Harmonics Theory is a fundamental theory of the universe based on the consequences of non-linearity of physics laws that predicts the structure of the universe. Because of non-linearity, all standing waves produce harmonics (exact frequency multiples) that are in turn standing waves, and in 3D these waves also produce noticeable harmonics once they gain sufficient energy. This theory is an additional aspect of understanding things, just like quantum physics and general relativity. It is not in conflict with those theories, but it does suggest that the universe is vastly older than big bang theory says. For the first time we can understand why there are galaxies, stars, planets, moons, ... cells, atoms, nucleons and quarks. Harmonics Theory explains many previously inexplicable observations and correctly predicted many subsequently observed phenomenon.