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  • richardmitnick 3:01 pm on November 6, 2018 Permalink | Reply
    Tags: , , METI, NIROSETI-Near-Infrared Optical SETI instrument at Lick on The Nickel Telescope   

    From Centauri Dreams: “SETI in the Infrared” 

    From Centauri Dreams

    November 6, 2018
    Paul Gilster

    One of the problems with optical SETI is interstellar extinction, the absorption and scattering of electromagnetic radiation. Extinction can play havoc with astronomical observations coping with gas and dust between the stars. The NIROSETI project (Near-Infrared Optical SETI) run by Shelley Wright (UC-San Diego) and team is a way around this problem. The NIROSETI instrument works at near-infrared wavelengths (1000 – 3500 nm), where extinction is far less of a problem. Consider infrared a ‘window’ through dust that would otherwise obscure the view, an advantage of particular interest for studies in the galactic plane.

    NIROSETI team from left to right Rem Stone UCO Lick Observatory Dan Werthimer UC Berkeley Jérôme Maire U Toronto, Shelley Wright UCSD Patrick Dorval U Toronto Richard Treffers Richard Treffers Starman Systems. (Image by Laurie Hatch)

    Would an extraterrestrial civilization hoping to communicate with us choose infrared as the wavelength of choice? We can’t know, but considering its advantages, NIROSETI’s instrument, mounted on the Nickel 1-m telescope at Lick Observatory, is helping us gain coverage in this otherwise neglected (for SETI purposes) band.

    UC Santa Cruz Shelley Wright at the 1-meter Nickel Telescope NIROSETI


    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).jpg

    I had the chance to talk to Dr. Wright at one of the Breakthrough Discuss meetings in Palo Alto, where she made a fine presentation on the subject. Since then my curiosity about infrared SETI has remained high.

    Meanwhile, at MIT…

    Then this morning I came across graduate student James Clark, who has just published a paper on interstellar beacons in the infrared in The Astrophysical Journal. Working at MIT’s Department of Aeronautics and Astronautics, Clark is not affiliated with NIROSETI. He’s wondering what it would take to punch a signal through to another star, and concludes that a large infrared laser and a telescope through which to focus it would be the tools of choice.

    The goal: An infrared signal at least 10 times greater than the Sun’s natural infrared emissions, one that would stand out in any routine astronomical observation of our star and demand further study. Clark believes that a 2-megawatt laser working in conjunction with a 30-meter telescope would produce a signal easily detectable at Proxima Centauri b, while a 1-megawatt laser working through a 45-meter telescope would produce a clear signal at TRAPPIST-1.

    But nearby stars are just the beginning, for in Clark’s view, either of these setups would produce a signal that could be detected up to 20,000 light years away, almost to galactic center. All of this may remind you of Philip Lubin’s work, recently described here, on laser propulsion. Depending on the system in play, one of Lubin’s DE-STAR 4 beams would be observed as the brightest star in the sky from 1000 light years away (see Trillion Planet Survey Targets M-31 for more on this). The NIROSETI website makes the same observation about laser visibility:

    “The most powerful laser beams ever created (e.g. LFEX) can produce optical pulses with 2 petawatts (2.1015W) peak power for an incredibly short duration, approximately one picosecond. Such lasers would outshine our sun by several order of magnitudes if seen by a distant receiver. It can be shown that strong pulsed signals at nanosecond (or faster) intervals can be distinguishable from any known astrophysical sources.”

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    An MIT study proposes that laser technology on Earth could emit a beacon strong enough to attract attention from as far as 20,000 light years away. Credit: MIT.

    The kind of system Clarke is talking about is not beyond our capabilities even now:

    “This would be a challenging project but not an impossible one,” Clark says. “The kinds of lasers and telescopes that are being built today can produce a detectable signal, so that an astronomer could take one look at our star and immediately see something unusual about its spectrum. I don’t know if intelligent creatures around the sun would be their first guess, but it would certainly attract further attention.”

    In terms of current capabilities, we can think about Clark’s 30-meter telescope in relation to plans for telescopes as huge as the 39-meter European Extremely Large Telescope, now under construction in Chile, or the likewise emerging 24-meter Giant Magellan Telescope.

    ESO/E-ELT,to be on top of Cerro Armazones in the Atacama Desert of northern Chile. located at the summit of the mountain at an altitude of 3,060 metres (10,040 ft).

    Giant Magellan Telescope, to be at the Carnegie Institution for Science’s Las Campanas Observatory, to be built some 115 km (71 mi) north-northeast of La Serena, Chile, over 2,500 m (8,200 ft) high

    How and where to build such a laser is the same sort of issue now being analyzed by Breakthrough Starshot, which conceptualizes a series of small lightsail missions to nearby stars using laser beaming.

    Breakthrough Starshot image. Credit: Breakthrough Starshot

    Caveats include safety issues for both humans and spacecraft equipment. Clark suggests the far side of the Moon would be the ideal place for such an installation.

    With METI (Messaging to Extraterrestrial Intelligence) continuing to be controversial, to say the least, whether or not we would ever choose to build an infrared laser as an interstellar beacon is up for question.

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

    But Clark’s analysis takes in the question of whether today’s technologies could detect such a signal if a civilization elsewhere put it into play and tried to communicate with us. As we’ve seen in other discussions of interstellar beacons, detection is highly problematic.

