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  • richardmitnick 7:12 pm on October 6, 2014 Permalink | Reply
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    From SPACE.com: “Aliens May Be Out There, But Too Distant for Contact” 

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    October 06, 2014
    Irene Klotz

    The Milky Way may be home to some 3,000 extraterrestrial civilizations but the vast distances between our galactic cousins will make contact extremely rare, a new study concludes.

    Data collected by NASA’s Kepler space telescope and other observatories scouting for planets beyond the solar system indicate Earth is one of some 40 billion potentially habitable worlds in the galaxy, with about one new life-friendly planet forming every year, astronomer Michael Garrett, head of the Dutch astronomy research foundation ASTRON, said at the International Astronomical Congress in Toronto.

    NASA Kepler Telescope

    Sounds promising, until you consider the sheer size of the Milky Way, which spans more than 100,000 light-years in diameter. Light travels at about 186,000 miles per second, but a signal will still take more than 4 years to reach neighboring system Alpha Centauri and 100,000 years to travel from one end of the galaxy to the other.

    “On average, you’d expect the civilizations to be separated by at least 1,000 light-years in the Milky Way. That’s a large distance, and for communication purposes you need to allow for twice the travel distance, so you’re talking about civilizations that have to be around for at least a few thousand years in order to have the opportunity to talk to each other,” Garrett said.

    “We don’t really know the time scales in which civilizations persist,” he added.

    The one example available — Earth — indicates that life essentially developed as soon as the conditions were right, but intelligent life arose comparatively late.

    “It’s really just essentially in the last few minutes of the overall evolution of life on the planet,” Garrett said. “I don’t want to be too negative about this, but … my basic conclusion is that SETI signals will be rare in the Milky Way.”

    That doesn’t mean astronomers shouldn’t look, he added. Quite the contrary, given the huge technological leaps in radio astronomy and in data processing techniques compared to what was available for Search for Extraterrestrial Intelligence, or SETI, programs 60 years ago.

    SETI also is benefitting from sister radio astronomy projects, such as the ongoing quest to find the source of mysterious transient radio bursts.

    SETI@home screensaver
    SETI@home from Space Science LabSpaceScienceLabs at UC Berkeley

    “SETI is not easy, but it’s a pursuit that is well worth doing. The question is so important,” Garrett said. “Everyone is interested, not just scientists and space enthusiasts. People in the street are interested to know what else is out there.”

    See the full article, with added material, here.

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  • richardmitnick 4:14 pm on August 18, 2014 Permalink | Reply
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    From Astrobiology: ” SETI Searches Kepler Candidates for Signals of Life” 

    Astrobiology Magazine

    Astrobiology Magazine

    Aug 18, 2014
    Nola Taylor Redd

    A recent search by the Search for Extraterrestrial Intelligence (SETI) studied 86 candidates in the Kepler space observatory’s field for radio signals that could potentially indicate the presence of an intelligent civilization.

    Of course, no radio signals were found, but the search did identify the most promising Kepler objects for wide-band observations using the Green Bank Telescope in West Virginia.

    NRAO Green Bank Telescope

    “The 86 target stars were selected because they hosted planets discovered by [the year] 2011 with properties that could be conducive to the development of life,” said Abhimat Gautam, of the University of California, Berkeley.

    Gautam, who just completed his senior undergratuate year at the University of California, Berkeley and was part of the Berkeley SETI Research Center, presented the results at the 224th summer meeting of the American Astronomical Society in Boston, Massachusetts in June.

    Widening the search

    By 2011, Kepler had revealed 1,235 planetary candidates (as of June 17, 2014, that number stands at 4,254, with 974 of them confirmed as planets). Gautam worked with Andrew Siemion and other scientists of the Berkeley SETI Research Center to select 86 planetary candidates that had surface temperatures between –50 and 100 degrees Celsius (-58 to 212 degrees Fahrenheit), a radius smaller than three times that of Earth, and an orbital period of more than 50 days. Such conditions placed the objects within the habitable zone around their stars, the region where liquid water can exist on the surface and where life might best be able to develop on a planet.

    Kepler-11, a sun-like star located approximately 2,000 light-years from Earth, hosts six transiting planets that were the target of a search for signals indicating advanced civilizations.

    The Green Bank Telescope (the world’s largest fully steerable radio telescope, located in Green Bank, West Virginia) targeted the parent stars using a wide-band signal. Scientists had performed previous searches of the Kepler field in the narrow-band with no success. Only 5 Hertz (Hz) wide on the radio spectrum, narrowband signals are only known to arise from artificial sources on Earth, Gautam said. The narrowband range is commonly used in SETI searches.

    By switching to wide-band, Gautam hoped for a number of benefits. Wide-band signals cover 2.5 Megahertz (MHz), which is half a billion times wider than previous searches. Increasing the region of the radio spectrum observed means that listening scientists can search for broader signals than those previously observed. The interstellar medium—the gas and dust between stars—can spread the signal out as it travels through the material, causing a delay that could provide a rough estimate of the distance to any detectable source and allowing SETI astronomers to track potential communications back to their origins.

    In addition, a wide-band signal may be more commonly used for intentional signaling, Gautam said.

    “An advanced alien civilization may even use a pulsar for signaling, which can be more easily and effectively detected in a wide-band search.”

    Located in the habitable zone around a sun-like star, Kepler-22b, shown in this artist’s interpretation, is 2.4 times the size of Earth. Credit: NASA/Ames/JPL-Caltech

    Gautam, who is pursuing a doctorate in astronomy at the University of California, Los Angeles, first took interest in SETI through theSETI@Home project while still in high school. He contacted Dan Werthimer, chief scientist for SETI@Home, in search of available research projects.

    SETI@home screensaver
    SETI @home

    “When UC Berkeley undergraduate students majoring in the physical sciences express an interest in continuing on for a graduate degree in their field, one of the first suggestions they receive is to seek out research opportunities,” SETI’s Andrew Siemion told Astrobiology Magazine in an email.

    Gautam presented the results while he was still an undergraduate student because“it was all his work,” Siemion said.

    “Abhimat [Gautam] was a fantastic member of our research group,” he said.

    Scanning the skies

    The SETI search focused both on active signals deliberately broadcast by a potential civilization, as well as passive signals such as those created by Earth’s television shows and airport radars.

    “We expect intentional, active signals to be brighter and easier to detect than non-intentional, passive signals,” Gautam said.

    With the Green Bank Telescope pointed at each target star, the radio beam would span approximately 4.2 light-years, wide enough to engulf the planetary system, including unknown bodies.

    According to Siemion’s SETI blog, the search also covered a region of the radio spectrum known as the “terrestrial microwave window,” which can travel through both interstellar space and Earth’s atmosphere with little distortion. Within that window, the SETI search covered the “water hole,” a region of the radio spectrum bounded by the two products of water — hydrogen and hydroxyl.

    “Some scientists have suggested that if an extraterrestrial intelligence were to deliberately signal other intelligent beings, they might chose this band,” Siemion wrote.

    The team found no sign of an intelligent civilization. They concluded that less than 1 percent of the stars in the region produce a radio signal greater than 60 times that of the Arecibo radio telescope in Puerto Rico.

    “The Arecibo Planetary Radar is the most powerful radio transmitter on Earth,” Gautam said.

    “This provides a good estimate for calculating estimates of the detectability of Earth-like technology in our search.”


    See the full article here.


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  • richardmitnick 2:49 pm on August 13, 2014 Permalink | Reply
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    From SPACE.com: “Hairspray Chemical Could Aid Search for Alien Life” 

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    August 13, 2014
    Charles Q. Choi

    Chemicals once found in hairspray may serve as signs of alien life on faraway worlds, researchers say.

    These compounds may reveal that extraterrestrials have disastrously altered their planets, scientists added.

    To detect biomarkers, or signs of life, on distant worlds, scientists have often focused on molecules such as oxygen, which theoretically disappears quickly from atmospheres unless life is present to provide a constant supply of the gas. By looking at light passing through atmospheres of alien worlds, past studies have suggested future instruments such as NASA’s James Webb Space Telescope could detect telltale traces of oxygen.

    But the search for extraterrestrial intelligence (SETI) has mostly concentrated on “technosignatures,” such as radio and other electromagnetic signals that alien civilizations might give off. Now researchers suggest that searches for atmospheric biomarkers could also look for industrial pollutants as potential signs of intelligent aliens.

    SETI Institute’s Allen Telescope Array

    SETI@home screensaver
    SETI@home, citizen science, Public Distributed Computing running on BOINC software

    Astronomers at Harvard University focused on tiny, superdense stars known as white dwarfs. More than 90 percent of all stars in the Milky Way, including our own sun, will one day end up as white dwarfs, which are made up of the dim, fading cores of stars.

    Image of Sirius A and Sirius B taken by the Hubble Space Telescope. Sirius B, which is a white dwarf, can be seen as a faint pinprick of light to the lower left of the much brighter Sirius A.

    Though white dwarfs are quite cold for stars, they would still be warm enough to possess so-called habitable zones — orbits where liquid water can exist on the surfaces of circling planets. These zones are considered potential habitats for life, as there is life virtually everywhere there is liquid water on Earth.

    The scientists examined how Earth-size planets in the habitable zones of white dwarfs might look if they possessed industrial pollutants in their atmosphere. They focused on chlorofluorocarbons (CFCs), which are entirely artificial compounds, with no known natural process capable of creating them in atmospheres.

    CFCs are nontoxic chemicals that were once used in hairspray and air conditioners, among many other products, before researchers discovered they were causing a hole in Earth’s ozone layer, which protects the planet from dangerous ultraviolet radiation.

    “Very hairy extraterrestrials may be a little easier to detect,” joked lead study author Henry Lin, a physicist at Harvard.

    CFCs are strong greenhouse gases, meaning they are very effective at absorbing heat. This means that if CFCs are in the atmosphere of a distant Earth-size planet, they could alter a white dwarf’s light when that world passes in front of that star — enough for the $8.8 billion James Webb Space Telescope (JWST), which is due to launch in 2018, to detect them.

    In addition, the researchers noted that CFCs are long-lived molecules, capable of lasting up to about 100,000 years in atmospheres. This means they could even serve as markers of long-dead alien civilizations. [10 Alien Encounters Debunked]

    The investigators simulated the amount of time it would take JWST to detect the fluorocarbon CF4 and the chlorofluorocarbon CCl3F in the atmosphere of an Earth-size planet in the habitable zone of a white dwarf. They modeled concentrations of these gases 100 times greater than the highs currently seen on Earth.

    The scientists found it would take JWST three days of looking at such a white dwarf to detect signs of CF4, and only a day and a half for CCl3F.

    NASA Webb Telescope

    “The most exciting aspect of the results is that within the next decade we might be able to search for excessive industrial pollution in the atmospheres of Earth-like planets,” study co-author Abraham Loeb, a theoretical astrophysicist and chair of Harvard’s astronomy department, told Space.com.

    Ironically, “aliens are often referred to as green little creatures, but ‘green’ also means ‘environmentally friendly,'” Loeb said. “Detectable CFC-rich civilizations would not be ‘green.'”

    The scientists did caution that it would take much longer to detect these industrial pollutants than it would biomarkers such as oxygen, which JWST could find after about three hours of looking at such a planet. Astronomers should only attempt to discover technosignatures such as CFCs if initial searches for fundamental biomarkers like oxygen were successful, the research team suggested.

    The astronomers cautioned it would be 100 times more difficult to detect industrial pollutants on planets orbiting yellow dwarf stars like the sun, making such searches beyond the capabilities of JWST. It would also take an unrealistically long time to detect CFC levels on alien planets that match those currently found on Earth, Loeb said.

    One potentially sobering future discovery might be of alien worlds that possess long-lived industrial pollutants such as CFCs but no longer have any short-lived biomarkers such as oxygen.

    “If we find graveyards of other civilizations, most rational people would likely get engaged in protecting the Earth from a similar catastrophe,” Loeb said.

