Science toys

EM Field Visualizer

See the electric and magnetic fields around moving charges, from any frame, up to near light speed.

Download for Windowsv1.0.0 · 62 MB · free

About

An interactive 3D view of the electric and magnetic fields around parallel streams of electrons and protons. Each moving charge carries its exact relativistic field, which flattens into a pancake as it approaches the speed of light.

Slide the observer frame to ride along with a stream and watch magnetism turn into electricity. Drag a probe charge around and compare the force it feels in the lab with the force computed in your moving frame.

  • Electron, proton and neutral-wire streams with adjustable speed and spacing
  • Observer frame slider with full Lorentz transformation
  • Probe charge with a live force diagram
  • Classical Galilean mode to show where pre-relativity physics breaks

Controls

Left-dragRotate
Right-dragPan
WheelZoom
Shift + left-dragMove the probe

Version history

  1. v1.0.0Oct 17, 2026Add release workflow that publishes a Windows zip

All releases and notes