Here's a breakdown:
* Doppler Effect: This is a phenomenon where the frequency of a wave (like light) changes depending on the relative motion of the source and observer. Imagine a siren approaching you. The sound waves compress, making the pitch higher. As the siren moves away, the waves stretch out, lowering the pitch.
* Redshift: When a light source is moving away from an observer, the light waves are stretched out, causing the wavelength to increase. This shift towards longer wavelengths makes the light appear redder, hence the term "redshift."
* Implications: Redshift is a crucial tool in astronomy. It allows us to:
* Determine the distance to galaxies and stars.
* Measure the expansion of the universe.
* Study the motion and evolution of celestial objects.
Important Note: The Doppler effect applies to sound as well as light. However, with light, the effect is more pronounced because light travels at a constant speed, whereas sound speed varies in different mediums.
