Lumos

Question: A photon starts moving in the random direction from the center of the square of size 3. Let’s say it first colloids to the glass wall AB. What is the expected distance traveled by the photon before hitting the wall AB again? . . C A P T A I N I N T … Continue reading Lumos

All men must die

Question: One day, an alien comes to Earth. Every day, each alien does one of four things, each with equal probability to: (i) Kill himself (ii) Do nothing (iii) Split himself into two aliens (while killing himself) (iv) split himself into three aliens (while killing himself) What is the probability that the alien species eventually dies out … Continue reading All men must die