B How good are our ears? (Detectable Interstellar signals)

[Canada Bob]

TL;DR Summary

Detectable Interstellar signals...

How good are our ears / what can SETI and the like detect ?

If we are listening for a radio signal broadcast by some advanced civilisation in our galaxy how sensitive would our "ears" have to be to detect a signal ? Obviously part of that equation would be how strong and how close the transmitter was, is there a physical limit to the strength of a generated signal that could be broadcast, if so how close would we need to be to detect the signal.

If memory serves me well the loudest signal ever broadcast from Earth was 1000 kW from Arecibo, almost 50 years ago, at what point would that signal become "practically" undetectable ? Can we reasonably deduce that since no one has returned the call that there's no technologically advanced civilsation within 20 light years from Earth ?

 

[PeroK]

Isn't it more a question of how powerful our radio telescopes are, than how good our ears are?

 

[Mark44]

Isn't it more a question of how powerful our radio telescopes are, than how good our ears are?

I think the OP was anthropomorphizing the radio telescopes as "ears."

 

[PeroK]

I think the OP was anthropomorphizing the radio telescopes as "ears."

Given that it's our eyes that detect electromagnetic radiation, perhaps "eyes" would have been more appropriate.

 

[Vanadium 50]

Obviously part of that equation would be how strong and how close the transmitter was

Which is why Seti is much more sensitive to radar than radio.

 

[Filip Larsen]

Arstechnica ran a piece recently about the planned emission mission "A Beacon in the Galaxy" from the Chinese FAST radio telescope:
https://arstechnica.com/science/202...'s-location-with-the-hope-of-reaching-aliens/

More details about that can be found in https://arxiv.org/abs/2203.04288

(I have not yet read the arxiv paper, nor much about FAST or the FAST mission).

 

[Canada Bob]

Isn't it more a question of how powerful our radio telescopes are, than how good our ears are?

Powerful ? do you mean sensitive ?

 

[Canada Bob]

j

Arstechnica ran a piece recently about the planned emission mission "A Beacon in the Galaxy" from the Chinese FAST radio telescope:
https://arstechnica.com/science/202...'s-location-with-the-hope-of-reaching-aliens/

More details about that can be found in https://arxiv.org/abs/2203.04288

(I have not yet read the arxiv paper, nor much about FAST or the FAST mission).

Thanks for responding, and for the article on the link, interesting reading...