Jim Al-Khalili explains the experiment that reveals the "central mystery of quantum mechanics": the double slit experiment. Sometimes called the "two-slit" or "Young's" experiment, it demonstrates that matter and energy can display the characteristics of both waves and particles, establishing the principle known as wave-particle duality. Furthermore, it questions the role of the observer in the outcome of events and demonstrates the fundamental limitation of an observer to predict experimental r

Nobel laureate Sir Roger Penrose explains one of the most iconic demonstrations of quantum physics: the double-slit experiment. This experiment shows how electrons can act like a wave and a particle. Electrons are fired through two slits and onto a screen. If you place a detector at the slits, you will see each electron act like a particle and travel through one of the slits and hit the screen at the back. But if you don't detect the electrons as they travel through the slits, the screen will sh