GuyWhoAsksQuestions

I'm not a scientist and not sure if this is the correct location to post this, so please bear with me. Just these random thoughts come into my head, so I have to ask. I was reading about the inverse square law as it applies to light, and I have two hypothetical questions. 1. Assume there is a light source at one end of a long tube one million miles long, from which light could only escape through the opposite end. Would the intensity of the light be equal along the entire distance of the inside of the tube? 2. Now assume you place a mirror over the end. Would the intensity of light within the tube be ever-increasing? Thanks