* Longer Wavelengths, Redder Colors: As the wavelength of light emitted from an object *increases*, it shifts towards the red end of the visible light spectrum. This is called a redshift.
* Shorter Wavelengths, Bluer Colors: Conversely, a decrease in wavelength shifts the light towards the blue end of the spectrum, known as a blueshift.
* Doppler Effect and Motion: The change in wavelength is caused by the Doppler effect. This effect describes how the frequency (and therefore wavelength) of waves changes when the source of the waves is moving relative to the observer.
* Moving Away: When an object is moving *away* from Earth, the light waves it emits are stretched, resulting in a longer wavelength and a redshift.
* Moving Towards: If an object is moving *towards* Earth, the light waves are compressed, resulting in a shorter wavelength and a blueshift.
In summary: When the wavelength of spectral light emitted from an object increases, it moves towards the red end of the visible light spectrum, indicating that the object is moving *away* from Earth.
