The Big Bang Theory (BBT) is currently widely accepted. The theory explains the expansion of galaxies by the action of "dark energy", a mysterious force that repels matter and causes space to expand at an accelerating rate. Within galaxies, the action of gravity prevails over the force of "dark energy" and no expansion occurs. This situation motivates the search for alternative physical interpretations based on verified observational data.A new physical interpretation of gravity is proposed to complement existing cosmological models. The theory is formulated both as a phenomenological framework and as a microscopic description explaining gravitational interaction at the atomic level. The proposed approach is constructed as a connected sequence of known physical phenomena, each of which has experimental confirmation. This provides a physically grounded basis for interpreting gravitational interaction across scales.A distinctive feature of the theory is its emphasis on the physical mechanisms underlying the formation and action of the gravitational field, while mathematical modeling is treated as a secondary descriptive tool. The theory offers a possible physical interpretation of the formation of cosmic structure driven by gravity alone. According to the proposed framework, gravitational interaction may manifest itself as either attraction or effective repulsion depending on the physical state of interacting matter. Within this interpretation, the observed expansion of the Universe may be described without invoking hypothetical forms of energy such as dark energy.