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.

Berlin, Johann Ambrosius Barth, 1900. Later full buckram. Stamp on verso of titlepage. Narrow inner margins (binding style with cords in margin). In: "Annalen der Physik", Vierte Folge, Band 1. VIII, 792 pp. + 3 folded engraved plates.(Entire volume offered). Planck's papers: pp. 69-122; 621-624;719-737. Internally fine and clean.

First edition of these 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".

"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.

Order-nr.: 49800