Jonathan Crowe

My Correct Views on Everything

Radio Waves

If, like me, you often wonder how far out radio signals can be detected before they’re drowned out by cosmic background radiation — for example, you’re working on a science fiction story that depends on being able to detect such signals from other stars — then, like me, you’ll be interested in this Ask MetaFilter thread and the SETI range calculator. Short version: broadcast radio signals fade out pretty fast thanks to the inverse square law, so it’s pretty unlikely that space aliens will be along to demand explanations for our 1950s television programs.