Category Archives: Uncategorized

Trailing APOD

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I’m not the biggest fan of the Astronomy Picture of the Day (APOD), but today’s post is pretty kewl. What you see above is a time-lapse image of the sky (well, actually, 477 30-second exposures taken over a period of 4.3 hours) that reveals the apparent motion of the stars that results from Earth’s rotation. I’ve never seen a wide-angle image that shows the celestial equator crossing directly across the image: thus, the star trails in the upper left and lower right appear to arc in different directions. Neato.

The image was taken (and is copyrighted) by Koen van Gorp.

Antarctic Mysteries

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An article in today’s New York Times describes new websites from NASA and from USGS, showing high-resolution imagery of Antarctica. Check it out now before it all melts away!

I have some quibbles with the operation of the USGS site (the Java applet behaves a little oddly, provides effectively no information about the location displayed, and shows a map of Antarctica surrounded entirely with white), but it holds promise. And the NASA site has some spiffy stuff…

The image above comes from the “Antarctic Mysteries” game, which presents several unidentified photos for the viewer to identify. As a “game,” well, it’s not the most compelling, but I imagine I’m not the only person who looks at the grid of pictures, wonders what such-and-such might be, then clicks on the link to find out. Abstract and unusual, the images seem quite compelling.

What I truly admire, however, is the little extra info that the site provides about each image. For example, the feature above is about 25 kilometers across, located at 79°S, 80°W. Even better, the description includes a note: “This image appears darker than bright white snow because it has been enhanced to make slight contrasts in the snow more visible.” Excellent! Now, that wasn’t so hard, was it? One itsy-bitsy little extra line of text? Good work, NASA!

New Mexico Sun Stories

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Tee hee. My friend David Beining sent me a link to this image with the subject “Sci Viz New Mexico Style.” It come from a blog entry on Duke City Fix about sunlight reflected off a shaving mirror buring streaks into a wooden wall (a daily event, and the two gaps represent cloudy days). It recollects another New Mexico treasure, the Sun Dagger at Fajada Butte in Chaco Canyon.

As usual, David’s offhand email got me to looking online for, well, something to link to about the Sun Dagger (e.g., the above). I came across the Exploratorium interactive (part of their much larger site about the site), and I have to say that, except for the annoying spinning zia symbol, it’s quite good. The U.C. Berkeley-based Traditions of the Sun also offers a great introduction to the archeoastronomy of Chaco Canyon. We Bay Area folk have Nuevo México down pat!

The Solstice Project interactive model also looks interesting, but I can’t play with it…

Anyway, from shaving mirrors to ancient archaeological sites, the sun plays an important role in our lives. As long as it doesn’t burn our house down, I suppose.

2,3 Turing Machine Type 1,2

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The above image comes from Stephen Wolfram’s blog announcing proof of the simplest universal Turing machine. Believe me, I’m not about to describe a Turing machine, but I will happily describe my utter confusion when seeing the image. It initially reminded me of a Sierpinski Triangle, but obviously, something else is going on, and there’s no explanation to help! In my typical, touchy way, I got annoyed at this silly little picture, lacking any caption or descriptive text, presented as some kind of straightforward statement of the problem and its solution. Grrr…

Then I started trying to figure it out. I’ve previously blogged about the Mathematica Player and Wolfram Demonstration Project, and indeed, there’s a similar (actually, mathematically identical) example of a Turing machine in the collection. That discovery clarifies things somewhat, and yet another actually makes it quite comprehensible. In fact, reading the “New Kind of Science” prize from Wolfram’s blog, it became obvious to me that Wolfram (at least, maybe others, for all I know) has a visual shorthand that he uses in describing Turing machines—and that Mathematica evidently uses in displaying them. And I then realized that I had gotten in a huff a little hastily.

Allow me to extol a bit of personal pedagogy. In general (as I’ve mentioned in my “What Is Viz?” presentation), I divide science visualization into three basic types: 1) communication with oneself, 2) communication with a peer group, and 3) communication with public audiences. In typical astronomer parlance, I will refer to these as Type 1, Type 2, and Type 3 visualizations. In this blog, I most often comment on Type 3 visualizations (those addressed to a broad audience), and I initially mistook the above image for that type.

But it’s not. Instead, I think Wolfram has devised a Type 1 visualization of the Turing machine that, thanks to Wolfram’s influence, has transitioned to a Type 2. Presumably, there’s some small audience of “peers” out there for whom the above makes plenty of sense—perhaps they can even extract useful information from it.

Back to Jupiter

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I know that I just blogged about the Jovian magnetosphere, but here I go again. And it’s another press release from SwRI, of all things. There’s a lot going on in this diagram! First off, kudos on getting the dipole to look right, but then things get a little confusing…

The profusion of orbit lines and magnetic field lines (or tubes, I guess, if I look at the high-resolution version of the image) might make sense to a well-informed viewer, but they seem confusing for the uninitiated. I’m also wondering why the faint structure that connects the moon Io to Jupiter, which indicates ionized gases trapped in Jupiter’s magnetic field, doesn’t actually follow a magnetic field line. Yeah, they got the dipole bit correct, but then garbled the message! And the Io torus, which also looks somewhat tubular in this depiction, doesn’t seem to lie in the same plane as the orbit lines. All very odd.

