Sunday, March 9, 2008

Stratigraphy, black bean soup, and hawks.







Drawing on my hundreds of hours of undergrad student labor analyzing soil samples using the Bouyoucos method (here's a study in good science and bad graphics on that topic,) I put our experimental color-coded plastic media into a 2.25 inch cylinder and inverted it, tried pumping in air (not good, bubbles stick to the particles), and other things, with interesting results. The color coding has problems, not all the material dyes properly.

I don't think I've ever seen a good demonstration of this. It's very interesting to watch in a small acrylic cylinder. There's a lot of turbulence as particles moving down displace water, and the largest don't end up at the bottom.

Neat thing is the final result looks a lot like what I see in streambanks, and we're onto something. The black bean soup Kate and I made last night (big pressure cooker batch) was full of angular particles chopped on a cutting board. Maybe we can use larger particles and different materials for this demonstration. How would carrot disks settle in a cylinder compared to sleek black beans? Seriously, we could do a lot of great visualizations with this.

Because it's a weekend: Kate and I are happy to report a pair of Cooper's hawks are nesting near our house again. We spotted them renovating their nest today. It's in a huge hickory tree 50 m or so from the house, a perfect spot, and this is the fifth year, I think, they've been back. We wake nearly every morning to their calls, it's part of our lives. Here's a little movie (7mb QuickTime) I made last year of delivery and feeding of a frog from the nearby pond. Not Animal Planet.

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