    “With current survey methods and instruments, it is unlikely that we would actually be lucky enough to image a beacon flash, assuming that extraterrestrials exist and are making them,” Clark says. “However, as the infrared spectra of exoplanets are studied for traces of gases that indicate the viability of life, and as full-sky surveys attain greater coverage and become more rapid, we can be more certain that, if E.T. is phoning, we will detect it.”

    We don’t know whether E.T. does astronomical surveys, but we know we do, and we are rapidly moving toward the study of small, rocky exoplanets through the spectra of their atmospheres. Thus Clark’s paper could be seen as a reminder to astronomers that an unusual signal could lurk within their infrared data, one that we should at least be aware of and prepared to analyze. A conversation between nearby stars at a data rate of a few hundred bits per second could eventually result.

    See the full article here .

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    Please help promote STEM in your local schools.

    Stem Education Coalition

    Tracking Research into Deep Space Exploration

    Alpha Centauri and other nearby stars seem impossible destinations not just for manned missions but even for robotic probes like Cassini or Galileo. Nonetheless, serious work on propulsion, communications, long-life electronics and spacecraft autonomy continues at NASA, ESA and many other venues, some in academia, some in private industry. The goal of reaching the stars is a distant one and the work remains low-key, but fascinating ideas continue to emerge. This site will track current research. I’ll also throw in the occasional musing about the literary and cultural implications of interstellar flight. Ultimately, the challenge may be as much philosophical as technological: to reassert the value of the long haul in a time of jittery short-term thinking.

     
  • richardmitnick 12:08 pm on October 28, 2018 Permalink | Reply
    Tags: , , , , , METI, ,   

    From Astronomy: Guest blog: Answers to your Laser SETI questions 

    Astronomy magazine

    From Astronomy Magazine

    August 17, 2017
    Alison Klesman

    The Search for Extraterrestrial Intelligence (SETI) is a humbling process, to be sure. It’s difficult in the extreme to find something when we don’t know where to look for it, or what it will look like when it appears.

    More on that shortly but, before I get any further, I’d like to thank three groups of people. This article wouldn’t exist without those who asked great questions: Tom Scarnati, Richard Hammer, Bartlomiej Król and daughter, Don Schmidt, Dr. Muhsin Sheriff, Michael J. Sloboda, Cormac McKay, Crystal Robin, Roshan Vemula. Because of the overlap and connectedness of their questions, I’ve aggregated my answers rather than addressing them one-by-one. Second, I want to share my deep personal gratitude to the over 500 people who’ve contributed and/or shared their support for the Laser SETI Indiegogo campaign. And of course, I’d be remiss if I didn’t thank my team and colleagues at the SETI Institute, who have moved this project forward in countless ways and constantly demonstrate the highest levels of scientific expertise and integrity.

    Now, how can we search when we don’t know what we’re looking for? The answer is easy to define as “an indication of something non-natural and not human.” Each SETI project refines this definition for their particular approach. In radio SETI, it’s traditionally a narrower signal than we’ve ever seen in nature, which is exactly what we always do to tune our communications to be more efficient. Optical SETI has historically looked for a clustering of photons on a very short timescale–nanoseconds. The SETI Institute’s latest project, Laser SETI, is also an optical SETI project but uses a broader definition of a single-color point source of light that comes from beyond the moon and starts and ends at a definite time, whether lasting nanoseconds or minutes.

    None of these systems are intended to immediately decipher and understand a signal, but really just detect its presence. This is different than communication systems we’re familiar with in everyday life, like WiFi, whose job it is to communicate lots of information, like pictures of cats.

    SETI has been carried out in various ways for nearly 60 years, what more is there to search?


    SETI@home, a BOINC project originated in the Space Science Lab at UC Berkeley

    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)

    The short answer and understatement of the year is “a lot.” The sum total of SETI experiments thus far haven’t yet covered even a tiny fraction of the space-time-frequency domain, and that’s looking for signals we can currently conceive of and detect. Clearly, the first thing to do is cover more of what we understand, starting with the most economical, then as we gain access to new technologies, like gravitational waves, we can search them too someday.

    Just which frequency (or color of radiation) to look for is a big problem. Project Ozma in 1960 searched two stars using a single-channel receiver over a miniscule portion of the radio dial.

    Howard E. Tatel Radio Telescope (85-1) at Green Bank site of the National Radio Astronomy Observatory (NRAO)

    Today, the SETI Institute’s purpose-built Allen Telescope Array searches over 1000 times that amount of radio spectrum using 70 million channels, but there’s another million-fold increase required to cover the full radio dial. And with the reasonable budgetary assumption that we’ll be conducting these experiments from the surface of the Earth, there’s another spectral “window” in our atmosphere that we colloquially refer to as light—from ultraviolet, through the visible, into the deep infrared. Infrared might be an ideal choice if someone is intentionally trying to signal us, for instance, as it passes through interstellar dust much better because of its longer wavelength, but our detectors for it are less suitable and more expensive. And remember that they’ll be moving with respect to us, and may or may not have measured our atmosphere, so we’ll see whatever signal is sent as a different color/frequency than it was sent.

    Then there’s the number of places to search. If we limit ourselves to stars—which may not be valid if ET has much brighter transmitters than we do, or spaceships—then there’s 18 million within 1000 light years, which is about 1% of the diameter of our galaxy, and contains over 100 billion stars and is itself just one of billions of galaxies. And the sum total of all searches thus far haven’t even examined 1% of those 18 million stars.

