TU Berlin doctoral candidate Moonsung Cho examines how spiders use their silk threads to get airborne
Thekla opens her parachute, faces into the wind and is propelled away. Thekla is not some kind of extreme athlete though; she is a spider. Who would have thought that this little arachnid could "fly"? This phenomenon is nicely referred to as "ballooning", as the wind shapes Thekla's delicate silk threads into a balloon and she takes off. South Korean Moonsung Cho is doing his doctorate at TU Berlin’s Institute of Biology. In his doctoral thesis, he examines which factors determine flight.
"Only a light wind is required to carry some species to heights of up to 4500 meters and for distances of several hundred kilometers."
The spider's abdomen contains what are known as spinnerets with several hundred spigots. Each spigot ejects a silk thread no more than 320 nanometers thick. This process can scarcely be perceived by the human eye in real time. Perhaps this explains why this phenomenon is underexplored?
Moonsung Cho plans to change this. He is doing his doctorate at the Institute of Biology under Professor Dr. Peter Neubauer, head of the Chair of Bioprocess Engineering, and Professor emeritus Ingo Rechenberg. "Currently there are only a few studies which have researched the behavior of flying spiders," he says. "The phenomenon is particularly common among young spiders. Some species suddenly fire threads into the air and only a light wind is required to carry them to heights of up to 4500 meters and for distances of several hundred kilometers."
"In my doctoral thesis I am examining which factors determine flight."
"Ballooning" plays an important role in the propagation of species of spiders. "In my doctoral thesis I am examining which factors determine flight. I am focusing particularly on gossamers." It is pure coincidence that spiders came to play the leading role in his doctoral thesis. "I made a video of spiders when I was taking a stroll on the Fliegeberg (The Fliegeberg is a hill serving as a monument to Otto Lilienthal's early efforts at flight.) in the Berlin district of Lichterfelde and observed that the spiders not only flew different distances, but also actually prepared themselves for flight," Moonsung Cho explains. "Directly before taking off, they stretched out one of their legs in order to test the wind speeds. I was fascinated by this at once."
"Young spiders require only a couple of threads to get airborne, while larger spiders require between 50 and 60."
This fascination is fully understandable given that flight behavior is Cho's area of expertise. Before coming to Berlin, 39-year-old Cho studied fluid mechanics. In order to examine the behavior of the flying spider, he placed 14 crab spiders on a small raised platform on the Fliegeberg and observed these passive aviators in their natural environment.
He then conducted the experiment in a laboratory, simulating different kinds of winds. One of the facts he discovered was that the spiders only take off when the wind speed is under three meters per second. He also observed that turbulent wind currents improved the spiders’ ability to float in the air. Of particular interest to note is that young spiders require only a couple of threads to get airborne, while larger spiders require between 50 and 60.
Cho still has some tests to conduct to complete his doctoral thesis. He is, however, already thinking about the possible wider application of his discoveries. "It may be possible to examine whether passive flying structures inspired by the phenomenon of thread gliding (Fadensegelflug) can be used to explore dangerous weather conditions such as tornadoes or clear-air turbulence. These are just considerations for now," Moonsung Cho concludes.
Test pilot Thekla is doing well, by the way. She and the other spiders were released back into nature after the laboratory experiments were concluded.
Image and video downloads:
For further information please contact:
Stefanie Terp | idw - Informationsdienst Wissenschaft
New way to look at cell membranes could change the way we study disease
19.11.2018 | University of Oxford
Controlling organ growth with light
19.11.2018 | European Molecular Biology Laboratory
Researchers at the University of New Hampshire have captured a difficult-to-view singular event involving "magnetic reconnection"--the process by which sparse particles and energy around Earth collide producing a quick but mighty explosion--in the Earth's magnetotail, the magnetic environment that trails behind the planet.
Magnetic reconnection has remained a bit of a mystery to scientists. They know it exists and have documented the effects that the energy explosions can...
Biochips have been developed at TU Wien (Vienna), on which tissue can be produced and examined. This allows supplying the tissue with different substances in a very controlled way.
Cultivating human cells in the Petri dish is not a big challenge today. Producing artificial tissue, however, permeated by fine blood vessels, is a much more...
Faster and secure data communication: This is the goal of a new joint project involving physicists from the University of Würzburg. The German Federal Ministry of Education and Research funds the project with 14.8 million euro.
In our digital world data security and secure communication are becoming more and more important. Quantum communication is a promising approach to achieve...
On Saturday, 10 November 2018, the research icebreaker Polarstern will leave its homeport of Bremerhaven, bound for Cape Town, South Africa.
When choosing materials to make something, trade-offs need to be made between a host of properties, such as thickness, stiffness and weight. Depending on the application in question, finding just the right balance is the difference between success and failure
Now, a team of Penn Engineers has demonstrated a new material they call "nanocardboard," an ultrathin equivalent of corrugated paper cardboard. A square...
19.11.2018 | Event News
09.11.2018 | Event News
06.11.2018 | Event News
19.11.2018 | Materials Sciences
19.11.2018 | Information Technology
19.11.2018 | Life Sciences