The surface of the Earth does not have an edge.
The expansion of the universe was NOT from a single point going outward. That is a misunderstanding. The expansion happens *everywhere*.
Did I mention the earth? Or anything spherical?
"The Big Bang Theory is the leading explanation for how
the universe began. Simply put, it says the universe as we know it started with an
infinitely hot and dense single point that inflated and stretched — first at unimaginable speeds, and then at a more measurable rate — over the next 13.8 billion years to the still-expanding cosmos that we know today."
The expantion was outward from that dense point as well as inside(objects getting further apart) as it expanded.
The stone in the pond....expantion was outward from that point where the rock hit as well as inside the ripples(objects getting further apart) as it expanded.
Edit... Oh! Forgot my joke...
"A man was found dead inside a old rock silo. They think he ran himself to death looking for a corner to pee in"