Radio leakage

edit

How far away could radio and television signals be detected? A brief search online didn't find any authoritative sources. -- Beland (talk) 17:53, 11 August 2016 (UTC)Reply

Radio waves would have to make sense to be recognized as a technosignature. Conversations and music obviously make some sense, as they require some planning characteristic of intelligent life. Using our planet as an example, a performance of a Bach fugue or an image of a Hokusai painting would be clear evidence of intelligence. The problem is that radio waves dissipate rapidly in accordance with th einverse square law. The only way in which to transmit such a sonic or visual signal would necessarily be by a laser, but such would assume that the transmission is pointed (with extreme precision) at a planet in a distant solar system. The giver and the recipient would have to know about each other. Pbrower2a (talk) 07:45, 10 November 2019 (UTC)Reply

Please update with: info on NASA grant that was recently reported

edit

Could you please update the page to contain information on this study, included like so in 2020 in science:

News reports the first SETI-specific grant that NASA has awarded in three decades. The grant funds the first NASA-funded search for technosignatures from advanced extraterrestrial civilizations other than radio waves, including the creation and population of an online technosignature library.[1][2][3][4]

I think it should at least be mentioned here somewhere in section "Scientific projects searching for technosignatures". If you see a problem with the item's content at or notability for 2020 in science please edit it.

Thank you.

--Prototyperspective (talk) 14:29, 23 July 2020 (UTC)Reply

Done, with some wording tweaks and removal of the Forbes "contributor" source (see WP:RSP). In the future, feel free to WP:Be bold and add such a thing yourself. Crossroads -talk- 22:24, 23 July 2020 (UTC)Reply

References

  1. ^ "NASA funds SETI study to scan exoplanets for alien "technosignatures"". New Atlas. 23 June 2020. Retrieved 5 July 2020.
  2. ^ Rice, Doyle. "Scientists are searching the universe for signs of alien civilizations: 'Now we know where to look'". USA TODAY. Retrieved 5 July 2020.
  3. ^ Fernandez, Elizabeth. "Scientists Move To Find Alien Civilizations Using "Technosignatures"". Forbes. Retrieved 5 July 2020.
  4. ^ "Does intelligent life exist on other planets? Technosignatures may hold new clues". phys.org. Retrieved 5 July 2020.

Light pollution: Grid frequency as a technosignature

edit

On detecting artificial light:

Such approaches assume that the radiant energy generated by a civilization would be clustered and can thereby be detected[32][33]

I think we all know that you don't need to resolve continents (or even the planet) to distinguish artificial light, at least for the planet we know: The Earth's nightside shines in 50 or 60 Hz depending on which continent is in view. Apart from blocking out our glaring sun, picking out this signal would merely require having the Earth somewhere within a pixel. Right? —Anordal (talk) 12:46, 21 August 2023 (UTC)Reply

There is one reason I forgot why it (statistically) won't work for contemporary light pollution: Three-phase electricity. Although there are going to be large areas and roads lit by electricity from the same phase, they are going to tend to drown each other out when viewed from afar.Anordal (talk) 12:38, 15 October 2023 (UTC)Reply