22. one point, from Lectures 21 and 22, diagrams, explanation on second diagram.

(a) .6 Six Spacetime Diagrams on One Graph.

Draw carefully and accurately, with the ct axis vertical and x axis horizontal, a spacetime diagram with six points or lines on it (.1 apiece) representing an event, the worldline of an object at rest, the worldline of an object traveling with constant speed less than c, the worldline of light, the worldline of an object traveling with constant speed greater than c (not physically possible), and the worldline of an object accelerating from rest to near the speed of light, but not quite getting there. Label both axes and all the worldlines or points. Make just one picture, big enough to clearly show all six motions.

Revised October 19, 1997.