Effective Range of Gravitation

It is generally believed that both gravitational and electromagnetic forces belong to macroscopic interactions. However, since the smallest unit of matter is impossible to be infinitely small, the gravity or electromagnetic force cannot be infinitely small too. When these two macroscopic interactions are less than a certain value, it can be considered that there is no longer any interaction. How to determine the interaction range of gravitation, this article mainly analyzes by using the Planck length as the smallest unit of spacetime. It is assumed that if the gravitational potential changes across spacetime of Planck length less than a certain energy value, it indicates that gravitational potential cannot cross the Planck length. The gravitation will disappear as a result. From this, it is inferred that the effective interaction range of the gravitational force is related to the size of the mass. According to the gravitational effective range of the sun, the gravitational effective range of the huge mass of the galaxy's center can be calculated, and then the diameter of the galaxy's core can be calculated.