How can they do this? What is the key of their amazing cohesion? This is one of the questions the STARFLAG project – Starlings in Flight – aims to answer. The project, which started in 2005, is an EC-funded collaboration of seven European institutes, coordinated by the Italian National Institute for the Physics of Matter (INFM-CNR). Physicist Giorgio Parisi is the head of this European network.
The prominent task of STARFLAG was to collect empirical data on large flocks of starlings in the field, and to test the predictions of former theories. The equipe headed by INFM-CNR researcher Andrea Cavagna, conducted experiments over the skies of Rome and discovered that the behaviour of flocking birds is very different from what believed up to now. Current computer models assume that each bird interacts with all birds within a certain physical distance. Empirical observations, however, show that each bird keeps under control a fixed number of neighbours (seven), irrespective of their physical distance. A flock under predator attack may expands dramatically, but birds can regroup very quickly because the cohesion does not depend on the physical distance among starlings, but rather on their ability to interact with a fixed number of neighbours.
The INFM-CNR results will be published today in the Proceedings of the National Academy of Sciences.
To obtain these empirical results the INFM-CNR equipe employed a multidisciplinary approach, using tools from stereometry, statistical physics and computer vision. The 3D position of individual birds has been reconstructed within flocks of thousands of starlings in the field. “Up to now numerical models of flocking had never been tested against empirical data, and it was impossible to select the right model. Now, thanks our data, we can really measure what goes on within a flock”, says Andrea Cavagna. “An interaction based upon the number of neighbours rather than their distance, implies rather complex cognitive capabilities in birds”- adds Irene Giardina, another INFM-CNR researcher.
According to Andrea Cavagna, “the STARFLAG findings may be important for fields as mobile robotics and control theory, where highly coordinated swarms of simple agents must solve complex tasks through a bottom-up approach.”
Giuditta Parolini | alfa
Nano-kirigami: 'Paper-cut' provides model for 3D intelligent nanofabrication
16.07.2018 | Chinese Academy of Sciences Headquarters
Theorists publish highest-precision prediction of muon magnetic anomaly
16.07.2018 | DOE/Brookhaven National Laboratory
For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.
Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...
13.07.2018 | Event News
12.07.2018 | Event News
03.07.2018 | Event News
16.07.2018 | Physics and Astronomy
16.07.2018 | Transportation and Logistics
16.07.2018 | Agricultural and Forestry Science