    Finally, there’s the issue of time. Whatever signal we receive, it will have travelled across exactly as many light years as it took years to get here. It’s wonderful to see into the past, but we don’t know if signals are washing across us every second, every century, or never. An intriguing possibility, enabled by our newfound knowledge of exoplanets, is to look for a signal when two exoplanets line up along our line of sight. We’re just starting to study such opportunities. And, hoping the signal repeats so we can study it better, how often will that happen, if ever? What if the signal arrives while we’re looking at another part of the sky?

    Fortunately, as I alluded to before, technology has been improving consistently, decade over decade. This was anticipated by the SETI community when, 20 years ago, they set three goals. One was to build what became the Allen Telescope Array. Another was to monitor the whole sky all the time. This is where Laser SETI comes in.

    Laser SETI, the future of SETI Institute research

    It is the first economical project to take the spatial and time dimensions off the table, by observing the whole sky all the time—and across the entire optical band. Its unique design allows for 4 cameras to observe any potential signal, in order to produce compelling evidence of its origin or easily discard it as a false positive. It may or may not be the last SETI project ever, but it’s a major step forward and an achievement if we complete it.

    Moving on, many people ask what would happen if we discovered a signal. First, we would check and double-check ourselves. SETI must exclude all natural and human sources, instrumentation is complex, and nobody wants to embarrass themselves with a false alarm. Next, because this is science, it requires peer review and independent verification, wherever possible. We would ask other astronomers to examine the source, and bring their expertise to bear on both its apparent origin as well as our instrument and data. The SETI community is working on a system to quantify the confidence in a received signal, call the Rio Scale. Previous potentially interesting signals have demonstrated that this process includes the press and is necessarily international.

    This radio message was transmitted toward the globular cluster M13 using the Arecibo telescope in 1979. Image Credit Arne Nordmann (norro) Wikipedia

    NAIC Arecibo Observatory operated by University of Central Florida, Yang Enterprises and UMET, Altitude 497 m (1,631 ft).

    Another aspect of contact many people ask about is if we would respond and what would we say. Speaking for myself and my discussions with every other SETI scientist I’ve discussed this with, listening is completely separate from transmitting. In most cases the equipment is different but, more importantly, if and how we respond is a decision for the whole planet, not any small group. I’ve even heard the argument that we shouldn’t listen for signals for fear of who would respond or what they’d say. That strikes me as simply enabling whoever you think might respond to do so in secret and guarantee you don’t have a say in the matter!

    I’ve spent a lot more time thinking about how to send a self-explanatory (“anti-cryptographic”) message, than the words to put into it. Efforts along these lines are referred to as METI (Messaging to Extra Terrestrial Intelligence) but are not formal or prescriptive.


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

    However, not to dodge the question and assuming the original signal didn’t have an obvious reply e.g. “Do you want to chat?” or “Can we eat all the humans?”, I would simply want to express greetings, thanks, and the hope that we could learn from each other. Since the round-trip time will likely be years, maybe millennia, that gives us a long time to think about it and probably include a lot more in response, perhaps even the sum of human knowledge—despite the guarantee that it would be out of date by the time it arrived.

    SETI is enthralling and empowering. It offers answers to questions we’ve had since the dawn of civilization, and the hope to unify all inhabitants of Spaceship Earth with the knowledge that we’re not alone. Contact would demonstrate to us that it’s possible to survive our technological adolescence. In today’s modern age, we all have a chance to participate in this thrilling process, whether via science and engineering, funding, or sharing our excitement with others. Thank you for your interest and please share your passion with others!

    See the full article here .


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    Please help promote STEM in your local schools.

    Stem Education Coalition

     
  • richardmitnick 10:30 am on August 12, 2018 Permalink | Reply
    Tags: A billion-year-old lake could help find alien life, , , , METI, Oxygenization   

    From METI and McGill via Futurity: “A billion-year-old lake could help find alien life” 

    1

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

    McGill University

    McGill University

    From METI International and McGill University

    via

    1

    Futurity

    July 18th, 2018 [Just appeared in social media.]
    Justin Dupuis-McGill

    1
    Credit: Getty Images

    A sample of ancient oxygen from a 1.4 billion-year-old evaporative lake deposit in Ontario provides fresh evidence of what the Earth’s atmosphere and biosphere were like leading up to the emergence of animal life, according to new research.

    The findings, which appear in the journal Nature, represent the oldest measurement of atmospheric oxygen isotopes by nearly a billion years. The results support previous research suggesting that oxygen levels in the air during this time in Earth history were a tiny fraction of what they are today due to a much less productive biosphere.

    “It has been suggested for many decades now that the composition of the atmosphere has significantly varied through time,” says Peter Crockford, a postdoctoral researcher at Princeton University and Israel’s Weizmann Institute of Science who led the study as a PhD student at McGill University. “We provide unambiguous evidence that it was indeed much different 1.4 billion years ago.”

    2
    An image of the history of life and atmospheric oxygen on Earth over its 4.6 billion year history. The magnifying glass shows a picture of cyanobacteria that would have dominated life on Earth across much of the Proterozoic beginning around 2.4 billion years ago. On the far right is an image of the Earth that highlights vegetation on the continents and cholorphyll concentrations in the ocean. What the new study shows is that these colors would have been much less vibrant in Earth’s deep past due to a smaller biosphere. (Credit: McGill)

    The study provides the oldest gauge yet of what earth scientists refer to as “primary production,” in which micro-organisms at the base of the food chain—algae, cyanobacteria, and the like—produce organic matter from carbon dioxide and pour oxygen into the air.

