Abstract: Ludwig Boltzmann is a towering figure in the history of physics，widely known as the founder of statistical mechanics. The name Boltzmann is commonly associated with the Maxwell-Boltzmann distribution, the Boltzmann entropy formula, and the Boltzmann H-function, while Planck was said to be the one who first introduced the concept of energy quantum in 1900. In fact, the word “quantum” appears frequently in the papers of Boltzmann and Wien well before 1900. To the best of the authors knowledge, Boltzmann was the first to introduce the concept of energy quantization. In 1868, he quantized kinetic energy (vis viva) to address the problem of molecular collisions, thereby deriving the Boltzmann principle of statistical mechanics. In 1872, Boltzmann derived the Maxwell distribution by employing the concept of energy quantization, and in 1877, he noted that the quantized energy must be counted from zero. Boltzmanns ideas and research methods profoundly influenced the subsequent development of physics; the brilliance of his thought is evidenced in the work of physicists such as Planck, Sommerfeld, Einstein, and Born over quantum theory..

Key words: Ludwig Boltzmann, Statistical mechanics, Collision, Maxwell’s law, Quantum, Energy quantum