When two particles are in the same exact spot as each other, the distance between them is exactly 0. The force of gravity they exert on one another is then undefined due to a division by zero. It only takes a single unit of Planck Time (the refresh rate of the universe) and both objects will be at the position (NaN,NaN,NaN), meaning they have became intangible. There is no getting them back, they are in the Intangible Void. It is likely that if anything winds up in the Intangible Void, their sudden NaN distance from everything else would cause the entire universe to get yanked into the Intangible Void and condensed into a singularity, as NaN squared is NaN, and dividing by NaN yields NaN. The entire universe can be destroyed by getting two particles to occupy the same exact spot in time and space. Good luck getting them to do so, though. Also, chances are, God must have put something in place to prevent something like this, knowing that someone among us is probably going to abuse this mathematical hole to wipe everyone out.