Category Archives: Uncategorized

Cycling on Water

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Images like the one above would captivate me as a child. Better even than some Richard Scarry book, they offered a chance to escape into a single-image story that quite often related to the real world (or universe) around me. I specifically remember water-cycle images as utterly entrancing.

I came across the above in a NASA press release on changes in freshwater distribution, which has some other interesting images that I’ll get to in a moment. But the diagram showing the water cycle usually has lots of arrows in it, kind of like the one associated with the Wikipedia article on the topic. But this one goes for a more organic style, replete with numerous labels (e.g., “soil heterogeneity”) but only a few, sparsely distributed arrows. I’m not sure I feel the connections as well as I’d like.

Of course, nowadays, one also has animations to illustrate the process, such as the 44.0MB epic (oddly entitled “EnergyUncomp640.mpg”), also linked to by the press release. In the animation, we see elements of the water cycle played out in sequence—cleverly coincident with the day-night cycle, beginning at dawn with evaporation and ending at night with clouds disappearing stage right. Again, no arrows. I wonder if the temporal element obscures the underlying process… In other words, does the beginning-to-end sequencing of a cycle not do justice to its cyclicity?

Nitpicks, but… I’m curious.

Both the animation and a high-resolution version of the above show up on GSFC’s excellent “Water Cycle” site, which offers much more detail on the processes involved and pays special attention to the human role in the environment.

But back to the aforementioned press release. It also shows diagrams of data from the Gravity Recovery and Climate Experiment (GRACE), which appear along the right-hand side of the web page (too tricky to reproduce here, since they show up as either uselessly tiny or overly large images on the site). One thing I like about the two images is that they use the same color scale (i.e., a given color represents the same quantity in both images); unfortunately, the color bar is unlabelled, so we have no idea what the units are, or really, what quantity we’re talking about at all. What annoys me, however, is that the sorry old crimson-to-violet color bar rears its ugly head, so we have a rainbow of colors with no logical change represented by, say, the shift from warm colors to cool colors (if there is such a meaning, it’s not described in the captions or in the text of the press release).

So, for example, if we have a map of the United States like the one shown in the press release, I’d want to know that the red regions represent, say, areas with decreasing water resources whereas green regions represent increasing freshwater availability. The color bar wouldn’t have to be labelled with units, but including words that describe what the colors mean would be nice—certainly better than numbers devoid of any context.

The GRACE website also includes a truly bizarre visualization of Earth’s gravitational anomolies. I, um, really don’t know quite what to say. Perhaps I should sleep on it…

What a Drag

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Recently, commenting on images seems to mean complaining about captions. How sad. But here I go again…

The image above accompanies a press release on a three percent reduction in upper-atmosphere density by the year 2017. The caption for the image reads simply, “The outermost layer of the atmosphere will lose three percent of its density over the coming decade.” Which is all well and good (I mean, the caption is all well and good), except that it leaves one wondering what the satellite is doing in the image. Perhaps the caption could be expanded slightly to read, “The outermost layer of the atmosphere, which extends as high as some satellite orbits, will lose three percent of its density over the coming decade.” Just as a first pass.

A little later in the press release, we find out that “lower density in the thermosphere, which is the highest layer of the atmosphere, would reduce the drag on satellites in low Earth orbit, allowing them to stay airborne longer.” Well, golly, that makes an even better caption: “The outermost layer of the atmosphere will lose three percent of its density over the coming decade, allowing satellites to stay aloft longer.” (Somehow, “airborne” seems inappropriate when applied to a satellite.)

And while I’m discussing language instead of images, what’s up with the headline for this press release? “Scientists Predict Carbon Dioxide Emissions Will Reduce Density of Earth’s Outermost Atmosphere by 2017.” Um, well, actually, emissions have already reduced the density, and they will most likely continue to reduce the denisty long after 2017. Somewhat deceptive.

Pencil versus CAD

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A Monday-afternoon lamentation on seeing ESO’s press release on the European Extremely Large Telescope. I noticed the above computer-generated rendering of the telescope, and I reflected back on my recent trip to Pasadena, where my coworkers and I wandered along the corridors of the Caltech astronomy department admiring the drawings of Russell W. Porter, who created remarkable illustrations of many of the telescopes at Mount Palomar.

Caltech’s archives offer mediocre reproductions of Porter’s work, but Bruce Weertman has assembled a much more impressive page of the drawings. Nothing compares to seeing the originals, however, and although I have heard tell of a book collecting his work, my (admittedly cursory) searches haven’t revealed anything definitive.

Looking at the above image, the little tiny figures on the lower half of the (oddly shiny) disk show two people and a pick-up truck to scale with the rest of the telescope. Extremely large indeed! Porter provides a similar sense of scale in virtually all of his drawings (an overview of the 200-inch telescope at Mt. Palomar, for example), and many of his illustrations also show the path light follows through the telescope in addition to mechanical deatils such as gears and supports. He packed a lot into his work.