    “We call industrial pollution a biomarker for intelligent life, but perhaps a civilization much more advanced than us with their own exoplanet program will classify industrial pollution as a biomarker for unintelligent life,” Lin said

    However, if astronomers discover a world heavy with CFCs that exists outside the habitable zone of its star, that could mean an extraterrestrial civilization may have intentionally “terraformed” that planet, making it livably warmer “by polluting it with greenhouse gases,” Loeb said. Scientists have previously suggested terraforming Mars by warming and thickening the Red Planet’s atmosphere so that humans can roam its surface without having to wear spacesuits.

    The scientists detailed their findings in a paper submitted to the Astrophysical Journal.

    See the full article here.

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  • richardmitnick 1:05 pm on July 7, 2014 Permalink | Reply
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    From space.com: "Should Humanity Try to Contact Intelligent Aliens?" 

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    July 07, 2014
    Leonard David

    Astronomers have detected nearly 2,000 alien planets to date. As that number continues to rise, so too does the prospect of finding intelligent extraterrestrial life.

    In terms of the search for extraterrestrial intelligence (SETI), it may no longer be a matter of answering the “are we alone” question, some scientists say. Rather, just how crowded is the universe?

    And if ET is out there, it may be possible to reach out with direct “radio waving” to potentially habitable exoplanets. This form of cosmic cryptography, called “Active SETI,” involves no longer merely listening for a signal but purposefully broadcasting to, and perhaps establishing contact with, other starfolk. [13 Ways to Hunt Intelligent Alien Life]

    Active SETI sounds like science fiction, but some astronomers are discussing it seriously today. The idea is, as it has been in the past, a controversial, hot-button issue, with some researchers wary of sending signals out to touch base with intelligent aliens.

    Work in progress

    “It’s a subject of discussion, I’ll put it that way,” said Seth Shostak, senior astronomer at the SETI Institute in Mountain View, Calif. There have been many workshops and symposia over the years to discuss Active SETI, he said, and because it has a highly emotional component, “it’s like a third rail in a way,” he said.

    Shostak told Space.com that he feels the topic is not something to worry too much about.

    “But there may not be that perception in the broader public … that we have discussed this to death. They haven’t seen these discussions nor participated in them,” he said.

    But exoplanet detections are making news around the world, Shostak said. “That’s putting the whole question of life in space in front of the public in a way that perhaps wasn’t true 20 years ago.”

    Still, trying to figure out what’s the best thing to do, in terms of Active SETI, is a work in progress, Shostak said. “What is the best way to communicate? What do you do…just ping them with a carrier wave and you encode Wikipedia? If you are going to do it, what’s the best way to communicate?”

    Long shot

    A few years ago, renowned British astrophysicist Stephen Hawking suggested that communicating with ET could be a threat to Earth.

    While it’s likely alien life exists, Hawking said, a visit to Earth by other starfolk might turn ugly, akin to when Christopher Columbus landed in America. That didn’t turn out so well for the Native Americans, he said.

    “Hawking stirred things up a few years ago saying we shouldn’t broadcast our existence because the outcome might be bad for us,” said Chris Impey, deputy head of the astronomy department at the University of Arizona in Tucson. He co-edited the 2013 book, Encountering Life in the Universe: Ethical Foundations and Social Implications of Astrobiology.

    Where Are the Aliens?

    “He’s right about our immaturity as a species,” Impey told Space.com, “but I think the argument is moot since intelligent civilizations are likely to be so sparsely distributed that communication in either direction is difficult or unlikely.”

    Active SETI, Impey said, “makes us feel a little more proactive, but I think it’s a long shot worse than buying a lottery ticket.”

    For Impey, the “promising approach” is not conventional SETI or broadcasting, but detection of civilizations by their energy or technology imprints, “and that avoids all the issues of intention and communication and the anthropocentric tangle people get into with that.” [The Search for Intelligent Life: 4 Key Questions (Video)]

    Great unsolved mysteries

    Adding his voice to the Active SETI dialogue is Steven Dick, the Baruch S. Blumberg NASA/Library of Congress Chair in Astrobiology at the Kluge Center in Washington, D.C.

    “I am for passive SETI programs, and in fact would advocate for renewed government funding after a 20-year lapse,” Dick told Space.com. “That’s because the existence of extraterrestrial intelligence is one of the great unsolved mysteries of science.”.

    Dick said that the current NASA astrobiology hunt is centered on microbes, but surely there should be an effort to go beyond micro-organisms and search for complex life with whatever means are available.

    “On the other hand, I would not propose government funding for messaging extraterrestrial intelligence. I think we need to find ET first, and then have a period where a team consisting of scientists, social scientists and humanities people consider what the message should be,” Dick said.

    Different alien minds

    However, Dick is not at all sanguine that communication with ET is possible. He thinks we underestimate how different alien minds can be compared to ours — even their science and mathematics.

    And that might account for the Fermi paradox, Dick said. That paradox, attributed to physicist Enrico Fermi, is the apparent contradiction between the high probability that extraterrestrial civilizations exist and the lack of contact with such civilizations. Hence, Fermi’s 1950 lunchtime query to colleagues: “Where is everybody?”(5 Bold Claims of Alien Life)

    “Having said that, it would be very difficult to regulate individual or institutional projects that wish to attempt messaging extraterrestrial intelligence, and I would not advocate attempting to regulate,” Dick said. In his opinion, there is an equal chance that ET will be good or bad.

    “We do not yet know enough about the evolution of altruism on Earth, much less among other possible intelligent life forms, to say ETs will all be good,” Dick said. “That is a hope rather than a fact.”

    Directed beam

    But haven’t we already revealed ourselves with TV signals, military radar and other outputs into the cosmos? Even music is wafting across the universe, purposely directed toward a specific star.

    That is true, Dick said, but it’s not the same as sending a directed beam to a habitable exoplanet target.

