METI and SETI

Discussion in 'Astronomy, Exobiology, & Cosmology' started by paddoboy, Dec 27, 2016.

  1. paddoboy Valued Senior Member

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    Scientists plan to send greetings to other worlds
    December 26, 2016 by Lisa M. Krieger, The Mercury News

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    This is the "South Pillar" region of the star-forming region called the Carina Nebula. Like cracking open a watermelon and finding its seeds, the infrared telescope "busted open" this murky cloud to reveal star embryos tucked inside finger-like pillars of thick dust. Credit: NASA
    After decades of fruitless scanning the skies for alien messages, scientists say it's time to try a basic rule of etiquette: Say "hello" first.


    A new San Francisco-based organization called METI, or Messaging Extra Terrestrial Intelligence, plans to send signals to distant planets, rather than waiting for them to call Earth.

    By the end of 2018, the project aims to send some conversation-starters via radio or laser signals to a rocky planet circling Proxima Centauri, the nearest star other than the sun, and then to more distant destinations, hundreds or thousands of light years away.

    It would be the first effort to send powerful, repeated and intentional messages into space, targeting the same stars over months or years.

    "If we want to start an exchange over the course of many generations, we want to learn and share information," said Douglas Vakoch, president of METI and former director of Interstellar Message Composition at the Search for Extraterrestrial Intelligence Institute in Mountain View, Calif.,, known as SETI.



    Read more at: http://phys.org/news/2016-12-scientists-worlds.html#jCp
     
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  3. paddoboy Valued Senior Member

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    http://www.nature.com/nphys/journal/v12/n8/full/nphys3852.html

    Searching for trouble?

    The search for signs of intelligent life elsewhere in the Universe has been underway since the pioneering efforts of Frank Drake in the 1960s. Most prominently, the privately funded SETI Institute has scrutinized radio signals for three decades and found nothing, despite widespread belief that the Universe must be teeming…
     
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  5. paddoboy Valued Senior Member

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    http://www.nature.com/nphys/journal/v12/n10/full/nphys3897.html

    In defence of METI

    Mark Buchanan's recent Thesis column1 — 'Searching for trouble?' — accurately summarizes key objections to Messaging Extra-terrestrial Intelligence (METI), in which powerful, intentional signals are transmitted to specific astronomical targets, in the hope of a reply. Most notably, Buchanan characterizes METI as seeming “inherently risky”.
     
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  7. paddoboy Valued Senior Member

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    I disagree with Professor Stephen hawking's view on contacting any ETI.
    Any ETI would be very distant, and to reach us would need technologies and scientific knowledge far in advance of what we have at this time.
    I don't believe that any sufficiently advanced civilisation would need to have aggressive tendencies, as they would not really want of anything, just as I believe we/us/humanity today, are not as aggressive or violent as our distant past relatives. Yes, we are still relatively violent and prone to greed and power and war, but I do believe that it is less then it was in our distant, and even not so distant past.
    Perhaps I'm over optimistic, perhaps.

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  8. paddoboy Valued Senior Member

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    Should we call the cosmos seeking ET? Or is that risky?
    February 13, 2015 bySeth Borenstein

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    This undated handout image provided by NASA shows a message carrying Golden Record that Voyager carried, a phonograph record-a 12-inch gold-plated copper disk containing sounds and images selected to portray the diversity of life and culture on Earth. Astronomers have their own cosmic version of the single person's Valentine's Day dilemma: Do you wait for that interesting person to call you or do you make the call yourself and risk getting shot down. Their version involves E.T. Instead of love, astronomers are looking for life out there in the universe. For decades, astronomers have sat by their telescopes, listened and waited for a call from E.T. only to be left alone. So now some of them want to aim their best radars and lasers out to the sky to say "We're here, call us" to the closest few thousand worlds. They can bring us all sorts of new technologies and answers to burning questions, some hope. (AP Photo/NASA)
    Astronomers have their own version of the single person's dilemma: Do you wait by the phone for a call from that certain someone? Or do you make the call yourself and risk getting shot down?



    Read more at: http://phys.org/news/2015-02-cosmos-risky.html#jCp
     
  9. paddoboy Valued Senior Member

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    https://arxiv.org/ftp/arxiv/papers/1612/1612.03844.pdf

    Presented in the International Congress of Astronautics, Jerusalem (4.1.1), October 2015 Accepted for publication in Acta Astronautica (2016).
    How far are Extraterrestrial Life and Intelligence after Kepler ?

    Abstract

    The Kepler mission has shown that a significant fraction of all stars may have an Earth-size habitable planet. A dramatic support was the recent detection of Proxima Centauri b. Using a Drake-equation like formalism I derive an equation for the abundance of biotic planets as a function of the relatively modest uncertainty in the astronomical data and of the (yet unknown) probability for the evolution of biotic life, Fb. I suggest that Fb may be estimated by future spectral observations of exoplanet biomarkers. It follows that if Fb is not very small, then a biotic planet may be expected within about 10 light years from Earth. Extending this analyses to advanced life, I derive expressions for the distance to putative civilizations in terms of two additional Drake parameters - the probability for evolution of a civilization, Fc , and its average longevity. Assuming "optimistic" values for the Drake parameters, (Fb~Fc~1), and a broadcasting duration of a few thousand years, the likely distance to the nearest civilizations detectable by SETI is of the order of a few thousand light years. Finally I calculate the distance and probability of detecting intelligent signals with present and future radio telescopes such as Arecibo and SKA and how it could constrain the Drake parameters.


    5. Summary

    The recent results of the Kepler mission significantly reduce the uncertainty in the astronomical parameters of the Drake equation. I derive expressions for the space density of biotic worlds as a function of the (yet unknown) probability for the evolution of biotic life and the uncertainty in the astronomical parameters. Similar expressions are derived for the distance to putative communicative civilizations, depending on two additional unknown factors in the Drake equation, the probability of evolution from simple biotic life to a communicative civilization and its longevity. Additionally, the probability to detect radio signals from other civilizations with present and future radio telescopes is estimated in terms of these factors. The extended analyses, updated by the Kepler results, presented in this paper suggests that our nearest biotic neighbor exoplanets may be as close as 10 light years. Even with a less optimistic estimate of the biotic probability, for example that biotic life evolves on one in a thousand suitable planets, our biotic neighbor planets may be expected within 100 light years. On the other hand, the distance to the nearest putative civilizations, even for optimistic values of the Drake parameters, is estimated to be thousands of light years.
     

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