Tagged: Frank Drake Toggle Comment Threads | Keyboard Shortcuts

  • richardmitnick 8:37 am on September 3, 2018 Permalink | Reply
    Tags: 235 ft), A team of Russian astronomers reported in 2015 that a telescope in the Caucasus region had intercepted a mysterious signal from a distant star, Carl Sagan’s novel "Contact", Ellie Arroway, , Frank Drake, Has an advanced extraterrestrial civilisation had built an “alien megastructure” around their star to harvest all of its energy?, , Rio 2.0, , SETI/Allen Telescope Array situated at the Hat Creek Radio Observatory 290 miles (470 km) northeast of San Francisco California USA Altitude 986 m (3, , , There are an estimated 400bn stars in the Milky Way and evidence shows that most have planets circling them, WOW!! signal   

    From The Guardian: “First contact or false alarm? New Richter-like scale for alien signals” 

    The Guardian Logo

    From The Guardian

    Rio 2.0 rates potential signs of extraterrestrial life from 0 to 10, with 10 equivalent to ‘an alien shaking your hand’.

    1
    Alien seeker … Jodie Foster as Ellie Arroway in the 1997 movie Contact, based on Carl Sagan’s novel. Photograph: Rex/Shutterstock

    When a team of Russian astronomers reported in 2015 that a telescope in the Caucasus region had intercepted a mysterious signal from a distant star, talk of extraterrestrials was not far behind. As some asked: was this proof aliens were trying to contact us?

    The answer came soon enough. Follow-up observations from other telescopes failed to confirm the signal and researchers came to the conclusion that the source of the signal was far closer to home. The chances are it came from a passing plane or a person on a citizens band radio, or was down to a glitch in the telescope’s electronics.

    It was not the first time public excitement had been whipped up by signals that turned out to be proof of something far less exciting than an advanced extraterrestrial civilisation. And in expectation that more false signals will come, scientists have now created their own Richter-like scale to explain whether a finding is a damp squib or has truly seismic implications.

    The new scale allows scientists to rate interesting signals detected in searches for extraterrestrial intelligence from 0 to 10, where 0 is nothing to get excited about and 10 is equivalent to “an alien space probe orbiting the Earth or an alien shaking your hand,” said Duncan Forgan, who worked on the project, at the University of St Andrews Centre for Exoplanet Science.

    There are many alternative explanations that need to be considered when evaluating a potential extraterrestrial signal. “There could be a problem with your telescope or a radio frequency coming from something on Earth,” Forgan said. “You might think you found an alien but actually you found a taxi rank.”

    Known as Rio 2.0, the scale is a proposed upgrade of an existing Rio scale that is already used by the alien-hunting community. It assigns scores to Seti (“search for extraterrestrial intelligence”) signals by taking into account both the potential implications of the signal and the likelihood that it is genuine, rather than down to natural or human-made phenomena.

    “We are talking about extraordinary claims here and so you need extraordinary evidence to go with them,” Forgan said. “Ideally this means multiple observations from multiple instruments – as well as from different research teams using the same instruments.”

    Under the proposals, scientists could issue their own Rio scale number for any interesting signals they detect, but so could fellow academics who review their work for publication. The rating system is also being made available to the public.

    “It is clear from citizen science projects that the general public are able to complete similar classification tasks with relatively low amounts of training,” the scientists write in the International Journal of Astrobiology.

    There are an estimated 400bn stars in the Milky Way, and evidence shows that most have planets circling them. But with so many stars being observed, there is a constant risk of technical glitches or spurious signals masquerading as potential alien transmissions.

    In one of the most recent false alarms, the periodic dimming of a star led to speculation that an advanced extraterrestrial civilisation had built an “alien megastructure” around their star to harvest all of its energy. Thousands of headlines and closer observations later, the real cause turned out to be dust.

    Jill Tarter, a co-founder of the Seti Institute in Mountain View, California, and an author of the paper, said the new scale could be used like the Richter scale, which describes the severity of earthquakes.

    SETI’s Jill Tarter

    SETI Institute

    SETI/Allen Telescope Array situated at the Hat Creek Radio Observatory, 290 miles (470 km) northeast of San Francisco, California, USA, Altitude 986 m (3,235 ft)

    Drake Equation, Frank Drake, Seti Institute

    Frank Drake with his Drake Equation. Credit Frank Drake

    A signal is scored immediately and then continuously updated as new data arrives. More credibility will be given to discoveries with multiple independent Rio scores.

    Tarter, who was the inspiration for the alien-seeking Ellie Arroway in Carl Sagan’s novel Contact and the subsequent movie with Jodie Foster, spotted potential extraterrestrial signals three times in her career, but each time found mundane explanations for them. The group of astronomers behind Rio 2.0 say it could be tested on fictional scenarios such as the one in the film, as well as on historical “false alarms” such as the famous “Wow!” signal.

    Wow! signal

    Andrew Siemion, another co-author, and director at the Seti Research Center at the University of California, Berkeley, added: “We absolutely encourage wide assessment of the Rio scale for any purported discovery, particularly by independent scientists. It is critical in any scientific process to have independent review of methods and interpretation.”

    The new Rio Scale has been submitted to the International Academy of Astronautics Permanent Committee on Seti for official ratification.

    See the full article here .

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

     
  • richardmitnick 7:43 am on October 4, 2017 Permalink | Reply
    Tags: , , Contact, Frank Drake, , , NIROSETI-Near-Infrared Optical SETI instrument at Lick, , ,   

    From Nautilus: “Why We’ll Have Evidence of Aliens—If They Exist—By 2035” 

    Nautilus

    Nautilus

    Oct 04, 2017

    SETI astronomer Seth Shostak


    Seth Shostak

    SETI Institute

    1
    The search for alien technology is about to get much more efficient. No image credit.

    I’ve bet a cup of coffee to any and all that by 2035 we’ll have evidence of E.T. To many of my colleagues, that sounds like a losing proposition. For more than a half-century, a small coterie of scientists has been pursuing the Search for Extraterrestrial Intelligence, or SETI. And we haven’t found a thing.

    I’m optimistic by nature—as a scientist, you have to be. But my hopeful feeling is not wishful thinking; it is firmly grounded in the logic of SETI.

    Half a century sounds like a long time, but the search is truly in its early days. Given the current state of SETI efforts and abilities, I feel that we’re on the cusp of learning something truly revolutionary.

    Most of our experiments so far have used large radio antennas in an effort to eavesdrop on radio signals transmitted by other societies, an approach that was dramatized by Jodie Foster in the 1997 movie Contact.

    NAIC/Arecibo Observatory, Puerto Rico, USA

    SETI@home, BOINC project at UC Berkeley Space Science Lab

    2
    Anybody out there: Jodie Foster as Ellie Arroway in the 1997 movie Contact, which was based on the bestseller by Carl Sagan. Getty Images

    Unlike other alien potboilers, Contact’s portrayal of how we might search for extraterrestrials was reasonably accurate. Nonetheless, that film reinforced the common belief that SETI practitioners paw through cosmic static looking for unusual patterns, such as a string of prime numbers. The truth is simpler: We have been searching for narrow-band signals. “Narrow-band” means that a large fraction of the transmitter power is squeezed into a tiny part of the radio dial, making the transmission easier to find. This is analogous to the way a laser pointer, despite having only a few milliwatts of power, nonetheless looks bright because the energy is concentrated into a narrow wavelength range.

    A modern SETI receiver simultaneously examines tens or even hundreds of millions of channels, each having a cramped 1-hertz bandwidth. That bandwidth is 5 million times narrower than a TV signal and lacks the capacity to carry information—a message. But the idea is to first discover aliens that are on the air, after which a far larger instrument would be built to dig out any modulation.

    To aim our antennas, SETI has traditionally used two approaches. One is to scan as much of the sky as possible; the other is to zero in on nearby star systems. You might think that the former would have an edge, since it makes no assumptions about where the aliens might be hanging out. But a sky survey spends most of its time looking at empty space. If you subscribe to the conventional view that extraterrestrials will most likely be ensconced on planets or moons, then it’s better to devote precious telescope time to examining nearby star systems.

    One current targeted search is the SETI Institute’s red dwarf survey, which takes place at the Allen Telescope Array, an ensemble of 42 antennas hunkered down in the California Cascades.

    SETI/Allen Telescope Array situated at the Hat Creek Radio Observatory, 290 miles (470 km) northeast of San Francisco, California, USA

    We are going down a list of 20,000 small stars that are prime candidates for hosting habitable planets. These ruddy runts are both numerous and, on average, old. Most have been around for billions of years, the time it took life on Earth to evolve from microscopic slime to high-tech hominids. Astronomers estimate that roughly one-half of all red dwarfs might have a rocky world in the habitable zone, where temperatures would abide liquid water.

    The SETI Institute is not the only band of alien hunters. Buoyed by a large infusion of money from the Russian billionaire Yuri Milner, the SETI group at the University of California, Berkeley, is renting time on the Green Bank Telescope in West Virginia and the Parkes Radio Telescope in the sheep country west of Sydney, Australia. Their decade-long project, known as Breakthrough Listen, also homes in on individual star systems.

    Breakthrough Listen Project

    1

    Lick Automated Planet Finder telescope, Mount Hamilton, CA, USA



    GBO radio telescope, Green Bank, West Virginia, USA


    CSIRO/Parkes Observatory, located 20 kilometres north of the town of Parkes, New South Wales, Australia

    By Hilary Lebow
    1
    The NIROSETI instrument saw first light on the Nickel 1-meter Telescope at Lick Observatory on March 15, 2015. (Photo by Laurie Hatch) UCSC Lick Nickel telescope

    Astronomers are expanding the search for extraterrestrial intelligence into a new realm with detectors tuned to infrared light at UC’s Lick Observatory. A new instrument, called NIROSETI, will soon scour the sky for messages from other worlds.

    “Infrared light would be an excellent means of interstellar communication,” said Shelley Wright, an assistant professor of physics at UC San Diego who led the development of the new instrument while at the University of Toronto’s Dunlap Institute for Astronomy & Astrophysics.