    “Still, the idea of planet Earth cowering and afraid to engage the universe is not a planet I would want to live on. SETI attempts are part of our rising cosmic consciousness, and as such cannot be stifled,” Dick said. “That this is the subject of such controversy…it’s an indication of how seriously the subject of intelligent life in the universe is now taken!”
    NASA’s twin Voyager spacecraft launched in August and September 1977. Aboard each spacecraft is a golden record, a collection of sights, sounds and greetings from Earth. There are 117 images and greetings in 54 languages, with a variety of natural and hum
    [Pin It] NASA’s twin Voyager spacecraft launched in August and September 1977. Aboard each spacecraft is a golden record, a collection of sights, sounds and greetings from Earth. There are 117 images and greetings in 54 languages, with a variety of natural and human-made sounds like storms, volcanoes, rocket launches, airplanes and animals.

    Credit: NASA

    Consequences of contact

    “Yes, the issue should be re-debated,” said Michael Michaud, author of the 2007 book, Contact with Alien Civilizations: Our Hopes and Fears about Encountering Extraterrestrials.

    Michaud is a former U.S. Foreign Service Officer for the U.S. Department of State and a long-time thinker and writer regarding the probability and consequences of coming into contact with an extraterrestrial civilization.

    “Active SETI advocates broke with the conventional wisdom of the SETI pioneers, which was to listen but not transmit,” Michaud told Space.com. “This change may have been driven by the impatience of younger SETI people after 40 years of unsuccessful searches.”

    “But Active SETI is not science,” said Michaud. “It is an attempt to provoke a response from an alien society whose capabilities and intentions are not known to us.”

    Those most eager to send high-powered messages want their efforts to have consequences, Michaud said, not just for themselves, but for the entire human species. “There is no scientific or historical evidence telling us that the consequences of contact will be those they prefer.”

    Deliberate, powerful signals

    Michaud says that an alien society able to detect our signals almost certainly would be more technologically advanced than our own, and might be capable enough and patient enough to send probes across light-years of space. Scientists and engineers have shown that robotic spacecraft able to reach nearby stars would be feasible for a civilization only slightly in advance of our own.

    Michaud takes issue with the old claim that we already have been detected or that detection is inevitable. Experts have shown that the normal signals emitted by Earth are too weak to be heard at interstellar distances without colossal antennas, he said.

    “Sending deliberate, unusually powerful signals is a decision that belongs properly with all Humankind,” Michaud said. “We should have an open debate about whether or not to call attention to ourselves by making our civilization more detectable than it already is.”

    See the full article here.

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  • richardmitnick 7:52 am on June 9, 2012 Permalink | Reply
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    A Look at SETI@home 



    Everything in this post was taken directly from the SETI@home web site, with the exception of a wee portion from Wikipedia. There is a lot more information to be found if you access the SETI@home web pages.

    SETI@home (“SETI at home”) is an Internet-based public volunteer computing project employing the BOINC software platform, hosted by the Space Sciences Laboratory, at the University of California, Berkeley, in the United States. SETI is an acronym for the Search for Extra-Terrestrial Intelligence. Its purpose is to analyze radio signals, searching for signs of extra terrestrial intelligence, and is one of many activities undertaken as part of SETI.

    SETI@home was released to the public on May 17, 1999, making it the second large-scale use of distributed computing over the Internet for research purposes, as Distributed.net was launched in 1997. Along with MilkyWay@home and Einstein@home, it is the third major computing project of this type that has the investigation of phenomena in interstellar space as its primary purpose.

    How SETI@home works

    The Problem — Mountains of Data

    Most of the SETI programs in existence today, including those at UC Berkeley build large computers that analyze that data from the telescope in real time. None of these computers look very deeply at the data for weak signals nor do they look for a large class of signal types. The reason for this is because they are limited by the amount of computer power available for data analysis. To tease out the weakest signals, a great amount of computer power is necessary. It would take a monstrous supercomputer to get the job done. SETI programs could never afford to build or buy that computing power. There is a trade-off that they can make. Rather than a huge computer to do the job, they could use a smaller computer but just take longer to do it. But then there would be lots of data piling up. What if they used LOTS of small computers, all working simultaneously on different parts of the analysis? Where can the SETI team possibly find thousands of computers they’d need to analyze the data continuously streaming from Arecibo?

    The UC Berkeley SETI team has discovered that there are already thousands of computers that might be available for use. Most of these computers sit around most of the time with toasters flying across their screens accomplishing absolutely nothing and wasting electricity to boot. This is where SETI@home (and you!) come into the picture. The SETI@home project hopes to convince you to allow us to borrow your computer when you aren’t using it and to help us “…search out new life and new civilizations.” We’ll do this with a screen saver that can go get a chunk of data from us over the internet, analyze that data, and then report the results back to us. When you need your computer back, our screen saver instantly gets out of the way and only continues it’s analysis when you are finished with your work.

    Screenshot of SETI@home Enhanced BOINC Screensaver (v6.03)

    It’s an interesting and difficult task. There’s so much data to analyze that it seems impossible! Fortunately, the data analysis task can be easily broken up into little pieces that can all be worked on separately and in parallel. None of the pieces depends on the other pieces. Also, there is only a finite amount of sky that can be seen from Arecibo. In the next two years the entire sky as seen from the telescope will be scanned three times. We feel that this will be enough for this project. By the time we’ve looked at the sky three times, there will be new telescopes, new experiments, and new approaches to SETI. We hope that you will be able to participate in them too!

    Breaking Up the Data

    Data will be recorded on high-density tapes at the Arecibo telescope in Puerto Rico, filling about one 35 Gbyte DLT tape per day. Because Arecibo does not have a high bandwidth Internet connection, the data tape must go by snail-mail to Berkeley. The data is then divided into 0.25 Mbyte chunks (which we call “work-units”). These are sent from the Seti@Home server over the Internet to people around the world to analyze.

    Extra Credit Section: How the data is broken up

    SETI@home looks at 2.5 MHz of data, centered at 1420 MHz. This is still too broad a spectrum to send to you for analysis, so we break this spectrum space up into 256 pieces, each 10 kHz wide (more like 9766 Hz, but we’ll simplify the numbers to make calculations easier to see). This is done with a software program called the “splitter”. These 10 kHz pieces are now more manageable in size. To record signals up to 10 KHz you have to record the bits at 20,000 bits per second (kbps). (This is called the Nyquist frequency.) We send you about 107 seconds of this 10 kHz (20kbps) data. 100 seconds times 20,000 bits equals 2,000,000 bits, or about 0.25 megabyte given that there are 8 bits per byte. Again, we call this 0.25 megabyte chunk a “work-unit.” We also send you lots of additional info about the work-unit, so the total comes out to about 340 kbytes of data.
    What is Astropulse?

