Current mathematical models of the universe involve what is termed 'hyper-dimension."
Ever read the book Flatland? It describes how a 2-dimensional being would perceive the intersection of a 3-dimensional object in "their" universe.
A Flatlander would never be able to comprehend a sphere. As a sphere intersected with their Flatland, it would first appear as a point, then a line, and shrink back to a point, and again disappear. All the Flatlander would "see" is a point, then line (of variable length), and then a point. Try as they might, Flatlanders running around with their instruments of measurement would never be able to comprehend what a sphere is.
God Itself could reveal to a special Flatlander what a sphere was, but even then would a Flatlander be able to really know what a sphere was?
By analogy, our 3-D universe is equally bound. String-theory requires 11 dimensions (as I recall)...and Relativity theory starts off with 64 dimensions (with mathematical simplifications, reduced to 17 [as I recall]). [I expect some corrections on this ]
The point being: Is it unimaginable, or inconceivable, that there is hyper-dimensional life?