    Wright worked on an earlier SETI project at Lick Observatory as a UC Santa Cruz undergraduate, when she built an optical instrument designed by UC Berkeley researchers. The infrared project takes advantage of new technology not available for that first optical search.

    Infrared light would be a good way for extraterrestrials to get our attention here on Earth, since pulses from a powerful infrared laser could outshine a star, if only for a billionth of a second. Interstellar gas and dust is almost transparent to near infrared, so these signals can be seen from great distances. It also takes less energy to send information using infrared signals than with visible light.

    5
    UCSC alumna Shelley Wright, now an assistant professor of physics at UC San Diego, discusses the dichroic filter of the NIROSETI instrument. (Photo by Laurie Hatch)

    Frank Drake, professor emeritus of astronomy and astrophysics at UC Santa Cruz and director emeritus of the SETI Institute, said there are several additional advantages to a search in the infrared realm.

    “The signals are so strong that we only need a small telescope to receive them. Smaller telescopes can offer more observational time, and that is good because we need to search many stars for a chance of success,” said Drake.

    The only downside is that extraterrestrials would need to be transmitting their signals in our direction, Drake said, though he sees this as a positive side to that limitation. “If we get a signal from someone who’s aiming for us, it could mean there’s altruism in the universe. I like that idea. If they want to be friendly, that’s who we will find.”

    Scientists have searched the skies for radio signals for more than 50 years and expanded their search into the optical realm more than a decade ago. The idea of searching in the infrared is not a new one, but instruments capable of capturing pulses of infrared light only recently became available.

    “We had to wait,” Wright said. “I spent eight years waiting and watching as new technology emerged.”

    Now that technology has caught up, the search will extend to stars thousands of light years away, rather than just hundreds. NIROSETI, or Near-Infrared Optical Search for Extraterrestrial Intelligence, could also uncover new information about the physical universe.

    “This is the first time Earthlings have looked at the universe at infrared wavelengths with nanosecond time scales,” said Dan Werthimer, UC Berkeley SETI Project Director. “The instrument could discover new astrophysical phenomena, or perhaps answer the question of whether we are alone.”

    NIROSETI will also gather more information than previous optical detectors by recording levels of light over time so that patterns can be analyzed for potential signs of other civilizations.

    “Searching for intelligent life in the universe is both thrilling and somewhat unorthodox,” said Claire Max, director of UC Observatories and professor of astronomy and astrophysics at UC Santa Cruz. “Lick Observatory has already been the site of several previous SETI searches, so this is a very exciting addition to the current research taking place.”

    NIROSETI will be fully operational by early summer and will scan the skies several times a week on the Nickel 1-meter telescope at Lick Observatory, located on Mt. Hamilton east of San Jose.

    The NIROSETI team also includes Geoffrey Marcy and Andrew Siemion from UC Berkeley; Patrick Dorval, a Dunlap undergraduate, and Elliot Meyer, a Dunlap graduate student; and Richard Treffers of Starman Systems. Funding for the project comes from the generous support of Bill and Susan Bloomfield.

    While these efforts are broadly similar to what’s been done for decades, they are not your daddy’s SETI. The rapid growth in digital processing means that far larger swaths of the radio dial can be examined at one go and—in the case of the Allen array—many star systems can be checked out simultaneously. The array now examines three stars at once, but additional computer power could boost that to more than 100. Within two decades, SETI experiments will be able to complete a reconnaissance of 1 million star systems, which is hundreds of times more than have been carefully examined so far. SETI practitioners from Frank Drake to Carl Sagan have estimated that the galaxy currently houses somewhere between 10,000 and a few million broadcasting societies.

    Carl Sagan

    Frank Drake

    Drake Equation, Frank Drake, Seti Institute

    If these estimates are right, then examining 1 million star systems could well lead to a discovery. So, if the premise of SETI has merit, we should find a broadcast from E.T. within a generation. That would spare me the expense of buying you a cup of coffee.

    Furthermore, scientists have been diversifying. For two decades, some SETI researchers have used conventional optical telescopes to look for extremely brief laser flashes coming from the stars. In many ways, aliens might be more likely to communicate by pulsed light than radio signals, for the same reason that people are turning to fiber optics for Internet access: It can, at least in principle, send 100,000 times as many bits per second as radio can. These so-called optical SETI experiments have been limited to looking at one star system at a time. But like their radio cousins, they’re poised to become speedier as new technology allows them to survey ever-wider tracts of sky.

    4
    NEUTRINOS IN THE ICE: The IceCube neutrino observatory in Antarctica has been searching for energetic cosmic neutrinos, which some astronomers have proposed—probably quixotically—as a medium for extraterrestrial communications.NSF/B. Gudbjartsson

    Physicists have also proposed wholly new modes of communications, such as neutrinos and gravitational waves. Some of my SETI colleagues have mulled these options, but we don’t see much merit in them at the moment. Both neutrinos and gravitational waves are inherently hard to create and detect. In nature, it takes the collapse of a star or the merger of black holes to produce them in any quantity. The total energy required to send “Hello, Earth” would be daunting, even for a civilization that could command the resources of a galaxy.

    IceCube, the University of Wisconsin’s big neutrino detector in Antarctica, is sensitive only to very high-energy particles, which are precisely those that would be costliest to produce.


    U Wisconsin ICECUBE neutrino detector at the South Pole

    In all the years it has been operating, the instrument has detected a total of a few dozen of these particles, even though it is a cubic kilometer in size. As for gravitational waves, the Laser Interferometric Gravitational-Wave Observatory has been able to detect colliding black holes over the final second of their infall.


    VIRGO Gravitational Wave interferometer, near Pisa, Italy

    Caltech/MIT Advanced aLigo Hanford, WA, USA installation


    Caltech/MIT Advanced aLigo detector installation Livingston, LA, USA

    Cornell SXS, the Simulating eXtreme Spacetimes (SXS) project

    Gravitational waves. Credit: MPI for Gravitational Physics/W.Benger-Zib

    ESA/eLISA the future of gravitational wave research

    1
    Skymap showing how adding Virgo to LIGO helps in reducing the size of the source-likely region in the sky. (Credit: Giuseppe Greco (Virgo Urbino group)

    It is hard to imagine that aliens would go to the trouble of smashing together two huge black holes for a second’s worth of signal.

    But there is a completely different approach that has yet to be explored in much detail: to look for artifacts—engineering projects of an advanced society. Some astronomers have suggested an alien megastructure, possibly an energy-collecting Dyson sphere, as the explanation for the mysterious dimming of Tabby’s star (officially known as KIC 8462852). It is a serious possibility, but no evidence has yet been found to support it.

    6
    This artist’s concept shows a swarm of comets passing before a star. NASA / JPL-Caltech

    It’s also conceivable that extraterrestrials could have left time capsules in our own solar system, perhaps millions or billions of years ago, on the assumption that our planet might eventually evolve a species able to find them. The Lagrange points in the Earth-moon system—locations where the gravity of Earth, moon, and sun are balanced, so that an object placed there will stay there—have been suggested as good hunting grounds for alien artifacts, as has the moon itself.

    LaGrange Points map. NASA

    Another idea is that we should search for the high-energy exhausts of interstellar rockets. The fastest spacecraft would presumably use the most efficient fuel: matter combining with antimatter. Their destructive “combustion” would not only shoot the craft through space at a fair fraction of the speed of light, but would produce a gamma-ray exhaust, which we might detect. Rockets could be sorted out from natural gamma ray sources by their relatively quick motion across the sky.

    The appealing thing about artifacts is that finding them is not time-critical. In contrast, to search for signals, you need to activate your instruments at the right time. It doesn’t help to look for radio pings, laser flashes, or neutrino bursts if E.T. reached out to touch us during the reign of the dinosaurs or will do so a hundred million years from now. Artifacts have no such synchronicity problem. That said, looking for artifacts has its own bummer factors. Anything beyond our solar system would need be truly huge to be visible; cousins of the starship Enterprise would be very difficult to find.

    SETI is not a traditional science problem in which a hypothesis can be falsified. We can never prove that the aliens are not out there, only that they are. But our ability to search improves with every technological innovation. I compare the situation to the year 1491. European civilization had been around for 2,500 years, yet the Americas were not on any map. Mesoamerican civilization, for its part, had been around for about as long, but also was ignorant of what lay over the oceans. With a glimpse and a shout from a sailor on the Pinta, everything changed.

    [No mention of Laser SETI, the latest attempt from The SETI Institute.

    Laser SETI

    Seth Shostak is the senior astronomer at the SETI Institute. He chaired the International Academy of Astronautics’s SETI Permanent Study Group for a decade and hosts the SETI Institute’s weekly hour-long science radio show, “Big Picture Science.” He is the co-author of a textbook on astrobiology and of Confessions of an Alien Hunter: A Scientist’s Search for Extraterrestrial Intelligence. Follow him on Twitter @SethShostak.

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    Welcome to Nautilus. We are delighted you joined us. We are here to tell you about science and its endless connections to our lives. Each month we choose a single topic. And each Thursday we publish a new chapter on that topic online. Each issue combines the sciences, culture and philosophy into a single story told by the world’s leading thinkers and writers. We follow the story wherever it leads us. Read our essays, investigative reports, and blogs. Fiction, too. Take in our games, videos, and graphic stories. Stop in for a minute, or an hour. Nautilus lets science spill over its usual borders. We are science, connected.

     
  • richardmitnick 9:01 pm on July 21, 2017 Permalink | Reply
    Tags: Frank Drake, Messier 13, , , , The Arecibo message,   

    From NYT: “Greetings, E.T. (Please Don’t Murder Us.)” 

    New York Times

    The New York Times

    JUNE 28, 2017
    STEVEN JOHNSON

    A new initiative to beam messages into space may be
    our best shot yet at learning whether we’re alone in the
    universe. There’s just one problem: What if we’re not?

    On Nov. 16, 1974, a few hundred astronomers, government officials and other dignitaries gathered in the tropical forests of Puerto Rico’s northwest interior, a four-hour drive from San Juan. The occasion was a rechristening of the Arecibo Observatory, at the time the largest radio telescope in the world.

