Re: Not useful
"Also WHY would anyone beam a transmission?"
They don't need to be beaming a transmission. SETI (as an example) wasn't looking for a transmission, it was looking for unusual EM activity. A reasonably powered radar system at a military airport was expected to be detected by SETI at a distance of several hundred light years.
However the means of detection, be it looking at how the spectral analysis of a star changes by the planet passing by, or a deliberate beacon of "we are here", it's all travelling to us at c and can be considered the same bubble of EM distortion.
Biting the hand that feeds IT
