What is 5 feet beyond the edge of the than the universe?

This concept is very difficult for most humans to understand but the is no edge.

Most astronomers believe the universe is flat and extends infinitely in all directions. The observable universe, that which we can see, extends about 13.5 billion light years in all directions.

But here is the problem. When astronomers look at the most distant galaxies which lie about 13 billion light years away what they find is that those galaxies are speeding away from us at almost the speed of light. That all by itself means there is another 13 billion light years of universe we cannot see. That is, that galaxy 13 billion light years away is where is was 13 billion years ago. And where it is traveling near the speed of light away from us means it sits about 26 billion light years away. Astronomers cannot say that there are not more galaxies at 14, 15, or 16 billion light years away but because of their distance their light has year to reach the earth.

Five feet beyond the edge of the universe cannot be determined because the edge of the universe itself is not well defined, and the idea of being "beyond the edge of the universe" is speculative and poorly defined within the context of our current understanding of cosmology.