Sal M. Onella wrote:
Such a quantum structure would not be coupled to the presence of matter. It
would exist without mass.

It could be the dark energy thought to make up ~65%
of the universe and be responsible for the universal
expansion of "empty" space.

The universe has discrete boundaries.

The volume of the universe could be *unbounded* and
finite, as is the surface area of the earth.

If EM waves reaching the boundary really do not escape and are not reflected
(???) then the boundary is absorbing them and has a theoretical impedance
of 377 ohms (same as what we innocently calculate for 'free space').

One can travel forever on the finite surface of the
earth without ever reaching a boundary. Without changing
direction on the two-dimensional surface of a sphere, one
simply arrives back at one's starting point. (The East
Indies can be reached by going the opposite direction.)

One can probably travel forever within the volume of a
finite universe without ever reaching a boundary. One
might even arrive back at one's starting point while
traveling only in a "straight line".
--
73, Cecil http://www.w5dxp.com