Great Galileo: the principle of relativity and mechanical transformation

The great Italian scientist and naturalist Galileo Galilei had an enduring historical influence on the development not only of specific sciences: physics, mechanics, astronomy, but also developed some fundamental principles for the development of science as a whole, Galileo's principle of relativity, Galileo's transformation had a significant influence on the formation of the present picture of the world.

The scientific motivation for the discovery by Galileo of the principle of relativity was the question of the fidelity of formulas reflecting the acceleration of the motion of bodies. As is known, in the absence of acceleration in the motion of the system relative to some other reference frame, the acceleration of the body, relative to both of these systems, will be constant.

Since earlier, according to Newton's laws, it was argued that it is precisely the acceleration that is the main parameter describing the kinematics of bodies (Newton's law 2), then the forces can be dependent only on the position and magnitude of the velocities of the bodies. Galileo questioned this dependence on the grounds that in this case all equations of mechanics would take the same form in any of the reference frames. The assertion advanced by Galileo, the principle of relativity, asserts that the laws of mechanics can not depend on the system in which they are examined by us. This principle can be more simply represented in the following way.

For example, if we conduct an experiment simultaneously in two rooms, where one moves relative to the other, the result of our experiment will be the same for both rooms.

The requirements formulated by Galileo, the principle of relativity, were perceived as a postulate. Along with the laws of Newton, these conclusions of Galileo, as well as its transformation, had a significant influence on the development of mechanics as a science.

The transformations of Galileo in the field of mechanics also practically changed many of the prevailing ideas about mechanical processes. In particular, the laws of transformation of coordinates that occur during the transition from one reference frame to another assume the same time, and therefore the notion of "absolute time" is advanced. In this case, what Galileo claimed, the principle of relativity, appears as a special case of the Lorentz concept, and is applicable only for small velocities (relative to the speed of light, of course).

It should be said that before Galileo the physicist was practically universally studied according to the works of Aristotle, in them metaphysical ideas about nature and man were affirmed. With regard specifically to physics, Aristotle, for example, argued that the speed of the fall of the body is directly proportional to its weight and that any movement occurs only as long as it is affected by an "incentive". Galileo refuted these conclusions and formulated the correct ones, which reflect the true processes of the fall and the dependence of velocity on the mass of the body when it moves.

The formulated mechanical principle of relativity of Galileo was first proposed in the book "Dialogue about two systems of the world". In the simplest presentation, it sounds like this: for objects that move uniformly, this movement does not affect only those objects that do not participate in this movement. This statement allowed the scientist to completely refute some of the postulates of astronomical heliocentrism, which stated that the mere fact of the Earth's rotation affects the course of events that occur on it.

What Galileo maintained, the principle of relativity, its mechanistic transformations, philosophical reasoning became the basis for the discovery of many laws of physics after the death of the great scientist. These include, for example, the laws of conservation of energy, the laws of pendulum swing and frequency distribution, he predicted and even introduced into circulation such a fundamental physical concept as the moment of force.