Soumendra Nath Thakur
April 04, 2025
In 1899—well before the advent of relativity—Max Planck introduced Planck units, deriving fundamental quantities such as Planck length, Planck mass, Planck time, and Planck temperature. He achieved this through dimensional analysis, using the speed of light (c) from Maxwell's equations, the Planck constant (h) which he himself discovered, and Newton's gravitational constant (G).
His groundbreaking work on black body radiation, evident in his rugged appearance during those years, led to the formulation of the Planck Equation (E = hf) in 1900—a fundamental energy-frequency relationship of the universe. This equation later influenced Einstein’s derivation of the famous energy-mass relation (E = mc^2). However, the frequency-mass relationship and the broader energy-mass equivalence principle were already recognized by classical scientists well before Special Relativity was formulated in 1905.
