Collision phenomena can be ordinary like a rain drop impacting onto a window, a leaf or a puddle, or extraordinary such as a meteorite or a bolide collision with Earth. Some are frequently encountered in science and everyday life, others are extremely rare. Being very different at first sight, collision phenomena in liquids and solids share many underlying common features.

The subject of the present book is highly cross-disciplinary with a very wide scope of applications in mind, and such a collection of topics in one book does not yet exist, as to our knowledge. One of the main motivations for providing such a collection of topics is to underline the commonality among the various occurrences of collision phenomena, which lead to similar physical and technological ideas and modeling approaches. An improved in-depth understanding of the phenomena can be expected after recognizing the common underlying physics involved. A second motivation is that the knowledge presently available on the subject is extremely widely scattered, mainly according to applications, and in a large number of different journals. For example, collisions in the solid mechanics context are considered as a totally different subject than impacts in the fluid mechanical context, whereas in reality inevitable geometric similarities dictate inevitable kinematic similarities, and in some cases similar rheological behavior, which greatly unifies these two fields to the extent still unrecognized by the majority of practitioners. This obscures the true state of the art, with the associated danger that research may be unintentionally and unnecessarily duplicated or some novel developments delayed.

A further motivation can be found in the rapid progress made over the last decade in this field, partly attributed to the much improved means for visualization of collision phenomena with high-speed cameras. In this respect the proposed book is timely. There is sufficient material to justify a concise and coherent collection of recent advances, which may also help initiate further research in a complementary manner.

Our personal research experience covers and spans practically all the topics covered in the book, which is a monograph significantly based on our own results published in peer-reviewed journals over the last 20 years.