    NAIC/Arecibo Observatory, Puerto Rico, USA

    The mammoth structure — an immense concrete-and-aluminum saucer as wide as the Eiffel Tower is tall, planted implausibly inside a limestone sinkhole in the middle of a mountainous jungle — had been upgraded to ensure its ability to survive the volatile hurricane season and to increase its precision tenfold.

    To celebrate the reopening, the astronomers who maintained the observatory decided to take the most sensitive device yet constructed for listening to the cosmos and transform it, briefly, into a machine for talking back. After a series of speeches, the assembled crowd sat in silence at the edge of the telescope while the public-address system blasted nearly three minutes of two-tone noise through the muggy afternoon heat. To the listeners, the pattern was indecipherable, but somehow the experience of hearing those two notes oscillating in the air moved many in the crowd to tears.

    That 168 seconds of noise, now known as the Arecibo message, was the brainchild of the astronomer Frank Drake, then the director of the organization that oversaw the Arecibo facility.

    1
    Frank Drake

    The broadcast marked the first time a human being had intentionally transmitted a message targeting another solar system. The engineers had translated the missive into sound, so that the assembled group would have something to experience during the transmission. But its true medium was the silent, invisible pulse of radio waves, traveling at the speed of light.

    It seemed to most of the onlookers to be a hopeful act, if a largely symbolic one: a message in a bottle tossed into the sea of deep space. But within days, the Royal Astronomer of England, Martin Ryle, released a thunderous condemnation of Drake’s stunt. By alerting the cosmos of our existence, Ryle wrote, we were risking catastrophe. Arguing that ‘‘any creatures out there [might be] malevolent or hungry,’’ Ryle demanded that the International Astronomical Union denounce Drake’s message and explicitly forbid any further communications. It was irresponsible, Ryle fumed, to tinker with interstellar outreach when such gestures, however noble their intentions, might lead to the destruction of all life on earth.

    Today, more than four decades later, we still do not know if Ryle’s fears were warranted, because the Arecibo message is still eons away from its intended recipient, a cluster of roughly 300,000 stars known as Messier 13. If you find yourself in the Northern Hemisphere this summer on a clear night, locate the Hercules constellation in the sky, 21 stars that form the image of a man, arms outstretched, perhaps kneeling. Imagine hurtling 250 trillion miles toward those stars. Though you would have traveled far outside our solar system, you would only be a tiny fraction of the way to Messier 13. But if you were somehow able to turn on a ham radio receiver and tune it to 2,380 MHz, you might catch the message in flight: a long series of rhythmic pulses, 1,679 of them to be exact, with a clear, repetitive structure that would make them immediately detectable as a product of intelligent life.

    In its intended goal of communicating with life-forms outside our planet, the Arecibo message has surprisingly sparse company. Perhaps the most famous is housed aboard the Voyager 1 spacecraft — a gold-plated audiovisual disc, containing multilingual greetings and other evidence of human civilization — which slipped free of our solar system just a few years ago, traveling at a relatively sluggish 35,000 miles per hour. By contrast, at the end of the three-minute transmission of the Arecibo message, its initial pulses had already reached the orbit of Mars. The entire message took less than a day to leave the solar system.

    NASA/Voyager 1

    8
    Voyager – The Interstellar Mission. THE GOLDEN RECORD.

    True, some signals emanating from human activity have traveled much farther than even Arecibo, thanks to the incidental leakage of radio and television broadcasts. This was a key plot point in Carl Sagan’s novel, ‘‘Contact,’’ which imagined an alien civilization detecting the existence of humans through early television broadcasts from the Berlin Olympic Games, including clips of Hitler speaking at the opening ceremony.

    9

    Those grainy signals of Jesse Owens, and later of Howdy Doody and the McCarthy hearings, have ventured farther into space than the Arecibo pulses. But in the 40 years since Drake transmitted the message, just over a dozen intentional messages have been sent to the stars, most of them stunts of one fashion or another, including one broadcast of the Beatles’ ‘‘Across the Universe’’ to commemorate the 40th anniversary of that song’s recording. (We can only hope the aliens, if they exist, receive that message before they find the Hitler footage.)

    In the age of radio telescopes, scientists have spent far more energy trying to look for signs that other life might exist than they have signaling the existence of our own. Drake himself is now more famous for inaugurating the modern search for extraterrestrial intelligence (SETI) nearly 60 years ago, when he used a telescope in West Virginia to scan two stars for structured radio waves. Today the nonprofit SETI Institute oversees a network of telescopes and computers listening for signs of intelligence in deep space.

    SETI Institute

    SETI/Allen Telescope Array situated at the Hat Creek Radio Observatory, 290 miles (470 km) northeast of San Francisco, California, USA

    A new SETI-like project called Breakthrough Listen, funded by a $100 million grant from the Russian billionaire Yuri Milner, promises to radically increase our ability to detect signs of intelligent life.

    Breakthrough Listen Project

    1

    Lick Automated Planet Finder telescope, Mount Hamilton, CA, USA



    GBO radio telescope, Green Bank, West Virginia, USA


    CSIRO/Parkes Observatory, located 20 kilometres north of the town of Parkes, New South Wales, Australia

    As a species, we are gathered around more interstellar mailboxes than ever before, waiting eagerly for a letter to arrive. But we have, until recently, shown little interest in sending our own.

    Now this taciturn phase may be coming to an end, if a growing multidisciplinary group of scientists and amateur space enthusiasts have their way. A newly formed group known as METI (Messaging Extra Terrestrial Intelligence), led by the former SETI scientist Douglas Vakoch, is planning an ongoing series of messages to begin in 2018.

    9
    METI (Messaging Extraterrestrial Intelligence) International has announced plans to start sending signals into space

    And Milner’s Breakthrough Listen endeavor has also promised to support a ‘‘Breakthrough Message’’ companion project, including an open competition to design the messages that we will transmit to the stars. But as messaging schemes proliferate, they have been met with resistance. The intellectual descendants of Martin Ryle include luminaries like Elon Musk and Stephen Hawking, and they caution that an assumption of interstellar friendship is the wrong way to approach the question of extraterrestrial life. They argue that an advanced alien civilization might well respond to our interstellar greetings with the same graciousness that Cortés showed the Aztecs, making silence the more prudent option.

    If you believe that these broadcasts have a plausible chance of making contact with an alien intelligence, the choice to send them must rank as one of the most important decisions we will ever make as a species. Are we going to be galactic introverts, huddled behind the door and merely listening for signs of life outside? Or are we going to be extroverts, conversation-starters? And if it’s the latter, what should we say?

    Amid the decommissioned splendor of Fort Mason, on the northern edge of San Francisco, sits a bar and event space called the Interval. It’s run by the Long Now Foundation, an organization founded by Stewart Brand and Brian Eno, among others, to cultivate truly long-term thinking. The group is perhaps most famous for its plan to build a clock that will successfully keep time for 10,000 years. Long Now says the San Francisco space is designed to push the mind away from our attention-sapping present, and this is apparent from the 10,000-year clock prototypes to the menu of ‘‘extinct’’ cocktails.

    The Interval seemed like a fitting backdrop for my first meeting with Doug Vakoch, in part because Long Now has been advising METI on its message plans and in part because the whole concept of sending interstellar messages is the epitome of long-term decision-making. The choice to send a message into space is one that may well not generate a meaningful outcome for a thousand years, or a hundred thousand. It is hard to imagine any decision confronting humanity that has a longer time horizon.

    As Vakoch and I settled into a booth, I asked him how he found his way to his current vocation. ‘‘I liked science when I was a kid, but I couldn’t make up my mind which science,’’ he told me. Eventually, he found out about a burgeoning new field of study known as exobiology, or sometimes astrobiology, that examined the possible forms life could take on other planets. The field was speculative by nature: After all, its researchers had no actual specimens to study. To imagine other forms of life in the universe, exobiologists had to be versed in the astrophysics of stars and planets; the chemical reactions that could capture and store energy in these speculative organisms; the climate science that explains the weather systems on potentially life-compatible planets; the biological forms that might evolve in those different environments. With exobiology, Vakoch realized, he didn’t have to settle on one discipline: ‘‘When you think about life outside the earth, you get to dabble in all of them.’’

    As early as high school, Vakoch began thinking about how you might communicate with an organism that had evolved on another planet, the animating question of a relatively obscure subfield of exobiology known as exosemiotics. By the time Vakoch reached high school in the 1970s, radio astronomy had advanced far enough to turn exosemiotics from a glorified thought experiment into something slightly more practical. Vakoch did a science-fair project on interstellar languages, and he continued to follow the field during his college years, even as he was studying comparative religion at Carleton College in Minnesota. ‘‘The issue that really hit me early on, and that has stayed with me, is just the challenge of creating a message that would be understandable,’’ Vakoch says. Hedging his bets, he pursued a graduate degree in clinical psychology, thinking it might help him better understand the mind of some unknown organism across the universe. If the exosemiotics passion turned out to be a dead end professionally, he figured that he could always retreat back to a more traditional career path as a psychologist.

    During Vakoch’s graduate years, SETI was transforming itself from a NASA program sustained by government funding to an independent nonprofit organization, supported in part by the new fortunes of the tech sector. Vakoch moved to California and joined SETI in 1999. In the years that followed, Vakoch and other scientists involved in the program grew increasingly vocal in their argument for sending messages as well as listening for them. The ‘‘passive’’ approach was essential, they argued, but an ‘‘active’’ SETI — one targeting nearby star systems with high-powered radio signals — would increase the odds of contact. Concerned that embracing an active approach would imperil its funding, the SETI board resisted Vakoch’s efforts. Eventually Vakoch decided to form his own international organization, METI, with a multidisciplinary team that includes the former NASA chief historian Steven J. Dick, the French science historian Florence Raulin Cerceau, the Indian ecologist Abhik Gupta and the Canadian anthropologist Jerome H. Barkow.

