PLANCK, MAX. - LAST STEPS TOWARDS QUANTUM THEORY.

Ueber irreversible Strahlungsvorgänge. (+) Nachtrag. (Beide:) (Für die Annalen bearbeitet vom Verfasser). (+) Bemerkungen zu einer Abhandlung über Thermodynamik des Hrn. K. Wesendonck. (+) Entropie und Temperatur strahlender Wärme.

Berlin, Johann Ambrosius Barth, 1900 a. 1901. Bound in one contemp. hcalf. Raised bands, gilt spine. Spine a bit rubbed. (1900) and the issue (1901) unbound. In: "Annalen der Physik", Vierte Folge, Band 1. a. Bd. 6, 12. Heft. VIII, 792 pp. + 3 folded engraved plates.(Bd. 1). + Halftitle and Titlepage to Bd. 6 and pp. 661-876 a. 1 plate (Heft 12).(Entire volume offered and entire issue offered). Planck's papers: pp. 69-122; 621-624;719-737 a. pp. 818-831. A stamp to margins of halftitle and titlepages. Internally clean and fine.

First edition of these four fundamental and highly influential Planck-papers in which he defines his concept of entropy and heat radiation and hereby ANTICIPATES HIS FAMOUS SEMINAL PAPER OF 1900 which redefined physics and took it to the 20th century. - The first two papers "Ueber irreversible Strahlungsvorgänge" were rewritten for the "Annalen" and was first introduced in "Sitzungsberichte d.k. Akad. Wissensch. zu Berlin", 1897-1901.

"By invoking the hypothesis of natural radiation Planck not only succeeded in obtaining a relation between the energy of the resonator and the intensity of radiation for a given wavelength or frequency, but also in defining the entropy of radiation by a proper expression such that the change of the total entropy was always a positive quantity". (Mehra, Jagdish. The historical development of quantum theory, 2001, p. 36). These results found in the period 1894-00 culminated in the present paper "Ueber irreversible Strahlungsvorgänge" and for the first time incorporates the concept of natural radiation and made a purely electromagnetic definition of entropy and of temperature.
"Entropie und Temperatur strahlender Wärme" is pivotal for understand how Planck reached his conclusions in "Zur Theorie des Gesetzes der Energieverteilung im Normalspectrum" and "Ueber des Gesetzes der Energiverteilung im Normalspectrum" (PMM 391) where by using the first two laws of thermodynamics first described by Rudolf Clausius and Ludwig Boltzmann Planck outlined the Quantum Hypothesis that energy from atom can be quantized. Planck established a connection between Wien's formula (Ueber die Energievertheilung im Emissionsspectrum eines schwarzen Körpers, 1896) and the analytic expression of the thermodynamic function. This paper represents a purely thermodynamic approach to the study of the properties of the radiation field which was fundamental in reaching the famous conclusions in his 1900- and 1901-paper.

Akademie No. 41, 42, 43, 50.

Order-nr.: 47461