Could Galileo Discover the Law of Universal Gravitation in 1611, Was There Newton’s Apple and What Is “Modern Physics”?.

The central problem of the article is the paradox in the history of Newton’s mechanics: prominent researchers of the genesis of the Principia did not believe Newton’s words about the origin of the idea of universal gravity. They did not believe that he could have come up with this idea as early as 1666, considering circular orbits, and believed that Newton invented the story of the falling apple. The article proposes a “subjunctive” scenario leading to the law of universal gravity and feasible at the level of Galileo’s knowledge and skills in 1611. The basis for such a scenario is the description of a thought experiment in Newton’s manuscript “The System of the World”, preceding the creation of Principia. The proposed reconstruction helps to consider and clarify the concept of “modern physics”, the birth of which was the main event of the Scientific Revolution of the XVI–XVII centuries. The traditional understanding reduces the essence of modern physics to a reliance on experience and on the language of mathematics. Such a definition, however, is not sufficient. The geometry of Euclid and the physics of Archimedes were mathematically perfect, and their axioms were based on objective experience. Despite the importance of the tools of mathematics and experiment, the key innovation of modern physics has become the belief in the hidden fundamental laws of the Universe and in the right of the researcher to invent invisible, “illogical”, “absurd” concepts and postulates, experimentally verifiable only together with the theory based on them. This postulate of fundamental cognitive optimism combines bold ingenuity with a humble need for empirical verification.