This book contains a new and complete theory on Gravity, formation of Galaxies and Light along with explanations that will change the way we perceive Gravity. The special curves like cycloid and helix used to depict Gravity is only due to the motion of the heavenly bodies and proves why inertial mass is equal to Gravitational mass. The new approach to find acceleration due to Gravity leads to new values of “g’ for heavenly bodies. This value leads to new interpretation of atmospheric conditions that depends on “g”. Here, an attempt is made to describe the atmospheric conditions of other planets due to this variation. This book contains Chapters on Formation of Galaxies, explanation for rotation curve of the Galaxy without the need of dark matter or energy, and a new theory combining the dual nature of light into a mono nature of light particles in a wave motion. It also contains a chapter on U-Craft, which is a flying object that uses directional centrifugal force to fly, unlike conventional space shuttle which uses thrust. It can be made for locomotion on the ground and also when required it can lift off and fly. This makes the U-craft suitable for low altitude flying as well as vertical lift and landing with minimum floor space surrounding disturbances even on other planets. This new principle in U-Craft can be used to make voyages to planets in new the Space age.