Editing Doppler Ball (section)

===Short Explanation===

Sound is a type of '''''Wave'''''. Sound waves are compression waves, which means they travel through matter, like air, by making pockets of high and low pressure. Sound waves travel pretty fast, but we can hear the difference in how fast an object is moving by listening to how the sound coming from it changes. When the ball is traveling towards you, the sound waves are ''slightly closer together'', which increases the pitch you hear. The opposite is also true; when the ball travels away from you, the sound waves are ''slightly farther apart'', which decreases the pitch. This change in pitch is known as the '''''Doppler Effect''''', which states that the sound you hear from a source can have a different pitch if the source is getting closer or farther from you.

The Doppler Effect also applies to Astronomy, since it is an effect that happens with all waves! With light, we call it the '''''Redshift/Blueshift Effect'''''. If you are observing a distant star, it might appear red even if the star isn't red. This means that the star is moving away from us, so the light waves coming from it are ''slightly farther apart'', making it appear more red! likewise, if the star is moving towards us, the light waves might appear ''slightly closer together'', which would make it look more blue!