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Reexamination of the Doppler effect through Maxwell's equations
1Department of Natural Sciences, Queens University of Charlotte, 1900 Selwyn Avenue, Charlotte, North Carolina 28274, USA. guow@queens.edu
Summary
The Doppler effect arises from a moving electric dipole source in two stages. Source motion induces frequency oscillations in the far-field electric field, leading to the observable Doppler effect.
Area of Science:
- Electromagnetism
- Wave Physics
- Acoustics (analogous principles)
Background:
- The Doppler effect is a well-known phenomenon observed in wave propagation.
- Understanding the underlying physics of the Doppler effect for electromagnetic fields requires detailed analysis.
Purpose of the Study:
- To analyze the electric field emitted by a moving electric point dipole.
- To illustrate the fundamental physics governing the Doppler effect in electromagnetism.
Main Methods:
- Analysis of the electric field generated by a nonrelativistic moving electric point dipole.
- Investigation of the dyadic Green function for the electric field in the far-field region.
Main Results:
- Source motion induces an oscillation frequency in the dyadic Green function of the electric field.
- This induced frequency is the precursor to the observable Doppler effect.
- The Doppler effect is exclusively observable in the far-field region of the source.
Conclusions:
- The Doppler effect for a moving electric dipole is a two-step process.
- Far-field analysis is crucial for observing the Doppler effect in this context.
- This work provides a clear physical illustration of the Doppler effect mechanism.
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