All prior posts in this Dark Matter series are summarized as follows: Spacetime Cavitation Summary Galaxies begin as regions of Spacetime Cavitation resulting from Universal Expansion, often taking on whirlpool-like shapes, which reflect the underlying curvature and motions of Spacetime itself, upon and within which they are formed (see image below). Matter has a counterpart within the realm of non-material Spacetime. When subjected to extreme cavitation, an applicable unit of Spacetime is converted into its material counterpart (mass and/or energy). Said another way: Matter is a byproduct of Spacetime Cavitation . This counterpart is almost always hydrogen and/or radiation. With respect to galaxy formation, hydrogen produced as a byproduct of Spacetime Cavitation, which generally lacks sufficient mass to coalesce into stars by reason of its own gravitation when sparsely distributed, instead reacts to the Gravity Well within which it was produced, spiraling and c...