Is Light a Wave or a Particle?
Light behaves in surprising ways. A simple experiment with a laser and two slits shows a pattern only waves can make. It changed how we understand light. Watch to find out why the mystery remains.
For hundreds of years, scientists argued over a simple question. What exactly is light? Is it made of tiny flying particles or does it move like ripples on water?
Thomas Young’s Double Slit Experiment brought this mystery to a turning point.
In this video, we show how a laser shining through two narrow openings creates a surprising pattern of bright and dark fringes on a screen. The pattern reveals something remarkable. Light waves spread out, collide and build each other up or cancel out. The result is a fingerprint that only a wave can make.
Young’s discovery shook science and opened the door to modern physics. Yet the story did not end there. Later experiments showed that light can also behave like a particle, which deepened the mystery even further.
Credits
- Presenter and Script Writer: Dr Michael Horbury (Research Associate; Materials and Biological Physics Research Cluster at the University of Sheffield)
- Director and Producer: Christina Metcalfe (Project Manager at The University of Sheffield)
- Videographer, Editor and Graphic Designer - (Digital Engagement Officer at the University of Sheffield)
