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Named after an Austrian Physicist Christian Doppler (1803-1853), it’s defined as the change in frequency of a wave for an observer moving relative to the source of the wave. The objective of this paper/experiment is to determine the Earth’s Velocity using Doppler shift. In Laboratory set up, an artificial source of light and a moving object may be used. The hypothesis, tested by other Quantum physicists (Hubble and Buys Ballot) later, they confirmed that the sound’s pitch was more than the frequency emitted when the source of sound approached and vice versa when the sound source receded. This is characterized by short wavelengths when the source is receding and longer wavelength when the source is approaching.
Relationship between Doppler effect and Earth’s Velocity
In astronomy it’s extensively used to determine the velocity factor in line-of- sight of a planet, star or galaxy in relative motion. (Hubble-1853) was the first to use Doppler Effect in measuring the velocity of distant galaxies.
The motion of a planet causes a shift of received wavelengths. While the Doppler Effect is dependent to the external property of the planet’s motion space relative to the observer, the pattern of lines formed are not independent to the internal physics of the planet itself. In Hubble’s Law Hubble argued that to determine the velocity of a moving galaxy-relative to the observing person, one has to multiply the Hubble Constant H (some use speed of light as Hubble’s constant)- H = 5 x 104ms-1Mpc-1, and the distant covered by the moving planet(Earth). The distant covered is determined by the shift of wavelength %u2206λ = λ new- λ static, where λ new is the observed wavelength and λ static is the wavelength you would have observe if earth was not moving.
The velocity of the Earth thus can be determined by multiplying the Hubble’s constant with the distant covered (scaled in reference to the distant of Earth from Sun) by the moving object as observed from the artificial source of light. In real life application, it is witnessed when an emergency car (ambulance, sheriffs van or train) passes you with its siren blaring and the tone that you had heard changes in pitch. It’s also used in Industrial chemistry, radars and satellite.