# Eight Lectures on Theoretical Physics

COLUMBIA UNIVERSITY IN THE CITY OF NEW YORK

PUBLICATION NUMBER THREE

OF THE ERNEST KEMPTON ADAMS FUND FOR PHYSICAL RESEARCH

ESTABLISHED DECEMBER 17th, 1904

**EIGHT LECTURES**

**ON THEORETICAL PHYSICS**

DELIVERED AT COLUMBIA UNIVERSITY

IN 1909

BY

MAX PLANCK

PROFESSOR OF THEORETICAL PHYSICS IN THE UNIVERSITY OF BERLIN

LECTURER IN MATHEMATICAL PHYSICS IN COLUMBIA UNIVERSITY FOR 1909

TRANSLATED BY

A. P. WILLS

PROFESSOR OF MATHEMATICAL PHYSICS IN COLUMBIA UNIVERSITY

NEW YORK

COLUMBIA UNIVERSITY PRESS

1915

CONTENTS.

First Lecture. | Introduction. Reversibility and Irreversibility |

Second Lecture. | Thermodynamic States of Equilibrium in Dilute Solutions |

Third Lecture. | Atomic Theory of Matter |

Fourth Lecture. | Equation of State for a Monatomic Gas |

Fifth Lecture. | Heat Radiation. Electrodynamic Theory |

Sixth Lecture. | Heat Radiation. Statistical Theory |

Seventh Lecture. | General Dynamics. Principle of Least Action |

Eighth Lecture. | General Dynamics. Principle of Relativity |

PREFACE TO ORIGINAL EDITION.

The present book has for its object the presentation of the lectures which I delivered as foreign lecturer at Columbia University in the spring of the present year under the title: “The Present System of Theoretical Physics.” The points of view which influenced me in the selection and treatment of the material are given at the beginning of the first lecture. Essentially, they represent the extension of a theoretical physical scheme, the fundamental elements of which I developed in an address at Leyden entitled: “The Unity of the Physical Concept of the Universe.” Therefore I regard it as advantageous to consider again some of the topics of that lecture. The presentation will not and can not, of course, claim to cover exhaustively in all directions the principles of theoretical physics.

The Author.

Berlin, 1909

TRANSLATOR'S PREFACE.

At the request of the Adams Fund Advisory Committee, and with the consent of the author, the following translation of Professor Planck's Columbia Lectures was undertaken. It is hoped that the translation will be of service to many of those interested in the development of theoretical physics who, in spite of the inevitable loss, prefer a translated text in English to an original text in German. Since the time of the publication of the original text, some of the subjects treated, particularly that of heat radiation, have received much attention, with the result that some of the points of view taken at that time have undergone considerable modifications. The author considers it desirable, however, to have the translation conform to the original text, since the nature and extent of these modifications can best be appreciated by reference to the recent literature relating to the matters in question.

A. P. Wills.

This work is in the **public domain** in the **United States** because it was published before January 1, 1923.

The author died in 1947, so this work is also in the **public domain** in countries and areas where the copyright term is the author's **life plus 70 years or less**. This work may also be in the **public domain** in countries and areas with longer native copyright terms that apply the **rule of the shorter term** to foreign works.