The Doppler Effect
When something that emits waves moves either towards you or away from you, the wavelengths and frequencies of the source appear different to when the source is stationary.
Blue shift = When something is closer to you, the wavelength seems longer and the frequency appears higher.
Red shift = When something is moving away from you, the wavelength seems shorter and the frequency appears lower.
It appears difficult, but really there's not much to learn!
End of this topic!
Drafted by Gina (Physics)