According to an article on Kevin Hulsey’s website, “famed artist Maxfield Parrish was quoted as saying the following about Porter’s drawings: ‘If these drawings had been made from the telescope and its machinery after it had been erected they would have been of exceptional excellence, giving an uncanny sense of reality, with shadows accurately cast and well nigh perfect perspective; but to think that any artist had his pictorial imagination in such working order as to construct these pictures with no other mechanical data than blue prints of plans and elevation of the various intricate forms is simply beyond belief.’ ”

Long before CAD programs made the job easy (or at least easier), Porter sketched out spectacular visualizations of these phenomenal mid-century achievements. I wonder what we lose by working in an almost exclusively computer-generated realm nowadays. I’m not suggesting going back (necessarily), but… Just wondering.

Colorful flutter-by

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Featured on the EurekAlert news service (but inexplicably, not on the GeorgiaTech site that supposedly ran the story), I found an intriguing article on adjusting the color of butterfly wings. The above image shows the effect of depositing different thicknesses of aluminum oxide on a wing, thereby changing its color. Spiffy.

The caption for the image also strikes me as rather spiffy: short and to the point. It reads, “An optical microscope image of coated butterfly wing scales show color differences related to the thickness of the deposited alumina.” Certainly enough info for me, since I know that “nm” means “nanometer,” which presumably refers to the thickness of the aluminum oxide, also mentioned in the image, albeit by its chemical formula (but at least I know that “Al” means “aluminum,” so I felt comfortable extrapolating from the caption). In short, it strikes me as an excellent caption for the scientifically literate, perhaps not so hot for a general audience.

Great picture, regardless. And the rest of the press release is sufficiently complicated that the caption really just serves as a litmus test for further comprehension, so my nit-picking is probably irrelevant.

The press release also contains the mildly amusing line, “The artificial wing scales produced by the researchers also reflect bluish light, though the color is of slightly longer wavelength than that of the original butterfly.” At least it’s amusing if you think of “original butterfly” as a unit of distance, as I did (probably because I was still finishing my first cup of coffee). A very long wavelength, indeed.

Cellular Derailment

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The weekend is wrapping up, I just got back from a long weekend in Chicago (without too many delays), and friends I ran into on the subway complimented me on this blog… I should be able to find something nice to say. But no.

I came across the above image in a press release from the Berkeley lab entitled “Regulating the Nuclear Architecture of the Cell” (which has a lot to say about how genetic material clumps in the nucleus, none of which I will discuss because I’m going to obsess over the accompanying image). Even though the press release also presents a nice picture of mutant cell nuclei and a straightforward conceptual diagram on the topic, the article leads with the above image. Why, why, why, why? I beg of you, please tell me why.

I can guess why. I’d call it the “planetarian effect,” simply because that’s where I first encountered the problem, but I suppose it could be called the “press-release effect” or “the b-roll effect” or something similar. In the classic planetarium show, cobbled together by a staff (often at the last minute), one often encounters a line of reasoning to pair images with text: “Hey, we mention the Horsehead Nebula here, so where’s a picture of the Horsehead Nebula?” And the first image that you can find is one that, yeah, shows the Horsehead, but it’s kinda small, since the picture really shows all of Orion’s belt, but at least it’s got the Horsehead in it, so the slide gets dropped in the slide tray (or the JPEG added to the file), and you end up with an image in your show that potentially causes viewers to stop, wonder what it has to do with the narration in the show, and get distracted by imagery that should in fact be helping people understand what’s going on.

I’m guessing that’s what happened here. The thought process probably went along the lines of… “Oh, we’re doing a press release on the nucleolus, so we should have an image that shows what that is.” An absolutely correct and well-intended goal! But then you have to find a decent image. And IMNSHO, the above does not qualify. The relevant part of the caption reads, “The nucleolus (dark blue) resides within the cell nucleus, surrounded by heterochromatin.” Okay. But how does the image fit into the cell as a whole? Is the entire thing the nucleus or just the blurry, less-pixelated part? And how ’bout those heterochromatin? Maybe those are the little diamond-shaped blobs? (Take a look at the Wikipedia article on “cell nucleus” for a decent image of a cell, which might help answer some of those questions. It’s actually quite similar to the one above, but with better labels and clearer lines—and intriguingly similar color choices.)

If you’re lucky, an uninitiated reader will shake their head slightly and continue reading the article. But you run the risk of losing them entirely! All because a poor image distracts or confuses them. The best intentions can completely derail your audience.

Or maybe I’m just grumpy after dealing with Newark and O’Hare in the same day.

