Hey guys and just to clarify, this question is directed more so in the sense of, “Is there an actual end to the universe?”
So, certain models (supported by experimental evidence) assume the Universe is infinitely big and has been for the 13.7 billion years since it sprang into existence. But language throws much confusion into the picture. We can only see part of the Universe, only within a sphere, cantered at Earth with a radius the distance light travels in the 13.7 billion-year age of the Universe.
Then there’s the, “Edge of the universe” theory?
The visible edge of the universe is, by definition, the most distant thing that we can see. That does not mean it is the most distant thing we can feel, however. According to astrophysicist Alexander Kashlinsky of NASA’s Goddard Space Flight Center, something from way beyond the edge seems to be pulling powerfully on galaxies in our universe, yanking them along in a motion he calls “dark flow.”
Kashlinsky and his team noticed this phenomenon while studying the cosmic microwave background, radiation left over from just after the Big Bang. Giant clusters of galaxies scatter the radiation in a way that makes it possible to determine how each cluster is moving. When Kashlinsky plotted those motions, he determined that the galaxies seem to be racing in a particular direction, roughly aligned with the constellation Centaurus. The phenomenon was so unexpected that he conducted an expanded survey, looking at more and brighter galaxy clusters.
In my opinion, we don’t really know what is at the edge of the universe or if it even ends, because if there is something there emitting light, it hasn’t had enough time to reach us. Say for example, that the universe is 20 billion light years in radius, and the universe has existed for 11 billion light years. Well, we have to wait another 9 billion light years for light from the edge to reach our planet (assuming that our planet is located at the center).
Every time you look at the night sky and the stars, you’re looking back in time. Every time you look at the sun, you are also looking back in time (it takes light 8 minutes from the Sun to reach the Earth). One important reason I wanted to find an answer to this question would be the problem with ‘entropy’, or the ultimate winding down of the universe. Entropy only holds in a closed, fixed system. But if the universe is infinite, or if outside matter and energy are somehow entering our universe, then entropy, or the ultimate, “heat death” of the universe doesn’t apply. In other words, the universe could go on existing forever.