In this photo, the red LED can represent the background magnetic field in space. The circle represents a charge particle in space. Charged particles orbit magnetic fields because of the Lorentz force. The radius of the circle is called the gyroradius of the charged particle. This radius is one of the physical length scales which helps us determine which approximations are valid for a particular question.
This photo illustrates the distinction between two important sets of equations for plasma physics. These equations are called models or regimes. The first regime is called magnetohydrodynamics and treats charged particles as a fluid. The second regime requires the orbits of individual particles. In this photo, we can view the bubble-like regions of the poi's trajectory as kinetic. Here the poi is acting like a particle orbiting a background field. Because kinetic computations are very costly, we cannot see the entire trajectory at once using these equations. However, we can view the overall trajectory using magnetohydrodynamics. For the magnetohydrodynamic portion of the photo, we see a smooth line instead of a spinning light.
This photo shows two poi being held in one hand to illustrate wave superposition. The poi handles are held together and visible as a red trace. The white and pink lines are the orbits of the poi. To understand superposition, we can think about the red wave as the sum of the other two waves.
