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Anonymous Coward writes:
https://www.businessinsider.com/alien-civilizations-may-have-already-colonized-galaxy-study-2019-8
The Milky Way could be teeming with interstellar alien civilizations — we just don't know about it because they haven't paid us a visit in 10 million years.
A study published last month in The Astronomical Journal[$] posits that intelligent extraterrestrial life could be taking its time to explore the galaxy, harnessing star systems' movement to make star-hopping easier.
The work is a new response to a question known as the Fermi paradox, which asks why we haven't detected signs of extraterrestrial intelligence.
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Fermi Paradox Paper: Aliens Could Take Their Time Settling the Galaxy
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* m2 stares at the monitor... it looks like a hamburger...
m2 - that's a bad sign
(Score: 2) by Muad'Dave on Wednesday September 11 2019, @12:44PM
Most of your analysis is spot-on, but I have to disagree with the way you used this factoid.
That's the power emitted by planet Earth itself, not Earth's inhabitants. Our radio signature is significantly stronger than 0.1 GW = 100MW - in fact, the Arecibo transmitter [wikipedia.org] alone outshines the Earth's RF emissions by 5 orders of magnitude on one frequency, at least in a very tight beam. Arecibo has "... four radar transmitters, with effective isotropic radiated powers of 20 TW (continuous) at 2380 MHz, 2.5 TW (pulse peak) at 430 MHz, 300 MW at 47 MHz, and 6 MW at 8 MHz."
If you discount that one as being too narrow, then add up all of the omnidirectional radar and shortwave transmitters. Many of the radar transmitters mentioned in table 2 of this doc [doc.gov] have EIRP's over a GW. Even though they're low duty cycle pulsed emissions, they'd still be detectable at very long distances.
Also, Earth's emissions are mostly in the HF band (as are Jupiter's). Seeing any emissions past UHF would indicate some other process, possibly intelligent, was at play.