What effect does the shape of the wing have on the maple seed model's ability to rotate? A model was constructed that rotated, using the knowledge about weight distribution and wing loading gained from earlier designs. The wing was made with an aileron-like fold that could be set at different positions. Then the model was tossed with the aileron's position varied. The results of these tosses are shown in the diagram below.
The model rotated only when the aileron was "closed", in the first and last examples. Opening the aileron caused the rotation to become very broad, as in the second and sixth examples. When the aileron was opened further, the seed became a glider. This is shown in the third and fifth examples, where the rotation becomes a "swoop". But with the aileron fully open, but flat (the fourth example), the model neither rotates or glides, but tumbles and falls. To test whether the flap was causing the model to rotate when in the fully closed position, but with some slight ability to affect the airflow, it was cut off.
It seems that the aileron does have some effect on the model's ability to rotate. Unless the model was tossed carefully, it would tumble and fall to the ground. A second model was made and tested, but this was even more surprising because it did not rotate at all, but swooped, glided, or tumbled, no matter how it was thrown. Carefully unfolding both models showed that the second was not folded like the first, and had a different weight distribution, with less weight at the top end (as seen in the photos). By refolding the model carefully, it was made to rotate. This suggests that weight distribution is a more important parameter for rotation than wing size or shape. As a final test of the hypothesis that weight distribution is more important than wing shape or structure, the part of the wing that was cut off was tucked under the left side of the model. The model then rotated reliably.For a relevant discussion about the role of craftmanship and reproducibility in science, read Changing Order - Replication and Induction in Scientific Practice, by H. M. Collins, University of Chicago Press, 1992. Chapter three has a particularly relevant case study of physicists' struggles to replicate a newly-invented type of laser, which conveys much of the frustration I felt when the second model seed failed to rotate. You might want to study the process of awareness that occurs when an attempt to replicate a design or experiment fails. This is problem-solving in an almost pure form. What happens during this process?
