Coins are supposed to sink. When you toss ‘em in a fountain, they drop right down to the bottom, right? Not always. There’s a trick that can actually make metal coins float.
The surface tension of water is just strong enough to keep an aluminium coin afloat if you’re know what you’re doing, with some key extra ingredients. Grant Thompson illustrates how it’s happening with coins, paper clips, dish soap, and chilli flakes in the video below.