Final answer:
The change in light wave frequency due to the universe's expansion would result in a red shift for objects moving away and a blue shift for those approaching, confirming the Doppler effect through observations of distant galaxies.
Step-by-step explanation:
When observing light waves from a source moving together with the universe, we would see a change in light wave frequency due to the Doppler effect. If the source is moving towards an observer, the light waves will appear to have a higher frequency and a shorter wavelength, a phenomenon known as blue shift. Conversely, if the source is moving away, the light waves will seem to have a lower frequency and a longer wavelength, known as red shift. In the universe, when we observe distant galaxies that are moving away from us, we typically see this red shift, which has been used to estimate the age of the universe at approximately 14 billion years.
The Doppler effect also applies to gravitational influence, where light escaping a strong gravitational field will appear red shifted, due to a longer wavelength and lower frequency, a phenomenon called gravitational redshift. All these observations are cornerstone evidence supporting the Big Bang theory.