As far as research can determine, spheres only cease existing if the creator removes all methods of entry and exit.

Of course, there is debate over this, and the exact reasoning why - but, for the sake of you, as neophytes to the concept of spheres, we won’t get into that too much.  The general consensus is that if a sphere has no viable way to enter and exit it, it becomes disconnected from the framework of the Maquette and is destroyed.

No disconnected sphere has ever resurfaced, and researchers no longer perform this experiment as it effectively ends their existence and engagement with the universe.