Seismic Waves are the waves (of energy) caused by sudden explosion or breaking of rocks within the earth. This is the energy that travels through the earth and gets recorded by the seismographs.

The fastest kind of body wave is called P wave or primary wave. The P wave can move through solid rock and fluids. It pushes and pulls the medium it moves through, just as sound wave pushes and pulls the air. Usually we feel the rattle and the bump of this wave. The second type of body wave is the S wave or the secondary wave. This is the second wave we feel in an earthquake.This moves rocks up and down or side to side.

Professor Goree will discuss how do we know that the earth's core is molten. he will describe how geologists can listen to the sound from distant earthquakes.One kind of sound is blocked by liquids like the molten core of the Earth, while another kind is not. He will also demonstrate a way to visualize sound in air so that we can actually see that sound consists of a wave.