In the Eye of the Beholder

Posted: Jan 30 2012 by David Mogk

Hubble's 20th anniversary image shows a mountain of dust and gas rising in the Carina Nebula. The top of a three-light-year tall pillar of cool hydrogen is being worn away by the radiation of nearby stars, while stars within the pillar unleash jets of gas that stream from the peaks.

Credit:,, and M. Livio and the Hubble 20th Anniversary Team

I recently had the pleasure of attending a multi-media performance, "A Universe of Dreams", which showed spectacular astronomical images acquired by the Hubble space telescope, set to the lilting Celtic music of the Ensemble Galilei, and with thought-provoking narrative and poetry read by Neil Conan (of NPR's "Talk of the Nation" fame). This program delivered an awe-inspiring integration of Science and Art. The images were fantastic beyond description. But, as I drifted through the images of the far universe during the presentation, I realized that I really had no idea what I was looking at. Beyond the aesthetic appeal, I had to admit that I was woefully ignorant (or at least uninformed) about the scientific significance of the images. As I searched for meaning in the gallery of images, I found myself reflecting on how the images were acquired, and for what purpose. Somebody made the decision to take a given image. What was it that they saw that compelled them to take just THAT image? What insights could they gain about the nature of the universe from this perspective? What wavelengths were recorded—the visible spectrum, infrared, ultraviolet, X-ray, or other? Are these true color images, or were these images enhanced by processing software? And most important (to me) what did the structures captured in these images reveal about cosmic history or processes? The multi-media presentation was lovely, but I wanted to know more. More

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Older but Wiser

Posted: Jan 2 2012 by Kim Kastens
Topics: History of Geosciences, Interpretation/Inference

photo of Marie TharpMarie Tharp's workspace with seafloor profiles aligned to facilitate comparing and contrasting multiple "cases." Source.
In a recent post, I wrote about "Case Based Reasoning," a powerful form of learning in which a person compares and contrasts multiple instances of something and extracts a common pattern or thread of insight. Without using that term, Ault (1998) described a very similar process for how geologists extract insight from nature, using the example of deep sea fans. Each fan is a little different from the others, and the essence of deep-sea-fan-ness lies in the aspects they have in common.

This reasoning process is found throughout geosciences. For example, Marie Tharp's discovery of the rift valley of the Mid-Atlantic Ridge came about as she slogged through thousands of kilometers of echo sounder profiles and extracted the common schema of a rift-shaped feature reminiscent of the East African Rift Valley. More

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Rocks as Models

Posted: Dec 17 2011 by Kim Kastens
Topics: Interpretation/Inference

I was leading an Earth Science teacher professional development workshop recently, and the subject turned to models: physical models, computer models, data models, mathematical models, graphical models, etc. Afterwards, one of the teachers said to me "Well, it seems like EVERYTHING we use in teaching Earth Science is a model."

And I said, "Well, it's not THAT extreme. Rocks aren't models....." More

Bad Diagrams

Posted: Dec 14 2011 by Kim Kastens
Topics: Spatial Thinking

All in all, I'm a fan of the New York State Earth Science Regents course and of the accompanying Earth Science Regents exam. New York state enrolls more students in high school level Earth Science than any other state, and confronting the common exam has helped to build a community of practice among New York State Earth Science teachers that is the envy of Earth Science teachers in other states. I especially like the emphasis on building and assessing representational competence–the ability to understand and make inferences from diagrams, maps, profiles, block diagrams, graphs and other visual representations.

However, I have to say that the most recent Earth Science Regents exam (August 20ll) had two really terrible diagrams, so bad that I think they are more likely to sow confusion than illuminate earth processes. More

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Questions we don't think to ask

Posted: Dec 1 2011 by Kim Kastens
Topics: Metacognition, Perception/Observation

The most interesting thing I learned over Thanksgiving arrived during a pre-dinner walk along a rural Massachusetts road heavily impacted by the Halloween storm. Many tree limbs were shattered, fallen to the ground or dangling from their parent trees. My cousin's daughter's friend Mike pointed out that the broken limbs still had their leaves, browned and stiff but still connected, while the healthy trees had lost all their leaves. The rest of us looked more carefully, and sure enough, his observation was correct, tree after tree. More