This is the additional part to the already submitted paper "The PRODUCTION and TRANSITION of ENERGY from the SOURCES to EM WAVES. DECODING the PLANCK CONSTANT. The MEANING of SYSTEM’S MASS, and the TRANSITION of ENERGY, NOT MASS" FRAGMENTS from my NEXT BOOK CHAPTER 2. MATTER – MASS and its PROPERTIES: WEIGHT, VELOCITY and ENERGY

In order to solve the problem of motion, it is necessary to separate the concept of mass from the concept of weight and decide when the mass bears weight. There isn’t any weight within any system: pressure due to the spatial volume of the systems exists, but the weight is absent. In the own outer space of any celestial body, any freely falling body acquires an acceleration of space and gets the weight relative to the acceleration of that space, if we neglect the presence of atmosphere. Forces never generate alone but only in their interaction. A motion of two relative units of matter interacts with a definite force.We can use such notions as a space and time only as a result of the motion. Space and time are interconnected entities and they make sense according to a certain motion of the matter only.