It's one of those enduring Zen koans of science that we've all grown up with: Light behaves as both a particle and a wave-at the same time. Einstein taught us that, so we're all generally on board, but to actually understand what it means would require several Ph.D.s and a thorough understanding of quantum physics.
What's more, scientists have never been able to devise an experiment that documents light behaving as both a wave and a particle simultaneously. Until now.
Why Should We Care About Quantum Computing?
That's the contention of a team of Swiss and American researchers, who say they've succeeded in capturing the first-ever snapshot of light's dual behavior. Using an advanced electron microscope – one of only two on the planet – at the EPFL labs in Switzerland, the team has generated a kind of quantum photograph of light behaving as both a particle and a wave.
The experiment involves firing laser light at a microscopic metallic nanowire, causing light to travel - as a wave - back and forth along the wire. When waves traveling in opposite directions meet, they form a "standing wave" that emits light itself - as particles. By shooting a stream of electrons close to the nanowire, the researchers were able to capture an image that simultaneously demonstrates both the wave-nature and particle-nature of light.