# The invisible rotational motions of the universe, the solution for the problem of the accelerating expansion

Sometimes answering complex questions is much easier than it sounds. The telescopes always detect the increasing velocity for celestial objects that shows the cosmic acceleration. These observations have proven the experimental Hubble law that shows that the farther a galaxy is, the faster it is receding from Earth. In this article, we have derived this experimental law, the Hubble law, mathematically for the first time to prove that our theory (Saleh theory) is correct. By deriving the experimental Hubble law, we have proven that the universe has two motions: linear and rotational. The linear motion is the expansion of the universe with constant speed because of the residual energy of the Big Bang. However, it is not complete, and we also have rotational motion. Due to the absence of an external force in rotational motion, the angular velocity must also be constant. As the angular velocity is constant, the only variable factor that affects the tangential velocity is the radius. This means that the linear motion increases the radius, and in the rotational motion with constant angular velocity, the tangential velocity will increase. The telescopes observe the resultant velocity of these two types of motion but not only the linear velocity. Therefore, they always detect the increasing velocity for celestial objects that shows cosmic acceleration. Furthermore, we have shown that this theory could additionally solve the dark matter.