Synopsis: Synchronized Rolling

Complex networks of disk bearings rotating in unison have an easier time maintaining this synchronization when the mass and radius of each bearing obeys a simple relationship.
Synopsis figure
N. A. M. Araújo et al., Phys. Rev. Lett. (2013)

Synchronized behavior occurs when different elements (or oscillators) interact in a way that coordinates their movements. A new model of closely packed bearings shows that these mechanical disks act like a complex network of interacting oscillators. The work, presented in Physical Review Letters, finds that bearings tuned with a particular mass-radius relationship will have a stronger (more stable) synchronization.

Common examples of synchronization include contraction of heart muscles and the rhythmic unison of musicians. Recent interest in synchronization focuses on which interactions might enhance or reduce coordination. One prediction is that a synchronized state is most stable when the interaction strength is inversely proportional to the number of interacting partners that a particular oscillator has.

To provide a test bed for this theory, Nuno Araújo of the Swiss Federal Institute of Technology (ETH) in Zurich and his colleagues turned to complex bearing networks. They devised a model in which two-dimensional bearings of various sizes fit together to fill a given volume. This system is synchronized when all the elements have the same tangential velocity (i.e., no slipping). The team calculated how such a synchronized state responds to perturbations and found the most stable case was when the mass of each bearing was directly proportional to its radius. As such, larger bearings, which typically touch (interact with) more of their neighbors, have a larger moment of inertia and thus are less affected by these interactions. In other words, elements with more partners compensate with weaker interactions, just as predicted. – Michael Schirber


Features

More Features »

Announcements

More Announcements »

Subject Areas

Complex Systems

Previous Synopsis

Interdisciplinary Physics

Alice and Bob Go Nonlinear

Read More »

Next Synopsis

Related Articles

Synopsis: Extending the Kuramoto Model to Arbitrary Dimensions  
Complex Systems

Synopsis: Extending the Kuramoto Model to Arbitrary Dimensions  

The generalized version of a theory describing synchronization in an ensemble shows that coherence arises differently depending on whether the number of dimensions is even or odd.   Read More »

Focus: Finding the Ideal Noise-Reducing Network
Statistical Physics

Focus: Finding the Ideal Noise-Reducing Network

The structure of a network, such as an electricity grid, can be optimized to reduce the effects of fluctuations in the network’s inputs. Read More »

Synopsis: Social Determinants of Epidemic Growth
Complex Systems

Synopsis: Social Determinants of Epidemic Growth

A new network model reveals that social mixing and mobility can determine the areas of a city that are critical in provoking an epidemic outbreak. Read More »

More Articles