From a four-dimensional perspective, a universe is the shell of a hollow sphere that encompasses everything just above and below a skein - surface of a hypersphere. The energy grid form the wall of the shell and set the boundaries of the universe. Between the skein and the energy grid walls is hyperspace.
Younger universes are within the sphere, past the infraspace energy grid. Older universes are without, through the ultraspace energy grid. The energy grid blocks travel between universes.
In theory, the evolution of a universe may be directed if modifications are made immediately after its creation.
From a seven-dimensional perspective, the life cycle of a typical universe may be traced over a hollow torus, with a Cosmic Centre at the centre of the torus. A universe appears as a flat circle, and its edge is always on the torus. As a new universe expands its diameter increases, and it moves up and over the rim of the torus. The universe reaches its maximum size along the outer surface of the torus, before contracting as it returns to the torus' centre. The universe collapses when it arrives back at the Cosmic Centre, where it is recycled to create new universes.
Universes born from the same Cosmic Centre tend to have similar typical life-spans.
Travel between universesEdit
The lifespan of a civilization is limited by the life of its parent universe. The ability to travel between universes removes this limitation by allowing the migration to younger universes as required.