Image of the Day: Making Waves
Image of the Day: Making Waves

Image of the Day: Making Waves

Slithering snakes mimic waves of light, “diffracting” as they pass by an obstacle.

Mar 6, 2019
Carolyn Wilke

ABOVE: A Western shovel-nosed snake moves through a force-sensitive set of rubber pegs.

In a study of how limbless animals move through environments like desert sand, researchers have found that after colliding with an obstacle, a snake’s motion changes similarly to the way light bends when passing through a slit or around an object’s edge, researchers reported February 25 in PNAS.

In the lab, the scientists watched shovel-nosed snakes (Chionactis occipitalis) move across shag carpet with an S-shaped trajectory and then through a line of six rigid posts. When the snakes hit a post as they navigated through, their bodies deformed, but they slithered along without losing speed. The motion of the snake mimics that of light when it moves around an object, continuing with the same waveform but at a different angle, according to the study’s authors.  

P.E. Schiebel et al., “Mechanical diffraction reveals the role of passive dynamics in a slithering snake,” PNAS, doi:10.1073/pnas.1808675116, 2019.