’s take a look at the accompanying images…

I admire their simplicity, but hey, with dark matter, what choice does a visualizer have? The depiction of the dark matter halo around the Milky Way looks a little clumpy to me, but again, what else can you do? A uniform blob of blue around a galaxy image doesn’t communicate much…

(Admittedly, at the scale of this image, simulations reveal the Milky Way’s dark matter environment to be somewhat clumpy, albeit not in the way depicted in the animation. It’d be keen to use computational data in a visualization such as this one, but I suppose limited time and resources prevent that.)

Anyway, I like the annotated version of the image above; in particular, the indication of the volume of space relevant to the survey.

The accompanying video (available in ESO’s typical plethora of formats) is also an exercise in simplicity, offering a straightforward revolution around the three-dimensional model used to produce the still above. I kinda wish they included the sphere around the Sun once again, just to convey the scale of the survey, but I can guess why they avoided it… Then you have to think about labels, and labels mean language, and it is the European Southern Observatory, after all. Gotta make good b-roll for Hungarian nightly news, I suppose.

And on a final note, not that I would ever nitpick, but… Are those actual galaxy locations in the background? I’ve flown around the Local Group quite a bit, and although adjusting the brightness of the nearby galaxies can change the appearance considerably, I don’t recognize anything in the background. Just curious.

Nice work from ESO, understated but effective. And maybe someday, these kind of press images can be more data-driven.

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.