    The newfound interest in messaging has been piqued in large part by an explosion of newly discovered planets. We now know that the universe is teeming with planets occupying what exobiologists call ‘‘the Goldilocks zone’’: not too hot and not too cold, with ‘‘just right’’ surface temperatures capable of supporting liquid water. At the start of Drake’s career in the 1950s, not a single planet outside our solar system had been observed. Today we can target a long list of potential Goldilocks-zone planets, not just distant clusters of stars. ‘‘Now we know that virtually all stars have planets,’’ Vakoch says, adding that, of these stars, ‘‘maybe one out of five have potentially habitable planets. So there’s a lot of real estate that could be inhabited.’’

    When Frank Drake and Carl Sagan first began thinking about message construction in the 1960s, their approach was genuinely equivalent to the proverbial message in a bottle. Now, we may not know the exact addresses of planets where life is likely, but we have identified many promising ZIP codes. The recent discovery of the Trappist-1 planets, three of which are potentially habitable, triggered such excitement in part because those planets were, relatively speaking, so close to home: just 40 light-years from Earth.

    The TRAPPIST-1 star, an ultracool dwarf, is orbited by seven Earth-size planets (NASA).

    If the Arecibo message does somehow find its way to an advanced civilization in Messier 13, word would not come back for at least 50,000 years. But a targeted message sent to Trappist-1 could generate a reply before the end of the century.

    Frank Drake is now 87 and lives with his wife in a house nestled in an old-growth redwood forest, at the end of a narrow, winding road in the hills near Santa Cruz. His circular driveway wraps around the trunk of a redwood bigger than a pool table. As I left my car, I found myself thinking again of the long now: a man who sends messages with a potential life span of 50,000 years, living among trees that first took root a millennium ago.

    Drake has been retired for more than a decade, but when I asked him about the Arecibo message, his face lit up at the memory. ‘‘We had just finished a very big construction project at Arecibo, and I was director then, and so they said, ‘Can you please arrange a big ceremony?’ ’’ he recalled. ‘‘We had to have some kind of eye-catching event for this ceremony. What could we do that would be spectacular? We could send a message!’’

    But how can you send a message to a life-form that may or may not exist and that you know nothing at all about, other than the fact that it evolved somewhere in the Milky Way? You need to start by explaining how the message is supposed to be read, which is known in exosemiotics as the ‘‘primer.’’ You don’t need a primer on Earth: You point to a cow, and you say, ‘‘Cow.’’ The plaques that NASA sent into space with Pioneer and Voyager had the advantage of being physical objects that could convey visual information, which at least enables you to connect words with images of the objects they refer to. In other words, you draw a cow and then put the word ‘‘cow’’ next to the drawing and slowly, with enough pointing, a language comes into view. But physical objects can’t be moved fast enough to get to a potential recipient in useful time scales. You need electromagnetic waves if you want to reach across the Milky Way.

    But how do you point to something with a radio wave? Even if you figured out a way to somehow point to a cow with electromagnetic signals, the aliens aren’t going to have cows in their world, which means the reference will most likely be lost on them. Instead, you need to think hard about the things that our hypothetical friends in the Trappist-1 system will have in common with us. If their civilization is advanced enough to recognize structured data in radio waves, they must share many of our scientific and technological concepts. If they are hearing our message, that means they are capable of parsing structured disturbances in the electromagnetic spectrum, which means they understand the electromagnetic spectrum in some meaningful way.

    The trick, then, is just getting the conversation started. Drake figured that he could count on intelligent aliens possessing the concept of simple numbers: one, three, 10, etc. And if they have numbers, then they will also very likely have the rest of what we know as basic math: addition, subtraction, multiplication, division. Furthermore, Drake reasoned, if they have multiplication and division, then they are likely to understand the concept of prime numbers — the group of numbers that are divisible only by themselves and one. (In ‘‘Contact,’’ the intercepted alien message begins with a long string of primes: 1, 2, 3, 5, 7, 11, 13, 17, 19, 23, and so on.) Many objects in space, like pulsars, send out radio signals with a certain periodicity: flashes of electromagnetic activity that switch on and off at regular rates. Primes, however, are a telltale sign of intelligent life. ‘‘Nature never uses prime numbers,’’ Drake says. ‘‘But mathematicians do.’’

    Drake’s Arecibo message drew upon a close relative of the prime numbers to construct its message. He chose to send exactly 1,679 pulses, because 1,679 is a semiprime number: a number that can be formed only by multiplying two prime numbers together, in this case 73 and 23. Drake used that mathematical quirk to turn his pulses of electromagnetic energy into a visual system. To simplify his approach, imagine I send you a message consisting of 10 X’s and 5 O’s: XOXOXXXXOXXOXOX. You notice that the number 15 is a semi-prime number, and so you organize the symbols in a 3-by-5 grid and leave the O’s as blank spaces. The result is this:

    4

    If you were an English speaker, you might just recognize a greeting in that message, the word ‘‘HI’’ mapped out using only a binary language of on-and-off states.

    Drake took the same approach, only using a much larger semiprime, which gave him a 23-by-73 grid to send a more complicated message. Because his imagined correspondents in Messier 13 were not likely to understand any human language, he filled the grid with a mix of mathematical and visual referents. The top of the grid counted from one to 10 in binary code — effectively announcing to the aliens that numbers will be represented using these symbols.

    Having established a way of counting, Drake then moved to connect the concept of numbers to some reference that the citizens of Messier 13 would likely share with us. For this step, he encoded the atomic numbers for five elements: hydrogen, carbon, nitrogen, oxygen and phosphorous, the building blocks of DNA. Other parts of the message were more visually oriented. Drake used the on-off pulses of the radio signal to ‘‘draw’’ a pixelated image of a human body. He also included a sketch of our solar system and of the Arecibo telescope itself. The message said, in effect: This is how we count; this is what we are made of; this is where we came from; this is what we look like; and this is the technology we are using to send this message to you.

    As inventive as Drake’s exosemiotics were in 1974, the Arecibo message was ultimately more of a proof-of-concept than a genuine attempt to make contact, as Drake himself is the first to admit. For starters, the 25,000 light-years that separate us from Messier 13 raise a legitimate question about whether humans will even be around — or recognizably human — by the time a message comes back. The choice of where to send it was almost entirely haphazard. The METI project intends to improve on the Arecibo model by directly targeting nearby Goldilocks-zone planets.

    One of the most recent planets added to that list orbits the star Gliese 411, a red dwarf located eight light-years away from Earth.

    On a spring evening in the Oakland hills, our own sun putting on a spectacular display as it slowly set over the Golden Gate Bridge, Vakoch and I met at one of the observatories at the Chabot Space and Science Center to take a peek at Gliese 411. A half moon overhead reduced our visibility but not so much that I couldn’t make out the faint tangerine glimmer of the star, a single blurred point of light that had traveled nearly 50 trillion miles across the universe to land on my retina. Even with the power of the Oakland telescope, there was no way to spot a planet orbiting the red dwarf. But in February of this year, a team of researchers using the Keck I telescope at the top of Mauna Kea in Hawaii announced that they had detected a ‘‘super-earth’’ in orbit around Gliese, a rocky and hot planet larger than our own.

    Keck Observatory, Maunakea, Hawaii, USA

    11
    Artist’s conceptions of the probable planet orbiting a star called GJ 411. Credit: Ricardo Ramirez.

    The METI group aims to improve on the Arecibo message not just by targeting specific planets, like that super-earth orbiting Gliese, but also by rethinking the nature of the message itself. ‘‘Drake’s original design plays into the bias that vision is universal among intelligent life,’’ Vakoch told me. Visual diagrams — whether formed through semiprime grids or engraved on plaques — seem like a compelling way to encode information to us because humans happen to have evolved an unusually acute sense of vision. But perhaps the aliens followed a different evolutionary path and found their way to a technologically advanced civilization with an intelligence that was rooted in some other sense: hearing, for example, or some other way of perceiving the world around them for which there is no earthly equivalent.

    Like so much of the SETI/METI debate, the question of visual messaging quickly spirals out into a deeper meditation, in this instance on the connection between intelligence and visual acuity. It is no accident that eyes developed independently so many times over the course of evolution on Earth, given the fact that light conveys information faster than any other conduit. That transmission-speed advantage would presumably apply on other planets in the Goldilocks zone, even if they happened to be on the other side of the Milky Way, and so it seems plausible that intelligent creatures would evolve some sort of visual system as well.

    But even more universal than sight would be the experience of time. Hans Freudenthal’s Lincos: Design of a Language for Cosmic Intercourse, a seminal book of exosemiotics published more than a half-century ago, relied heavily on temporal cues in its primer stage. Vakoch and his collaborators have been working with Freudenthal’s language in their early drafts for the message. In Lincos, duration is used as a key building block. A pulse that lasts for a certain stretch (say, in human terms, one second) is followed by a sequence of pulses that signify the ‘‘word’’ for one; a pulse that lasts for six seconds is followed by the word for six. The words for basic math properties can be conveyed by combining pulses of different lengths. You might demonstrate the property of addition by sending the word for ‘‘three’’ and ‘‘six’’ and then sending a pulse that lasts for nine seconds. ‘‘It’s a way of being able to point at objects when you don’t have anything right in front of you,’’ Vakoch explains.

    Other messaging enthusiasts think we needn’t bother worrying about primers and common referents. ‘‘Forget about sending mathematical relationships, the value of pi, prime numbers or the Fibonacci series,’’ the senior SETI astronomer, Seth Shostak, argued in a 2009 book.

    SETI astronomer Seth Shostak

    ‘‘No, if we want to broadcast a message from Earth, I propose that we just feed the Google servers into the transmitter. Send the aliens the World Wide Web. It would take half a year or less to transmit this in the microwave; using infrared lasers shortens the transmit time to no more than two days.’’ Shostak believes that the sheer magnitude of the transmitted data would enable the aliens to decipher it. There is some precedent for this in the history of archaeologists studying dead languages: The hardest code to crack is one with only a few fragments.

