What if I take a photo with two cameras facing each other at the same time? Would the light that hits the sensor or film in one camera reflect and travel into the other camera? If so, this process could repeat thousands of times in the split second that the shutters remain open. With each reflection, the photons dwindle back and forth while gradually losing energy, as some light gets absorbed each time they visit the camera's interior. So, does the photon “die” (lose all energy) first, or does the shutter close first?