The astrophysical phenomenon of a jet outflow of gas and dust from the nuclear disk of spiral galaxies, which for a long time escaped the attention of astronomers, is discussed. This phenomenon plays an extremely important role in the surrounding us cosmic world. Without taking it into account, it is impossible to understand and adequately explain both the spiral structure and the nature of the evolution of galaxies, as well as the processes that are observed today and occurred in Solar System and on Earth in the distant past. The author has constructed a model of the spiral structure of optical galaxies, which takes this phenomenon into account for the first time. Using the example of the galaxy M 31, the existence of spiral branches of mechanical and electromagnetic physical nature in spiral galaxies has been proven. The history of the jet outflow phenomenon discovery is instructive and dramatic. It was known to people in ancient times, but was later forgotten. In newest times, this phenomenon was de facto discovered in our Galaxy in 1900 by Ja. Kapteyn based on the motion of stars close to Sun. In 1928, J. Jeans attempted to theoretically explain this phenomenon based on a constructed gas-dynamic model. However, little was known about galaxies in those years, and astronomers recognized the works of Kapteyn and Jeans as erroneous. But long before that, back in 1812, the paleontologist Je. Cuvier drew attention to the “catastrophic” consequences of this phenomenon for Earth. In the second half of the 20th century, the jet stream phenomenon could have become a firmly established fact more than once, but it so happened that over last 40 years the author had to prove and study this phenomenon using astronomical and geological data. The results of these studies are summarized in the book: Barenbaum (2002), and then in its second edition: Barenbaum (2010) This article is a translation into English of the first chapter of both monographs. Although its text was written more than 30 years ago, today the significance of the constructed spiral model of galaxies has increased many times over. In support of this, we provide a reference to the work (Barenbaum, 2023), in which an adequate spiral model of Galaxy is constructed taking into account geological data.