Alex mused, rubbing his chin even more vigorously, almost as though trying to feel the stubble that had yet to break through his skin.
'A droplet of water in the air or an air bubble in water—the interior, exterior, pressure difference, separation, and surface tension all play a role.
'A spatial dimension likewise has an interior, an exterior, and a boundary separating the two. This isn't necessarily a physical boundary, but rather a region where the properties of the interior interact and transition into those of the exterior, much like the interface between water and oil.
'As long as the properties of the two spaces—the interior and exterior—differ, natural conditions should give rise to a boundary. This boundary will persist until the difference is overcome and one space is absorbed into the other.
'Hence, in theory, I should be able to control the formation and shape of a boundary by influencing the properties of the interior or exterior regions.'
