Just because physicists have experimentally shown that specific systems with interacting entities can synchronize just if the elements inside the system are different from one another.
Discovering this could offer another twist to the previous comprehension of how collective behavior found in nature, for example, fireflies flashing in unison or pacemaker cells cooperating to create a heartbeat—can emerge in any event, when the individual insects or cells are different.
Now, scientists from Northwestern University explained that identical entities naturally behave identically—until they start interacting.
Adilson Motter, who led the research, said, “When identical entities interact, they often behave differently from each other. But we identified scenarios in which the entities behave identically again if you make them suitably different from each other.”
Northwestern’s Takashi Nishikawa said, “It is interesting that systems need to be asymmetric to exhibit behavioral symmetry. This is remarkable mathematically, let alone physically. So, many colleagues thought that experimentally demonstrating this effect was impossible.”
Scientists used three identical electric generators. Every generator oscillated at a frequency of precisely 100 cycles for every second. At the point when separated, the identical generators behaved identically.
When connected to form a triangle, their frequencies diverged—but only until the generators were properly mismatched to have different energy dissipations. At that point, they synchronized again.
Molnar explained, “This can be visualized by putting a small lamp between each pair of generators. When the generators are identical, the lamp flickers, meaning that the generators are not synchronized. But when the generators’ dissipation is tweaked to different levels, the flickering stop, indicating that the generator voltages are oscillating in sync.”
This phenomenon is also known as converse symmetry breaking as it represents the opposite of the previously known event of symmetry breaking, which underlies superconductivity, the Higgs mechanism, and even the appearance of zebra stripes.
Motter said, “It might seem counterintuitive. But our theory predicts that this is true across many systems, not just electromechanical ones.”
Scientists are now working on the design of a power grid that is more stable while allowing the incorporation of an increasing share of energy from renewable sources.
The research will publish on Monday, Jan. 20 in the journal Nature Physics. Motter coauthored the paper with Northwestern’s Takashi Nishikawa and Ferenc Molnar, a former postdoctoral researcher at Northwestern who is now at Notre Dame University.