    An image of Cyanobacteria, Tolypothrix

    Our planet, 1.4 billion years ago

    “This study shows that primary production 1.4 billion years ago was much less than today,” says senior coauthor Boswell Wing, an associate professor of geological sciences at the University of Colorado at Boulder who helped supervise Crockford’s work at McGill.

    “This means that the size of the global biosphere had to be smaller, and likely just didn’t yield enough food—organic carbon—to support a lot of complex macroscopic life,” says Wing.

    To come up with these findings, Crockford teamed up with colleagues who had collected pristine samples of ancient salts, known as sulfates, found in a sedimentary rock formation north of Lake Superior.

    The work also sheds new light on a stretch of Earth’s history known as the “boring billion” because it yielded little apparent biological or environmental change.

    “Subdued primary productivity during the mid-Proterozoic era—roughly 2 billion to 800 million years ago—has long been implied, but no hard data had been generated to lend strong support to this idea,” notes study coauthor Galen Halverson, an associate professor of earth and planetary sciences.

    “That left open the possibility that there was another explanation for why the middle Proterozoic ocean was so uninteresting, in terms of the production and deposit of organic carbon.” Crockford’s data “provide the direct evidence that this boring carbon cycle was due to low primary productivity.”

    Beyond Earth

    The findings could also help inform astronomers’ search for life outside our own solar system.

    “For most of Earth history our planet was populated with microbes, and projecting into the future they will likely be the stewards of the planet long after we are gone,” says Crockford.

    “Understanding the environments they shape not only informs us of our own past and how we got here, but also provides clues to what we might find if we discover an inhabited exoplanet,” he says.

    Researchers from Rice University; Yale University; the University of California, Riverside; Lakehead University in Thunder Bay, Ontario; and Louisiana State University also contributed to the work.

    Funding from the Natural Sciences and Engineering Research Council of Canada, the Fonds de recherche du Québec—Nature et Technologies, and the University of Colorado Boulder supported the research.

    Article part from McGill

    Billion-year-old lake deposit yields clues to Earth’s ancient biosphere

    18 July 2018

    Contact Information

    Peter Crockford
    peter.crockford@weizmann.ac.il

    Secondary Contact Information

    Justin Dupuis
    Media Relations Office
    justin.dupuis@mcgill.ca
    Office Phone:
    514-398-6751

    3
    No caption or credit.

    A sample of ancient oxygen, teased out of a 1.4 billion-year-old evaporative lake deposit in Ontario, provides fresh evidence of what the Earth’s atmosphere and biosphere were like during the interval leading up to the emergence of animal life.

    The findings, published in the journal Nature [link is above] , represent the oldest measurement of atmospheric oxygen isotopes by nearly a billion years. The results support previous research suggesting that oxygen levels in the air during this time in Earth history were a tiny fraction of what they are today due to a much less productive biosphere.

    “It has been suggested for many decades now that the composition of the atmosphere has significantly varied through time,” says Peter Crockford, who led the study as a PhD student at McGill University. “We provide unambiguous evidence that it was indeed much different 1.4 billion years ago.”

    The study provides the oldest gauge yet of what earth scientists refer to as “primary production,” in which micro-organisms at the base of the food chain – algae, cyanobacteria, and the like – produce organic matter from carbon dioxide and pour oxygen into the air.

    See the full article here .

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

    Please help promote STEM in your local schools.

    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 3:25 pm on March 16, 2018 Permalink | Reply
    Tags: , , , , , Language arts, METI, , Speak like a human to ET   

    From METI: “Speak like a human to ET” 

    1

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

    METI International

    3.16.18

    Morris Jones

    Much attention in the METI world is focused on designing codes or languages that could be understood by extraterrestrials. We don’t think they would speak any languages commonly used by humans, so attempts are made to produce something close to a “universal language”. Mathematics heavily influences this process, and with good reason. It’s a more objective reflection of the universe, and taps into rules and laws that would apply to extraterrestrials as much as us. Addition works the same way on Earth and Proxima Centauri. But even the way humans interpret and communicate mathematics is subjective. It’s not only the code and symbolism we use. It could even reflect cognitive processes that could be unique to humans, and not necessarily shared by creatures with different minds.

    Other attempts at communication involve photographs and pictograms. But even these efforts can be less clear than we think. What we show, and what we expect to be interpreted, can be very different. People read different messages into the same image, even if they speak the same language. These differences can be profound between members of the same species. Imagine how this would affect communication between different planets!

    This analyst thus seeks to highlight a paradigm that approaches extraterrestrial messaging from another angle. Speak like a human! We don’t know how extraterrestrials think or communicate. Any effort we make in this regard is likely to have problems. But we know how humans communicate very well. Our languages and media (including all the arts) are vivid and profound. We have a lot to say, and the means to do so. Our systems are not always perfect, but they are effective.

    SETI and METI scientists love to invoke analogy in their considerations of extraterrestrials. We know about humans but we know essentially nothing about extraterrestrials. So it makes sense to work with what you have. Extrapolating human factors to extraterrestrials is hazardous, but it does have some degree of utility. There is likely to be a lot in common, even though there could be profound differences.

