Human Migration

Imagine finding a spray-painted handprint on a cave wall. Over thousands of years, a thin, glassy layer of minerals, like limescale in a kettle, grew on top of it. Scientists used a high-tech laser to analyze that mineral layer. By measuring the natural radioactive decay of elements within it, they figured out the layer is about 71,600 years old. Since the handprint is underneath that layer, it must be at least that old, with the most conservative estimate being 67,800 years. This makes it one of the oldest pieces of art ever found and proves that the early humans who lived on this Indonesian island, who had to cross the ocean to get there, were creating symbolic art.