Comments by "" (@zachrodan7543) on "Listening for Alien Civilizations at a Temporal "Waterhole"" video.

  1. I think the radio waterhole seems more likely to yield a detection than anything else. if we assume that the aliens sending the signals are advanced enough to be engaging in long-range space travel, and we assume they have the same sort of selfishness seen in virtually all life on earth (which is a driving force behind natural selection; there is a tendency, at least on earth, for lifeforms to prioritize the survival of themselves and their progeny above all else.), aliens likely do use targetted signals for communications (more energy efficient than sending the signal in all directions, assuming you know where to aim). however, these are likely meant primarily as one-way communications, at least beyond a certain distance, due to the time-delay caused by the universal speed limit. there are only two ways we pick up on such a signal: either it is aimed at us, or it is aimed at everywhere. if the signal is aimed at us, the question is why. it seems inefficient to try and pulse all the planets that you find in the hopes that they are paying attention, and what purpose does it serve for you? unless you know a civilization is there to recieve it, it seems like it would be too resource intensive to send signals into the potential void that often. and they might have no more reason to believe us to be here than we do to believe that they are in whatever specific location they call home. we haven't seen any sign of them, and we probably know of more exoplanets that could support life than we could afford to try and ping this way, and the same logic works in reverse. instead, it seems much more likely for us to pick up a signal if it is aimed at "everywhere" (or some non-trivial subset of "everywhere" which happens to include us). again, the question is why such a signal would be sent: what reason could aliens have for trying to send a signal in as many directions as possible, as efficiently as possible? the only thing that comes to mind for me is a sort of distress signal/info dump: "our ship is in a situation where we can no longer proceed with what we set out to do. here is what caused our crisis, so that whoever out there happens to receive this message knows not to make the same mistake as us. if our home planet happens to recieve this message, this is our current location." the most logical way I can think of for such a message to be sent out is by spinning the transmitter around in a circle. this would likely result in us detecting it as something akin to a pulsar, but with an artificial message encoded amid the pulses of the beam sweeping over us.
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