This book contains complete new explanation for Gravity, Formation of Galaxies, Light, Heat and Black Holes along with other explanations that will change the way we perceive Gravity and Light. The special curves like cycloid and helix used to derive mathematically that acceleration produced (known as acceleration due to gravity) is only due to two velocities namely rotation and revolution of the heavenly bodies not due to any gravity force, which 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 the heavenly bodies of our solar system. This value leads to new interpretation of atmospheric conditions that depends on “g”. An attempt is made to describe the atmospheric conditions of other planets due to this variation. This book contains Chapters on Formation of Galaxies giving explanation for rotation curve of the spiral galaxy without need for dark matter or energy. It also gives new explanation for dual nature of light by describing it as particles in a wave motion combining both the explanation of wave and particle nature. In the same chapter new interpretation of spectra supports an evident that light indeed is a particle in a wave motion as an electron gets converted to electromagnetic radiations spread into space and which in turn gets converted back to an electron, when it falls on an Atom. It also contains chapter on Black holes describing it as just an empty space.