Theoretically, the radio signals from our earliest broadcasts have been spreading outwards through space since the beginning of radio.
They’ve travelled over 100 light-years by now and, according to researchers from Cornell, may have reached thousands of star systems. Of the 75 astronomers have been able to search for planets, 29 of them possess potentially habitable worlds.
But the further a radio signal travels, the weaker it becomes according to something called the inverse square law: if you double the distance, the signal strength will become four times weaker.
Combine that with the distortions (refraction, dispersion and scintillation) caused by our own atmosphere and communication satellites in orbit, as well as interaction with a whole lot of matter and gravity in space.
The result? When the signals finally reach a (very, very sensitive) radio receiver somewhere out there, it’s unlikely to be decipherable against the background cosmic noise of the Universe.
Truly lost in space.
This article is an answer to the question (asked by Jonathan Holmes, Bristol) 'Could someone across the cosmos pick up old radio programmes?'
To submit your questions, email us at questions@sciencefocus.com, or message our Facebook, X, or Instagram pages (don't forget to include your name and location).
Check out our ultimate fun facts page for more mind-blowing science
Read more:
