Throw a rock

into a pond and the ripples you produce will carry all the way to the edge, regardless of its size. Some of the energy will dissipate into the distant shore, given away as heat and sound from a collision that is never perfectly inelastic, but what’s left of that ripple will reflect, interacting with itself, and other ripples, and the complexities of the shoreline, until the next collision, and the process repeats. That ripple will still be measurable, on some level, a year from now. Some would say that the universe will end before it disappears completely.

One stone.