In this book, describe the experiment of discovery of the origin of gravitation: the moving photons produce gravitation, meanwhile in this book also show that the essence of light is particle. For show this discovery is valid, apply this discovery calculate the spectrum line of all elements.In this book, describe the experiment of discovery of the origin of gravitation: the moving photons produce gravitation, meanwhile in this book also show that the essence of light is particle. For show this discovery is valid, apply this discovery calculate the spectrum line of all elements.