New Doppler Effect

Florian Ion Petrescu

Short description

The Doppler effect (or Doppler shift), named after Austrian physicist Christian Doppler who proposed it in 1842 in Prague, is the change in frequency of a wave for an observer moving relative to the source of the wave.

It is commonly heard when a vehicle sounding a siren or horn approaches, passes, and recedes from an observer.

The received frequency is higher (compared to the emitted frequency) during the approach, it is identical at the instant of passing by, and it is lower during the recession.

The relative changes in frequency can be explained as follows.

When the source of the waves is moving toward the observer, each successive wave crest is emitted from a position closer to the observer than the previous wave.

Therefore each wave takes slightly less time to reach the observer than the previous wave.

One proposes to study the Doppler Effect for the light waves, generally for the electromagnetic waves.

Author Bio

Nihil sine Deo Ph.D. Eng. Florian Ion PETRESCU Senior Lecturer at UPB (Bucharest Polytechnic University). Expert in Industrial Design, Engineering Mechanical Design, Engines Design, Mechanical Transmissions, Dynamics, Vibrations, Mechanisms Machines Robots and Mechatronics, Aircraft, Vehicles, Trains, Physics, Energy, Power, Nuclear Physics, Quantum, Atomic and Nuclear Fields. Association: Member ARoTMM - IFToMM, SIAR-FISITA, ARR. Languages known: -French; -English.