Aliens miniaturize you and place you on a fresh Cheerio floating on milk. You are a few millimetres away from another Cheerio. They give you the option of taking them up on a challenge, “We will give you $1 million if your Cheerio does not touch the other Cheerio; otherwise, we will remove your hand.” Do you accept the challenge?
Answer
Do not take the risk. Milk rises between two nearby Cheerios by capillary action. The surface tension of the milk has a horizontal component that will pull your Cheerio to the other one like an irresistible magnet (try the experiment in the safety of your own cereal bowl.)