I only have limited knowledge of relativity and quantumphysics but as far as I know, the uncertainty principle relates the uncertainty of space and momentum of a particle. Einstein however, explained that space and time are tied together and the real fabric of the universe is spacetime through which all objects navigate.
It feels as if space uncertainty should therefore be spacetime uncertainty. Is this wrong? Can it be that you know the position of a particle but not the exact time when it was there, and that that gives rise to uncertainty in momentum? If so, wouldn't this be a more elegant way to express the uncertainty principle?
Googling for "spacetime uncertainty" gives papers that go far over my head. While my math is good, we barely touched on quantum mechanics in physics.