What you’ll learn4 learning objectivesChoose one objective for a focused lesson, or study the complete topic.—C.5.1—Doppler effect• Nature of the Doppler effect for sound waves and electromagnetic waves.Syllabus objective—C.5.2—Doppler wavefront diagrams• Represent Doppler effect with wavefront diagrams for moving source or observer.Syllabus objective—C.5.3—Light Doppler approximation• For light at low relative speed: Δf/f = Δλ/λ ≈ v/c.Syllabus objective—C.5.4—Spectral line shifts• Spectral line shifts reveal motion of stars and galaxies.Syllabus objective