Introduction to Science and Technology Studies: An Overview of Dialectics of Nature

Author: Zhang Gongyao
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Publish Date: 2004-10-01
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The earliest studied field is the electromagnetic field, which was described by James Clerk Maxwell's electromagnetism in the mid-19th century. However, there was a major flaw in electromagnetism in the 19th century. According to this theory, it seemed that there was an asymmetry not derived from nature itself but from the theory of electromagnetism. Einstein introduced the concept of special relativity of space and time to overcome this theoretical difficulty. The study of the gravitational field began with Newton. However, Newton himself did not propose the concept of the "gravitational field." The study of gravity as a field began with Einstein's general relativity. Therefore, general relativity is essentially Einstein's theory of the gravitational field. In the 1930s, strong interaction force fields and weak interaction force fields were successively discovered. By then, humanity's concept of fields gradually became clearer. The fundamental manifestation of a field is radiation. Light is radiation, and heat is also radiation. Can the laws of thermal radiation be used to describe all fields that exist in the form of radiation? In 1927, Paul Adrien Maurice Dirac (1902—1984) published the paper "Quantum Principles of Emission and Absorption," which directly addressed this question. From this point on, the physics of all radiation problems attempted to move toward quantum field theory. Classical quantum field theory is quantum electrodynamics. Its greatest achievement is the prediction of the existence of antimatter and the conversion of matter-antimatter annihilation into energy. Quantum electrodynamics is limited to the dynamics of the electromagnetic field and electrons, which is somewhat inconsistent with the later discovery of quarks (particles smaller than neutrons and protons). Thus, quantum chromodynamics was further developed. Quantum electrodynamics primarily involves electromagnetic and weak interactions. Quantum chromodynamics primarily involves the strong interaction between protons in nature. The prospects for unifying these two theories are currently not very clear. However, there is one point that supports our understanding of fields as a universally existing form of matter. Quantum electrodynamics holds that, mathematically, an "absolute vacuum" does not exist; any space is filled with particles. A radiation field is merely a vibrational property of particles. The so-called vacuum state is simply the vibrational state of the lowest energy. According to Heisenberg's uncertainty principle, when a vibrational particle is in the lowest energy state, its positional uncertainty tends to infinity, and only when the particle is in an infinitely large momentum state does its positional uncertainty tend to zero. The mystery of the "absolute vacuum" lies in our inability to determine the positions of these vibrational particles. Quantum chromodynamics further points out that any field carries an electric charge and has the function of existing as a field source itself. In other words, any field can itself act as a field source to interact with things it touches. Therefore, a field is not only a form of matter but also a form of matter that can independently interact with surrounding things. There is a close connection between different components, with a rigorous and coherent logical structure. Different scientists and philosophers of science have different views on the structure of scientific theories. Thus, they have proposed different structures for scientific theories.