What exists beyond the solar system?
The universe is a concept of space and time. These two
dimensions (so strongly associated with each other in relativistic
physics that they are combined in the idea of space-time) may not
exist outside this universe. The word "beyond" is already related
to space-time. We cannot define what is outside, beyond, before, or
after our universe because these concepts are only known to apply
in the space-time universe itself. Time and space exist because
this universe has these two dimensions. Other dimensions and
concepts may be scattered across all that we do not know. It does
not have to be time after this universe or by that matter before.
For example, where does the mass that is pulled into black holes go
to? It is clear that it is no longer in our space and time, because
all that stellar matter would not fit in a single point. There is
no simple answer to this question. Since we do not possess the
capabilities to explore a space that is beyond our senses at the
moment, we cannot know what is beyond. As it is unobservable, it is
only a subject of our speculation. There are mysteries inside that
we have not unraveled yet.