    Snapshot of BOINC SETI@home Astropulse Screensaver.

    Astropulse is a new type of SETI. It expands on the original SETI@home, but does not replace it. The original SETI@home is narrowband, meaning that it is listening for a particular radio frequency. That’s like listening to an orchestra playing, and trying to hear when anyone plays the note “A sharp”. Astropulse listens for short-time pulses. In the orchestra analogy, it’s like listening for a quick drum beat, or a series of drumbeats. Since no one knows what extraterrestrial communications will “sound like,” it seems like a good idea to search for several types of signals. In scientific terms, Astropulse is a sky survey that searches for microsecond transient radio pulses. These pulses could come from ET, or from some other source. I’ll define each of those terms:

    Sky survey: The telescope we use (Arecibo Observatory) scans across the sky, searching for signals everywhere. This differs from a directed SETI search, in which the telescope examines a few stars carefully.
    Microsecond: A millionth of a second. Astropulse is better than previous searches at detecting signals that last for a very short length of time. The shorter the signal, the better Astropulse is at detecting it, to a lower limit of 0.4 microseconds. Astropulse can detect signals shorter than 0.4 microseconds, it just stops getting better and better in comparison to other searches.
    Transient: A signal is transient if it is short, like a drumbeat. A transient signal can be repeating (it beats over and over again) or single pulse (it beats only once.)
    Radio: The signals are made of the same type of electromagnetic radiation that an AM or FM radio detects. (Actually of substantially higher frequency than that, but still considered “radio.”) Electromagnetic radiation includes radio waves, microwaves, infrared light, visible light, ultraviolet light, x-rays, and gamma rays. Click here for more information on electromagnetic radiation.

    Sources of pulses

    Where would a microsecond transient radio pulse come from? There are several possibilities, including:
    ET: Previous searches have looked for extraterrestrial communications in the form of narrow-band signals, analogous to our own radio stations. Since we know nothing about how ET might communicate, this might be a bit closed-minded.
    Pulsars and RRATs: Pulsars are rotating neutron stars that can produce signals as short as 100 microseconds, although typically much longer. 0.4 microseconds seems like a stretch. Astropulse is capable of detecting pulsars, but is unlikely to find any new ones. RRATs are a recently discovered pulsar variant. Perhaps Astropulse will discover a new type of rotating neutron star with a very short duty cycle.
    Exploding primordial black holes: Martin Rees has theorized that a black hole, exploding via Hawking radiation, might produce a signal that’s detectable in the radio. Click here to learn about black holes.
    Extragalactic pulses: Some scientists recently saw a single transient radio pulse from far outside the Milky Way galaxy. No one knows what caused it, but perhaps there are more of them for Astropulse to find.
    New phenomena: Perhaps the most likely result is that we will discover some unknown astrophysical phenomenon. Any time an astronomer looks at the sky in a new way, he or she may see a new phenomenon, whether it be a type of star, explosion, galaxy, or something else.
    Dispersed pulses

    As a microsecond transient radio pulse comes to us from a distant source in space, it passes through the interstellar medium (ISM). The ISM is a gas of hydrogen atoms that pervades the whole galaxy. There is one big difference between the ISM and ordinary hydrogen gas. Some of the hydrogen atoms in the ISM are ionized, meaning they have no electron attached to them. For each ionized hydrogen atom in the ISM, a free electron is floating off somewhere nearby. A substance composed of free floating, ionized particles is called a plasma.
    The microsecond radio pulse is composed of many different frequencies. As the pulse passes through the ISM plasma, the high frequency radiation goes slightly faster than the lower frequency radiation.When the pulse reaches Earth, we look at the parts of the signal ranging from 1418.75 MHz to 1421.25 MHz. This is a range of 2.5 MHz. The highest frequency radiation arrives about 0.4 milliseconds to 4 milliseconds earlier than the lowest frequency radiation, depending on the distance from which the signal originates. This effect is called dispersion. Click here to see how dispersed and undispersed pulses can be composed of many different frequencies.

    In order to see the signal’s true shape, we have to undo this dispersion. That is, we must dedisperse the signal. Dedispersion is the primary purpose of the Astropulse algorithm.
    Not only does dedispersion allow us to see the true shape of the signal, it also reduces the amount of noise that interferes with the signal’s visibility. Noise consists of fluctuations that produce a false signal. There could be electrical noise in the telescope, for instance, creating the illusion of a signal where there is none. Because dispersion spreads a signal out to be up to 10,000 times as long, this can cause 10,000 times as much noise to appear with the signal. (There’s a square root factor due to the math, so there’s really only 100 times as much noise power, but that’s still a lot.)

    The amount of dispersion depends on the amount of ISM plasma between the Earth and the source of the pulse. The dispersion measure (DM) tells us how much plasma there is. DM is measured in “parsecs per centimeter cubed”, which is written pc cm-3. To get the DM, multiply the distance to the source of the signal (in parsecs) by the electron density in electrons per cubic centimeter. A parsec is about 3 light years. So if a source is 2 parsecs away, and the space between the Earth and that source is filled with plasma, with 3 free electrons per cubic centimeter, then that’s 6 pc cm-3. The actual density of free electrons in the ISM is about 0.03 per cubic centimeter.
    Astropulse algorithm

