How magnetic chaos scrambles particles differently than we thought

Charged particles like cosmic rays scatter off turbulent magnetic fields, and how much they scatter depends on how the field lines themselves wander through space. Using simulated turbulence with realistic magnetohydrodynamic wave polarizations, researchers found that field line diffusion varies dramatically depending on wave type: magnetosonic waves produce a quartic (fourth-power) dependence on field strength, not the quadratic scaling assumed in standard models. The result matters because it changes how we predict cosmic ray propagation in astrophysical environments from supernovae to galaxies.