
441.21
Consider the case of the cheese tetrahedron (see Sec.
623.20), where we
push one of the faces toward the opposite vertex. We
can move that face in until it is
congruent with the opposite vertex. There is now no
volume, but we have agreed that the
condition of symmetry is a constant of the abstractly
conceptual system, the tetrahedron:
the sixness and the foumess are still there, but they
are empty. With one face congruent
with the opposite vertex, we have all four planes of
the tetrahedron going through the
same exact point at the same time, or theoretically
as close as we can ever get to exactly.
We also have six edges of the tetrahedron going through
the same point at the same time.
We have agreed that this is a condition that can never
happen in reality, but in the vector
equilibrium, where there is no size, we have the only
possible time when this would seem
to occur.
