Mystery #3Tier 2sound / waves
Why does a siren drop in pitch as it races past you?
An ambulance speeds towards you and its siren wails at a high, urgent pitch. The instant it passes and tears away, the very same siren suddenly sounds lower and sadder, even though the driver hasn't touched a thing. The siren never changed its note. So what did?
Your guess
What's your hunch about why the pitch drops the moment the siren passes you?
There's no single magic word to type, have a go in your own words, then reveal the answer to see how close you got.
Make a guess to unlock the hints and the answer.