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).
Waves are a means of transferring energy, without actually transporting matter. Waves can be either transverse or longitudinal. Transverse waves can be set up on a string or on the surface of water. For this type of wave, the disturbance is at a right angle to the movement of the wave. Longitudinal waves can be set up on a spring, in the air when a sound wave passes, or in heavy traffic.