How long, he thinks, and is struck by the sheer simplicity of such a question. It’s a question that throws him back to his five-year-old self, a young boy looking up to everyone and trying to see the world through their eyes. He’d asked how long, and missed the answer because he was distracted by the fact that time is measured by length rather than width, height, depth. “Movement of shadow” actually seems the most logical, or should it be “Movement of light”?
In any case, movement isn’t measured by length. So when he asks how long, he thinks more in terms of a distance that’s measured by an invisible piece of string. Like the length of a loved one’s thoughts of him, or how far it takes for something lost to be found, and it converges on him like a tunnel of light that he has to strain to see.
He rubs his eyes with the heels of his palms, and wonders how much further he has to go.