alt Hacker NewsThe fact that all SETI endeavors haven’t really found anything is actually a very valuable result, because it constrains “they’re everywhere, we just haven’t been looking” arguments quite a bit.
Even humanity’s (weak) radio emissions would be detectable from tens of light years away, and stronger emissions from much further. So the idea that intelligent life is absolutely everywhere that was liberally tossed around a few decades ago is pretty much on life support now.
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netsharc • today at 12:57 PM
Probably due to the Great Filter: https://www.youtube.com/watch?v=UjtOGPJ0URM
>Even humanity’s (weak) radio emissions would be detectable from tens of light years away, and stronger emissions from much further.
That's not true. Non-directional radio transmissions (e.g. TV, broadcast radio) would not be distinguishable from cosmic background radiation at more than a light year or two away [0]. Highly directional radio emissions (e.g. Arecibo message) an order of magnitude more powerful than the strongest transmitters on Earth would only be visible at approximately 1000 light years away [1], and would only be perceptible if the detector were perfectly aligned with the transmission at the exact time it arrived.
[0] https://physics.stackexchange.com/a/245562
[1] https://arxiv.org/pdf/astro-ph/0610377.pdf