the sensation was like exploring with your hands some other region of the world which your sight could never reach because once you pried open the earth that world would change , things would squirm away that had been there before and your very act of digging would move the particles to different places and rub them against each other ; i touched tiny pebbles and balls of wood , hunks of gravel and twigs in the earth ; then the earth from above caved onto the backs of my hands , streamed down the side of the earth pyramid and trickled over the back of my wrists .