Quantum laser pointers brings you the infamous double slit experiment right in the palm of your hand. In 1801 English physicist Thomas Young performed this experiment to determine if light was a particle or a wave. A laser shines a coherent beam of light through a film disc containing two parallel slits. Light striking the wall behind the slits producers a classic interference pattern. This surprising result means light passes through the parallel slits not as particles but as waves. When the peaks of two waves overlap it creates a band of light. When the peak of one wave meets the valley of another, light is cancelled out. Variations of this experiment spurred public debates between Albert Einstein and Neils Bohr on the true nature of reality. It’s been called the granddaddy of all quantum weirdness. This convenient and affordable double slit laser was designed for personal enjoyment and education.