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Aerodynamic capabilities of spiders have puzzled scientists for hundreds of years. Charles Darwin himself meditated on how hundreds of creatures managed to descend on the Beagle by a calm day at sea and later taking off the ship with great speeds on the windless day.
Scientists have attributed the flight behavior of these arthropods to "swell," where spiders can be transported thousands of miles by releasing silk trails that propel them upward and upwind.
However, the fact that the balloon was observed when there is no wind when the sky is overcast and even in rainy conditions, raises the question: how do spiders take off with low levels of drag? aerodynamic?
Biologists at the University of Bristol believe they have found the answer.
several silk strands that fan out, suggesting that there must be a repulsive electrostatic force, "says Erica Morley, senior scientist, expert in sensory biophysics.
Researchers fail to predict hot air balloon trends using wind alone as a driver. Why are some days there are large numbers taking air, while on other days no spider will try to inflate at all? We wanted to know if there were any other external forces as well as the aerodynamic drag that could trigger the bloating and what sensory system they could use to detect this stimulus. "
The solution to the mystery could lie in the Atmospheric Potential Gradient (APG), a global electrical circuit that is always present in the atmosphere The APGs and electric fields surrounding all matter can be detected by insects, for example, bumblebees can detect electromagnetic fields between themselves and flowers, and bees can use their charge to communicate with the hive.
Spider silk has long been known as an effective electrical insulator, but until now, it was not known that spiders could detect and react to electronic fields in the same way as bees.
In their study, the results of which appear today in the journal Current Biology Bristol researchers exposed Linyphiid spiders to laboratory-controlled electronic fields that were quantitatively They are equivalent to these and are found in the atmosphere. They noticed that turning on and off the electromagnetic field caused the spider to move up or down, proving that spiders can fly off the ground. 39, no wind when subjected to electric fields.
"Previously, wind or thermal dragging forces were thought to be responsible for this mode of dispersion, but we show that electric fields, at concentrations found in the atmosphere, can trigger swelling and provide a lift in the absence of air movement. the fields as well as the drag could provide the forces necessary for the dispersion of the balloon in nature. "
Discoveries have applications beyond the world of arthropods Aerial dispersal is also a crucial biological process for many caterpillars and spider mites, and a better understanding of the mechanisms of dispersal is important for the future. global ecology because it can lead to better descriptions of population dynamics, species distribution, and ecological resilience.
There is still a lot of work to be done, Dr. Morley said, "The next step will be to check if other animals also detect and use balloon electric fields, and we hope to deepen our investigation of the physical properties of ballooning silk and to perform balloon studies on the ground.
History Source: [19659014] Materials Provided by University of Bristol . Note: Content may be in style and length.
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