Here’s the image caption, BTW: “About [one] ton of volcanic gases are spewed out by Jupiter’s moon Io every second. When ionized, these gases become trapped in Jupiter’s strong magnetic field (shown in blue) and form a vast ring (shown in red) around the planet with Jupiter’s 10-hour spin period. Jupiter’s strong magnetic, rapid rotation and Io’s prodigious source of material result in a giant magnetosphere whose dynamics are very different from the Earth.” Not such a bad explanation, really, although it helps to know that the ionized material rotates along with Jupiter’s 10-hour period, whereas Io orbits more slowly, so the stuff gets smeared out along the length of the moon’s orbit.

If you’re interested in a bit more on the topic, you can also check out an actual image of the Io torus and even see its rotation with Jupiter (the latter page actually has a much better description of the torus than the above as well). Um, did I mention I almost did a Master’s project looking at the Io torus…?

Brightness and Darkness

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A brief note. I just ran across “Brightness and Darkness as Perceptual Dimensions” on PLoS. I can’t say I fully grok the contents, but the authors suggest that brightness and darkness behave not simply as polar opposites, rather as axes of a brightness-darkness space (i.e., the brain processes the two differently). Hrm.

As the authors state, “Vision scientists have long adhered to the classic opponent-coding theory of vision, which states that bright–dark, red–green, and blue–yellow form mutually exclusive color pairs.” But, “Here we provide direct evidence that brightness and darkness form the dimensions of a two-dimensional (2-D) achromatic color space. […] Our 2-D model generalizes to the chromatic dimensions of color perception, indicating that redness and greenness (blueness and yellowness) also form perceptual dimensions. Collectively, these findings suggest that human color space is composed of six dimensions, rather than the conventional three.”

Definitely merits a closer reading…

Preaching to the Choir

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A press release from the Southwest Research Institute describes observations made of Jupiter’s magnetosphere by the New Horizons spacecraft. The above image (sorry, it’s quite low-res, and to take a closer look, you’ll need to open up the huge version linked from the above) summarizes some of the results. To summarize my response: it would work quite well in a scientific publication, but it just doesn’t cut it for public use.

I admit that it’s nice to see actual data represented—and nice to see an attempt at providing context for them—but the context in which the data fails to help much; furthermore, it really only conveys the context for an expert viewer—one who knows about the solar wind, magnetic fields, and such. In a previous post, I complained about depictions of Earth’s magnetosphere; I won’t bother reiterating my gripes, but they can be applied to the top portion of the above image. Honestly, some version of the schematic portion of the image would probably have sufficed for a press release, but it would have required significant work to be made more comprehensible.

Also, we’re given no hint as to how to read the spectrograms below the schematic diagram, and furthermore, they utilize opaque units such as “Energy/Q [eV/q]” and “DOY 2007 [UT].” Oh, yeah, and pseudocolor. ’Nuff said.

Making matters worse, the picture’s caption incorporates a trult impressive quantity of jargon. To call it “incomprehensible,” at least for public audiences, would be kind. The press release is better, but not by much. The only audience I can imagine picking up on this story is a quite sophistication publication such as Scientific American. I guess that’s all well and good (better than nothing), but a little more effort could make this result more accessible to broader audiences.

(I’ll just add that the New Horizons folks actually produced a spiffy press kit that describes the fly-by, with some decent diagrams, too.)

BTW, I’m in Athens attending the Communicating Astronomy with the Public conference. Fun stuff! And I finally achieved my goal of presenting a PowerPoint using no bullet point slides. A personal victory.

XOX, XO

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An article in today’s San Francisco Chronicle (yes, I do read my new hometown’s daily paper) features the above image of the XO laptop designed as low-cost hardware to be supplied to children around the world. What attracted me to the image is the manner in which it anthropomorphizes the technology: the screen swiveled at an angle as if the XO had just turned to face us, the ear-like antennae perked up as if it were listening, and of course, the images of children to bring home the point. It would be difficult to make technology appear any more friendly.

And indeed, the technology seems quite friendly! Not just in terms of its use, but also in terms of its creators’ goals. One Laptop per Child (OLPC) intends “to provide children around the world with new opportunities to explore, experiment and express themselves,” through an innovative combination of hardware, software, and economic strategy. I’ve had an opportunity to see several XO laptops, but I haven’t played with one much. Very clever, in more ways than one.

BTW, the OLPC website features an interactive showing how the wee laptops communicate: the ear metaphor for the antennae actually suggests how the hardware daisy-chains together connecting one another. Humanizing and illustrative!