"The spot is placed to give the maximum factor of safety."
"Good."
"Now, after considering the probable velocity of escape from
Seventy-nine, which would be a lifeship leaving the mother vessel at
a ninety-degree relative course at full lifeship speed, we find a
vector combination of velocities and courses that diverge from the main
course."
From the red knot another line went out at a small angle to the
original course, thin and red.
"But because we have no way of knowing what the axial attitude of
Seventy-nine was at the moment of escape, the volume of probability now
becomes a cone."
The angled red line revolved about a green course line describing
a thin cone, its base pointed toward the star, Castor. As the line
revolved about the axis of the cone, it left a faint residue behind it,
which became a thin, transparent cone.