Yes, the Doppler Effect applies to all wave phenomena, including those that do not require a medium for propagation, such as electromagnetic waves and gravitational waves. The Doppler Effect describes the change in frequency (or wavelength) of a wave as observed by an observer moving relative to the source of the wave.
In the case of sound waves, which require a medium to propagate, the Doppler Effect is commonly experienced. As an object emitting sound waves moves toward an observer, the waves are compressed, resulting in an increase in frequency and a higher pitch. Conversely, when the object moves away from the observer, the waves are stretched, resulting in a decrease in frequency and a lower pitch.
For electromagnetic waves, such as light, the Doppler Effect also applies. When an object emitting light moves toward an observer, the waves are compressed, resulting in a shift towards higher frequencies (a "blue shift"). On the other hand, when the object moves away from the observer, the waves are stretched, resulting in a shift towards lower frequencies (a "red shift"). This effect is used in various fields, such as astronomy, to determine the motion and velocity of celestial objects.
Gravitational waves, which are ripples in the fabric of spacetime caused by massive objects in motion, also exhibit the Doppler Effect. As gravitational waves propagate through space, their frequency can be affected by the relative motion of the source and the observer. If the source of gravitational waves is moving towards the observer, the waves will be compressed, resulting in a higher frequency. Conversely, if the source is moving away, the waves will be stretched, resulting in a lower frequency. This allows scientists to infer information about the motion and properties of the objects that generate gravitational waves.
In summary, the Doppler Effect applies to all wave phenomena, regardless of whether they require a medium for propagation or not. It describes the observed change in frequency or wavelength of a wave due to relative motion between the source and the observer.