The Waves.docx

On July 17, 1998, three huge waves – "tsunamis" – up to 15 meters high struck the north coast of Papua New Guinea, killing at least 2,200 people. A major earthquake, itself consisting of waves traveling through the Earth, triggered an underwater landslide that created the tsunamis. Radio stations reported the disaster by transmitting electromagnetic radio waves to listeners around the world. Listeners were able to hear the news transported by sound waves created by their radios. Waves of one form or another can be found in an amazingly diverse range of physical applications, from the oceans to the science of sound. Put simply, a wave is a traveling disturbance. Ocean waves travel for thousands of kilometers through the water.Earthquake waves travel through the Earth, sometimes bouncing off the core of the Earth and making it all the way back to the surface. Sound waves travel through the air to our ears, where we process the disturbances and interpret them.

Ancient wave theories Much of our current understanding of wave motion has come from the study of acoustics. Ancient Greek philosophers, many of whom were interested in music, hypothesized that there was a connection between waves and sound, and that vibrations, or disturbances, must be responsible for sounds. Pythagorasobserved in 550 BCE that vibrating strings produced sound, and worked to determine the mathematical relationships between the lengths of strings that made harmonious tones. Scientific theories of wave propagation became more prominent in the 17th Century CE, when Galileo Galilei (1564-1642) published a clear statement of the connection between vibrating bodies and the sounds they produce. Robert Boyle, in a classic experiment from 1660, proved that sound cannot travel through a vacuum.Isaac Newton published a mathematical description of how sound travels in his work Principia (1686). In the 18th Century, French mathematician and scientist Jean Le Rond d'Alembert derived the wave equation, a thorough and general mathematical description of waves, which laid the foundation for generations of scientists to study and describe wave phenomena.