FILL IN THE BLANK (pls help) When a vibrating object is moving **(toward, away from, alongside)** an observer, the measured frequency of the vibrations will be lower than if the object and observer are both stationary. If the vibrating object is moving **(toward, away from, alongside)** an observer, the measured frequency of the vibrations will be higher than the actual rate of vibration of the object. When a star is moving towards an observer on Earth, the light spectrum of the star will appear **(redshifted, blueshifted, the same)** compared to the light spectrum of the sun, which is considered to be in Earth's frame of reference.