SoCal Plasma Zoom Seminar: More is Different. Anomalous Is Normal. That’s Why Turbulence

 

In a famous 1972 publication, Philip Anderson argued that the behavior of complex systems cannot be reduced to the interactions of elementary entities. Instead, at each level of complexity entirely new properties emerge due to the many-body correlations involved. Simply put, more is different. While non-interacting particles move in a random fashion, called normal diffusion, correlated particles move in a less random way, called anomalous diffusion. Anomalous diffusion is so common in the natural world that scientists often conclude: anomalous is normal. The marriage between increasing complexity and anomalous transport often results in turbulent dynamics of the many-body system. Dusty plasmas are ideal media for the investigation of these phenomena.

a) Non-interacting particles move randomly (normal diffusion.)

 

b) Correlated particles can make huge jumps in space (anomalous diffusion.)

Here we study turbulence in a dusty plasma by computing the spectrum of energies available to the dust particles as a function of random disorder and properties of nonlocal interactions mediated by the plasma. We argue that at critical scales within the system, anomalous dust diffusion, guided by nonlocal interactions, leads to enhancement of energy transport and increased probability for turbulent dynamics. These theoretical predictions are compared against results from many-body simulations and dusty plasma experiments conducted on board the International Space Station.