This question relates to the practicality of searching for intelligent life in other solar systems by detecting their radio broadcasts (or aliens find us from ours). the closest stars are 4 light years away from us. how far away must you be from a 475 khz radio station with power 50.0 kw for there to be only one photon per second per square meter? assume that the photons spread out spherically. the area of a sphere is .