    Single Pulse Loops
    Astropulse has to analyze the whole workunit at nearly 15,000 different DMs (14,208, to be precise.) At each DM, the whole dedispersion algorithm has to be run again for the entire workunit. The lowest DM is 55 pc cm-3, and the highest is 800 pc cm-3. Astropulse examines DMs at regular intervals between those two. Without going into detail about how to examine a piece of a workunit at a given DM, here is the organization with which Astropulse handles the data: it divides the DMs to be covered into large DM chunks of 128 DMs each, and then small DM chunks of 16 DMs each. It divides the data into chunks of 4096 bytes, and processes them one at a time. Once it has dedispersed the data, Astropulse co-adds the dedispersed data at 10 different levels, meaning that it looks for signals of size 0.4 microseconds, then twice that, 4 times, 8 times, and so on. (0.4 microseconds, 0.8, 1.6, 3.2, 6.4, …) On the lowest level of organization, astropulse looks at individual bins of data. A bin corresponds to 2 bits of the original data, but after dedispersion, it requires a floating point number to represent it. Here’s the breakdown of Astropulse’s loops:
    1 workunit => 111 large DM chunks
    1 large DM chunk => 8 small DM chunks
    1 small DM chunk => 2048 data chunks
    1 data chunk => 16 DMs
    1 DM => 10 fold levels
    1 fold level => 16384 bins (or less)
    1 bin = smallest unit
    So each workunit is composed of 111 large DM chunks, each of which is 0.901% of the whole. Each large DM chunk is composed of 8 small DM chunks, each of which is 0.113% of the whole. And so on.
    The number of large DM chunks will probably change before the final version of Astropulse is released.

    Fast Folding Algorithm
    At the end of each small and large DM chunk, Astropulse performs the Fast Folding Algorithm. This algorithm checks for repeating pulses over a certain range of periods. (The period is the length of time after which the pulse repeats.) When the fast folding algorithm is performed after each large DM chunk, it searches over an entire 13 second workunit, and looks for repeating signals with a period of 256 times the sample rate (256 * 0.4 microseconds) or more. When the FFA is performed after each small DM chunk, it searches over a small fraction of the workunit, and looks for repeating signals with a period of 16 times the sample rate or more.”

    SETI People

    David is a computer scientist, with research interests in volunteer computing, distributed systems, and real-time systems. He also runs the BOINC project.
    David is a rock climber, mountain climber, classical pianist, and father of Noah (born Oct 2005).

    Dan specializes in signal processing for radio astronomy. He has been doing SETI since 1979, and he runs the SERENDIP, Optical SETI, and CASPER projects.
    Dan dabbles in jazz piano, and is the father of a 4-year old son, William.

    BOINC is a leader in the field(s) of Distributed Computing, Grid Computing and Citizen Cyberscience.BOINC is more properly the Berkeley Open Infrastructure for Network Computing, developed at UC Berkeley.

    Visit the BOINC web page, click on Choose projects and check out some of the very worthwhile studies you will find. Then click on Download and run BOINC software/ All Versons. Download and install the current software for your 32bit or 64bit system, for Windows, Mac or Linux. When you install BOINC, it will install its screen savers on your system as a default. You can choose to run the various project screen savers or you can turn them off. Once BOINC is installed, in BOINC Manager/Tools, click on “Add project or account manager” to attach to projects. Many BOINC projects are listed there, but not all, and, maybe not the one(s) in which you are interested. You can get the proper URL for attaching to the project at the projects’ web page(s) BOINC will never interfere with any other work on your computer.


    SETI@home The search for extraterrestrial intelligence. “SETI (Search for Extraterrestrial Intelligence) is a scientific area whose goal is to detect intelligent life outside Earth. One approach, known as radio SETI, uses radio telescopes to listen for narrow-bandwidth radio signals from space. Such signals are not known to occur naturally, so a detection would provide evidence of extraterrestrial technology.

    Radio telescope signals consist primarily of noise (from celestial sources and the receiver’s electronics) and man-made signals such as TV stations, radar, and satellites. Modern radio SETI projects analyze the data digitally. More computing power enables searches to cover greater frequency ranges with more sensitivity. Radio SETI, therefore, has an insatiable appetite for computing power.

    Previous radio SETI projects have used special-purpose supercomputers, located at the telescope, to do the bulk of the data analysis. In 1995, David Gedye proposed doing radio SETI using a virtual supercomputer composed of large numbers of Internet-connected computers, and he organized the SETI@home project to explore this idea. SETI@home was originally launched in May 1999.”

    SETI@home is the birthplace of BOINC software. Originally, it only ran in a screensaver when the computer on which it was installed was doing no other work. With the powerand memory available today, BOINC can run 24/7 without in any way interfering with other ongoing work.

    The famous SET@home screen saver, a beauteous thing to behold.

    einstein@home The search for pulsars. “Einstein@Home uses your computer’s idle time to search for weak astrophysical signals from spinning neutron stars (also called pulsars) using data from the LIGO gravitational-wave detectors, the Arecibo radio telescope, and the Fermi gamma-ray satellite. Einstein@Home volunteers have already discovered more than a dozen new neutron stars, and we hope to find many more in the future. Our long-term goal is to make the first direct detections of gravitational-wave emission from spinning neutron stars. Gravitational waves were predicted by Albert Einstein almost a century ago, but have never been directly detected. Such observations would open up a new window on the universe, and usher in a new era in astronomy.”

    MilkyWay@Home Milkyway@Home uses the BOINC platform to harness volunteered computing resources, creating a highly accurate three dimensional model of the Milky Way galaxy using data gathered by the Sloan Digital Sky Survey. This project enables research in both astroinformatics and computer science.”

    Leiden Classical “Join in and help to build a Desktop Computer Grid dedicated to general Classical Dynamics for any scientist or science student!”

    World Community Grid (WCG) World Community Grid is a special case at BOINC. WCG is part of the social initiative of IBM Corporation and the Smarter Planet. WCG has under its umbrella currently eleven disparate projects at globally wide ranging institutions and universities. Most projects relate to biological and medical subject matter. There are also projects for Clean Water and Clean Renewable Energy. WCG projects are treated respectively and respectably on their own at this blog. Watch for news.

    Rosetta@home “Rosetta@home needs your help to determine the 3-dimensional shapes of proteins in research that may ultimately lead to finding cures for some major human diseases. By running the Rosetta program on your computer while you don’t need it you will help us speed up and extend our research in ways we couldn’t possibly attempt without your help. You will also be helping our efforts at designing new proteins to fight diseases such as HIV, Malaria, Cancer, and Alzheimer’s….”

