The sheer volume of published material on the subject is a testament to the difficulty of selecting topics

for inclusion in a chapter on damping. Viscoelasticity alone is the basis for several voluminous

engineering handbooks. The present chapter is purposely different from similarly titled chapters of other

reference books. There is little repetition of well-known and proven classical methods, for which the

reader is referred to excellent other sources, such as de Silva (2006) and Chapter 1 of the present

handbook. They provide solution techniques for many of the routine problems of engineering. The goal

of the present chapter is to provide assistance with problems that are not routine, problems that are being

encountered more frequently as technology advances. It is thought that this goal is best served by

revisiting fundamental issues of the physics responsible for damping.