As a seismologist with extensive experience in the study of seismic waves, I can provide a detailed explanation regarding the behavior of P waves. P waves, or primary waves, are a type of elastic wave that can travel through solids, liquids, and gases. They are the fastest moving seismic waves and can move in all directions through a medium. When P waves encounter a boundary between two mediums with different elastic properties, such as a change from solid rock to liquid magma or vice versa, they can indeed be refracted. Refraction occurs when a wave changes direction due to a change in its speed as it moves from one medium to another with different elastic properties. The phenomenon you're referring to, where P waves change direction as they pass from the solid mantle into the liquid outer core and then back into the solid mantle, is a well-documented observation in seismology. This change in direction is crucial for understanding the Earth's interior structure, as it was one of the key pieces of evidence that led to the discovery of the Earth's liquid outer core. Similarly, when seismic waves, including P waves, travel through the Earth's crust and encounter different rock types with varying elastic properties, they are also subject to reflection and refraction. These wave behaviors are fundamental to the study of seismology and are used to analyze and interpret seismic data. read more >>

S waves cannot pass through the liquid outer core, but P waves can. When P waves pass from solid to liquid, then from liquid to solid, there are sudden changes in direction �C they are reflected and refracted. Seismic waves are also reflected and refracted as they pass into different rock types.read more >>