Flying snakes like Chrysopelea paradisi, the paradise tree snake, normally lives among the trees of South and Southeast Asia. There, they sail along the branches of the trees and, sometimes, to get to the ground or another tree, they launch themselves into the air and slide down into a corner.
They wave their serpentine bodies as they glide through the air, and it turns out that these special movements are what allows these limbless creatures to make such extraordinary flights.
This is according to some new research in the magazine Physics of nature this involved placing motion capture tags on seven snakes and then shooting with high-speed cameras as snakes flew through a giant four-story theater.
How far they can really go depends on how high they are when they jump, says Jake Socha at Virginia Tech, who has studied these snakes for nearly a quarter of a century. Remember that he once saw a snake start at about 30 feet and then land almost 70 feet away. “It was a spectacular slide,” recalls Socha.
Part of the way snakes do this is by flattening their bodies, he says. But snake bodies also perform wavy movements. “The snake appears to be swimming in the air,” he says. “And when it swims, it’s wavy.”
He wondered for a long time whether these undulations served any purpose. Maybe, he thought, it’s just something snakes do out of habit.
“All snakes wave when they move. And so on the ground, on a tree, in the water, they are creating these waves from one side to the other,” says Socha. “It’s not foolish to think that when the snake blows up, the snake says,” Hey, I’m a snake. Undulated. Here’s what I should do. “”
The other possibility, however, is that ripple actually helps snakes fly. And a few years ago, Socha was talking about snakes with someone he had just met at Virginia Tech. “This guy said, ‘Oh, well, you know, maybe you’d be interested in The Cube,” says Socha. “And I was like” The cube? What is the cube? “”
The Cube, apparently, is a vast theatrical space that resembles an empty black box, equipped with high-tech and super expensive cameras. “When I entered this black box theater,” Socha says, “I just looked around and said,” Oh, this is perfect. So I want to slide my snakes into this space. “”
After convincing decision-makers that snakes would not hurt themselves or flee The Cube, Socha and her colleagues prepared the arena by placing foam padding on the floor and attacking a fake tree there to serve as a target for a flying creature. .
So they had to prepare the snakes. Normally, in motion capture made for Hollywood movies, the actors wear small reflective tags that are placed all over the body. So, along the bodies of the snakes, the researchers placed 11 to 17 pieces of reflective tape.
“These spotlights were able to indicate where different parts of the body were in 3D space,” says Socha. “And our cameras were recording it at almost 180 frames per second. And that’s fast enough that we got many representations of the snake as it crossed its full glide.”
For Isaac Yeaton, a mechanical engineer at Johns Hopkins University’s Applied Physics Laboratory, these experiments were the first time he saw a flying snake really do its thing. He says that the actual glide is rather short, only one or two seconds long.
“It happens very quickly. And it’s difficult to see all the details by eye. That’s why we need high-speed cameras and high-speed motion capture,” says Yeaton.
Snakes often bounced from the foam padding on the floor, while neighboring snake managers waited to pick up the animal after landing, he recalls. Once, he was standing on the perimeter of the room when a flying snake made his way to him.
“I was able to get my hands out and get it,” says Yeaton. “So it was different!”
For about two weeks, the researchers filmed dozens of glides. Yeaton claims to have discovered that ripple has some distinct features besides the large horizontal S-shaped movements that are easier to see.
“There is a vertical wave. And this was really strange. We didn’t expect to see it,” says Yeaton, who says that the only other example of what he is aware of is in the side snakes that move on the sand. The researchers also found that the back half of the flying snake’s body makes some sort of up and down bending movement.
The researchers used all the information gathered on these movements to create a computer model: a virtual representation of a flying snake. Using this virtual snake, they could “deactivate” different aspects of his movement to see what would happen to his flight.
What they discovered, says Yeaton, is that without ripple, snake slides have become unstable: flying creatures would plummet or plummet.
“Snakes usually wave by propulsion – they use it to push against the environment,” says Yeaton. “But flying snakes are wavy for stability.”
Jennifer Rieser, a Georgia Tech physicist who studied snake crawling and who was not part of the research team, says it is an “interesting” discovery. The ripple of snakes in the air, he says, “actually appears to have a fairly important consequence for their movement.”
Do you think this would be interesting to explore in biologically inspired flying robot snakes.
“As far as I know, there is no such thing as an aerial snake-like robot yet,” says Perrin Schiebel, a researcher at Harvard University. He also discovered that this is an intriguing study and claims that he suggests ways to potentially modify existing snake robots to give them new skills.
Some other “flying” animals, such as squirrels and lizards, appear to have a static pose, Schiebel notes. He thinks it is really surprising that the same types of maneuvers that help snakes move through water and sand can also help them when they slide through the air.