The complete absence on the other hand jars our perception. Indefinite concepts become abstract. One of such ideas is vacuum — the absolute empty space. I find it rather hard to imagine. Since there is nothing to experience, how can I sense or perceive it? It remains a construct, an idea without a sensory experience. The mind is lost, as there is nothing to hang on or relate to. Even the ‘silence’ we speak of is not absolute. Artificially created complete lack of noise is uncomfortable, almost like a sound itself — a ‘white noise’ — the shrill ringing in our ears. In natural conditions, there are always sounds, small and barely audible noises, that form the (sound) landscape we inhabit.
Composer and music theorist John Cage6 has explored the idea of silence and space in his music and writings. This is also the key theme in 4’33, an orchestra piece composed in 1952, during which not a single note is played. For the duration of four and a half minutes, the audience sees and listens to a silent orchestra, the only audible thing being the natural sounds of the audience and musicians themselves and the pages of scores being turned as the time passes. Perhaps bizarre at the first impression, Cage’s idea is a brilliant use of the sense of absence: by removing all sounds made by musical instruments Cage exposed the audience to the experience that is normally ignored or discarded. He transcends the audience's perception into an absolute awareness of the current moment of time and space. He showed that "empty" spaces are in fact not empty at all, it is filled with even smaller things, sounds and sensations that we perceive as silence.
Empty spaces and silence are similar in the way that they create possibility. In empty spaces, we are free to wander and discover, to notice and pick up details that do not demand attention but are just as essential. Space enables us to focus our perception on what we choose to experience.