I told myself: 'I am surrounded by unknown things.' I imagined man without ears, suspecting the existence of sound as we suspect so many hidden mysteries, man noting acoustic phenomena whose nature and provenance he cannot determine. And I grew afraid of everything around me – afraid of the air, afraid of the night. From the moment we can know almost nothing, and from the moment that everything is limitless, what remains? Does emptiness actually not exist? What does exist in this apparent emptiness?