From ancient times of its existence, human minds have tried to comprehend the essence of the surrounding world, the laws of nature, the history of their own origin and destiny in this universe. This desire gave rise to completely diverse pictures of the world in different eras and in different parts of the planet: the personification of natural elements with a divine principle, the idea of the struggle between darkness and light in Persian Zoroastrianism, the creation of the world and the apocalypse in Judaism, and much more.
However, the breakthrough made by the thinkers of ancient Greece is considered to be the real germ of rational-scientific knowledge of the world. So, one of the most important concepts of Aristotle was the introduction of the concept of "emptiness", complete emptiness - a space where nothing exists. The idea of emptiness was a frightening phenomenon for the philosopher, however, in his opinion, it was impossible in nature. After all, the empirical data then available to man could not reveal the concept of absolute vacuum, and all ordinary space is filled with air. For example, if you try to blow air out of a hollow tube, then its walls will shrink. That is, not only emptiness will remain inside, but also the space itself. And the water in the pipes always rose behind the piston, preventing the formation of a void.
Torricelli experience: description
The notion that there can be no space in the world that is not filled with liquid, solid or gaseous matter, lived successfully until the New Age - the era of human thought and scientific achievements. It was then that people regained their faith in the possibility of practical and rational knowledge of the world. Torricelli's experience, however, was not only the result of scientific research, but also of chance. During the construction of fountains at the palace of one of the dukes of the famous Medici dynasty, it was noticed that the water actually rises through the pipes, filling the resulting void, but only to a certain height, after which it stops moving. This fact could not but arouse interest in the homeland of the Renaissance.
For explanations, they turned to the well-known at that time (and even more famous today) physicist and mathematician Galileo Galilei. However, he, not finding an acceptable answer in logic, decided to resort to an experimental path. The experiments were entrusted to two of his students - Viviani and Torricelli. The second one achieved interesting results. Torricelli's experiment involved placing a certain volume of mercury in a glass tube (it is heavier than water, therefore it shows more visual results with small volumes of the container) so that air does not get into it. In this case, the upper end was sealed, and the open lower end was placed in a cup with mercury. It turned out that mercury also did not fill the entire space of the tube, leaving a certain amount of emptiness on top. However, this empirical knowledge is not immediatelyreceived their theoretical justification.
Explanation of experience
Torricelli's experience soon became known throughout enlightened Europe, whose scientists argued about the nature of such a phenomenon. The explanation of the fact was given by Evangelista Torricelli himself. Since there was no air above the mercury in the glass tube closed at the top, he explained that the height of the mercury column is determined literally by the air pressure on the mercury in the cup, forcing it to go more and more into the glass tube. Atmospheric pressure was discovered experimentally for the first time. Torricelli's formula stated that this pressure corresponds to the height of the mercury column: P atm=P mercury. Further research was picked up by the Frenchman Blaise Pascal, who expressed in numbers the dependence of the height of the column on the gravity of the air at a particular moment, thus giving mankind the opportunity to determine atm. pressure.
