In physics, the dynamics modified, or briefly MOND., the hypothesis that tries to reform the law of gravitation, etc., please rotate the Galactic explain. In galaxies، the speed of rotation of stars and gases around the center of the galaxy is uniform, which is inconsistent with the prediction of Newton's universal law of gravity. The law stipulates that distant objects should rotate at slower speeds. It's like a solar system where farther planets orbit the sun at a slower pace.< < > this hypothesis was proposed in 1983 by Moti Milgram to model these results.< < > he states that Newton's law of gravity is only enlarged when the acceleration of gravity is sufficiently large and needs to be modified for very small accelerations. This theory states that under such conditions، acceleration is not linearly proportional to the applied gravitational force and has a nonlinear relationship.< < > this hypothesis stands in contrast to the more popular hypothesis of dark matter, which attributes abnormal observations to the existence of an unknown type of matter in galaxies that differentiates the mass distribution in galaxies from The which is observed only with the usual mother. In this approach dark matter alone and without the need to modify the law of gravity.it justifies uniform acceleration in galaxies.