Since ancient times, its existence, human minds have tried to grasp the essence of the world, the laws of nature, the history of their own origin and destiny in the universe.This desire was generated entirely different picture of the world at different times and in different parts of the world: the personification of natural elements with the divine, the idea of the struggle of darkness and light in the Persian Zoroastrianism, the Creation and the Apocalypse in Judaism and many others.
However, the actual germ of rational-scientific knowledge of the world is considered to be a breakthrough, the perfect thinkers of ancient Greece.So, one of the most important concepts of Aristotle was the introduction of the concept of "emptiness", full of emptiness - the space where nothing exists.The idea of emptiness was the philosopher frightening phenomenon, but, in his opinion, and impossible in nature.After all, the empirical data available then the person could not disclose the concept of absolute vacuum, and all space is filled with ordinary air.For example, if a hollow tube to try to blow the air, its wall will shrink.That is, there will be within not only the voids but also the space itself.And the water in the pipes always rises behind the piston, preventing the void.
experience Torricelli: description
The idea that the world can not be spaces that are not filled with liquid, solid or gaseous substance, successfully live up to modern times - the era of human thought and scientific achievements.It was then that people are once again regained their faith in the possibility of a practical and rational knowledge of the world.Torricelli experience, however, was not only the result of scientific research, but also the chance.During the construction of fountains in the palace of one of the famous Dukes of the Medici dynasty, it was observed that the water piped really rises to fill the void, but only to a certain height and then stops its movement.This fact could not generate interest in the birthplace of the Renaissance.
For explanations appealed to the well-known at that time (and even more famous now) physics and mathematics to Galileo Galilei.However, he did not find an acceptable answer in logic, I decided to resort to the experimental way.Experiments have been instructed to put two of his disciples - Torricelli and Viviani.Interesting results reached second.Experience Torricelli assumed premise in a glass tube of a volume of mercury (it is heavier than water, because showing a demonstrable results with small volumes of capacity) so that there did not get air.The upper end is sealed, and the open bottom was placed into the cup with mercury.It was found that mercury is also not fill the entire space of the tube, leaving a certain amount of top voids.However, the empirical knowledge did not immediately get their theoretical justification.
Explanation experience
experience Torricelli soon became known throughout educated Europe, where scientists have argued about the nature of this phenomenon.Explanation fact gave himself Evangelista Torricelli.Since the closed glass tube on top of the air above the mercury was not, he explained that the height of mercury is determined by the air pressure literally mercury in the cup, causing it to go more into a glass tube.For the first time experimentally it opened the atmospheric pressure.Torricelli's Law states that the pressure corresponds to the height of mercury: P = P atm mercury.Further research caught the Frenchman Blaise Pascal, expressed in the number of dependent on the severity of the height of the column of air at a given moment, thus giving humanity the ability to define atmospheres.pressure.
