After 100 years after scientists have voiced the possibility of water in tying knots, physicists have invented and implemented a similar experiment in the laboratory. Special attention deserves the way in which researchers have been able to determine that itself is in a liquid.
For the first time on the related "ring vortices" in the 1860s, spoke Lord Kelvin. He suggested that atoms are a kind of tornado twisted into closed loop and tied around themselves. In the view of the entire space pervaded Kelvin certain liquid — air. In it, each atom was a certain node.
However, the "periodic table of chemical elements Kelvin" has not been published elsewhere and, therefore, acknowledged. But the ideas of Lord led to the flourishing of the mathematical theory of knots, which is part of the topology. Later, the researchers concluded that the sites are of great importance in some of the physical processes.
Of course, a host of water to put it mildly, is not as easy as of shoelaces, say physics at the University of Chicago Klöckner Dustin (Dustin Kleckner) and William Irwin (William Irvine). Least because such sites are not the beginning and the end of a string. The simplest examples of such structures: the trefoil knot and link Hopf (Hopf link).
To link to a similar unit water flow, it is necessary to twist it in a certain area of liquid. Klöckner and Irvine have created similar structures in water using 3D-printed on the printer models of nodes that were in the form on the cut of an airplane wing or hydrofoil.
Many known that the wing causes air flows into the atmosphere rotate twist in the form of vortices. Due to the processes taking place at the same time there is the lift that makes the plane to soar into the sky. When the wing starts abruptly stop, two vortices are formed, which are unwound in opposite directions.
U.S. researchers have placed their plastic model of nodes in a tank of water and gave them a sudden acceleration to create a knotted structure.
But how to verify that the reality of physics got exactly what they wanted? Show hosts in the water helped a special imaging technique. Typically for understanding how moving fluid flows scientists use colorants. Irwin and Klöckner introduced in small gas bubbles, which were sent to the center knotted vortex ejector forces produced by the movement of the plastic pieces.
High-speed laser scanner, which took pictures of liquid 76,000 times per second, has helped scientists understand how moving bubbles. Reconstructing what was happening, and saw the physics nodes. In the future, scientists want to try to create out of the water more complex structures.
"The authors have made great strides, visualizing knotted vortices" — says Americans achieve physicist Mark Dennis (Mark Dennis) from the University of Bristol, which at one time was able to tie in the vortices of light rays.
The latest study, in his opinion, makes abstract reasoning about the physical processes involving the nodes in the ideas that can be tested in the laboratory.
"Knotted vortex flows — an ideal model system that allows us to examine all the details of self-untangling knots in the real physical processes," — says Irwin.
We add that in this case it is not so much more understandable to the average person falling ropes, spaghetti and the pouring honey or moving hair in a pony tail. It's about more complex processes. Related vortices are present in different areas of physics. So scientists studying elementary particles, suggested that glueballs (glueball) — hypothetical agglomerates gluons — the particles that bind quarks to form photons and neutrons — are closely tied quantum fields.
In addition, recently, astronomers showed that the relaxed ("decoupled") tied magnetic fields that may be responsible for the transfer of heat into the solar corona, or outer atmosphere of sun. This process explains why the plasma in this region of the star is much hotter than the surface.
Development of Chicago physicists also help to understand superconductivity, superfluidity of liquid and behavior of liquid crystals