A new condition has been discovered by physicists at the University of Leicester.
In recent years, active, self-propelled particles have gained increasing interest in the scientific community. Examples of active particles and their systems are many and very diverse, ranging from bacteria films to flocks of birds or crowds. These systems can exhibit unusual behavior that is difficult to understand or model.
To this end, large-scale models of active particles were scrutinized by experts at Leicester to understand the basic principles of active particle dynamics and apply them in a scenario of an evacuation strategy for customers in busy places. Unexpectedly, the ‘super particles’ milling in a circular motion were bumped into by Leicester physicists who then coined the phenomenon as ‘swirling’.
The “whirl” – a new state of active matter – exhibited an astonishing behavior where instead of moving with acceleration, the quasi-particle groups moved at a constant speed, proportional to the applied force and in the same direction of the force. This behavior seemingly contradicts Newton’s Second Law, which is currently taught in secondary schools in the UK.
Professor Nikolai Brilliantov, who led the research at the University of Leicester, said: – “We were completely baffled to see how these quasi-particles spin around in active matter and behave like individual super particles with surprising properties, including not moving with acceleration when force is applied. , and coalesce on impact to form eddies of greater mass.
These patterns have previously been observed in animals at various stages of evolution, ranging from plant animal worms and insects to fish, but rather as single structures, not as a phase adjacent to other phases, resembling gaseous and liquid phases of ‘normal’ matter. “
Professor Ivan Tyukin, Director of Research in Applied Mathematics said: “It is always exciting to consider deepening our understanding of new phenomena and their guiding physical principles. What we know so far is so much less than what there is to know. The phenomenon of the “swirlon” is part of the tip of the iceberg of hidden knowledge. It leaves us with the eternal question, ‘what don’t we know’? “
The world of active particles has many practical applications, including in the most advanced fields of artificial intelligence, space data and robotics. Since one of the possible practical applications of active particles could be self-assembly, experts at the University of Leicester agree that it is essential that physicists continue to push for discoveries based on simulation work. This ensures that materials, substances and groups work in real life in ways that are reliable, expected and predictable, without inevitable uncertainties.
Reference: “Swirlonic state of active matter” by Nikolai V. Brilliantov, Hajar Abutuqayqah, Ivan Yu Tyukin and Sergey A. Matveev, October 8, 2020, Scientific reports
DOI: 10.1038 / s41598-020-73824-4