    GPUGrid.net “GPUGRID.net is a distributed computing infrastructure devoted to biomedical research. Thanks to the contribution of volunteers, GPUGRID scientists can perform molecular simulations to understand the function of proteins in health and disease.” GPUGrid is a special case in that all processor work done by the volunteers is GPU processing. There is no CPU processing, which is the more common processing. Other projects (Einstein, SETI, Milky Way) also feature GPU processing, but they offer CPU processing for those not able to do work on GPU’s.


    These projects are just the oldest and most prominent projects. There are many others from which you can choose.

    There are currently some 300,000 users with about 480,000 computers working on BOINC projects That is in a world of over one billion computers. We sure could use your help.

    My BOINC


  • richardmitnick 3:03 pm on January 30, 2012 Permalink | Reply
    Tags: , , , , , , , SETI@home   

    From Dennis Overbye at the New York Times: “LIFE OUT THERE | THE COST OF DREAMS: 

    Search for Aliens Is on Again, but Next Quest Is Finding Money

    Dennis Overbye is the best journalist I have found in any of my Science reading. I highly value his work. Mr Overbye “… graduated from M.I.T. with a physics degree….”


    This is copyright protected material, so just enough to get you enthused.

    “E.T. might be phoning, but do we care enough to take the call?…Operating on money and equipment scrounged from the public and from Silicon Valley millionaires, and on the stubborn strength of their own dreams, a band of astronomers recently restarted one of the iconic quests of modern science, the search for extraterrestrial intelligenceSETI, for short — which had been interrupted last year by a lack of financing.

    Early in December, a brace of 42 radio telescopes, known as the Allen Telescope Array, nestled here [Hat Creek, CA] in the shadow of Lassen Peak, came to life and resumed hopping from star to star in the constellation Cygnus, listening for radio broadcasts from alien civilizations. The lines are now open, but with lingering financial problems, how long they will remain that way is anybody’s guess.

    But the story of SETI is the story of a dream deferred by politics, a lack of money and the technological challenges of searching what astronomers call “the cosmic haystack”: 100 billion stars in the galaxy and 9 billion narrow-band radio channels on which aliens, if they exist, might be trying to hail us.”

    See the full article here.

    You can visit the SETI Institute to learn more about the history and science of the search.

    [Full disclosure: I am a teeny weeny financial supporter of the SETI Institute.]

    You can also participate on the search on you own by joining up with SETI@home, a project in Public Distributed Computing running on personal computers via software from the Berkeley Open Infrastructure for Network Computing, or BOINC

    It need to be very clear that SETI@home is totally independent of the SETI Institute.

    Please visit the BOINC web site and then the SETI@home web site, take a look, see what you think, and, maybe lend us a hand.

  • richardmitnick 2:55 pm on October 13, 2011 Permalink | Reply
    Tags: , , , , , , , , , , SETI@home   

    Citizen Scientists, Unite!! Around two LHC@home Projects 

    Join your colleagues at the LHC in two Public Distributed Computing projects working for the Large Hadron Collider at CERN.

    LHC@home/Sixtrack works on magnet tuning so that there is less lost effort in the beam line.


    LHC@home 2.0 simulates collision events


    So, what do you do? First, if you are not already “crunching” for other worthwhile scientific projects, you go to the BOINC UC Berkeley Space Science Lab web site for a wee bit of software, which you install on your computer(s). Then, you visit the above two web sites, and attach to the two projects. For LHC@home 2.0 you might need to register and await an invitation. This project is very new and is in “beta”. LHC@home/Sixtrack is a mature project, so no waiting. At each project web site, you can find explanations of what is happening, the science. You can find forums in which you can participate.

    Historically, projects running on BOINC software used the idle CPU cycles of your computer. In fact, the grand daddy of all projects, SETI@home , actually ran in a screen saver. Today, with greater power, protected memory, “sandboxed” technology, projects run all the time and in no way interfere with whatever else you are doing on your computer.

    We need your help. There are over 1 billion computers in the world. BOINC counts all of its current users at about 295,000. The LHC is the largest and most complex basic scientific research experiment ever mounted by Modern Man. It ranks with the pyramids, penicillin, and Starbucks.

    SET@home, the largest and oldest project, based at the birthplace of BOINC, currently has 147,000 crunchers on 222,000 computers. To paraphrase Seth Shostak of the SETI Institute (no relation to SETI@home) they haven’t found pond scum. Not even dead pond scum. But, they are processing 423 TeraFLOPS per second. That’s half a PetaFLOP. That would put them at about #15 in the TOP500 world supercomputers list, except, of course, they are distributed.

    We deserve to be that big. We need to scale up and vie with our friends at SETI@home (I crunch for SETI@home on four of my six computers.)

    So, please, visit the sites. Take a look. Tell your colleagues. Be part of something great.

    [If you are at any school, university, institution of any sort, never ever install BOINC software on their computers without written permission of an authority.]

    Meet CERN in a variety of places:

    Cern Courier








  • richardmitnick 12:33 pm on June 23, 2011 Permalink | Reply
    Tags: , , , , SETI@home,   

    From CNN Money: “A supercomputer made of unused PCs” 


    David Goldman
    June 23, 2011

    “Buying a supercomputer costs millions of dollars, then thousands more each year to maintain it. That’s not to mention the hefty electric bill to keep the massive system running.

    So it goes without saying that average Joes can’t just get themselves a supercomputer. But many scientific researchers also don’t have access to them, even if they work at a university that owns one…But if you link millions of ordinary PCs together and split the calculations across them, you get a virtual supercomputer. That’s exactly what some people are doing…Multiplied a thousand or even million times, the combined processing power of all of those PCs is formidable.

    The concept is called volunteer grid computing, and it’s being used by projects like World Community Grid (WCG).

    SETI@home is perhaps the most well-known of the projects. It was set up by University of Berkeley researchers in 1999 with the goal of finding radio signals indicative of intelligent life outside of Earth.

