Part 3/10:
Moving beyond static objects, the discussion extends to light. While light does not possess rest mass, theories suggest it embodies energy and momentum. A fascinating paper titled "Light Is Heavy" by Martin van der Mark and Gerard 't Hooft elaborates on how light exhibits inertia and weight due to its energetic properties.
When a container reflects light, the concept raises a pivotal question: can light in a confined space create mass? Surprisingly, the answer is affirmative; light's energy translates into inertial mass through momentum exerted on the container's walls. Thus, we emerge with the realization that light does, in fact, carry mass-like properties.