- Why does the sound of an ambulance or car engine seem to change as the vehicle passes by?
- Why do we hear a loud bang when a supersonic jet flies by?
- What does all this have to do with the Big Bang?
I’d like you to do me a favour. This is especially important if you’re in a public place, surrounded by lots of strangers.
I’d like you to imitate, out loud and at a significant volume, the sound of a racecar going by.
The noise you made probably sounded something like, “weeeeeeeeEEEEEOOOOOOOooooo”. It’s a fairly common sound effect, one most people can perform even if they’ve never attended a car race. But why does it sound like that? Why does the car’s engine go from a higher pitch to a lower one as it passes us by?