It's nice to see a few of the more obvious absurdities of the spacetime paradigm summed up in such a succinct little paragraph. Shoot your laser beam in any direction you choose and space will simply expand at the speed of light to make sure it can't escape the universe. Hmmm!?? Gravity curves spacetime right back on itself so that the observer observes his earlier self. Hmmm!?? The space between widely separated galaxies is expanding at a speed faster than lightspeed, whereas it expands at a lesser speed for those which are closer together. Hmmm!??Wilson wrote:One way of thinking about space, in the sense of spacetime, is that it is not possible for anything to ever go outside the space of our universe. Shoot a laser beam in any direction at all, and it can never leave the universe. In the early universe, it would have been theoretically possible, I believe, for an exploding star to send out light in all directions, and after a finite time, some of that light that didn't encounter an obstacle would return to an observer on what's left of that star. The theoretical observer would see his earlier self, very faintly. This is, I assume, due to the effect of gravity curving spacetime. At this point, you could send out a beam of light and even if it didn't run into something it wouldn't return, because space is expanding at a speed faster than light.
These are just a sample few of the embedded inconsistencies which a spatial universe casts up and physics is utterly unable to resolve them. These notions can only be expressed in the language of mathematics, which is an infinitely versatile tool which can be used to model any pre-existing paradigm. However if the pre-existing paradigm is a dodgy one, then the equations which are devised to model it are nothing more than nerds playing clever games. The 26 dimensions (at last count) of M theory are an excellent case in point. Just because the sums look pretty this doesn't mean we live in a 26 dimensional universe and luckily even the M theorists themselves are not willing to suggest that we do. Maths can only be used to model a paradigm of reality, not to define the paradigm itself. In the case of spacetime this important qualification seems to have been overlooked.
Regards Leo