You seem to have a problem with the term theoretical, as well as the probability that theoretical sometimes operates beyond the constraints of known science and can change known science. But it is not a religion , there is no deity or worship involved.<quoted text>
Of course there are many unknown things in existence, even each person knows slightly different things. So you're really not able to answer the simple question so that we could agree on these simple terms? Seriously?
Your answer should have been the same as Chimney's yet you seem to be totally unable to produce a simple answer. it smells like religion on your part to me...
Do you have term for "absolutely everything that exists (known and unknown)" if you don't accept Universe to be that term?
In classical physics and what we consider "known" , nothing exists outside the universe.
But that doesn't mean it's true, remember science is falsifiable. Before Einstein there was no warping of space/time and no absolute speed of light. Under Newtons laws of motion acceleration can continue into infinity. But the theoretical physics of Einstein changed that. Just as QM changed the micro scales of physics, cosmology has the ability to change the understanding of the macrocosm of this universe and beyond.
Do you think theoretical physics is a religion?
If you do then Einstein was a preacher.