    Let’s apply this principle to communication. The languages of humans are known to us. They could even be more universal than we realize. Cognitive scientists and linguists claim that much of the basis of language seems to be hardwired into our brains, whether we speak Spanish or Swahili. There could even be principles of logic and information theory that mandate certain factors in communication, regardless of biology. Extraterrestrials may not think exactly the same way or communicate as we do, but they could still decipher much of what we want to say.

    Our languages are more than just means of communicating ideas. They presumably convey knowledge about the minds and societies that developed them. Some of these mechanisms are known to us, but others could be yet undiscovered by our own scholars. Extraterrestrials may know better. Furthermore, they could presumably conduct comparative linguistic studies with their own languages or those of other civilizations they have encountered.

    Furthermore, human languages are really a more open and direct way of saying what who we are. They are a part of us, and we should communicate our languages as much as we communicate anything else.

    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 8:37 pm on November 20, 2017 Permalink | Reply
    Tags: , , , , METI, New Keys to Help Extraterrestrials Unlock Our Messages,   

    From SA: “New Keys to Help Extraterrestrials Unlock Our Messages” 

    Scientific American

    Scientific American

    November 20, 2017
    Douglas Vakoch

    A 19th-century proposal for contacting aliens is being rebooted in the latest transmission to nearby star.

    1
    Artist’s impression of GJ273 star system. Credit: Danielle Futselaar, METI

    When the esteemed German mathematician Carl Friedrich Gauss contemplated communication with extraterrestrials at the beginning of the 19th century, targeting the moon seemed obvious. Our planet’s natural satellite provided the nearest plausible home for life beyond Earth.

    The form and content of the message we could send was equally clear to Gauss. He is credited with the idea of communicating with inhabitants of the moon by clearing large swaths of the Siberian forest of its trees and in their place planting massive wheat fields in the shape of carefully arranged geometrical shapes, which would be visible from the moon. Specifically, he wanted to show Lunarians that Earthlings are familiar with the Pythagorean theorem by creating massive landscapes demonstrating that the sum of the squares of the legs of a right triangle equals the square of the hypotenuse: a2 + b2 = c2.

    Nearly two centuries after Gauss’s proposal, our team has turned to him for inspiration, using math as a universal language for interstellar communication by radio.

    We of course now know that our moon is inhospitable to life. But in the last two decades we have learned of the existence of planets around other stars. Some of these exoplanets orbit within their star’s “Goldilocks zone,” where it is not too hot, and not too cold, but just right to allow for the existence of liquid water—a prerequisite for life as we know it. Recently we sent a series of radio messages that included a numerical description of the Pythagorean theorem to one such exoplanet, in the hope of eliciting a response from any geometry-savvy inhabitants.

    CALLING E.T.

    The exoplanet is a super-Earth named GJ 273b, which orbits Luyten’s Star, a red dwarf only 12.4 light years from our solar system. It has the distinction of being the nearest known exoplanet that is potentially habitable while also being in view of the two-megawatt transmitter of the European Incoherent Scatter Scientific Association (EISCAT) in Tromsø, Norway, north of the Arctic Circle. On three successive days in mid-October 2017, a project dubbed “Sónar Calling GJ 273b” celebrated the 25th anniversary of Barcelona’s Sónar music festival with radio transmissions from EISCAT, which included a sampling of music by the festival’s artists.

    To increase the intelligibility of the signals, we at METI—a research organization dedicated to Messaging Extraterrestrial Intelligence—crafted a mathematical and scientific tutorial within the transmissions.

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

    METI’s tutorial differs from earlier interstellar messages in several ways. Past messages—like the radio message transmitted from a radio telescope in Arecibo, Puerto Rico, and the Golden Record onboard NASA’s Voyager spacecraft—have attempted to be encyclopedic in scope.

    NAIC/Arecibo Observatory, Puerto Rico, USA, at 497 m (1,631 ft)

    NASA/Voyager 1

    Voyager 1- The Interstellar Mission gold plated disc

    The downside of trying to say everything in an interstellar message is that we are communicating so much information that it may come across as an incoherent jumble. METI’s message takes the opposite approach, explaining a few essentials of math and science with greater depth and clarity.

    SIMPLE STEPS TO LINK FORM AND CONTENT

    In past interstellar messages, the link between the form and content of the message has been arbitrary, making decoding by any intelligent recipients all the more challenging. In METI’s tutorial, we focus on concepts we can directly demonstrate through the radio signal itself. We explain time through pulses that have a clearly defined duration—one that can be described numerically, as well as directly shown by pulses of corresponding duration. We expand into the realm of electromagnetic phenomena by discussing the fact that radio waves have specific frequencies, doing so by pointing to the two frequencies we used for the transmission itself.

    Throughout, we build step-by-step from simple to more complex concepts. After counting, we introduce arithmetic. Combinations of numbers that illustrate the Pythagorean theorem let us move into trigonometry. Once we can describe the relationships between the sides of a triangle—though simple division—we can describe sine waves, and thus radio waves themselves.

    In a second round of transmissions set for April 2018, we will expand our tutorial to demonstrate fundamental elements of musical melodies—by turning the transmitter into a musical instrument capable of sending signals at several different frequencies, not just two frequencies as in our first set of messages. By expanding the range of frequencies at which we can transmit, we will mimic the relationships between musical notes, which are separated from each other by specific, mathematically precise intervals. Through some basic math and physics, we will introduce aliens to human melodies.

