What if gravity is neither a fundamental force nor a curvature of space-time, but an emergent phenomenon, born of quantum and thermodynamic principles? What if the mysterious "dark matter" is not composed of exotic particles, but is ordinary baryonic matter in extreme states of quantum cold? In An Effective Theory of Quantum Gravity, researcher Rogelio Pérez Casadiego presents a revolutionary proposal: the Effective Theory of Quantum Gravity (NETQG), a new vision of the cosmos that challenges established paradigms and offers a coherent, falsifiable, and deeply physical reinterpretation of some of the greatest enigmas of modern science. Through an innovative theoretical framework, the book introduces the central concept of the effective gravitational velocity (vg), a parameter that explains phenomena such as the gravitational redshift, the perihelion precession of Mercury, and the time delay in GPS systems-without resorting to the curved geometry of general relativity. Furthermore, NETQG offers a radical alternative to the standard model of dark matter: it proposes that what we observe as "invisible mass" could be ultracold matter, such as Bose-Einstein condensates or ionic crystals, whose light is neither emitted nor absorbed, but is refracted, generating gravitational illusions detected in events such as the Bullet Cluster. This book combines scientific rigor with a bold vision, exploring deep connections between quantum mechanics, thermodynamics, and cosmology. It also analyzes promising technological implications, from quantum gravity sensors to interplanetary communications, and compares NETQG with other theories such as General Relativity and MOND, highlighting its predictive advantages and unifying potential. Aimed at scientists, students, and readers interested in the limits of physical knowledge, An Effective Theory of Quantum Gravity is more than a theoretical work: it is an invitation to rethink the ultimate nature of the universe, from a perspective where physics, reason, and the contemplation of cosmic order converge in a profound search for truth.