Stories from Physics for 11-14 14-16 16-19
In 1969, Buzz Aldrin reported seeing flashes of light in his vision whilst on the Apollo 11 mission. Subsequently, other astronauts have reported unusual visual phenomena whilst in space, such as faint spots or streaks of light seen when their eyes were closed and adapted to the dark. The cause of these flashes is thought to be an interaction between a charged particle - a cosmic ray - and the visual system. Experiments with particle accelerators on the ground have shown the phenomenon is reproducible and a variety of different particles (including muons, neutrons and pions) have been found to produce effects including stars, flashes and bright points of light in participants’ visual fields.