Walking Though Walls

Mass Without Substance

If an atom were the size of the Thomas and Mack Center, the nucleus would be the size of a grain of salt and the electrons would be the size of dust specks flying around the nucleuswhere the walls are !! Thus, we are composed of almost 100% empty space !! Since there is so much empty space and thesubatomic"particles" are really just probability or standing waves, not solid matter, why can't we just walk through walls or doors ?