Shadows, traditionally formed when an object blocks light, are an everyday phenomenon. They result from light’s inability to penetrate opaque objects, creating a region devoid of illumination.

or translucent objects like this clear silicone lid. But a shadow forms when an opaque, or non-transparent, object blocks light from passing through and reaching a surface on the other side.

The closer to the light source an object is, the bigger the shadow will be. This is because the object blocks more of the light. The further away from the light source an object is, the smaller ...

Can light itself cast a shadow? It may sound like a philosophical riddle, but researchers have found that under certain conditions, a laser beam can act like an opaque object and cast a shadow.