Standard cosmology can answer almost nothing about how the structure of a galaxy is formed. Why the visible matters of a disk galaxy are distributed in a thin plane as opposed to how dark matter occurs in a spherical distribution is a critical open question. In a paper recently published in Reports in Advances of Physical Sciences, Dr. Nagao offers a promising theory of galaxy formation. Simulations by the Energy Circulation Theory, which are characterized by the force working on momentums, produced galaxy shapes such as disk, double–disk with or without spiral arms, ring, barred ring, and barred arm galaxies as well as bulge and bar–bulge forms.