The Dynamics of Particles and of Rigid, Elastic and Fluid Bodies

Excerpt from The Dynamics of Particles and of Rigid, Elastic, and Fluid Bodies: Being Lectures on Mathematical Physics The science of Dynamics may be variously classified. In by far the greater number of universities in both Europe and America it is dealt with by professed mathematicians, and is properly considered an essential part of mathematical discipline. Nevertheless it is but an application of mathematics to the most fundamental laws of Nature, and as such is of the highest importance to the physicist. The whole of modern Physics experiences the attempt to "explain" or describe phenomena in terms of motion, with conspicuous success in the departments of Light, Electricity, and the Kinetic Theory of Gases. It is therefore evident that no one can expect to materially advance our knowledge of Physics who is ignorant of the principles of Dynamics. It is nevertheless to be feared that this subject is often slighted by the physical student, partly on account of its difficulty, and partly because of the fact that the many excellent treatises on Dynamics existing in English address themselves chiefly to the mathematician, and often seem to lay more stress on examples in analysis or trigonometry than on the elucidation of physical laws. The aim of this book is to give in compact form a treatment of so much of this fundamental science of Dynamics as should be familiar to every serious student of physics (and in my opinion no less should suffice for the student of mathematics). The classical English treatises usually fill one or even two large volumes with one of the subdivisions of the subject, such as Dynamics of a Particle, Rigid Dynamics, Hydrodynamics or Elasticity. The student confronted with the five volumes of Routh, the three of Love, and the large work of Lamb is likely to be appalled at the size of the task before him. It is practically impossible for the physical student, while spending the necessary amount of time in the laboratory, to road through all these or similar works, and thus his knowledge of the whole subject generally remains fragmentary. The great work of Lord Kelvin and Tait, while treating the whole subject, is far too difficult for most students, though it must ever remain a mine of information for those sufficiently advanced. This book has grown out of the lectures which I have given at Clark University during the last fourteen years primarily to my own students of Physics. It is obvious that it leads to no particular examinations, from which we in America are to a large extent fortunately free. The text is not interrupted by examples for the student to work, which are found in groat numbers in the usual treatises, and to which I could hardly add. The attempt has been made to treat what is essential to the understanding of physical phenomena, leaving out what is chiefly of mathematical interest.