Chapter 3: The Relation of Physics to Other Sciences

Physics serves as the foundational science underlying all natural phenomena, providing the fundamental principles that govern every other scientific discipline through atomic and molecular interactions. The relationship between physics and chemistry demonstrates this interconnection most clearly, as quantum mechanics explains the rules governing chemical reactions, while statistical mechanics analyzes the random thermal motion of atoms to understand thermodynamic processes in both inorganic and organic systems. In biological sciences, all life processes ultimately reduce to atomic movements, from nerve function through ion transport across cellular membranes to the complex biochemical machinery within cells. Enzymes, large protein molecules that catalyze reactions by reducing activation energy barriers, exemplify this molecular basis of life, while DNA's double helix structure encodes genetic information through complementary base pairs that direct protein synthesis. The mechanism of DNA replication is well understood, but the precise genetic code translation from nucleotide sequences to amino acid arrangements at ribosomes remains biology's central unsolved problem. Astronomical observations reveal that stellar compositions mirror terrestrial elements, determined through spectroscopic analysis of starlight, while nuclear fusion processes converting hydrogen to helium provide stellar energy and synthesize the heavier elements comprising planets and living organisms. Earth sciences demonstrate physics applications through geological instruments, though fundamental processes like volcanism, mountain formation, and seismic activity remain poorly understood due to the unsolved physics problem of turbulent fluid flow analysis. Psychology presents unique challenges where memory formation involves unknown physical changes in nervous systems, highlighting the distinction between scientific approaches and non-empirical methods like psychoanalysis. This interdisciplinary perspective emphasizes that natural phenomena transcend artificial academic boundaries, requiring physics as the universal descriptive language of atomic and molecular behavior to comprehend all scientific observations and processes.