The nature of matter and the universe and their behaviors have been discussed for many years, and based on these discussions, many unanswered questions have been arisen. The current scientific theory holds that light has a dual wave-particle nature, and its speed is limited to a constant, c. There are two contradictory views of behavior of light - and separately, neither of these views thoroughly explains the phenomena of light. In this paper, a new particle called "M Particle" is presented. Based on this theory and an experiment conducted by the author, in this part, brief explanations for a number of phenomena, including motion, light, thermal wave, electricity, magnetism, radio wave, bending of light near massive objects, redshift and blueshift, photoelectric effect, and dark matter are presented. It is concluded that the laws of motion need to be defined based on the concept of the motion of momentum and not in reference to the motion of an object as Newton defined. In addition, it also concluded that light is a wave of motion of momenta which are conveyed by an ensemble of M particles that acts harmonically and propagates throughout space. Light waves are longitudinal waves similar to sound waves. Furthermore, the experimental results indicate that the speed of light, c, is not constant. Thus, the theories of Special and General relativity are denied.