    Sending all of Google would be a logical continuation of Drake’s 1974 message, in terms of content if not encoding. ‘‘The thing about the Arecibo message is that, in a sense, it’s brief but its intent is encyclopedic,’’ Vakoch told me as we waited for the sky to darken in the Oakland hills. ‘‘One of the things that we are exploring for our transmission is the opposite extreme. Rather than being encyclopedic, being selective. Instead of this huge digital data dive, trying to do something elegant. Part of that is thinking about what are the most fundamental concepts we need.’’ There is something provocative about the question Vakoch is wrestling with here: Of all the many manifestations of our achievements as a species, what’s the simplest message we can create that will signal that we’re interesting, worthy of an interstellar reply?

    But to METI’s critics, what he should be worrying about instead is the form that the reply might take: a death ray, or an occupying army.

    6

    Before Doug Vakoch had even filed the papers to form the METI nonprofit organization in July 2015, a dozen or so science-and-tech luminaries, including SpaceX’s Elon Musk, signed a statement categorically opposing the project, at least without extensive further discussion, on a planetary scale. ‘‘Intentionally signaling other civilizations in the Milky Way Galaxy,’’ the statement argued, ‘‘raises concerns from all the people of Earth, about both the message and the consequences of contact. A worldwide scientific, political and humanitarian discussion must occur before any message is sent.’’

    One signatory to that statement was the astronomer and science-fiction author David Brin, who has been carrying on a spirited but collegial series of debates with Vakoch over the wisdom of his project. ‘‘I just don’t think anybody should give our children a fait accompli based on blithe assumptions and assertions that have been untested and not subjected to critical peer review,’’ he told me over a Skype call from his home office in Southern California. ‘‘If you are going to do something that is going to change some of the fundamental observable parameters of our solar system, then how about an environmental-impact statement?’’

    The anti-METI movement is predicated on a grim statistical likelihood: If we do ever manage to make contact with another intelligent life-form, then almost by definition, our new pen pals will be far more advanced than we are. The best way to understand this is to consider, on a percentage basis, just how young our own high-tech civilization actually is. We have been sending structured radio signals from Earth for only the last 100 years. If the universe were exactly 14 billion years old, then it would have taken 13,999,999,900 years for radio communication to be harnessed on our planet. The odds that our message would reach a society that had been tinkering with radio for a shorter, or even similar, period of time would be staggeringly long. Imagine another planet that deviates from our timetable by just a tenth of 1 percent: If they are more advanced than us, then they will have been using radio (and successor technologies) for 14 million years. Of course, depending on where they live in the universe, their signals might take millions of years to reach us. But even if you factor in that transmission lag, if we pick up a signal from another galaxy, we will almost certainly find ourselves in conversation with a more advanced civilization.

    7
    Carl Sagan holding the Pioneer plaque in Boston, in 1972. Credit Jeff Albertson Photograph Collection/UMass Amherst Libraries.

    It is this asymmetry that has convinced so many future-minded thinkers that METI is a bad idea. The history of colonialism here on Earth weighs particularly heavy on the imaginations of the METI critics. Stephen Hawking, for instance, made this observation in a 2010 documentary series: ‘‘If aliens visit us, the outcome would be much as when Columbus landed in America, which didn’t turn out well for the Native Americans.’’ David Brin echoes the Hawking critique: ‘‘Every single case we know of a more technologically advanced culture contacting a less technologically advanced culture resulted at least in pain.’’

    METI proponents counter the critics with two main arguments. The first is essentially that the horse has already left the barn: Given that we have been ‘‘leaking’’ radio waves in the form of Leave It to Beaver and the nightly news for decades, and given that other civilizations are likely to be far more advanced than we are, and thus capable of detecting even weak signals, then it seems likely that we are already visible to extraterrestrials. In other words, they know we’re here, but they haven’t considered us to be worthy of conversation yet. ‘‘Maybe in fact there are a lot more civilizations out there, and even nearby planets are populated, but they’re simply observing us,’’ Vakoch argues. ‘‘It’s as if we are in some galactic zoo, and if they’ve been watching us, it’s like watching zebras talking to one another. But what if one of those zebras suddenly turns toward you and with its hooves starts scratching out the prime numbers. You’d relate to that zebra differently!’’

    Brin thinks that argument dangerously underestimates the difference between a high-power, targeted METI transmission and the passive leakage of media signals, which are far more difficult to detect. ‘‘Think about it this way: If you want to communicate with a Boy Scout camp on the other side of the lake, you could kneel down at the end of the lake and slap the water in Morse code,’’ he says. ‘‘And if they are spectacularly technologically advanced Boy Scouts who happened also to be looking your way, they might build instruments that would be able to parse out your Morse code. But then you whip out your laser-pointer and point it at their dock. That is exactly the order of magnitude difference between picking up [reruns of] ‘I Love Lucy’ from the 1980s, when we were at our noisiest, and what these guys want to do.’’

    METI defenders also argue that the threat of some Klingon-style invasion is implausible, given the distances involved. If, in fact, advanced civilizations were capable of zipping around the galaxy at the speed of light, we would have already encountered them. The much more likely situation is that only communications can travel that fast, and so a malevolent presence on some distant planet will only be able to send us hate mail. But critics think that sense of security is unwarranted. Writing in Scientific American, the former chairman of SETI, John Gertz, argued that ‘‘a civilization with malign intent that is only modestly more advanced than we are might be able to annihilate Earth with ease by means of a small projectile filled with a self-replicating toxin or nano gray goo; a kinetic missile traveling at an appreciable percentage of the speed of light; or weaponry beyond our imagination.’’

    Brin looks to our own technological progress as a sign of where a more advanced civilization might be in terms of interstellar combat: ‘‘It is possible that within just 50 years, we could create an antimatter rocket that could propel a substantial pellet of several kilograms, at half the speed of light at times to intersect with the orbit of a planet within 10 light-years of us.’’ Even a few kilograms colliding at that speed would produce an explosion much greater than the Hiroshima and Nagasaki detonations combined. ‘‘And if we could do that in 50 years, imagine what anybody else could do, completely obeying Einstein and the laws of physics.’’

    Interestingly, Frank Drake himself is not a supporter of the METI efforts, though he does not share Hawking and Musk’s fear of interstellar conquistadors. ‘‘We send messages all the time, free of charge,’’ he says. ‘‘There’s a big shell out there now 80 light-years around us. A civilization only a little more advanced than we are can pick those things up. So the point is we are already sending copious amounts of information.’’ Drake believes that any other advanced civilization out there must be doing the same, so scientists like Vakoch should devote themselves to picking up on that chatter instead of trying to talk back. METI will consume resources, Drake says, that would be ‘‘better spent listening and not sending.’’

    METI critics, of course, might be right about the frightening sophistication of these other, presumably older civilizations but wrong about the likely nature of their response. Yes, they could be capable of sending projectiles across the galaxy at a quarter of the speed of light. But their longevity would also suggest that they have figured out how to avoid self-destruction on a planetary scale. As Steven Pinker has argued, human beings have become steadily less violent over the last 500 years; per capita deaths from military conflict are most likely at an all-time low. Could this be a recurring pattern throughout the universe, played out on much longer time scales: the older a civilization gets, the less warlike it becomes? In which case, if we do get a message to extraterrestrials, then perhaps they really will come in peace.

    These sorts of questions inevitably circle back to the two foundational thought experiments that SETI and METI are predicated upon: the Fermi Paradox and the Drake Equation. The paradox, first formulated by the Italian physicist and Nobel laureate Enrico Fermi, begins with the assumption that the universe contains an unthinkably large number of stars, with a significant percentage of them orbited by planets in the Goldilocks zone. If intelligent life arises on even a small fraction of those planets, then the universe should be teeming with advanced civilizations. And yet to date, we have seen no evidence of those civilizations, even after several decades of scanning the skies through SETI searches. Fermi’s question, apparently raised during a lunch conversation at Los Alamos in the early 1950s, was a simple one: ‘‘Where is everybody?’’

    The Drake Equation is an attempt to answer that question. The equation dates back to one of the great academic retreats in the history of scholarship: a 1961 meeting at the Green Bank observatory in West Virginia, which included Frank Drake, a 26-year-old Carl Sagan and the dolphin researcher (and later psychedelic explorer) John Lilly. During the session, Drake shared his musings on the Fermi Paradox, formulated as an equation. If we start scanning the cosmos for signs of intelligent life, Drake asked, how likely are we to actually detect something? The equation didn’t generate a clear answer, because almost all the variables were unknown at the time and continue to be largely unknown a half-century later. But the equation had a clarifying effect, nonetheless. In mathematical form, it looks like this:

    N= R* x ƒp x ne x ƒl x ƒi x ƒc x L

    N represents the number of extant, communicative civilizations in the Milky Way. The initial variable R* corresponds to the rate of star formation in the galaxy, effectively giving you the total number of potential suns that could support life. The remaining variables then serve as a kind of nested sequence of filters: Given the number of stars in the Milky Way, what fraction of those have planets, and how many of those have an environment that can support life? On those potentially hospitable planets, how often does life itself actually emerge, and what fraction of that life evolves into intelligent life, and what fraction of that life eventually leads to a civilization’s transmitting detectable signals into space? At the end of his equation, Drake placed the crucial variable L, which is the average length of time during which those civilizations emit those signals.

    What makes the Drake Equation so mesmerizing is in part the way it forces the mind to yoke together so many different intellectual disciplines in a single framework. As you move from left to right in the equation, you shift from astrophysics, to the biochemistry of life, to evolutionary theory, to cognitive science, all the way to theories of technological development. Your guess about each value in the Drake Equation winds up revealing a whole worldview: Perhaps you think life is rare, but when it does emerge, intelligent life usually follows; or perhaps you think microbial life is ubiquitous throughout the cosmos, but more complex organisms almost never form. The equation is notoriously vulnerable to very different outcomes, depending on the numbers you assign to each variable.

    The most provocative value is the last one: L, the average life span of a signal-transmitting civilization. You don’t have to be a Pollyanna to defend a relatively high L value. All you need is to believe that it is possible for civilizations to become fundamentally self-sustaining and survive for millions of years. Even if one in a thousand intelligent life-forms in space generates a million-year civilization, the value of L increases meaningfully. But if your L-value is low, that implies a further question: What is keeping it low? Do technological civilizations keep flickering on and off in the Milky Way, like so many fireflies in space? Do they run out of resources? Do they blow themselves up?

