riparian rap

Maple seed vortex visualization.

We’re in the throes of NSF grant writing again, and I’m way behind on blogging, which is frustrating, because we have lots of cool things going on at LRRD.

Vimeo hosts this interesting visualization of a maple tree’s single wing “helicopter” seed via Science News. has a nice write-up on this work by David Lentink and others, some of which was published in Science.

The researchers also used a scaled up artificial seed in mineral oil. We’re working on these issues of similitude in fluid mechanics at LRRD, though we always scale down, and unfortunately there seems to be no good way to reduce viscosity, unless we fill our river models with dangerous hydrocarbons or use very hot water.

I’ve always loved to watch maple seeds fall in the spring, and if you’ve studied forestry you know they’re called single wing samaras. Steven Vogel (emeritus at Duke now) writes eloquently (and with great humor) about biomechanical things like this in his books. His Life in Moving Fluids is one of my favorite science books.

And speaking of backyard science, see this video captured in a study of the spectacular dives of male hummingbirds. It’s a great video, and I like the embedded data graphics at the end.