Nature Of Physical Constants

Based on nature, the fundamental constants are grouped into three categories namely-

• A: Characteristic of a particular system. (Characteristic of light)
• B: Characteristic of a class of physical phenomena. (Characteristic of electromagnetic phenomena)
• C: Universal Constants. (Discovered after the discovery of special relativity)

Few Physical constants can take the dimensional form like – the speed of light; in contrast, few are dimensionless like- fine structure constant. Some physical constants are material constants which means they possess constant value for a material.

A constant can be expressed using multiple equivalent units like – SI, natural units, atomic mass unit, CGS units etc. Some physical constants are redefined by fixing the SI values. But this certainly increases the uncertainty in the value of physical constants.