The study was able to find an order hidden in seemingly “messy” rotating physical systems, such as proteins and vortices
A new theoretical study led by a researcher from Tel Aviv University was able to find an order hidden in seemingly “messy” rotating physical systems, such as proteins and vortices. The researcher is Dr. Naomi Oppenheimer from the School of Physics and Astronomy at the Raymond and Beverly Sackler Faculty of Exact Sciences, and research fellow Dr. Matan-Ya Ben Zion and researchers from the United States were also involved in the study. The study was published in the journal Nature Communications.
Protein movement in the cell membrane is one of the problems of many physicists, chemists and biologists. On the other hand, on a scale several billion times larger, various atmospheric and oceanographic phenomena are also in the eye of the storm of physical occupation. Although these systems appear to be completely messy and based on random and chaotic movement, the study suggests that there are orderly structures within both, and they behave according to the same set of physical rules.
Dr. Oppenheimer explains: “In the new study we showed that the dynamics of proteins in a membrane are the same as those of vortices in an ideal flow such as in weather phenomena. This is very surprising, because the physical description of these systems is reflected in different equations and on different scales.
A membrane is a very viscous liquid, like honey, so the frictional forces in it are very strong, and if we do not try to actively exert force – nothing will move inside it. On the other hand, in an ideal flow, the viscosity is negligible, which means that there is almost no friction and everything continues to flow forever at ease, without interruptions. “
The researchers came up with the new study with insights from previous studies they conducted, according to which some of the proteins embedded in the cell membrane rotate, forming small vortices, colliding with each other and finally organizing in a hexagonal structure.
Dr. Oppenheimer expands on the interesting feature that emerged during the study: “We examined a case where there is a large amount of vortices. The movement of the vortices is chaotic, but we asked ourselves whether there is still an order hidden in the mess, even if there are no collisions between the vortices. It turns out that although there are no collisions, there are still restrictions on the distribution of vortices on the surface. “
Here, the researchers claim, are entering a game of conservation laws. In nature there are a number of fundamental conservation laws such as energy conservation, momentum conservation and cargo conservation. About a century ago, the German-Jewish physicist Emmy Natar cracked the connection between symmetry and conservation laws. She distilled it into a sentence of great mathematical beauty and which was named after her.
“In the case of vortices,” Dr. Oppenheimer adds, “there are geometric conservation laws that result from the symmetry in the structure of the system. “These laws dictate to the system different spatial constraints on the distribution of vortices – it is fascinating to see that even though the motion is chaotic and messy, vortices never move too far away from each other and do not get too close to each other, and this is precisely because of conservation laws.”
The feature that Dr. Oppenheimer talks about and which prevents the vortices from approaching or moving away from each other and producing a kind of non-trivial order, is called “hyper-uniformity”. This feature is quite common in nature, More.
Dr. Oppenheimer adds, “The second and no less interesting phenomenon we have seen is that when there are two types of vortices, one type is slow and the other type is fast, a strange dynamic happens that at a certain time the slow vortices are outside and the speed is inside, because the so-called fast vortices steal. ‘Order from the slow vortices. We were also able to explain this phenomenon in terms of the system’s conservation laws and other considerations. “One of the hottest issues in physics today is projection from microscopic to macroscopic systems and vice versa, so our research creates exactly that bridge, and I believe there will be many follow-up studies around this magical dynamic.”
Basically the study is valid for anything that moves in liquid or air as long as the dynamics are two-dimensional, so hurricanes and proteins are just examples. One might say in general – vortices.
In previous articles we have not talked about hyperioniformity or phase separation. That is, if in the first article we looked at proteins that are large and can collide, in this article we also look at the more “pure” case where the interaction is of vortices only, that is, only through the liquid, without collisions. We have seen these two interesting phenomena. The first, hyperioniformity, is an order hidden within the mess. Even though the movement is chaotic there is order in their dance, vortices never get too close but also do not move too far away (a bit like us as a society within this plague).
“The second phenomenon we see is a kind of phase separation, as oil and water separate. But in this case the separation is dynamic, meaning unlike thermodynamic phase separation here the system is not equilibrium. Nevertheless we show that one can borrow tools from the thermodynamic world to understand it.” Dr. Oppenheimer concludes.
To the scientific paper
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