- Iain Chapman
See the effect of relative velocity on axes, coordinates and causality
Start by using the first slider to change the relative velocity. Notice how the axes change. Now tick the check box for Event 1. Notice how its coordinates change in the two frames of reference as the relative velocity changes. You can click and drag on the event to move it. To display the lightcone, move the second slider. The lightcone really extends indefinitely, but you can set the size to keep the screen from getting too cluttered. Now tick the check box for Event 2. Can you find a way to position the two events so that causality is violated?