Toward Astrophysical Turbulence in the Laboratory
  Turbulence is a ubiquitous phenomenon in space and astrophysical plasmas,
driving a cascade of energy from large to small scales and strongly influencing
the plasma heating resulting from the dissipation of the turbulence. Modern
theories of plasma turbulence are based on the fundamental concept that the
turbulent cascade of energy is caused by the nonlinear interaction between
counterpropagating Alfven waves, yet this interaction has never been
observationally or experimentally verified. We present here the first
experimental measurement in a laboratory plasma of the nonlinear interaction
between counterpropagating Alfven waves, the fundamental building block of
astrophysical plasma turbulence. This measurement establishes a firm basis for
the application of theoretical ideas developed in idealized models to
turbulence in realistic space and astrophysical plasma systems.
