I weigh nothing, but you can see me. Put me in a bucket and I make it lighter. What am I?

This clever riddle plays on our perception of presence and absence. An empty space, often referred to as a void, genuinely possesses no mass, and therefore, no weight. Despite this lack of physical substance, we can clearly identify and perceive its boundaries against a surrounding material. Our eyes register the demarcation where something *is* present versus where it *is not*, allowing us to visually "see" the emptiness.

The most intriguing part of the puzzle lies in how this void can seemingly reduce the weight of a container. The trick is not that the absence itself has negative weight, but rather its effect on what the container holds. If you imagine a bucket filled with water, and then a hole appears in its side or bottom, the water will inevitably escape. As the contents drain out, the combined weight of the bucket and its remaining contents decreases, thus making the bucket system lighter than it was when full.

This riddle is a classic example of lateral thinking, challenging us to consider definitions and consequences beyond their most literal interpretations. It highlights how we conceptualize non-existence and the impact of an "absence" on tangible objects. Such thought experiments are not just for fun; they encourage critical thinking and a deeper understanding of fundamental concepts in physics, logic, and even philosophy, where the nature of nothingness has been pondered for centuries.