Friday fold: sandbox

The Friday fold is a lovely little sandbox analogue model by Prof. Marco Martins-Ferreira, who posted it on Twitter this week:  As deformation proceeds, you can see the layers develop folds that then morph into faults, shoving deeper layers atop more shallow strata. As a bonus, you can hear Marco’s baby cooing in the … Read more

History of Science: Antiquity to 1700, by Lawrence Principe

My most recent commuting audio has been this course from The Great Courses: Johns Hopkins professor Lawrence Principe‘s History of Science: Antiquity to 1700. I checked it out from my local library: 36 lectures, each about 30 to 45 minutes long. I found it quite interesting, well-paced, and insightful. Principe is an organic chemist-turned-historian-of-science, and … Read more

The Pentagon’s Brain, by Annie Jacobsen

This book is a comprehensive account of everything unclassified that DARPA and its predecessor ARPA, has ever done. The subtitle is: “An Uncensored History of DARPA, America’s Top-Secret Military Research Agency.” It begins with testing nuclear bombs at Bikini Atoll in 1954, where theoretical calculations about the Castle Bravo bomb’s explosive yield get a sobering … Read more

Friday fold: tension gashes near Sunflower, Arizona

Reader John Christian shared these folds with me via email last week. They are quartz veins in slightly metamorphosed Precambrian igneous rocks found near Sunflower, AZ in the Mazatzal Mountains. The second photo is a close-up shot of the curviest, cleanest batch of folds from the first shot. These are beautiful examples of folds in … Read more