Mystery #4Tier 2sound and air
How does blowing across the top of an empty bottle make a note?
Find an empty glass bottle, hold it to your lips, and blow gently across the top. Out comes a low, hooting note, the kind of sound that belongs in a ghost story. You are barely doing anything, just puffing over a hole. So where is that spooky note actually coming from?
Your guess
What's your hunch? When you blow across the bottle, what is actually making that note?
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.