There is a challenge involving a lemon floating in a jug of water which seems impossible to beat. I've noticed it in several pubs of Edinburgh.
The challenge is as follows:
- There is a jug half filled with water.
- Floating in the water, there's a lemon. The lemon doesn't touch either the bottom nor the edges of the jug.
- The challenge is to successfully balance a coin on the lemon.
- Modifying, moving, or more generally touching the lemon are not allowed.
Any attempt to balance a coin on the lemon seems to result in the lemon flipping over, and the coin to sink in the water.
Why is it so hard to balance the coin while it's extremely easy to balance a coin on a lemon set on a table? How do you beat the lemon challenge?