Empty Relations

My mother had a boyfriend who explained to me that everything is at its heart just empty space. The universe is mostly empty space between galaxies, galaxies mostly empty space between stars and planets, matter mostly empty space between molecules and atoms, atoms mostly empty space between the electrons and the nucleus... At each level of scale there seems to be a great deal of empty space however the scale below is conceived of as full. Galaxies full of stars, a glass full of water, a memory full of pain. The conceptualization of an amalgamation of smaller elements in space-time abstracts away the empty space between them. It seems we give great significance to the elements rather than their circumstances and interrelation. It might be argued that all that we perceive are relationships. Relationships of previously perceived relationships. Patterns of patterns. Perception itself is a relationship. What is at the deepest level and what is at the highest level? The alpha and the omega? Can anything exist without its opposite? Should I say "be perceived" rather than "exist?" Is it all just waves on a sea of empty space?