Hello. In the Fermi Paradox episode Dr. Gay said that we (humans) search for radio waves emitted by other civilizations but some planets atmospheres might be to thick (or for whatever reason) to allow radio signals to escape into space.
If a civilization on one of these planets were using radio signals wouldn't these signals be piling up on one another in the atmosphere? Could an instrament be used to listen to a transmission released from a source from the long past in this atmosphere? For example, if Earths atmosphere never released radiowaves could i, on this date, tune into a radio broadcast from the 1950's or pick up the broadcast of the Beatles playing on Ed Sullivan?
If X amount of our radio emissions leak out of the atmosphere than are some of these old transmissions still roaming around for detection within our grasp?
My last question out of a select few of many. If another civilization had been broadcasting is it possible that the signal has already passed us? For example, planet 'A' sends a signal towards a planet called 'B'. History of Planet 'A': They used radio signals for 150 years and then moved completely to fiber optic communication. The first waves start to enter planet 'B's range of detection within 5000 years time, relative to planet 'A'. The last wavelength leaves Planet 'B's range of detection in 5500 years. Well, during this 500 year window Planet 'B' was inhabited by dinasaurs who were to busy hunting and gathering instead of developing ways to find radio emmissions from other civilalizations. 70 million years later planet 'B' has the capability to listen to these waves but it is now 70 million years to late and the signal and even the civilization which sent it out are now long gone.
EDIT: I just realized there are other forums for questions like these. I am sorry if this post should be somewhere else.