According to quantum mechanics light acts as both a particle and a wave, but now we can finally see what that looks like.
Quantum mechanics is an incredibly complex field for a simple reason: So much of what it studies can be two different things at the exact same time. Light is a great example since it behaves like both a particle and a wave, but only appears in one state during experiments. Mathematically speaking, we have to treat light as both ways for the universe to make sense but actually confirming it visually has been impossible. Or at least that was the case until scientists from Switzerland's École polytechnique fédérale de Lausanne developed their own unique photography method.
The image was created by shooting a pulse of laser light at a metallic nanowire to make its charged particles vibrate. Next the scientists fired a stream of electrons past the wire holding the trapped light. When the two collided, it created an energy exchange that could be photographed from the electron microscope.
So what does this mean when looking at the photograph? When the photons and electrons collide, they either slow down or speed up, which creates a visualization of a light wave. At the same time the speed change appears as a quanta - packets of energy - transferred between the electrons and photons as particles. In other words, it's the first case of observing light particles and waves simultaneously.
"This experiment demonstrates that, for the first time ever, we can film quantum mechanics - and its paradoxical nature - directly," research leader Fabrizio Carbone explained. This has enormous implications not only for quantum research, but also quantum-based technologies still in development. "Being able to image and control quantum phenomena at the nanometer scale like this opens up a new route towards quantum computing," he continued.
The experiment results were posted in today's Nature Communications, which will help other scientists build on this research with further studies. After all, it's not like we've unlocked all of light's secrets yet - we can barely even tell what color a dress is sometimes.