History

• The discovery of the "wave" can be attributed primarily to a 19th century physicist named James Clerk Maxwell, who realized that electric and magnetic fields traveled through space in the form of waves. This became known as Maxwell's theory of electromagnetism.
  A contemporary of Maxwell's was a man by the name of Heinrich Hertz. Hertz was the first scientist who successfully proved Maxwell's theory of electromagnetism. Hertz designed a rudimentary radio that proved the existence of sound waves. From this successful experiment, Hertz was able to determine that light waves displayed the same characteristics as sound waves and could be transmitted in much the same way.
  Hertz's findings were instrumental in the creation of the radio, telegraph, telephone, and even television. His discoveries were so significant that a unit of frequency was named after him.
  
  

Significance

• Wave velocity has allowed scientists in the past century to make huge strides towards better understanding how various types of waves act and can be manipulated.
  Although astronomers and physicists have been trying to pinpoint the speed of light for hundreds of years, it is only in the last century that accurate measurements of the speed of light have been made. This is due in large part to scientists taking observations and data and applying it to the wave velocity equation.
  Probably the most famous physicist of all time, Albert Einstein, used wave velocity in his calculations and conclusions about various scientific problems, most notably his special theory of relativity which states that "the speed of light in a vacuum [empty space] is the same for all observers, regardless of their relative motion or of the motion of the source of the light."
  Because of Einstein's application of wave velocity to his special theory of relativity, we now know just how astonishingly fast light travels. For instance, a light wave could travel the circumference of Earth 7 times in 1 second.
  Scientists are still working on how to travel at or past the speed of light, but they have already figured out how to travel past the speed of sound.
  With the wave velocity equation, scientists realize that sound waves are relatively slow. For instance, we are used to seeing lightning before we hear thunder, but in actuality the two happen at the same time. We see the lighting first because light waves travel much faster than sound waves.
  Understanding wave velocity allows geologists to predict the epicenter of an earthquake and just how quickly the earthquake travels from this epicenter to other points on the globe.
  
  

Function

• Wave velocity shows us how fast or slow a wave is traveling in a given field. Wave velocity can show how we interpret and register different kinds of waves. For instance wave velocity can show why when we hold a prism at a certain angle, the light refracted from it can be multicolored even though the light going into it is one color.
  The way light passes through a prism is very unique. As Einstein proved in his special theory of relativity, light in empty space always travels at the same velocity with the same wavelength. When we put a prism in that space however, the light's wavelength changes because of a phenomenon known as refraction.
  When light comes in contact with an object such as a prism, that object acts to slow down and change the direction of a light wave. This can be seen especially when a prism is held up to the light. The light enters the prism at one speed, but the glass slows down the light's speed and essentially "breaks" that light up into separate colors. This is due to the geometry of a prism.
  All forms of waves and wave velocities can encounter and change due to refraction, but light is the most visible wave medium.
  
  

Identification

• Looking at the electromagnetic spectrum, one can see the velocity of different types of waves. In its simplest form, the electromagnetic spectrum shows the size and comparative speed of the different types of waves. Radio waves are the slowest and largest types of waves while gamma waves are the fastest and smallest. To give a comparative example, if you imagine radio waves are about the size of a football field, gamma waves would be smaller than the nucleus of an atom.
  
  

Types

• The movement of waves can be broken up into two main categories:
  A transverse wave is a wave in which the particles move perpendicular to the motion of the wave. In other words, the particles move vertically.
  A longitudinal wave is a wave in which the particles move parallel to the motion of the wave. In other words, the particles move horizontally.
  Sound waves are longitudinal waves. Waves traveling through a liquid such as water or gas are always longitudinal waves due to the ease at which waves can move in these mediums.
  Some of the most intensely studied waves and wave velocities are those emitted by earthquakes. The types of waves emitted by earthquakes are called seismic waves and can be measured by the use of a seismograph. The two main types of earthquake waves are body waves, which travel through solid ground and surface waves which travel through liquid.
  Body waves generally don't have the velocity and reach of surface waves because they encounter more dense resistance. Body waves from an earthquake can cause more localized property damage because they originate on solid ground.
  Surface waves move with a relatively quick velocity due to the lack of resistance. The biggest danger from surface waves emitted from an earthquake is tsunami. A surface wave from an underwater earthquake created the giant Indonesian tsunami in December 2004.