Please try again later. Ahmed Rashid, former Pakistani revolutionary, journalist and an expert on Taliban, explains why Pakistan is in a such a mess. He lists the factors that led Pakistan to the situation it is in right now.lease try again later. Ahmed Rashid, former Pakistani revolutionary, journalist and an expert on Taliban, explains why Pakistan is in a such a mess. He lists the factors that led Pakistan to the situation it is in right now.
Body waves travel through the interior of the Earth. On the other hand, surface waves propagate only at the interface between two different media, like the interface between Earth and atmosphere (i.e. the surface of the Earth).Body waves are of two types: Primary waves (also called P-waves, or pressure waves) and Secondary waves (S-waves, or shear waves).n the other hand, surface waves propagate only at the interface between two different media, like the interface between Earth and atmosphere (i.e. the surface of the Earth). Body waves are of two types: Primary waves (also called P-waves, or pressure waves) and Secondary waves (S-waves, or shear waves).
Wave (physics). The general term applied to the description of a disturbance which propagates from one point in a medium to other points without giving the medium as a whole any permanent displacement. Waves are generally described in terms of their amplitude, and how the amplitude varies with both space and time.