The theory of relativity, presented to the scientific community at the beginning of the last century, made a splash. Its author, A. Einstein, determined the main directions of physical research for decades to come. However, do not forget that the German scientist in his work used numerous achievements of his predecessors, including the famous principle of relativity of Galileo, the famous Italian scientist.
The Italian scientist devoted a significant part of his life to the study of mechanics, becoming one of the founders of such a branch of physics as kinematics. Galileo's experiments allowed him to come to the conclusion that there are no fundamental differences in the states of rest and uniform motion - the whole point is which reference point will be taken. The famous physicist pointed out that the laws of mechanics are valid not for any one chosen coordinate system, but for all systems. This principle has gone down in history asGalileo's principle of relativity, and the systems began to be called inertial.
The scientist with pleasure confirmed his theoretical calculations with numerous examples from life. The example with the book on board the ship was especially popular: in this case, relative to the ship itself, it is at rest, and relative to the observer on the shore, it moves. Galileo's principle confirms his thesis that there is no difference between rest and motion.
The principle of relativity formulated in this way by Galileo made a splash among his contemporaries. The thing is that before the publication of the works of the Italian scientist, everyone was convinced of the truth of the teachings of the ancient Greek scientist Ptolemy, who argued that the Earth is an absolutely motionless body, relative to which other things move. Galileo destroyed this idea, opening up new horizons for science.
At the same time, neither Galileo's principle of relativity nor the law of inertia should be idealized. After all, based on this formulation, we can conclude that all these provisions are absolutely valid for any parameters of speed and distances between bodies, but this is not so. The first step from the doctrine of Galileo-Newton to the theory of relativity was the development by Gauss, Gerber and Weber of the theoretical foundations of the phenomenon, which was called "potential delay".
Neither Galileo nor Newton, due to the level of knowledge that existed at that time, could evenguess that when the speed of a body approaches the speed of light, the laws of inertia simply cease to operate. And, in general, Galileo's principle of relativity is ideal only for those systems that consist of two bodies, that is, the influence of other objects and phenomena on them is so insignificant that it can be neglected. Movement in such a system (an example is the rotation of the Earth around the Sun) was later called absolute, all other movements were called relative.
