A2. A light beam falls radially inwards towards the center of a black hole. First it passes shell A at a distance rA from the center of the black hole. It then passes the shell B at a distance rB from the center of the black the hole. We call the two shell passes event A and event B. Where large is the time interval between these two events and how can did you figure it out? Explain with a maximum of 3 sentences (plus any equations if you wish).

A2. A light beam falls radially inwards towards the center of a black hole. First it passes shell A at a distance rA from the center of the black hole. It then passes the shell B at a distance rB from the center of the black the hole. We call the two shell passes event A and event B. Where large is the time interval between these two events and how can did you figure it out? Explain with a maximum of 3 sentences (plus any equations if you wish).