    Since Drake first sketched out the equation in 1961, two fundamental developments have reshaped our understanding of the problem. First, the numbers on the left-hand side of the equation (representing the amount of stars with habitable planets) have increased by several orders of magnitude. And second, we have been listening for signals for decades and heard nothing. As Brin puts it: ‘‘Something is keeping the Drake Equation small. And the difference between all the people in the SETI debates is not whether that’s true, but where in the Drake panoply the fault lies.’’

    If the left-hand values keep getting bigger and bigger, the question is which variables on the right-hand side are the filters. As Brin puts it, we want the filter to be behind us, not the one variable, L, that still lies ahead of us. We want the emergence of intelligent life to be astonishingly rare; if the opposite is true, and intelligent life is abundant in the Milky Way, then L values might be low, perhaps measured in centuries and not even millenniums. In that case, the adoption of a technologically advanced lifestyle might be effectively simultaneous with extinction. First you invent radio, then you invent technologies capable of destroying all life on your planet and shortly thereafter you push the button and your civilization goes dark.

    The L-value question explains why so many of METI’s opponents — like Musk and Hawking — are also concerned with the threat of extinction-level events triggered by other potential threats: superintelligent computers, runaway nanobots, nuclear weapons, asteroids. In a low L-value universe, planet-wide annihilation is an imminent possibility. Even if a small fraction of alien civilizations out there would be inclined to shoot a two-kilogram pellet toward us at half the speed of light, is it worth sending a message if there’s even the slightest chance that the reply could result in the destruction of all life on earth?

    Other, more benign, explanations for the Fermi Paradox exist. Drake himself is pessimistic about the L value, but not for dystopian reasons. ‘‘It’s because we’re getting better at technology,’’ he says. The modern descendants of the TV and radio towers that inadvertently sent Elvis to the stars are far more efficient in terms of the power they use, which means the ‘‘leaked’’ signals emanating from Earth are far fainter than they were in the 1950s. In fact, we increasingly share information via fiber optics and other terrestrial conduits that have zero leakage outside our atmosphere. Perhaps technologically advanced societies do flicker on and off like fireflies, but it’s not a sign that they’re self-destructive; it’s just a sign that they got cable.

    But to some METI critics, even a less-apocalyptic interpretation of the Fermi Paradox still suggests caution. Perhaps advanced civilizations tend to reach a point at which they decide, for some unknown reason, that it is in their collective best interest not to transmit any detectable signal to their neighbors in the Milky Way. ‘‘That’s the other answer for the Fermi Paradox,’’ Vakoch says with a smile. ‘‘There’s a Stephen Hawking on every planet, and that’s why we don’t hear from them.’’

    In his California home among the redwoods, Frank Drake has a version of the Arecibo message visually encoded in a very different format: not a series of radio-wave pulses but as a stained-glass window in his living room. A grid of pixels on a cerulean blue background, it almost resembles a game of Space Invaders. Stained glass is an appropriate medium, given the nature of the message: an offering dispatched to unknown beings residing somewhere in the sky.

    There is something about the METI question that forces the mind to stretch beyond its usual limits. You have to imagine some radically different form of intelligence, using only your human intelligence. You have to imagine time scales on which a decision made in 2017 might trigger momentous consequences 10,000 years from now. The sheer magnitude of those consequences challenges our usual measures of cause and effect. Whether you believe that the aliens are likely to be warriors or Zen masters, if you think that METI has a reasonable chance of making contact with another intelligent organism somewhere in the Milky Way, then you have to accept that this small group of astronomers and science-fiction authors and billionaire patrons debating semi-prime numbers and the ubiquity of visual intelligence may in fact be wrestling with a decision that could prove to be the most transformative one in the history of human civilization.

    8
    Frank Drake in front of the National Radio Astronomy Observatory Green Bank 300-foot radio telescope in West Virginia in the mid-1960’s.
    Credit National Radio Astronomy Observatory.

    All of which takes us back to a much more down-to-earth, but no less challenging, question: Who gets to decide? After many years of debate, the SETI community established an agreed-­upon procedure that scientists and government agencies should follow in the event that the SETI searches actually stumble upon an intelligible signal from space. The protocols specifically ordain that ‘‘no response to a signal or other evidence of extraterrestrial intelligence should be sent until appropriate international consultations have taken place.’’ But an equivalent set of guidelines does not yet exist to govern our own interstellar outreach.

    One of the most thoughtful participants in the METI debate, Kathryn Denning, an anthropologist at York University in Toronto, has argued that our decisions about extraterrestrial contact are ultimately more political than scientific. ‘‘If I had to take a position, I’d say that broad consultation regarding METI is essential, and so I greatly respect the efforts in that direction,’’ Denning says. ‘‘But no matter how much consultation there is, it’s inevitable that there will be significant disagreement about the advisability of transmitting, and I don’t think this is the sort of thing where a simple majority vote or even supermajority should carry the day . . . so this keeps bringing us back to the same key question: Is it O.K. for some people to transmit messages at significant power when other people don’t want them to?’’

    In a sense, the METI debate runs parallel to other existential decisions that we will be confronting in the coming decades, as our technological and scientific powers increase. Should we create superintelligent machines that exceed our own intellectual capabilities by such a wide margin that we cease to understand how their intelligence works? Should we ‘‘cure’’ death, as many technologists are proposing? Like METI, these are potentially among the most momentous decisions human beings will ever make, and yet the number of people actively participating in those decisions — or even aware such decisions are being made — is minuscule.

    ‘‘I think we need to rethink the message process so that we are sending a series of increasingly inclusive messages,’’ Vakoch says. ‘‘Any message that we initially send would be too narrow, too incomplete. But that’s O.K. Instead, what we should be doing is thinking about how to make the next round of messages better and more inclusive. We ideally want a way to incorporate both technical expertise — people who have been thinking about these issues from a range of different disciplines — and also getting lay input. I think it’s often been one or the other. One way we can get lay input in a way that makes a difference in terms of message content is to survey people about what sorts of things they would want to say. It’s important to see what the general themes are that people would want to say and then translate those into a Lincos-like message.’’

    When I asked Denning where she stands on the METI issue, she told me: ‘‘I have to answer that question with a question: Why are you asking me? Why should my opinion matter more than that of a 6-year-old girl in Namibia? We both have exactly the same amount at stake, arguably, she more than I, since the odds of being dead before any consequences of transmission occur are probably a bit higher for me, assuming she has access to clean water and decent health care and isn’t killed far too young in war.’’ She continued: ‘‘I think the METI debate may be one of those rare topics where scientific knowledge is highly relevant to the discussion, but its connection to obvious policy is tenuous at best, because in the final analysis, it’s all about how much risk the people of Earth are willing to tolerate. . . . And why exactly should astronomers, cosmologists, physicists, anthropologists, psychologists, sociologists, biologists, sci-fi authors or anyone else (in no particular order), get to decide what those tolerances should be?’’

    Wrestling with the METI question suggests, to me at least, that the one invention human society needs is more conceptual than technological: We need to define a special class of decisions that potentially create extinction-level risk. New technologies (like superintelligent computers) or interventions (like METI) that pose even the slightest risk of causing human extinction would require some novel form of global oversight. And part of that process would entail establishing, as Denning suggests, some measure of risk tolerance on a planetary level. If we don’t, then by default the gamblers will always set the agenda, and the rest of us will have to live with the consequences of their wagers.

    In 2017, the idea of global oversight on any issue, however existential the threat it poses, may sound naïve. It may also be that technologies have their own inevitability, and we can only rein them in for so long: If contact with aliens is technically possible, then someone, somewhere is going to do it soon enough. There is not a lot of historical precedent for humans voluntarily swearing off a new technological capability — or choosing not to make contact with another society — because of some threat that might not arrive for generations. But maybe it’s time that humans learned how to make that kind of choice. This turns out to be one of the surprising gifts of the METI debate, whichever side you happen to take. Thinking hard about what kinds of civilization we might be able to talk to ends up making us think even harder about what kind of civilization we want to be ourselves.

    Near the end of my conversation with Frank Drake, I came back to the question of our increasingly quiet planet: all those inefficient radio and television signals giving way to the undetectable transmissions of the internet age. Maybe that’s the long-term argument for sending intentional messages, I suggested; even if it fails in our lifetime, we will have created a signal that might enable an interstellar connection thousands of years from now.

    Drake leaned forward, nodding. ‘‘It raises a very interesting, nonscientific question, which is: Are extraterrestrial civilizations altruistic? Do they recognize this problem and establish a beacon for the benefit of the other folks out there? My answer is: I think it’s actually Darwinian; I think evolution favors altruistic societies. So my guess is yes. And that means there might be one powerful signal for each civilization.’’ Given the transit time across the universe, that signal might well outlast us as a species, in which case it might ultimately serve as a memorial as much as a message, like an interstellar version of the Great Pyramids: proof that a technologically advanced organism evolved on this planet, whatever that organism’s ultimate fate.

    As I stared at Drake’s stained-glass Arecibo message, in the middle of that redwood grove, it seemed to me that an altruistic civilization — one that wanted to reach across the cosmos in peace — would be something to aspire to, despite the potential for risk. Do we want to be the sort of civilization that boards up the windows and pretends that no one is home, for fear of some unknown threat lurking in the dark sky? Or do we want to be a beacon?

    Correction: June 30, 2017

    An earlier version of this article misstated the impact a few kilograms traveling half the speed of light would have if they collided with Earth. The impact would be less than that of the asteroid that killed off the dinosaurs, not more.

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

     
  • richardmitnick 10:32 am on May 18, 2017 Permalink | Reply
    Tags: , , , , Colossus project, , Frank Drake, ,   

    From Centauri Dreams via METI International: “A ‘Census’ for Civilizations” 

    1

    METI International

    2

    Centauri Dreams

    May 17, 2017
    Paul Gilster

    We’ve been talking about the Colossus project, and the possibility that this huge (though remarkably lightweight) instrument could detect the waste heat of extraterrestrial civilizations.

