If B is controlled
by the ticking of an *inertially expanding* clock, then these events are

These two events are marked by a square and a diamond in Figure 9. The constant is the proper time corresponding to .

It follows from Eqs.(12) that the scattering
event measured by B is

These three events, , and , are marked in Figure 9 by a square, a circle, and a diamond.

Ulrich Gerlach 2003-02-25