A poem is sound pressed between two silences.
A word cannot sound without the silence surrounding it. Without intermittent silence, speaking would be a mush of mumbling, nothing but indistinguishable sound. The same for the printed page, the empty spaces between words are necessary. An atom is composed of mostly empty space, and a poem is composed mostly of silence, the silence found between words and the silence compressed within words.
It takes a lot of silence to make a poem.