    2

    But what are the chances of this, if we work out the numbers based on the calculations the Colossus team is working with? After all, Frank Drake put together his famous equation as a way of making back-of-the-envelope estimates of SETI’s chances for success, working the numbers even though most of them at that time had to be no more than guesses.

    Drake Equation, Frank Drake, Seti Institute

    SETI Institute

    SETI/Allen Telescope Array situated at the Hat Creek Radio Observatory, 290 miles (470 km) northeast of San Francisco, California, USA

    Bear in mind as we talk about this that we’d like to arrive at a figure for the survival of a civilization, a useful calculation because we have no idea whether technology-driven cultures survive or destroy themselves. Civilizations may live forever, or they may die out relatively quickly, perhaps on a scale of thousands of years. Here Colossus can give us useful information.

    The intention, as discussed in a paper by Jeff Kuhn and Svetlana Berdyugina that we looked at yesterday (citation below), is to look out about 60 light years, a sphere within which we have numerous bright stars that a large instrument like Colossus can investigate for such detections. We’re making the assumption, by looking for waste heat, that civilizations living around such stars could be detected whether or not they intend to communicate.

    3
    Image: Figure 1 from Kuhn & Berdyugina, “Global Warming as a Detectable Thermodynamic Marker of Earth-like Extrasolar Civilizations: The case for a Telescope like Colossus.” Caption: Man-made visible light on the Earth in 2011. From DMPS/NASA. The brightest pixels in this 0.5 × 0.5 degree resolution map have a radiance of about 0.05 × 10−6 W/cm2/sr/micron. Credit: Jeff Kuhn/Svetlana Berdyugina.

    Let’s take the fraction of stars with planets as 0.5, and the fraction of those with planets in the habitable zone as 0.5, numbers that have the benefit of Kepler data as some justification, unlike Drake’s pre-exoplanet era calculations. Kuhn and Berdyugina have to make some Drake-like guesses as they run their own exercise, so let’s get really imaginative: Let’s put the fraction of those planets that develop civilizations at the same 0.5, and the fraction of those that are more advanced than our own likewise at 0.5. These numbers operate under the assumption that our own civilization is not inherently special but just one of many.

    Work all this out and we can come up with a figure for the fraction of civilizations that might be out there. But how many of them have survived their technological infancy?

    Let me cut straight to the paper on the outcome of the kind of survey contemplated for Colossus, which is designed to include “a quantifiably complete neighborhood cosmic survey for [Kardashev] Type I civilizations” within about 20 light years of the Sun, but one that extends out to 60 light years. In the section below, Ω stands for the ratio of power production by an extraterrestrial civilization to the amount of stellar power it receives (more on this in a moment).

    From the paper:

    “…current planet statistics suggest that out of 650 stars within 20 pc at least one quarter would have HZEs [Habitable Zone Earths]. Assuming that one quarter of those will develop Ω ≥ 0.01 civilizations, we arrive at the number of detectable civilizations in the Solar neighbourhood ND = 40fs, where fs is the fraction of survived civilizations (i.e., civilizations that form and survive). Hence, even if only one in 20 advanced civilizations survive (including us at the time of survey), we should get a detection. Taking into account the thermodynamic nature of our biomarker, this detection is largely independent of the sociology of detectable ETCs.”

    Independent because we are not relying on any intent to communicate with us, and are looking for civilizations that may in fact be advanced not far beyond our own level, as well as their more advanced counterparts, should they exist.

    Suppose we detect not a single extraterrestrial civilization. Within the parameters of the original assumptions, we could conclude that if a civilization does reach a certain level of technology, its probability of survival is low. That would be a null result of some consequence, because it would place the survival of our own civilization in context. We would, in other words, face old questions anew: What can we do to prevent catastrophe as a result of technology? We might also consider that our assumptions may have been too optimistic — perhaps the fraction of habitable zone planets developing civilizations is well below 0.5.

    But back to that interesting figure Ω. The discussion depends upon the idea that the marker of civilization using energy is infrared heat radiation. Take Earth’s current global power production to be some 15 terawatts. It turns out that this figure is some 0.04 percent of the total solar power Earth receives. In this Astronomy article from 2013, Kuhn and Berdyugina, along with Colossus backers David Halliday and Caisey Harlingten, point out that in Roman times, the figure for Ω was about 1/1000th of what it is today. Again, Ω stands for the ratio of power production by a civilization to the amount of solar power it receives.

    The authors see global planetary warming as setting a limit on the power a civilization can consume, because both sunlight from the parent star as well as a civilization’s own power production determine the global temperature. To produce maximum energy, a civilization would surely want to absorb the power of all the sunlight available, increasing Ω toward 1. Now we have a culture that is producing more and more waste heat radiation on its own world. And we could use an instrument like Colossus to locate civilizations that are on this course.

    In fact, we can do better than that, because within the 60 light year parameters being discussed, we can study the heat from such civilizations as the home planet rotates in and out of view of the Earth. Kuhn and Berdyugina liken the method to studying changes of brightness on a star. In this case, we are looking at time-varying brightness signals that can identify sources of heat on the planet, perhaps clustered into the extraterrestrial analog of cities. A large enough infrared telescope could observe civilizations that use as little as 1 percent of the total solar power they intercept by combining visible and infrared observations. A low value of Ω indeed.

    4
    Image: Figure 3 from the Kuhn/Berdyugina paper “Global Warming as a Detectable Thermodynamic Marker of Earth-like Extrasolar Civilizations: The case for a Telescope like Colossus.” Caption: Fig. 3. Expanded view of a representative North American region illustrating temperature perturbation due to cities (left, heated cities are seen in red) and corresponding surface albedo (right). From NEO/NASA.

    You can see what a challenge this kind of observation presents. It demands, if the telescope is on the ground, adaptive optics that can cancel out atmospheric distortion. It also demands coronagraph technology that can distinguish the glow of a working civilization from a star that could be many millions of times brighter. And because we are after the highest possible resolution, we need the largest possible collecting area. The contrast sensitivity at visible and infrared wavelengths of the instrument are likewise crucial factors.

    I’ll refer you to “New strategies for an extremely large telescope dedicated to extremely high contrast: The Colossus Project” (citation below) for the ways in which the Colossus team hopes to address all these issues. But I want to back out to the larger view: As a civilization, we are now capable of building technologies that can identify extraterrestrial cultures at work, and indeed, instruments like Colossus could be working for us within a decade if we fund them.

    We can add such capabilities to the detection of non-technological life as well, through the search for biomarkers that such large instruments can enable. More on that tomorrow, when I’ll wrap up this set on Colossus with a look at photosynthesis signatures on exoplanets. Because for all we know, life itself may be common to habitable zone planets, while technological civilization could be a rarity in the galaxy. Learning about our place in the universe is all about finding the answers to questions like these, answers now beginning to come into range.

    The Colossus description paper is Kuhn et al., “Looking Beyond 30m-class Telescopes: The Colossus Project,” SPIE Astronomical Telescopes and Instrumentation (2014). The paper on Colossus and waste heat is Kuhn & Berdyugina, “Global warming as a detectable thermodynamic marker of Earth-like extrasolar civilizations: the case for a telescope like Colossus,” International Journal of Astrobiology 14 (3): 401-410 (2015).

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    The primary objectives and purposes of METI International are to:

    Conduct scientific research and educational programs in Messaging Extraterrestrial Intelligence (METI) and the Search for Extraterrestrial Intelligence (SETI).

    Promote international cooperation and collaboration in METI, SETI, and astrobiology.

    Understand and communicate the societal implications and relevance of searching for life beyond Earth, even before detection of extraterrestrial life.

    Foster multidisciplinary research on the design and transmission of interstellar messages, building a global community of scholars from the natural sciences, social sciences, humanities, and arts.

    Research and communicate to the public the many factors that influence the origins, evolution, distribution, and future of life in the universe, with a special emphasis on the last three terms of the Drake Equation: (1) the fraction of life-bearing worlds on which intelligence evolves, (2) the fraction of intelligence-bearing worlds with civilizations having the capacity and motivation for interstellar communication, and (3) the longevity of such civilizations.

    Offer programs to the public and to the scholarly community that foster increased awareness of the challenges facing our civilization’s longevity, while encouraging individual and community activities that support the sustainability of human culture on multigenerational timescales, which is essential for long-term METI and SETI research.

     
  • richardmitnick 10:35 am on May 1, 2016 Permalink | Reply
    Tags: , , , Frank Drake, ,   

    From Science Alert: “Physicists have calculated that we’re *probably* not the only advanced civilisation ever in the Universe” 

    ScienceAlert

    Science Alert

    29 APR 2016
    PETER DOCKRILL

    Trying to find an answer to the question of whether humanity is all alone in the cosmos is what the search for extraterrestrial intelligence (SETI) is all about, and a new equation ought to give hope to the sky-watching optimists among us.

    SETI Institute
    SETI/Allen Telescope Array situated at the Hat Creek Radio Observatory, 290 miles (470 km) northeast of San Francisco, California, USA
    SETI Institute; SETI/Allen Telescope Array situated at the Hat Creek Radio Observatory

    SETI@home, BOINC project at UC Berkeley Space Science Lab
    SETI@home, BOINC project at UC Berkeley Space Science Lab

    At least, kind of. Instead of seeking to estimate whether technologically advanced species currently exist elsewhere in the Universe – the focus of the famous but arguably flawed Drake equation – the researchers are interested in a broader question: are we the only advanced civilisation ever? And by their calculations, the odds are against us being unique.

    Drake Equation, Frank Drake, Seti Institute
    Drake Equation, Frank Drake, SETI Institute

    According to astronomer Adam Frank from the University of Rochester, one of the problems with the Drake equation is that it incorporates the hypothetical length of time advanced civilisations exist for – something we’re perhaps not well equipped to be speculating about.

    “The fact that humans have had rudimentary technology for roughly 10,000 years doesn’t really tell us if other societies would last that long or perhaps much longer,” says Frank.

    But by reformulating the equation to look at the history of the whole Universe instead, the team argues that they can avoid the ambiguity of longevity estimates.

