The universe is spread out as a space time warp, we know from Doppler effect or the red shift that distant stars and galaxies are moving farther away from us. Moving ever further in a rapidly expanding universe to where? If everything was expanding further away then we would not even exist because matter would become extremely rare with vast areas of empty space between us which is not the case because looking from a bigger perspective everything seems to exist forever in perfect harmony. So expanding it is but not like a balloon in every direction. The direction cannot be outward - that brings us to the question what is the boundary of the universe which we know does not exist because that conclusion would nullify the assumption itself - that if there is a boundary then what is beyond? That also answers the question about the expanding universe - the expansion is happening in another dimension which is not yet understood by us. Probably it is simultaneously expanding and 'turning' inwards in another dimension just as anything sucked into a black hole emerges out the other end. We know black holes are spread out across the entire universe and within its vicinity all your laws of physics fail as time itself gets trapped inside its intense gravitational force.
Thus scientists continue to design new models to help explain seemingly paradoxical observations. This theory of a 'hologram' fits well with many observations however, to my knowledge it does not explain time completely, meaning it only explains in one area of the observable universe but not all areas. As I said earlier the universe is dotted with entire galaxies spread out across aeons of space. Any attempt at explain the 'entire universe' is bound to be fruitless.
No-one know how, if at all the universe is expanding or otherwise. Sure, peeking through a 'scope and applying the basics of scientific research with calculations and definitive answers from what is witnessed, based on those calculations is given as an answer, but only within the concept of 'what is, and what isn't' possible in the 'still primitive' clever minds of our top scientists.
The 'Big Bang THEORY' is just that, a theory. OUR universe is not ours, there would have been matter existing to create a Big Bang, therefore it is NOT a beginning of anything, it is only an assumption of possibilities..... based again on the miniscule knowledge and understanding by Earth's scientists of how little we know about the centre of our being, The Universe.
When any article is published on any subject, look for the word 'could' in the article, many people miss it and take the article as fact, as you may see or hear weather reports, "It COULD rain, snow, be hotter than hot tomorrow."
Assuming is useless.......we want the facts, if they are not available .... we will wait until they are available and act accordingly.
Mankind COULD be on Mars by the year 2020, why, the Martians left and went to a better planet......40 million years ago.