On the nature of fundamental physical constants

Abstract The present paper deals with various aspects of epistemologically diverse roles played by the fundamental constants in modern physics, cosmology and metrology. The primary aim of this contribution is to turn reader’s attention to some weak points in the current interpretations of these remarkable entities. The fundamental constants represent a rich blend of physical quantities of a very different nature, such as conversion factors, characteristics of certain micro-physical objects, free-space-related universal constants $$\hbar$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>ħ</mml:mi> </mml:math> and c or genuine dimensionless fundamental constants, as is the fine structure constant α. Since the numerical values of the fundamental constants are closely related to an arbitrary system of units used, a strong “objectivization” trend to construct a system of physical units, which would be free of anthropic elements, has thus appeared in modern physics. The Planck system of natural units, reputedly retaining its meaning for all times and civilizations, extra-terrestrial beings included, may serve as an example. This program was later completed by, among theoreticians very popular non-dimensionalization, which we critically analyse. Finally, a conceptually simple example of a typical conversion factor, the Boltzmann fundamental constant k , which is a key constant in statistical physics and thermodynamics, is discussed. In conclusion, the usefulness of the anthropic approach to the problem of fundamental constants is declared.