    We have gone to great pains to send messages that will come out intact after a journey of more than 70 trillion miles. On each of the three days that we transmitted in October, we sent our METI tutorial three times. This provides alien codebreakers on GJ 273b with a simple rule to deal with the inevitable errors that will creep into the message as it traverses the vast distances between the stars. The recipient only needs to recognize that the message is sent three times; line up the three versions, one on top of the other; and finally, look for any discrepancies. Whenever there is a difference between the three parts, the extraterrestrial cryptographer has a simple rule to figure out what we intended: go with whatever appears two out of three times.

    KEYS TO UNDERSTANDING

    Our new METI tutorial provides novel features designed to increase comprehensibility, but it is not the final word. Instead, to craft increasingly sophisticated messages in the coming years, we should learn lessons from the history of the Search for Extraterrestrial Intelligence, or SETI. In 1960 astronomer Frank Drake conducted Project Ozma, the first SETI experiment. The 1960s and 1970s saw a handful to additional searches, each relatively limited in the number of stars observed, as well as the range of frequencies. No signs of intelligence beyond Earth were detected. With the completion of each project, however, astronomers and engineers became increasingly sophisticated in developing signal processing algorithms, ruling out false alarms, and articulating a case for each of their chosen target stars.

    The power of today’s SETI searches is easily a trillion times as great as that of Ozma, thanks to more sensitive antennas that can search at billions of frequencies rather than only one.

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

    But has our sophistication in creating interstellar messages increased over the same time by even a factor of 10? I doubt it.

    Using as an analogy the history of SETI, in which much was learned by conducting a series of modest follow-up searches, the best way to develop increasingly sophisticated messages is to keep targeting additional stars, each getting its own distinctive message. Rather than simply replicating the messages that have been sent in the past, we should continually explore alternatives for both form and content.

    An interstellar message is like a treasure chest, offered by one civilization to another with the hope it will have value. Much of this value comes after the recipient can unlock the message’s secrets. But what may seem an obvious clue to us about how to do so may be obscure to an extraterrestrial. In our future messages, we would do well to include multiple keys, each providing a unique way to open the message. These efforts may one day let intelligent extraterrestrials begin to see the universe from a truly human perspective.

    See the full article here .

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    Scientific American, the oldest continuously published magazine in the U.S., has been bringing its readers unique insights about developments in science and technology for more than 160 years.

     
  • richardmitnick 7:53 am on October 8, 2017 Permalink | Reply
    Tags: , , , , , , METI, ,   

    From Futurism: “First Contact With Extraterrestrials Might Be a Very Good Thing” 

    futurism-bloc

    Futurism

    March 16, 2017 [Another plum comes to social media.]
    Neil C. Bhavsar

    1
    Getty Images

    The Debate

    When many people look at the stars, they see a vast, unbound infinity that fills them with a feeling that’s difficult to describe but impossible to forget. That feeling pushes humanity to want to explore the great unknown reaches of space in the hopes of discovering that we aren’t alone in it.

    But let’s assume for one moment that extraterrestrial life does exist. Should we really be trying to contact it?

    Some view the idea of reaching out to extraterrestrials as dangerous. In fact, Stephen Hawking made a strong point against the idea of making contact by comparing it to the Native Americans’ first encounter with Christopher Columbus and the European explorers, a situation that “didn’t turn out so well” for the former civilization. Hawking went on to note that advanced alien life could be “vastly more powerful and may not see us as any more valuable than we see bacteria.”

    While that does sound like it could be a possibility, not everyone agrees with Hawking. In fact, many have equally convincing arguments in support of contact with aliens.

    Nothing to Lose

    To some, the question is a no-brainer. Why wouldn’t we want to meet other intelligent lifeforms? That’s the thought shared by the people at the SETI (Search for Extra Terrestrial Intelligence) Institute.

    SETI Institute

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

    Laser SETI, the future of SETI Institute research

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

    [Not a part of the SETI Institute.]

    In fact, SETI is now far more proactive in its search for alien life than ever before.

    Initially, the organization focused on passively looking for signals indicating signs of intelligent life, but now it is taking action in the form of METI (Messaging Extra Terrestrial Intelligence).

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

    METI International sends greetings to specific locations in space in the hopes of alerting alien astronomers of our existence.

    Though Hawking and others worry that our interstellar friendship search will lead to the annihilation or subjugation of our species as a whole, Douglas Vakoch, the president of METI International and a professor in the Department of Clinical Psychology at the California Institute for Integral Studies, strongly disagrees with this assertion. He believes that claims that we should hide our existence as a species are unfounded. After all, we have already leaked nearly 100 years of transmissions from radio and television broadcasts as electromagnetic radiation.

    Vakoch goes on to note an inconsistency in Hawking’s reasoning. He asserts that any civilizations able to travel between stars will absolutely have the ability to pick up our “leaked” signals. By that logic, they must already be aware of our existence and are simply waiting for us to make the first move. Vakoch urges us to test the Zoo Hypothesis and the Fermi Paradox through standard peer-review methods, insisting that we target nearby star systems 20 or 30 light-years away with repeat messages to generate a testable hypothesis within a few decades.

