According to some hypotheses, the forces of gravity are slowing down the rate of expansion and, eventually, will bring it to a stop. At that time the universe will begin to contract, falling in upon itself and returning to the infinitely small point that existed before the "Bang." This contraction will take just as many years as did the expansion.
Then what? Will there be another "Big Bang"? Will the entire cycle repeat itself, including creation of new worlds and inhabitants?
If so, then how many times has this cycle been repeated in the past? And how many other "universes" are out there, perhaps 100 billion or more light years away?
Does this now restore the concept of the infinite in both time and space? The word universe, therefore, should be corrected, since ours is a finite system while "universe" is by definition infinite.
So, try as we might, we can never actually reach the horizon of our knowledge. The farther we travel in pursuit of knowledge, the farther will our horizon recede, forever.