Can there be such a thing as infinity if the universe isn't growing constantly? Or is it a finite universe? I tried to ask myself this but is it really possible to understand?
The notion of infinity boggles the mind, but maybe that is because our minds are conditioned by a temporal component since birth. Consider how the earth's rotation and revolution would instill in all earthly beings some concept of time. We observe time, or at least perceive that we do, all around us, always. We think, speak, and behave in coordination with space-time.
Consider that perhaps there is a dimension that transcends space and time. If space and time are subset to some extra dimension, then maybe that dimension exists without time at all; if so, then it is also true that we exist in that dimension -- though we may not intellectually perceive it.
The resulting premise is this: If time applies to all things in the space-time set and there is infinity, then there must be some additional dimension that is superset to space-time and so time does not apply to it.
For further thought, consider dark matter1:
Dark matter is a hypothetical kind of matter that is invisible to the entire electromagnetic spectrum, but which accounts for most of the matter in the Universe. The existence and properties of dark matter are inferred from its gravitational effects on visible matter, radiation, and the large-scale structure of the Universe.
Dark matter is hypothetical and only indirectly observed, yet it has been conceded that dark matter accounts for most of what we perceive as the universe. Our indirectly observing dark matter seems comparable to a 2-dimensional being that exists only on a flat plane observing a 3rd dimension of height indirectly through another entity's ability seemingly to transport to another perceived location via 3-dimensional movement.
Perhaps dark matter is of space-time's superset, and so we continue to struggle to understand it as we may only indirectly observe it; further, imagine our difficulty in observing it if time somehow does not apply to it. The 2-dimensional being may observe a third dimension indirectly, but likely would fail to describe that dimension in terms that transcend its 2-dimensional universe -- which, by the way, could well be the same universe as the one in which we exist.