The subject of wave phenomena is well-known for its inter-disciplinary
nature. Progress in this field has been made both through the desire to
solve very practical problems, arising in acoustics, optics,
radiophysics, electronics, oceanography, me- teorology and so on, and
through the development of mathematical physics which emphasized that
completely different physical phenomena are governed by the same (or
similar) equations. In the immense literature on physics of waves there
is no lack of good presentations of particular branches or general
textbooks on mathematical physics. But if one restricts the attention to
pulse propagation phenomena, one no- tices that many useful facts are
scattered among the various books and journals, and their connections
are not immediately apparent. For example, the problems involv- ing
acoustic pulse propagation in bubbly liquids and those related to
electromagnetic pulses in resonant media are usually treated without
much cross reference in spite of their obvious connections. The authors
of this book have attempted to write a coherent account of a few pulse
propagation problems selected from different branches of applied
physics. Although the basic material on linear pulse propagation is
included, some topics have their own unique twists, and a comprehensive
treatment of this body of material can hardly be found in other sources.
First of all, the problem of pulse propagation in non- equilibrium media
(unstable or admitting attenuation) is far more delicate than it is
apparent at a first glance.
