Winging It

Environmental & Science Education, STEM

Ed Hessler

The falling of seeds from trees is often enchanting, especially when those seeds are winged, helicopter seeds; technically fruit and known as samara. Here are eleven examples. The physics of descent has been studied, e.g., here. And samaras have also been widely used in science education, e.g., here. A Connecticut Performance Assessment was designed for high school physics classes to study maple seeds followed by the design of a study to explain their spinning patterns based on the evidence collected.

Samaras have also been the inspiration for designs from nature. One of the most recent was just reported in the journal Nature by Shamini Bundell. 

The featured video shows "tiny electronic devices that float through the air. These 'circuit chips with wings' fall slowly and can carry a whole host of electronic components such as sensors and wireless communication antennae. They can be manufactured in large numbers and dropped from a height to allow high-resolution data collection over a large area." Furthermore the "seeds" are really small and are biodegradable.

The featured investigator is John Rogers, Northwestern University.

There is a link to the film (4m 24s) and to the original paper (behind a membership wall but the abstract and authors/institutions can be read). I have one quibble with the presentation. Rogers says "We think we've beaten biology." Evolutionary biology is a tinkerer rather than a designer of optimal solutions. Evolution deals in good enough solutions and what works for the problem at hand with only one goal: survival of the species. Clearly the various solutions for samaras have worked very well for tree reproduction. Here, for example, is a fossil samara, 48 myo.