    Folding@home is a Stanford project for researching protein folds, and Einstein@home is a Max Planck Institute research program to study gravitational waves. Of the university projects, Folding@home is the largest, with about 350,000 donated PCs.”

    The article does severely overstate the size of WCG. Active users are about 98,000 “crunchers”. You can visit the WCG page at BOINCStats to see the current statistics.

    Also, the article does not mention that the software on which WCG runs originated at the Space Science Labs, UC Berkeley, being birthed out of the afore mentioned seti@home project.

    Suffice it to say we are at 240 TeraFLOPS at WCG, which is pretty darn big. But, even our 98,000 “crunchers” and 195,000 machines is a drop in the bucket of over a billion computers in the world. Please visit the WCG web site and look at the projects in AIDS, Cancer, Dengue Fever, Clean Energy, Clean Water, and the Human Proteome Project. With very little effort, you could help on any or all with your unused CPU cycles.

    See the full article here.

  • richardmitnick 1:57 pm on April 29, 2011 Permalink | Reply
    Tags: , , , , SETI@home   

    From SETI INstitute:”Carl Sagan: Darkness” 

    Are you satisfied that we are all alone in the universe? I am not so sure. Many of us are not so sure. The SETI Institute is the best hope that we have for answering the questions about what – or who – might be “out there”.

    And right now the SETI Institute needs our help.

    The SETI Mission Statement

    The mission of the SETI Institute is to explore, understand and explain the origin, nature and prevalence of life in the universe.

    We believe we are conducting the most profound search in human history — to know our beginnings and our place among the stars.

    The SETI Institute is a private, nonprofit organization dedicated to scientific research, education and public outreach. [The SETI Institute receives no public taxpayer dollars.]

    The Institute comprises 3 centers, the Center for SETI Research, the Carl Sagan Center for the Study of Life in the Universe and the Center for Education and Public Outreach.

    Founded in November 1984, the SETI Institute began operations on February 1, 1985. Today it employs over 150 scientists, educators and support staff. Research at the Institute is anchored by two centers. Dr. Jill Tarter leads the Center for SETI (Search for Extraterrestrial Intelligence) Research as Bernard M. Oliver Chair for SETI. Dr. David Morrison is the Director for the Carl Sagan Center for the Study of Life in the Universe. Edna DeVore leads our Center for Education and Public Outreach.”3

    Here is a video presented to us by The SETI Institute

    The Allen Telescope Array

    “he Allen Telescope Array is a joint effort between The SETI Institute and University of California at Berkeley. The array is currently under construction in Hat Creek, 300 miles north-east of San Francisco. The remote location ensures that interference from man-made radio sources is minimal.
    The Allen Telescope Array (ATA), when finished, will consist of 350 six meter dishes covering the frequency range of 0.5-11 GHz instantaneously, and will be the first instrument dedicated to Search for Extraterrestrial Intelligence. “

    The Allen Telescope Array is a superb scientific machine, with the single purpose of finding evidence of like in and on other worlds.

    Federal and state funding cutbacks for operations of U.C. Berkeley’s Hat Creek Radio Observatory (HCRO) force hibernation of Allen Telescope Array – In an April 22, 2011 email (PDF) to Allen Telescope Array stakeholder level donors, SETI Institute CEO Tom Pierson described in detail the recent decision by U.C. Berkeley, our partner in the Array, to reduce operations of the Hat Creek Radio Observatory (and thus the Allen Telescope Array) to a hibernation state effective this month. NSF University Radio Observatory funding to Berkeley for HCRO operations has been reduced to approximately one-tenth of its former level and, concurrently, growing State of California budget shortfalls have severely reduced the amount of state funds available for support of the HCRO site.

    What next for the ATA? – The SETI Institute is working on numerous efforts to insure the Array comes back on line as soon as possible. Pierson’s email outlines potential work the ATA may be performing for the United States Air Force. Donor support is also needed to restart SETI observations on the Array. For the first time in history, SETI researchers are poised to use the ATA to examine the bounty of smaller planetary systems starting to be revealed by NASA’s Kepler Mission. We are also working with a consortium of big thinkers to develop exciting opportunities for the public to participate in the future of SETI, making the science much less vulnerable to government budget cycles. Watch for these future developments in the realm of our citizen science. In the interim, if you haven’t already done so, check out the early results of these efforts at setiQuest.org and setiQuest Explorer.

    Public help is needed – Donate now – Help return the ATA to operations and support the exciting SETI exploration of the Kepler planets over the next two years. “

    The SETI Institute will gratefully accept your donations.

    Please take note, The SETI@home project running on BOINC software is a separate and distinct entity which continues to function.

    You can visit BOINC, download the application, attach to SETI@home, and donate your unused CPU cycles to this effort.

  • richardmitnick 6:33 pm on April 4, 2011 Permalink | Reply
    Tags: , Fresh Air, , , SETI@home   

    From Fresh Air at NPR: “The High Probability Of Finding ‘Life Beyond Earth'” 


    Life Beyond Earth on Fresh Air this is an audio link

    The Crab Nebula

    April 4, 2011

    “Scientific interest in extraterrestrial life has grown in the past 20 years. The field of astrobiology now includes researchers from a wide variety of disciplines — microbiologists studying bacteria that survive in the most extreme conditions on Earth; astronomers who believe there may be billions of planets with conditions hospitable to life; chemists investigating how amino acids and living organisms first appeared on Earth; and scientists studying rocks from Mars are seeing convincing evidence that microbial life existed on the Red Planet.

    In First Contact: Scientific Breakthroughs in the Hunt for Life Beyond Earth, Marc Kaufman, a science writer and national editor at The Washington Post, explains how microbes found in some of Earth’s most inhospitable environments may hold the key to unlocking mysteries throughout the solar system…”

    Listen to this engrossing interview at the audio link above.

    Read the full article here.

    Then, think about helping in this quest by giving the free CPU cycles on your computer(s) to the Public Distributed Computing project SETI@home. Visitthe web site, take a look around. SETI@home was the original project which resulted in the software from Berkeley Open Infrastructure for Network Computing- BOINC on which now run some of the most important scientific projects anywhere on the globe. Visit the BOINC site and see what it is all about.

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