In Chapter 6, the focus is on Max Planck and his contributions to the field of thermodynamics, particularly in the context of electromagnetic radiation. Unlike Gibbs and Einstein, who focused on mechanics and molecular thermodynamics, Planck dedicated his career to understanding the thermodynamics of electromagnetic radiation. Initially skeptical of the existence of atoms, Planck later accepted the statistical nature of entropy. In the late 1890s, he attempted to derive the Second Law from Maxwell’s equations, but this effort was incorrect, as Maxwell’s equations are time-reversible. Planck's later work led him to the concept of quantum mechanics and the realization that the Second Law is probabilistic rather than absolute. The chapter also discusses the properties of blackbody radiation, which was a significant area of study by the early 20th century. Blackbody radiation refers to the electromagnetic radiation emitted by a perfect absorber and emitter of light, known as a black body. Kirchhoff's law states that the ratio of emissivity to absorptivity of a black body is independent of the material properties. Stefan's law describes the total energy emitted by a blackbody as proportional to the fourth power of its temperature, and Wien's displacement law relates the wavelength of maximum radiation intensity to the temperature. Boltzmann's work further refined these relationships, showing that the energy density of blackbody radiation can be expressed in a specific form.In Chapter 6, the focus is on Max Planck and his contributions to the field of thermodynamics, particularly in the context of electromagnetic radiation. Unlike Gibbs and Einstein, who focused on mechanics and molecular thermodynamics, Planck dedicated his career to understanding the thermodynamics of electromagnetic radiation. Initially skeptical of the existence of atoms, Planck later accepted the statistical nature of entropy. In the late 1890s, he attempted to derive the Second Law from Maxwell’s equations, but this effort was incorrect, as Maxwell’s equations are time-reversible. Planck's later work led him to the concept of quantum mechanics and the realization that the Second Law is probabilistic rather than absolute. The chapter also discusses the properties of blackbody radiation, which was a significant area of study by the early 20th century. Blackbody radiation refers to the electromagnetic radiation emitted by a perfect absorber and emitter of light, known as a black body. Kirchhoff's law states that the ratio of emissivity to absorptivity of a black body is independent of the material properties. Stefan's law describes the total energy emitted by a blackbody as proportional to the fourth power of its temperature, and Wien's displacement law relates the wavelength of maximum radiation intensity to the temperature. Boltzmann's work further refined these relationships, showing that the energy density of blackbody radiation can be expressed in a specific form.