Crisis in Modern Physics

A concept put forward by French mathematician and physicist Poincaré in his book The Value of Science in 1905. It referred to a typical mistaken view of some natural scientists, due to the deep-rooted metaphysical thinking pattern, towards the overall development of physics and even the whole natural science. This erred view came into being since some natural scientists did not understand materialist dialectics, and thus could not correctly understand and explain the dialectical development process for a relative truth to become an absolute truth. This view was quite typical at the end of the 19th Century and the beginning of the 20th Century, consequently Lenin regarded it as a key point of the critique in the Chapter 5 of Materialism and Empirio-Criticism.

Chapter 8 of Poincaré’s The Value of Science was titled as the “Present Crisis of Mathematical Physics”. Poincaré argued there were mainly three development periods of and two “crises” in physics from Newton’s era to the end of 19th century and beginning of 20th century. He named the first period “the physics of central forces”, which meant that due to the brilliant achievements of Newton’s mechanics, after the law of Newton was put forward, some physicists attempted to explain all phenomena and effects by applying the theory of the interaction among massive bodies, i.e., all bodies follow a uniform linear motion, and the magnitude of forces change inversely proportional to the square of the distance. However, it was later discovered that this theory could not explain some phenomena, especially thermal and electromagnetic ones. Therefore, Poincaré argued physics encountered the first “crisis”, and it entered the second development period highlighting summarization and a series of basic laws and principles. Poincaré enumerated five basic principles in this chapter: Carnot’s principle (the principle of the degradation of energy), the principle of relativity, Newton’s principle, Lavoisier’s principle (the principle of the conservation of mass), and Mayer’s principle (the principle of the conservation of energy). In his opinion, due to new and more drastic development of physics, these principles were “overthrown” one by one, consequently physics encountered the second “crisis” and entered the third stage of development. Poincaré’s so-called “crisis of modern physics” refers to the second “crisis” in the development of physics. In essence, as the nature itself is developing dialectically, consequently with the continuous improvement of human practice and understanding levels, people’s understanding of the objective world is also expanding and deepening. People’s understanding of the objective world has the characteristic of dialectically developing from relative truth to absolute truth. In other words, with the strengthening of practical capability and deepening of their understanding, people’s previous cognition encounters a process of constant enrichment, modification, supplement and development. If all previous cognitions are rigidly evaluated and regarded as the golden rule and as the “last word” in science, then once new facts, phenomena and laws are discovered which can no longer be forcibly incorporated into the old framework, such state of affairs will be regarded as the “overthrow” of the old principles. Then, it will be bound to come to the conclusion that the old situation has encountered a crisis, just as Poincaré pointed out.

Lenin pointed out that the so-called crisis of modern physics was neither a crisis in the development of physics itself, nor a crisis which materialism has encountered in the development process of physics. According to Lenin, the essence of the “crisis” was nothing but “the materialist theory of knowledge, instinctively accepted by the earlier physics, has been replaced by an idealist and agnostic theory of knowledge, which against the wishes of the idealists and agnostics, has been taken advantage of by fideism”. Lenin firmly argued that “The basic materialist spirit of physics, as of all modern science, will overcome all crises, but only by the indispensable replacement of metaphysical materialism by dialectical materialism.”