Gorrillas off the Map

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The image above comes from a Max Planck press release about the effects of ebola on gorilla populations in southern Africa, which was also published in the current issue of Science magazine. The research has disturbing implications (as discussed in a New York Times piece today), but of course, I’m interested in the diagram…

The caption for the image reads simply enough: “Protected areas with major ape populations.” But it took me a moment to absorb exactly what the image was communicating. The grey area represents the range of the gorilla; the outlined regions indicate protected areas (as per the caption). The color of the protected areas is tan if unaffected by ebola, or in the range from white to dark blue depending on the year of the outbreak(s). For some reason, I found this initially unclear.

I think it’s because the affected areas vary in value—i.e., from a very light color to a very dark color—whereas, if I were creating a similar map, I would opt for varying the value between affected and unaffected regions. To represent the dates, I’d most likely use variation in hue while keeping the value pretty much the same. (If you’re unclear on my usage of the terms “value” and “hue,” I’d recommend a page from Charlotte Jirousek’s online textbook on “Art, Design, and Visual Thinking” at Cornell University.)

Aside from the color choice, I think this is a pretty decent diagram. A fair bit of information crammed into a quite small space.

You Got Frost in My Crater!

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I’m on the road again, with less-than-stellar Internet access, but here goes. Malin Space Science Systems posted a page on Cantauri Crater and another on Sirenum Crater, both of which show evidence that suggests water flowed on Mars within the last decade—in not just one but two locations! A NASA press release also describes the findings.

It’s hard to come up with a better example of a picture being worth a thousand words, because the pair of images above make the story quite clear. The light-colored gully just looks like what planetary geologists suggest that it is. N.B., however, that the later image was taken in 2005. It’s not like they downloaded the data from the Mars Global Surveyor and posted them the next day! The science team went back and observed the same features over a period of a year, under a variety of lighting conditions, in order to make sure they weren’t falling victim to a trick of light.

So with the clarity comes a caveat: the picture may tell a story in and of itself, but good researchers don’t rely on a single image to form their results.

Well-Behaved Sheep

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I always wonder how people without a physics background perceive images such as the one above. It illustrates an ellipse of cobalt atoms (the series of peaks encircling the colorful, rippled interior) enclosing electrons (basically the ripples). So much symbolic language is built into this illustration that I can’t imagine it communicating much of anything to an audience not steeped in the visual parlance of physics. The cartesian plane representing the substrate on which the cobalt atoms are placed, the color-coded quantity in arbitrary units, the unexplained labels “F1”and “F2” right in the middle of everything… What does all this say to the non-specialist?

The image caption describes the enclosed electrons as “behav[ing] like standing waves in a pond.” So if uninitiated readers can wrap their heads around the idea that electrons (which they probably imagine as little particles) behave like waves, then the description might mean something to them.

That description is a far sight better than the press release from the Max Planck Society, which claims that “randomly vapour-deposited atoms arrange themselves in regular structures within the circular fencing – as if they were sheep arranging themselves neatly in a pen.” Now, I didn’t grow up on a farm or anything, but sheep don’t strike me as the most self-organized critters. I mean, if you pack any roughly regularly-shaped objects tightly enough, you often end up with patterns, but that’s not what they’re talking about here. The analogy falls short.

In short, the image above neatly illustrates a problem I touch on in my “What Is Viz?” PowerPoint, namely the challenge of a well-developed visual language getting in the way of communicating. Graphic elements that make sense when presenting data to one’s peers can prove insurmountable to a wider audience unacquainted with the (often complex) grammar and vocabulary of such a visual language.

Follow the Arrows

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The above image comes from a Vanderbilt Medical Center Reporter article about mathematical modeling the behavior of tumors. Aside from the minuscule size (they seem to have no larger version online), there’s at least one bizarre omission.

In case you can’t read the teeny-tiny text in the image, it says, in clockwise order from top left: “tumor,” “tumor slice,” “tumor in lattice,” “tumor cells,” “mathematical representation of tumor growth and invasion,” and… Nothing. The last image in the series has no label. From the article, you can glean that the final result is a prediction of tumor growth, but it does seem as though that could be directly addressed in the teeny-tiny graphic.

Or maybe the message is that “mathematical representation of tumor growth and invasion” leads to… Pretty flower-like pictures? Small explosions? Low-res graphics and trapped white space?

Visualize Slacking!

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The folks at Slacker Astronomy interviewed me for podcast SG 4.0, and I show up about a third of the way in (that’s 23 minutes into the MP3, although you really should listen to the entire podcast).

Aside from a not-so-hot Skype connection and a fair bit of stammering, it came out pretty well. I talk a bit about my job, the blog, and a recent astro-viz conference. If only I’d known they were chatting about Apothis earlier in the show, I could have described a bit about its uncredited cameo in Cosmic Collisions. C’est la vie. La vie de slack.