Ages ago, I learned that our best receivers would not be able to detect our most powerful radio/TV broadcasts from more than half a lightyear away. I lack the k

Ages ago, I learned that our best receivers would not be able to detect our most powerful radio/TV broadcasts from more than half a lightyear away. I lack the knowledge to determine if that's true, but if it is, all those romantic notions of aliens learning about us from our radio/TV shows will sadly (or fortunately) never be true. This article doesn't explicitly point out the distinction between broadcast (which taper off rapidly in power) and narrow beam signals (which lose far less power over distance), but it's pretty clear that it is largely about that distinction. It lists signals aimed at specific spacecraft that hit only a limited number of stars. That tighter beam hopefully means a significant signal will be detectable there. It's cool that they calculate when the return signal might arrive here. It would have been even cooler if they'd calculated how strong the signal would be when it arrives at that star. But it's possible that's far too uncertain to determine; stars near the edge of the beam probably receive far less power than those in the center.