Savchenko Problem 14.3.12

The key insight is that a moving charge creates both an electric and magnetic field, and their strengths depend on the direction relative to the velocity—this is a relativistic effect. Rather than treating them separately, recognize that the fields are strongest perpendicular to the motion (where the charge "compresses" the field lines due to length contraction) and weaken along the direction of motion. You'll need to use Lorentz transformations or the Liénard-Wiechert potentials to show how $E$ and $B$ vary with angle $\theta$ from the velocity vector, revealing the characteristic "pancake" pattern of relativistic field concentration.

The key insight is that a moving charge creates both an electric and magnetic field, and their strengths depend on the direction relative to the velocity—this is a relativistic effect. Rather than treating them separately, recognize that the fields are strongest perpendicular to the motion (where the charge "compresses" the field lines due to length contraction) and weaken along the direction of motion. You'll need to use Lorentz transformations or the Liénard-Wiechert potentials to show how $E$ and $B$ vary with angle $\theta$ from the velocity vector, revealing the characteristic "pancake" pattern of relativistic field concentration.