Laboratory simulation of a process of galaxy spiral structure production (theory and experiment)

Laboratory simulation of the galaxy spiral structure production process is carried out. Consideration is given to a hypothesis that under velocity and density gradients in the gas galaxy disc hydrodynamic instabilities may be developed which exceed the gravitational ones as to the main parameters. A new predicted theoretically instability of shallow water rotating with a tangential velocity break, is detected experimentally. This instability is supposed to be responsible for the galaxy spiral structure production