The Fermi paradox revisited: Technosignatures and the contact era
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Re: The Fermi paradox revisited: Technosignatures and the contact era
#2Re: The Fermi paradox revisited: Technosignatures and the contact era
#3Another Fermi Paradox thread.
Take a shot any time von Neumann probes are mentioned.
Regarding the paper (or at least its abstract) it's worth mentioning that our own radio transmissions have become significantly less likely to be detected after our transition to digital, and that electromagnetic signals dissipate, so they might no longer be recognizable as intelligent signals beyond a certain distance. That would seem to restrict the "Contact Era" window from "a few hundred to a few thousand" years to a century or less. One would expect that advanced civilizations became essentially radio silent to us long before we were even capable of detecting their transmissions in theory.
Re: The Fermi paradox revisited: Technosignatures and the contact era
#4Another Fermi Paradox thread. Take a shot any time von Neumann probes are mentioned. Regarding the paper (or at least its abstract) it's worth mentioning that our own radio transmissions have become significantly less likely to be detected after our transition to digital, and that electromagnetic signals dissipate, so they might no longer be recognizable as intelligent signals beyond a certain distance. That would se…
I post this on every Fermi paradox thread.
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 100 light years away [1], and would only be perceptible if the detector were perfectly aligned with the transmission at the exact time it arrived.
Space is really big, and radio emissions are comparatively really weak.
Re: The Fermi paradox revisited: Technosignatures and the contact era
#5The first alien we will ever encounter is likely a neural network we built with our hands.
Re: The Fermi paradox revisited: Technosignatures and the contact era
#6The first alien we will ever encounter is likely a neural network we built with our hands.
I think the first alien we ever encounter will be something like a bacterium or virus, it will spur a debate as to whether it's really life, and it might already have happened.
Re: The Fermi paradox revisited: Technosignatures and the contact era
#7Another Fermi Paradox thread. Take a shot any time von Neumann probes are mentioned. Regarding the paper (or at least its abstract) it's worth mentioning that our own radio transmissions have become significantly less likely to be detected after our transition to digital, and that electromagnetic signals dissipate, so they might no longer be recognizable as intelligent signals beyond a certain distance. That would se…
I post this on every Fermi paradox thread. 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 100 light years away [1], and would…
I feel the same way. How do the SETI people explain this away and justify their search? One light year is tiny, I think it would take an incredibly generous Drake equation estimate to make that contain intelligent life. Same for 100 light years too. But I lean towards pessimistic Drake equation values. Life is even more rare and precious the more I dig into the equation.
> The true stellar density near the Sun is estimated as 0.004 stars per cubic light year, or 0.14 stars pc−3.
> There are around 60,000 stars within 100 light-years, and the same again with 100-200 light-years, and then the numbers fall quickly. By the time we're 1,000 light-years out, there are fewer than 8,000 stars and, at 1,300 light-years, fewer than 5,000 stars.
Re: The Fermi paradox revisited: Technosignatures and the contact era
#8The first alien we will ever encounter is likely a neural network we built with our hands.
But that wouldn't technically be an alien, since it's not extra-terrestrial.
Re: The Fermi paradox revisited: Technosignatures and the contact era
#9Another Fermi Paradox thread. Take a shot any time von Neumann probes are mentioned. Regarding the paper (or at least its abstract) it's worth mentioning that our own radio transmissions have become significantly less likely to be detected after our transition to digital, and that electromagnetic signals dissipate, so they might no longer be recognizable as intelligent signals beyond a certain distance. That would se…
I post this on every Fermi paradox thread. 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 100 light years away [1], and would…
> Non-directional radio transmissions (e.g. TV, radio) would not be distinguishable from cosmic background radiation at more than a light year or two away
this is going to come across as sarcastic in text, I genuinely mean this.
Why don't the authors know this? Why doesn't someone tell them?
Re: The Fermi paradox revisited: Technosignatures and the contact era
#10Earlier quoted context omitted.
I post this on every Fermi paradox thread. 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 100 light years away [1], and would…
I feel the same way. How do the SETI people explain this away and justify their search? One light year is tiny, I think it would take an incredibly generous Drake equation estimate to make that contain intelligent life. Same for 100 light years too. But I lean towards pessimistic Drake equation values. Life is even more rare and precious the more I dig into the equation. > The true stellar density near the Sun is est…
There are other techno-signatures to look for: Dyson swarms (marked by irregular dimming). Infinitely more powerful transmitters - i.e. irregular pulsars. Oumuamua type fly-bys. "Unnatural" gasses in atmospheres.
All purely theoretical, of course. As far as we know, we might not even notice life on Alpha Centauri planets 4ly away.