    NASA estimates that there are 40 billion habitable planets in our galaxy. While he strongly urges caution in making first contact, even Hawking is curious as to whether any of those planets beyond our solar system host life. To that end, he has launched a $100 million initiative to seek out 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

    If we ever do find extraterrestrial life, either through Hawking’s search, SETI, or any of the number of other projects in the works, we might just want to take a beat before saying “Hello.”

    See the full article here .

    Please help promote STEM in your local schools.

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    Futurism covers the breakthrough technologies and scientific discoveries that will shape humanity’s future. Our mission is to empower our readers and drive the development of these transformative technologies towards maximizing human potential.

     
  • richardmitnick 7:13 am on October 8, 2017 Permalink | Reply
    Tags: , , , , , METI, , , ,   

    From New Scientist: “We still haven’t heard from aliens – here’s why we might never” 

    NewScientist

    New Scientist

    26 April 2017 [Where did this come from? Just found in social media.]
    Leah Crane

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

    THE most ambitious search so far for extraterrestrial intelligence has released its first data – and there are no aliens yet. The lack of success could be explained by the result of a new approach to calculating the likelihood of detecting alien signals. This calculation suggests we might never make contact, even if extraterrestrial life is common.

    The search for extraterrestrial intelligence (SETI) has been active for decades.

    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

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

    Breakthrough Listen aims to be the largest, most comprehensive search ever. [Using only three telescopes? There are a lot more available.]

    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

    The $100 million initiative uses three of the world’s most sensitive telescopes to look for alien signals from the 1 million closest stars to Earth and the 100 closest galaxies.

    “It’s like finding a needle in a haystack,” says Seth Shostak at the SETI Institute in California. “But we don’t know how many needles are there.”

    Breakthrough Listen team members have analysed the light from 692 stars so far. They have found 11 potential alien signals, none of which remained promising after further analysis.

    “It’s the beginning of a very exciting time,” says Avi Loeb at Harvard University. “But while it’s exciting, it’s still very risky. We could find nothing.”

    That’s exactly what an assessment by Claudio Grimaldi at the Swiss Federal Institute of Technology in Lausanne predicts.

    Most methods for calculating the likelihood of detecting alien signals start with an expected number of sources. Instead, Grimaldi started with what volume of the galaxy could be reached by alien signals, a value that requires fewer assumptions about the nature and abundance of extraterrestrial life.

    Grimaldi assumed that signals from an extraterrestrial emitter might get weaker or be blocked as they travel, so they would only cover a certain volume of space. It’s relatively simple to calculate the probability that Earth is within that space and so able to detect the signal. “Not all signals can be visible at the same time – only those that intersect with the Earth,” says Grimaldi.

    He found that even if half of our galaxy was full of alien noise, the average number of signals that we would be able to detect from Earth is less than one (Scientific Reports, doi.org/b562).

    This implies that, even if there are lots of aliens out there, we might never be able to hear from them. But some researchers take umbrage: Grimaldi’s method still requires you to plug in numbers for how far alien signals could be detectable and how long they last – neither of which is known.

    “You have to make some assumptions about what the aliens are doing in all these calculations, unfortunately, and the data set that we have with alien activity is fairly sparse,” says Shostak. Our only example of intelligent life is on Earth, and there’s little reason to expect that ET resembles us.

    But, says Loeb, extraterrestrial signals should be no harder to find than other astronomical events.

    “The question of whether you can detect a signal has nothing to do with whether it’s artificial or natural, and astronomers routinely detect lots of kinds of signals,” he says.

    “In SETI, theory is great, but observation is the gold standard,” says Douglas Vakoch, president of METI International, which aims to send messages to extraterrestrial intelligence.

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

    It’s not difficult to think up a different signal that we would be able to detect, he says.

    For example, if there were alien life at the TRAPPIST-1 planets, just 40 light years away, they wouldn’t need particularly advanced technology to contact us.

    A size comparison of the planets of the TRAPPIST-1 system, lined up in order of increasing distance from their host star. The planetary surfaces are portrayed with an artist’s impression of their potential surface features, including water, ice, and atmospheres. NASA

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

    It seems implausible that we would miss their call.

    See the full article here .

    Please help promote STEM in your local schools.

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  • richardmitnick 1:19 pm on September 24, 2017 Permalink | Reply
    Tags: , , , , , METI,   

    From Futurism: “Stephen Hawking Has Flawed Ideas About Alien Life, According to Former SETI Scientist” 

    futurism-bloc

    Futurism

    September 24, 2017
    Christianna Reedy

    Calling All Aliens

    As autumn brings with it cooler temperatures and clearer night skies, Douglas Vakoch, president of Messaging Extraterrestrial Intelligence (METI), wants you to take the opportunity to survey the glory of our galaxy — and to contemplate the existence of alien life.

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

    “You look at the night sky — virtually all of those stars have planets,” Rosenberg said in an exclusive interview with Futurism. “Maybe one out of five has it at just the right zone where there’s liquid water. And so we know there are a lot of places that there could be life. Now the big question is, are they actually trying to make contact, or do they want us to try?”

    METI’s stance is that we should assume the latter, and the collection of scientists have taken it upon themselves to reach out to any potential alien civilizations. In fact, the next transmission planned for next year. However, there have long been voices opposed to this strategy — perhaps the most prominent of which being Stephen Hawking.

