Hey there, future physicist! 🌌 Let's dive into the Doppler effect, a fascinating phenomenon you can observe every day – whether you know it or not! You may not be an Austrian scientist like Christian Doppler, but after reading these notes, you'll be one step closer to understanding the magical world of physics.

• Definition: The Doppler Effect (also known as the Doppler Shift) is the change in frequency or wavelength of a wave in relation to an observer.
• Real-life Example: Ever heard an ambulance siren approaching and noticed that the pitch of the siren seemed to change as it passed by? The sound seemed high-pitched as the ambulance approached, and then lower-pitched as it moved away from you. That, my friend, is the Doppler Effect in action!

• How it Works: The Doppler effect occurs because the frequency of a wave depends on the relative speed between the source of the wave (e.g., the siren on an ambulance) and the observer (that's you!).
• Sound & Light: The Doppler effect isn't just limited to sound. It can occur with any type of wave, including light. A French scientist named Amand Fizeau even extended this phenomenon to the spectral shifts in light from stars.