A Cosmic Ruler Made of Seventeen Lenses
A lamp is hidden behind a large aquarium filled with water. You see not one light source but several reflections and refractions — the water bends the path of the rays.
The Navigator Who Recalculates the Route on the Fly
A navigator with a paper chart plots the route before setting sail. If the ocean changes—the current shifts, the wind picks up—the chart stays the same. The ship follows an outdated path, and the crew has to correct the course by hand.