# Doppler Effect (Simplified)

Topics: Big Bang, Universe, Redshift Pages: 3 (1013 words) Published: June 9, 2013
Doppler Effect Predicts the Future of Universe

Have you ever observed a speeding Car? What do you observe of the Sound it produces? The Sound of the Car increases as it approaches you, takes highest peak when close to you, and recedes as it speeds away from you! Why do you hear a varying sound level as the car speeds by you? Couldn’t have the sound been at constant level? Wondering what makes the sound behave like that?

Sound is a disturbance caused in a particle medium, which is propagated in the form of High Particle Concentration Region or Contraction and Low Particle Concentration Region or Rarefaction. During propagation, the distance between two Rarefactions or two Contractions determines the sound intensity. Intensity of sound increases with the reduction of this distance. The sound velocity is determined by the rate at which the disturbances are propagated, which again depends on the nature of the medium. In air medium, a sound wave travels at about 333.3m/s. Sound is a particle property and hence travels much faster in a denser medium. The sound intensity depends on the time taken by one Rarefaction/Contraction to create another Rarefaction/Contraction in air. This time brings about a distance between them that defines the intensity. Traveling at higher velocities means reduction of this defined distance. At higher velocities, the second wave of disturbance is made to follow close to the first wave. How does this happen?

After the first disturbance has been released, the wave travels away from the source at a velocity of about 333.3 Km/h. Let’s say that the normal distance between each Rarefaction and Contraction is 2 metres. The intensity is maintained if this distance is constant. Let’s assume that the car is to release a new wave after each released wave has travelled 2 metres, and travel itself for a metre. When the car releases the second wave, how far is it from the first wave? Is it one metre or two metres? When the car releases the...