In a room, there is a small box on the floor. Drusilla is standing on one side of the room, and Elvin is standing on the opposite side. Between Drusilla and Elvin, a tall opaque barrier is set up that reaches the ceiling. If Drusilla places a mirror on the floor, angled towards the ceiling, on her side of the barrier, can Elvin see the top of the box by looking at the mirror from his side? Provide a very brief response.
Elvin cannot see the top of the box using the mirror from his side of the barrier. The opaque barrier prevents direct line of sight between the two sides of the room. For Elvin to see the top of the box via the mirror, light would need to travel from the box, be reflected by the mirror, and then reach Elvin's eyes. However, since the barrier extends to the ceiling, it blocks any path the light from the top of the box could take to the mirror and then to Elvin after reflection. Elvin would only be able to see the reflection of the box top if there were no barrier or if the barrier did not completely block the path of light between the box, the mirror, and his eyes.