    “Rather than asking how many civilisations may exist now, we ask ‘Are we the only technological species that has ever arisen?'” said fellow researcher Woodruff Sullivan from the University of Washington. “This shifted focus eliminates the uncertainty of the civilisation lifetime question and allows us to address what we call the ‘cosmic archaeological question’ – how often in the history of the universe has life evolved to an advanced state?”

    Given that this calculation would still involve a lot of unknowns, the team frames the question by calculating the odds against intelligent life occurring elsewhere in the Universe.

    Armed with new knowledge about exoplanet occurrence and habitability zones since the Drake equation was formulated back in 1961, the researchers calculate that human civilisation is likely to be unique in history only if the odds of a civilisation developing on a habitable planet are less than about 1 in 10 billion trillion.

    In other words, while the chances of technologically advanced species developing on alien worlds might be slim per Drake’s equation, they’d have to be really, really, really slim for there to have never been any other advanced civilisations existing ever in the Universe.

    “One in 10 billion trillion is incredibly small,” said Frank. “To me, this implies that other intelligent, technology producing species very likely have evolved before us.”

    But while the hypothesis might give hope to those who’d like to think we’re not totally alone on our little rock in space, the extreme breadth of the team’s temporal analysis comes with some harsh reality. Over such a long time frame, impermanent civilisations would be extremely unlikely to exist alongside one another at any moment in time.

    “The Universe is more than 13 billion years old,” said Sullivan. “That means that even if there have been a thousand civilisations in our own galaxy, if they live only as long as we have been around – roughly 10,000 years – then all of them are likely already extinct. And others won’t evolve until we are long gone.”

    But on the bright side, perhaps the importance of the research isn’t in pointing out the unlikeliness of bumping into our cosmic neighbours, so much as saying that: yes, once upon a time, somebody else was probably out there – and they likely looked up at the sky wondering about us too.

    “From a fundamental perspective the question is ‘has it ever happened anywhere before?'” says Frank. “And it is astonishingly likely that we are not the only time and place that an advanced civilisation has evolved.”

    The findings are reported in Astrobiology*.

    *Science paper:
    A New Empirical Constraint on the Prevalence of Technological Species in the Universe

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

     
  • richardmitnick 7:33 pm on March 3, 2015 Permalink | Reply
    Tags: , , , Frank Drake, ,   

    From Space.com: “The Father of SETI: Q&A with Astronomer Frank Drake” 

    space-dot-com logo

    SPACE.com

    February 26, 2015
    Leonard David

    Arecibo Observatory

    Detecting signals from intelligent aliens is a lifelong quest of noted astronomer Frank Drake. He conducted the first modern search for extraterrestrial intelligence (SETI) experiment in 1960. More than five decades later, the hunt remains front-and-center for the scientist.

    5
    Frank Drake

    Drake also devised a thought experiment in 1961 to identify specific factors believed to play a role in the development of civilizations in our galaxy. This experiment took the form of an equation that researchers have used to estimate the possible number of alien civilizations — the famous Drake Equation.

    The Drake equation is:

    N = R*. fp. ne. fl. fi. fc. L

    where:

    N = the number of civilizations in our galaxy with which radio-communication might be possible (i.e. which are on our current past light cone);

    and

    R* = the average rate of star formation in our galaxy
    fp = the fraction of those stars that have planets
    ne = the average number of planets that can potentially support life per star that has planets
    fl = the fraction of planets that could support life that actually develop life at some point
    fi = the fraction of planets with life that actually go on to develop intelligent life (civilizations)
    fc = the fraction of civilizations that develop a technology that releases detectable signs of their existence into space
    L = the length of time for which such civilizations release detectable signals into space

    Drake constructed the “Arecibo Message” of 1974 — the first interstellar message transmitted via radio waves from Earth for the benefit of any extraterrestrial civilization that may be listening.

    The message consists of seven parts that encode the following (from the top down):[4]

    The numbers one (1) to ten (10)
    The atomic numbers of the elements hydrogen, carbon, nitrogen, oxygen, and phosphorus, which make up deoxyribonucleic acid (DNA)
    The formulas for the sugars and bases in the nucleotides of DNA
    The number of nucleotides in DNA, and a graphic of the double helix structure of DNA
    A graphic figure of a human, the dimension (physical height) of an average man, and the human population of Earth
    A graphic of the Solar System indicating which of the planets the message is coming from
    A graphic of the Arecibo radio telescope and the dimension (the physical diameter) of the transmitting antenna dish

    3
    This is the message with color added to highlight its separate parts. The actual binary transmission carried no color information.

    Space.com caught up with Drake to discuss the current state of SETI during an exclusive interview at the NASA Innovative Advanced Concepts (NIAC) 2015 symposium, which was held here from Jan. 27 to Jan. 29.

    Drake serves on the NASA NIAC External Council and is chairman emeritus of the SETI Institute in Mountain View, Calif. and director of the Carl Sagan Center for the Study of Life in the Universe.

    Space.com: What’s your view today concerning the status of SETI?

    Frank Drake: The situation with SETI is not good. The enterprise is falling apart for lack of funding. While NASA talks about “Are we alone?” as a number one question, they are putting zero money into searching for intelligent life. There’s a big disconnect there.

    We’re on the precipice. The other thing is that there are actually negative events on the horizon that are being considered.

    Space.com: And those are?

    Drake: There are two instruments, really the powerful ones for answering the “are we alone” question … the Arecibo telescope[above] and the Green Bank Telescope [GBT].

    NRAO GBT
    GBT

    They are the world’s two largest radio telescopes, and both of them are in jeopardy. There are movements afoot to close them down … dismantle them. They are both under the National Science Foundation and they are desperate to cut down the amount of money they are putting into them. And their choice is to just shut them down or to find some arrangement where somebody else steps in and provides funding.

    So this is the worst moment for SETI. And if they really pull the rug out from under the Green Bank Telescope and Arecibo … it’s suicide.

    Space.com: What happens if they close those down?

    Drake: We’re all then sitting in our living rooms and watching science fiction movies.

    Space.com: How about the international scene?

    Drake: The international scene has gone down too because all the relevant countries are cash-strapped also.

    There is a major effort in China, a 500-meter [1,640 feet] aperture spherical radio telescope. The entire reflector is under computer control with actuators. They change the shape of the reflector depending on what direction they are trying to look. The technology is very complicated and challenging. The Russians tried it and it never worked right. But … there are serious resources there.

    Space.com: Why isn’t SETI lively and bouncing along fine given all the detections?

    Drake: You would think. All those planetary detections are the greatest motivator to do SETI that we ever had. But it hasn’t had any impact, at least yet.

    Space.com: How do you reconcile the fact that exoplanet discoveries are on the upswing, yet mum’s the word from ET?

    Drake: People say that all the time … saying that you’ve been searching for years and now you’ve searched thousands of stars and found nothing. Why don’t you just give up … isn’t that the sensible thing?

    There’s a good answer to all that. Use the well-know equation and put in the parameters as we know them. A reasonable lifetime of civilizations is like 10,000 years, which is actually much more than we can justify with our own experience. It works out one in every 10 million stars will have a detectable signal. That’s the actual number. That means, to have a good chance to succeed, you have to look at a million stars at least — and not for 10 minutes — for at least days because the signal may vary in intensity. We haven’t come close to doing that. We just haven’t searched enough.

    Space.com: What are we learning about habitable zones?

    Drake: Actually the case is very much stronger for a huge abundance of life. The story seems to be that almost every star has a planetary system … and also the definition of “habitable zone” has expanded. In our system, it used to be that only Mars and Earth were potentially habitable. Now we’ve got an ocean on Europa … Titan.

    The habitable zone goes out. A habitable zone is not governed just by how far you are from the star, but what your atmosphere is. If you’ve got a lot of atmosphere, you’ve got a greenhouse effect. And that means the planet can be much farther out and be habitable.

    6
    “Radio waving” to extraterrestrials. Outward bound broadcasting from Earth has announced humanity’s technological status to other starfolk, if they are out there listening.
    Credit: Abstruse Goose

    Space.com: What is your view on the debate regarding active SETI — purposely broadcasting signals to extraterrestrials?

    Drake: There is controversy. I’m very against sending, by the way. I think it’s crazy because we’re sending all the time. We have a huge leak rate. It has been going on for years. There is benefit in eavesdropping, and you would have learned everything you can learn through successful SETI searches. There’s all kinds of reasons why sending makes no sense.

    7
    Frank Drake, center, with his colleagues, Optical SETI (OSETI) Principal Investigator Shelley Wright and Rem Stone with the 40-inch Nickel telescope at Lick Observatory in California. Outfitted with the OSETI instrument, the silver rectangular instrument package protrudes from the bottom of the telescope, plus computers, etc.
    Credit: Laurie Hatch Photography

    That reminds me of something else. We have learned, in fact, that gravitational lensing works. If they [aliens] use their star as a gravitational lens, they get this free, gigantic, super-Arecibo free of charge. They are not only picking up our radio signals, but they have been seeing the bonfires of the ancient Egyptians. They can probably tell us more about ourselves than we know … they’ve been watching all these years.

    Space.com: Can you discuss the new optical SETI efforts that you are involved with? You want to search for very brief bursts of optical light possibly sent our way by an extraterrestrial civilization to indicate their presence to us.

    Drake: It’s alive and well. We’ve gotten a couple of people who are actually giving major gifts. There’s no funding problem. There is a new instrument that has been built, and it’s going to be installed at the Lick Observatory [in California] in early March.

    The whole thing is designed to look for laser flashes. The assumption is — and this is where it gets to be tenuous — the extraterrestrials are doing us a favor. It does depend on extraterrestrials helping you by targeting you. These stellar beams are so narrow that you’ve got to know the geometry of the solar system that you’re pointing it at. They want to communicate. They have to be intent on an intentional signal specifically aimed at us. That’s a big order. So there are required actions on the part of the extraterrestrials for this to work. The big plus is that it’s cheap and relatively easy to do.

    See the full article here.

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

     
c
Compose new post
j
Next post/Next comment
k
Previous post/Previous comment
r
Reply
e
Edit
o
Show/Hide comments
t
Go to top
l
Go to login
h
Show/Hide help
shift + esc
Cancel
%d bloggers like this: