Geoscientist Matt Kuchta explains why wet sand makes a better castle than dry sand — and what you can do to make your sand fortress even more impenetrable. Hint: The secret ingredient is window screens.
Dry quicksand was a mythical substance — normal-looking sand that could swallow you in a flash. That is, until 2004, when scientists made the stuff in a lab. (Mark told you about that development.)
In this video, geologist Matt Kuchta explains how dry quicksand is different from both wet quicksand and stable sand. Hint: Think "Jenga".
The car in this photo was 13 kilometers northeast of Mount St. Helens when that volcano erupted on May 18, 1980. This photo was taken about a month later by researchers from the United States Geological Survey. At the Rosetta Stones blog, Dana Hunter has a really fascinating story — with more eerie photos — about why geologists would want to study totaled vehicles and what we can learn from machines that we can't learn from people.
Here's a weird, great geological feature I spotted yesterday while out hiking in rural Oklahoma. We were out in a flat, flat plan that was dotted with a few tall, angular sandstone mounds and narrow sandstone canyons carved out by erosion. This rock was sticking out of the side of one of the mounds. It was the only place we saw anything like these vertical, tube-like structures, which stretched from the ground up to probably about my shoulder.
When I posted this image on Twitter yesterday, several people suggested that the tubes might be skolithos — tube-shaped fossils that were probably made by some kind of ancient worm creature and turn up sometimes in sandstones. While the pictures on Wikipedia don't look very similar to what I saw, there are apparently lots of different forms these things (and similar tube fossils) can take.
Remember when you had to build a bridge out of popsicle sticks in high school science class? The goal was to construct the miniature bridge that could withstand the most physical stress. Your materials were just sticks and glue. So the real challenge was to find strong shapes.
On the day of testing, we all learned very quickly what those shapes were. Bridges built out of lots of squares collapsed almost instantly. Bridges built out of triangles made the finals.
This is a pretty basic lesson, but it's not one that the global construction industry has learned yet, says the US Geological Survey's Ross Stein. Last week at the meeting of the American Geophysical Union, he began a talk on "Defeating Earthquakes" by demonstrating the difference between the cube-centric structures we build all over the world and how much stronger those structures can be if you just add triangles in the corners. It's a powerful demonstration of how simply having the technology to solve a problem isn't enough. You have to get people to use it.
This whole video is worth watching and easy for laypeople to follow. And it's just one of a huge collection of lecture videos from AGU 2012 that are now available online. They cover everything from the chemistry of lighting to the geology of volcanoes to the effects of space storms and solar flares. Very cool stuff!
One of the great mythologies of any kind of religious fundamentalist movement is that the beliefs of that movement, and the way they choose to interpret their scripture, represent some kind of true reflection of history. This is how things always were. It's the people who believe differently who changed.
But that's not necessarily true. Take fundamentalist Christianity. A few weeks ago, the Slacktivist blog had some excellent posts recently, documenting the fact that evangelicals were once pro-choice. Another great example comes from an article in the Geological Society of America Today — the magazine of the GSA.
Written by the University of Washington's David R. Montgomery, the piece traces the birth of modern Creationism and the way it has changed since the 19th century. In general, he writes, you can really think of Creationism as a response to geology — arising as a backlash against the rise of modern geology.
The roots of modern creationism run directly back to George McCready Price (1870–1963), an amateur geologist with no formal training. In a book designed to look like a geology textbook, Price (1923) asserted that there was no order to the fossil record. Rejecting the idea of fossil succession, he argued that the succession of organisms that geologists read in the fossil record was really just a mixed-up sampling of communities that lived in different parts of the antediluvian world. He considered the fossil record too incomplete to confidently reconstruct the past, citing the occasional discovery of animals thought to be extinct and known only from fossils.
Leading fundamentalists praised Price’s book, calling it a “great and monumental” work of an “up-to-date scientist”—“a masterpiece of real science” by one of “the world’s leading Geologists,” and “the sanest, clearest and most irrefutable presentation of the Science of Geology from the standpoint of Creation and the Deluge, ever to see the light of day” (Numbers, 1992, p. 98). But even some of Price’s most ardent supporters had questions about his new flood geology. In a 1924 review in the evangelical journal Bibliotheca Sacra, the editor credited Price with throwing “a wrench into the smooth running machinery of the evolutionary theory” butwondered why it was that when fossils were found in the wrong order, they were always in exactly the reverse of that predicted by geologists (Numbers, 1992, p. 95). How could strata have gotten flipped upside down after Noah’s Flood laid them down if the Bible did not mention subsequent catastrophes? Despite such qualms, fundamentalist proponents of flood geology were inclined to assess Price’s credibility by the conclusions he reached rather than the strength of his arguments or evidence.
Image: David Montgomery's photo of Siccar Point, Scotland. Montgomery writes, "the contact between the gently inclined Devonian Old Red Sandstone and vertically dipping Silurian graywacke that established a compelling case for the vast scope of geologic time. The expanse of time required to uplift and erode the two mountain ranges that were the source for the sand in these deposits was unimaginable to [James] Hutton."
Via Cort Sims