Back to Main.
This animation uses two speeds/velocities, not one:
Each velocity vector starts at the origin (in the center), and ends in a single dot. The βx-component is vertical, and the βy-component is horizontal (as shown by the axes in the center.) The center has speed=0, and the large outer circle with the degree divisions represents the speed limit (speed=1).
The β boost between grids is positive in the direction of the +βx-axis. It starts out as the classical aberration formula, and the form stays as a circle. As speeds increase, the form changes to an ellipse, contracts, and compresses against the speed limit (β=1) circle.