Meet The Swirlon, A New State Of Active Matter That Bends The Laws Of Physics

A new state of active matter, known as a swirlonic state, is described in a study published in the journal Scientific Reports. According to researcher Nikolai Brilliantov, the swirlonic state is visible in examples of group motion, such as starling swarms and shape-shifting schools of fish, which often fascinate the human eye.

Professor Nikolai Brilliantov of the University of Leicester and colleagues investigated large systems of Active Particles in their new study. They observed the formation of conventional gaseous, liquid, and solid phases and the formation of a new State of Active Matter known as the Swirlonic State.

Active particles consume energy from their surroundings and drive themselves out of equilibrium. There are numerous examples of Active Particles Systems in living matter. Other examples include robotics, biomedicine, and social science.

Active matter is a substance made up of active particles that exhibit motility or move and perform mechanical work at the expense of metabolic energy.

Active matter behaves in a very different manner than passive matter. Brilliantov claims that different states of passive matter can coexist. A glass of liquid water, for example, can gradually evaporate into a gaseous state while still leaving liquid water behind. On the other hand, the active matter did not exist in multiple phases; it was either all solid, all liquid, or all gas. The particles also formed large conglomerates, or quasi-particles, milled together in a circular pattern around a central void.

Newton's Second Law states that the acceleration of an object is determined by both the force acting on it and the object's mass. Its acceleration increases in proportion to the force applied, and as its mass increases, its acceleration decreases. These things do not occur in the case of swirlons.

The researchers demonstrated, using computer simulations, that active matter in a swirlonic state does not obey Newton's second law. When a force was applied to particles in this state, they did not accelerate but instead maintained a constant velocity, according to Brilliantov.

Professor Nikolai Brilliantov, who led the research, said, "We were completely baffled to witness how these quasi-particles swirl within active matter, behaving like individual super-particles with surprising properties including not moving with acceleration when force is applied, and coalescing upon collision to form swirlons of a larger mass."

He also said, "These patterns have previously been observed for animals at different evolution stages, ranging from plant-animal worms and insects to fish, but rather as singular structures, not as a phase which borders other phases, resembling gaseous and liquid phases of "normal" matter."

The team's next step in their investigation will be to conduct simulations with the real-world, complex active matter. Such experiments will bring scientists closer to understanding the physical laws that govern the schooling, swarming, and flocking of certain animals – information that will be useful in future endeavors involving self-assembling materials, Brilliantov said.

Professor Ivan Tyukin, also from the University of Leicester and Director of Research in Applied Mathematics, added, "It is always exciting to consider deepening our understanding of novel phenomena and their guiding physical principles." 

"What we know to date is so much less than what there is to know."