Convergence of the Planes

Imagine a number of discs being spun around a thin metal rod. Each one spins at a slightly different pace so no single disc is following the same orbit. However, every so often, seemingly at random, the orbits of the individual discs line up with one another. For a very brief moment in time, each disc falls into perfect sync with the others before falling out of sync again.
In addition, the discs oscillate in their vertical separation from each other, stretching farther apart and squishing closer together like a spring. These oscillations tend to coincide with how "in sync" the discs orbits are.
This is the nature of the Planes of Existence, with each disc representing a distinct plane and the rod representing the Planar Spires: great towers of pure mithral that can be found on every major Plane.
When the Planes orbits fall into sync and approach in proximity, the "borders" between each is blurred and the Planes overlap. This is often a time of chaos on the Material Plane; supernaturally strong storms sweep the land, volcanic activity increases, strange creatures appear seemingly out of nowhere, and careless wanderers are liable to find themselves on a wholly new Plane of Existence.
But despite the potential for calamity a Convergence comes with, it is a natural and necessary aspect of existence. Much like a forest fire burning away dead matter to make way for new life, Convergence's are believed to have done much for the biodiversity of the Material Plane. In addition, it is believed that the movement of the Planes is what powers the magical Weave that permeates all of existence, allowing all manners of magical effects to be wrought by those who know how to pluck its strings.
However, were something to artificially alter the natural motions of the Planes, the effects could be disastrous. Adding or taking away momentum from this Planar Dance could cause the Planes to collide violently rather than gently oscillating. The ramifications of this can only be guessed at, but such an event would likely be apocalyptic for all living beings not just on the Material Plane but on all Planes.