    Hawking, a noted physicist and author, supports the search for aliens, but regularly cautions against attempting contact. Hawking argued in “Stephen Hawking’s Favorite Places,” a video on the platform CuriosityStream, that aliens could be “vastly more powerful and may not see us as any more valuable than we see bacteria.”

    Paying Our Dues?

    These are not warnings that Vakoch takes lightly. “Well, when Stephen Hawking, a brilliant cosmologist, has said, ‘whatever you do, don’t transmit, we don’t want the aliens to come to Earth,’ You’ve got to take it seriously,” Vakoch told Futurism.

    But there’s one key point that Hawking really doesn’t seem to take into consideration in this assessment, Vakoch said.

    “It’s the fact that every civilization that does have the ability to travel to Earth could already pick up I Love Lucy. So we have been sending our existence into space with radio signals for 78 years. Even before that, two and a half billion years, we have been telling the Universe that there is life on here because of the oxygen in our atmosphere. So if there’s any alien out there paranoid about competition, it could have already come and wipe us out. If they’re on their way, it’s a lot better strategy to say we’re interested in being conversational partners. Let’s strike up a new conversation.”

    It’s Vakoch’s belief that humanity’s first contact with alien life will occur within our lifetimes. But even if it does not, he believes the METI project will be foundational to any relationship our world builds with others.

    “Sometimes people talk about this interstellar communication as an effort to join the galactic club. What I find so strange is no one ever talks about paying our dues or even submitting an application. And that’s what METI does,” Vakoch said. “It’s actually contributing something to the galaxy instead of saying gimme gimme gimme me. What can we do for someone else.”

    See the full article here .

    Please help promote STEM in your local schools.

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    Futurism covers the breakthrough technologies and scientific discoveries that will shape humanity’s future. Our mission is to empower our readers and drive the development of these transformative technologies towards maximizing human potential.

     
  • richardmitnick 10:28 am on August 2, 2017 Permalink | Reply
    Tags: , , , , METI, , , When Satellites Confuse SETI   

    From METI: “When Satellites Confuse SETI” 

    1

    METI International

    8.2.17
    Morris Jones

    SETI astronomers sometimes pick up strange signals.

    SETI Institute

    They don’t look like the regular type of radio transmissions we get from stars and other natural things in space. When this happens, they pay attention. These signals could be transmissions from extraterrestrials.

    There are protocols for dealing with a potential extraterrestrial discovery. You perform follow-up observations of the same source, or the same area of space. You ask other observatories to perform their own observations. You also avoid saying too much in public until you know the real source of the signal.

    SETI observations have gone down this path many times, and in all cases, no evidence of extraterrestrial intelligence was found. Sometimes, signals have come from aircraft. But an increasing source of strange signals comes from our own fleet of satellites.

    Recently, the red dwarf star Ross 128 was the subject of one such incident.

    1
    Image from Aaron Hamilton. http://www.orionsarm.com/eg-article/491700c65734d

    Astronomers from the famous Arecibo radio telescope picked up weird transmissions from the directions of this star, even though they were not actively conducting a SETI search.

    NAIC/Arecibo Observatory, Puerto Rico, USA

    They alerted other astronomers and even published news of these investigations on a Web page. The media got hold of the story and published it. Much hype was made about the potential discovery, despite the fact that the astronomers had downplayed the likelihood of extraterrestrial involvement. But that doesn’t sound so juicy to journalists hunting for a big story.

    It was quickly shown that extraterrestrials were not beaming messages into space from Ross 128. But something else was certainly transmitting. The most likely cause, it seems, was a satellite orbiting the Earth. It just happened to be passing over the telescope’s field of view when these observations were taken.

    There’s a tremendous amount of artificial radio transmissions on Earth and in space. That’s how we sustain our information society. But the widespread use of radio waves causes problems for radio astronomers, SETI or otherwise. In the future, astronomers may need to go deeper into space, perhaps to the far side of the Moon, to escape the radio noise of Earth.

    That’s a luxury SETI astronomers can’t afford right now. All they can do is check any strange signals carefully, and accept that there will probably be more interference from satellites in the future.

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

    This also means that discipline needs to be practiced in reaching wild conclusions too quickly. Look before you leap. Check before you talk. In 2016, there was a torrent of publicity over a strange signal received by the RATAN-600 radio telescope, which was suspected of being an extraterrestrial transmission.

    2
    RATAN-600 (short for Radio Astronomical Telescope of the Academy of Sciences) is a radio telescope located near the village of Zelenchukskaya in the Caucasus Mountains, in Russia, at an altitude of 970 meters.

    Follow-up observations dispelled any chance of this, and it seems that once again, astronomers were tricked by a satellite. In this case, there was clearly too much talk before the signal had been properly investigated.

    These two incidents serve as lessons for SETI practitioners, the media and the public. Any strange signal detected by a SETI project is probably not from extraterrestrials. The most likely cause will probably be a satellite launched by humans from Earth. We all need to avoid leaping to wild conclusions without firm evidence. Getting that evidence takes time, and patience will be needed.

    We would all love to find evidence that humanity is not alone in the universe. It’s one of the most significant questions confronting science. But science shouldn’t run on emotions. It needs caution and deduction. SETI is mostly a well-run pursuit. But journalists and the public should still be cautious of any claims they encounter.

    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 10:32 am on May 18, 2017 Permalink | Reply
    Tags: , , , , Colossus project, , , METI,   

    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.

     
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